BlastholeDrilling_lr.pdf

Blasthole Drillingin Open Pit Mining

First edition 2009www.atlascopco.com/blastholedrills

www.atlascopco.com

Copyright © 2008 Atlas Copco Drilling Solutions Inc.

Introducing the new and expanded line of the Pit Viper Series drills from Atlas Copco. The venerated PV-351, PV-275, and PV-271 are being joined by the all new PV-235 series. And throughout the line, we’re crafting a better user experience by improving your comfort, control and visibility. Plus, our new power systems add to your bottom line with increased fuel efficiency. So, whether you’re mining precious metal or mineral, follow the line and mine with us.

We’re redrawing the line between productivity and innovation.

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Atlas Copco Viper Ad 2 8.5x11.5.pdf 1 10/1/09 1:49 PM

Find out more at www.atlascopco.com/blastholedrills

Introducing the new and expanded line of the Pit Viper Series drills fromAtlas Copco. The venerated PV-351, PV-275, and PV-271 are being joinedby the all new PV-235 series. And throughout the line, we’re crafting abetter user experience by improving your comfort, control and visibility.Plus, our new power systems add to your bottom line with increasedfuel efficiency. So, whether you’re mining precious metal or mineral,follow the line and mine with us.

We’re redrawing the line between productivity and innovation

Blasthole Drilling in open pit Mining 1

Foreword

2 ForewordbyBrianFox VicePresidentMarketing AtlasCopcoDrillingSolutionsLLC

Talkingtechnically 3 FromgunpowdertoPitViper 11 Ergonomicsandsafety 13 Anintroductiontosurfacemining 19 Puttingrotarydrillingintoperspective 25 Automatedsurfaceblastholedrilling 31 Triconerotaryblastholedrilling 35 Optimizingtherotarydrillstring 37 IncreasedproductivitywithDTHdrilling 41 SelectingtherightDTHdrillingtools 47 Takingadvantageofsingle-passdrilling 49 Blastinginopencutmetalmines 59 DrillinginArcticconditions 61 ThenewmidrangePitViper235 65 Developmentthroughinteraction-PitViper270 69 Largediameterdrilling–PitViper351 73 Peaceofmind 75 Theeconomiccaseforroutinebitgrinding 79 SecorocGrindMaticJazz

Casestudies 81 Bolidenmineseconomiesofscale–Copper/Sweden 85 PitVipersbeatthechill–Copper/USA 89 Innovationthroughinteraction–Gold/USA 91 Unforgivingground–Gold/USA 95 Increasingtheblastholediameter

atGeita–Gold/Tanzania 97 GoingforgoldinGuerrero–Gold/Mexico101 CoalminingineasternAustralia–Coal/Australia107 BoostingSiberianenergy–Coal/Russia

109 Hiddentreasure–Coal/USA113 Movingmountains–Coal/USA

Productspecifications117 Drillingmethodsguide118 Specificationsguide119 Blastholedrillrigs143 Drillrigoptions154 Triconerotaryblastholedrilling160 Bitselection165 Whentochangeabit166 Howarockbitdrills168 Importanceofrecords170 Airpractices180 Rockformation&drillability183 Guidesforbestbitperformance186 DTHhammerspecifications188 Secorocgrindingtools196 DRILLCare198 Glossaryofterms204 Wheretofindus

For latest updates contact your local Atlas Copco Customer Center or refer to www.atlascopco.com/blastholedrills

Contents

Front cover:Pit Viper 271 working in Southwest US copper mine.Photographer: Scott Ellenbecker

Produced by: Atlas Copco Drilling Solutions LLC, PO Box 462288, Garland, TX 75046, USA, Phone +1 972 496 7400. Publisher: Ulf Linder, [email protected]: Rafaella Turander, ahrt informationsdesign, Örebro, Sweden, [email protected] team: Ulf Linder, Diane Norwood, Patsy Thomas, Nichole Schoch, Mark Bausch, Gunilla Lindberg, Marino Wallsten, Torbjorn VibergAdviser: Dustin Penn, [email protected]: Brian Fox, John Stinson, Dustin Penn, Clarence Zink, Rick Meyer, Leif Larsson, Darwin Hollar, Jeff Rose, Bo Persson, Guy Coyne,Ron Buell, Gunnar Nord, Sverker Hartwig, Jim Langford, Jon Torpy, Stig Fredriksson, all name.surname@country code.atlascopco.com William Hustrulid, Hans Fernberg, Stephen Boyce, Kyran Casteel, Scott Ellenbecker, Kenneth Moffitt, Ewald Kurt,

Digital copies of all Atlas Copco reference editions can be ordered from the publisher, address above, or online at www.atlascopco.com/rock.Reproduction of individual articles only by agreement with the publisher.

Printed by: Prinfo Welins, Örebro, Sweden. www.welins.se

Legal notice© Copyright 2009, Atlas Copco Drilling Solutions LLC, Garland, Texas, USA. All rights reserved.Atlas Copco is committed to comply or exceed all applicable laws, rules and regulations. Photos in this publication may show situations which complies with such laws, rules and regulations in the country where the photo has been taken but not necessarily in other parts of the world. In any case think safety first and always use proper ear, eye, head and other protection to minimize risk of personal injury. This publication, as well as specifications and equipment, is subject to change without notice.

2 Blasthole Drilling in open pit Mining

Foreword“If it can’t be grown, it must be mined.” It is a common saying in our industry, but it bears repeating. As the world population grows, mining must keep up to supply the material needs of people everywhere. Open pit operations continue to account for the majority of mined materials. In their 2008 Mining Project Review, Raw Materials Group (as published in Engineering & Mining Journal) shows open pit methods accounting for over 90 percent of planned capital expenditures for known projects.

Atlas Copco is proud to be part of the open pit mining industry. The rotary and down-the-hole (DTH) blasthole drills and tooling we offer account for only a small part of an open pit mine’s capi-tal and operating cost. However, they play a critical role as they kick off the material movement portion of the mining process with the drilling of blast holes. No matter how powerful shovels, draglines or loaders might be, they can’t dig solid rock.

Since the acquisition of Ingersoll-Rand Drilling Solutions in July 2004, Atlas Copco has made significant investments in

product development, technology, production facilities and customer centers around the world. We have established our-selves as a leader in open pit mining with machines running in widely varying operations and conditions across the globe. We’re happy to share some of these case studies and technical articles with you, and anticipate that the information can be put to use to help improve the productivity and reliability of open pit mines everywhere.

Going forward, we will continue to aggressively develop new and improved products aimed to safely increase production and minimize operating cost and downtime. We can only do this through interaction with our mining customers. We encourage feedback from the production and maintenance personnel who work with our rigs to help guide our improvements, and hope to be able to share our mutual success stories in future editions of this Blasthole Drilling in Open Pit Mining reference guide.

We hope you enjoy this first edition.

BrianFox

Vice President, MarketingDrilling Solutions LLC

[email protected]


TalkingTeChniCally

gunpowder

The application of blasting agents apparently began in Hungarian mines sometime during the sixteenth cen-tury. To make better use of the explo-sive force, miners started to place the powder in holes and it is certain that drilling and blasting were used in sev-eral German and Scandinavian mines early in the seventeenth century, for instance at the Nasafjäll silver mine in Lappland in 1635, and in 1644 at the Röros mine in Norway.

One-man drilling with the help of a drill steel and sledgehammer was the established technology used in the eighteenth century. This physically

demanding technique evolved only slowly but, despite the mechanization of other industries, remained in quite widespread use until well into the twentieth century. However, powered drills did start to mount a challenge in the 1800’s, the competition in the USA being symbolized by John Henry who in 1870 hammered through 14 feet in 35 minutes while the steam drill only completed nine feet.

The first patented rock drilling ma-chine was a steam driven percussion drill invented by J. J. Couch in Phila-delphia in 1849 but it may have been preceded by a machine manufactured by the Scottish engineer James Nasmyth ten years earlier. This patent spurred a period of rapid development, acceler-ated in the 1860s by Nobel’s inventions of the blasting cap and safe dynamite explosives. From 1850 to 1875 some

110 rock drill patents were granted to American inventors and seven for drill carriers while 86 patents were issued in Europe during this period.

In 1851 James Fowle, who had worked with Couch, patented a rock drill that could be powered by steam or compressed air and could rotate the drill steel by means of a ratchet wheel controlled by the piston's back-and-forth movement. In the 1860’s large scale rock drilling machines were built for tunnelling by engineers in Europe and the United States. One of the most successful of these early rock drills was the second refined version of the Burleigh rock drill, which was put into service in October 1866 at the Hoosac tunnel in Massachusetts. The perform-ance at this tunnel project showed that rock drill development had taken the step from an experimental product to a proven and rather reliable technology.

The Pit Viper is designed for production drilling of large holes in hard rock conditions.

FromgunpowdertoPitViperDrillingandblastingThe rotary blasthole drilling rig was a long time coming. Gun-powder was invented in China about 1000 A.D. But in Europe at least it took another 500 years or more before miners started to use it for blasting and a further three centuries for the introduction of mechanized drilling in surface mines. Mobile blasthole drilling rigs have been in use for only some sixty years.

Drilling with sledgehammer was the established method before the development of the rock drill.


TalkingTeChniCally

In 1871 the American inventor Simon Ingersoll patented a steam powered rock drill, later to be operated on compressed air. Ingersoll formed the Ingersoll Rock Drill Company in the same year, during the following year purchased the Fowle-Burleigh patents and also merged with the Burleigh company. The new com-pact rock drill launched by Ingersoll was a simple and strong design with few moving parts. The designers had kept in view the tough conditions in which the rock drill had to work, and the contemporary technical opinion regarded his new rock drill as the best yet available on the market. During the years to come Ingersoll bought out many small firms and expanded his company. The Ingersoll Rand name came into use in 1905 through the combination of Ingersoll-Sergeant Drill Company and Rand Drill Company.

The AB Atlas enterprise had been founded in February 1873 at a time when the Swedish railway net was being rapidly expanded. Three years later, now with 700 employees and the Stockholm shops completed, AB Atlas had delivered more than 600 railway wagons. Diminishing demand from the railroad sector, combined with years of losses, led to a reconstruction in 1890. During the years to follow new product lines were added, including compressed

air tools, compressors, diesel engines and the first Atlas rock drill which was launched in 1905.

Furtherdevelopment

The design of the first Atlas rock drill featured an advanced rif le bar rota-tion but with a weight of 280 kg (617 lb) it was very heavy for manual use. Immediately and for the next 25 years Atlas focused on light weight hand rotated drills like the Cyclop, Rex, and Bob. The real Atlas winner among lightweight hand-held rock drills was the RH-65 from the year 1932. This machine had more efficient shank and chuck designs for better steel guidance

and longer shank life. Used with the new pusher leg feed system developed in the 1930s, the RH 65 was the most important element in what was later to become known as the "Swedish method" of underground drilling.

In the United States Ingersoll-Rand expanded into pneumatic tools in 1907 by acquiring the Imperial Pneumatic Tool Company of Athens, Pennsylvania. In 1909 the company bought the A.S. Cameron Steam Pump Works and en-tered the industrial pump business. Ingersoll Rand also acquired the J. George Leyner Engineering Works Com-pany. This firm had developed a small, pneumatic hammer that could be operated by one man. This “Jackhamer”

The Ingersoll rockdrill was a simple and strong design with few moving parts.

In 1871, a number of patents were issued to the inventor Simon Ingersoll, who started the Inger-soll Rock Drill Company The machine produced by Ingersoll was at this time regarded as the best rock drill yet produced, and it was followed in the mid 1880s by another success, the famous “Ingersoll Eclipse” machine.

The first drill made by Atlas "pneumatic rock drill No. 16" had a weight of 280 kg (617 lb) and was heavy and difficult to handle - at least two men were needed to move it.


TalkingTeChniCally

introduced in 1912 became a popular item, and the company progressively developed the design as well as sup-plying compressors to the expanding construction and mining industries in North and South America

Rockdrillingtools

The parallel improvement of drill steel quality had started during the 1890s with development of heat treated drill steel that could better resist deformation. But sharpening the tips required exten-sive haulage of tons of drill steel between drilling sites and the work shops. The detachable drill bit was developed in 1918 by A L Hawkesworth, a foreman at the Anaconda copper mine in Butte, Montana. The first versions used a dove-tail joint to the drill steel while later ver-sions were threaded or tapered. The rods were retained at the workings and used with new or re-forged bits.

In Europe during the German col-lapse in 1918 a team was formed at the Osram lamp factory to develop cemented tungsten carbide as a substi-tute for industrial diamonds. In 1926 the first cemented tungsten carbide became available as a “magical” machine tool for turning and milling operations. Early tests were made in 1928 trying to use tungsten carbide bits for rock drilling in German mines and before World War II promising results were obtained. By this time the research team had scattered and some members had been forced to leave the country. One of these, Hans Herman Wolff, found refuge in Sweden where he worked at the Luma lamp fac-tory. Dr Wolff manufactured a number of bits according to designs provided by Erik Ryd at Atlas. The bits were tested in the Atlas test mine. In 1942 Atlas, Sandvik and Fagersta signed a coop-erative agreement and it was not until 1945, after a long improvement process, that the new cemented tungsten carbide drill bits were as economical to use as conventional steel bits.

The post-war years saw Atlas achieve further major advances. In 1948 the com-pany introduced an RH 65 upgrade, the RH 656, which was designed to use the new cemented carbide tipped drill-steels.The superior performance of the “Light Swedish Method” was exploited

worldwide and culminated in 1962 with the completion of the Mont Blanc tunnel. With development of highly mechanized drill rigs and with the introduction in 1973 of the COP 1038 hydraulic top hammer drill Atlas Copco laid the foundation to become a world leader in top hammer drilling technol-ogy. (See article from wagon drill to SmartRig, Surface drilling, Fourth Edition 2008).

Rotarybits

Rotary drilling with drag bits was the common method used in oil drilling. These bits were suitable when drilling in soft formations like sand or clay but not in rock. The solution for drilling large diameter holes in rock was by using rotary crushing technology instead of trying to cut hard rock with drag bits. The roller cone bit was developed by Hughes and Sharp, and the US patent for a dual roller cone bit was issued to Howard Hughes Sr. in 1909. This new type of bit had two interlocking wheels with steel teeth, and penetrated the rock by crushing and chipping. The success of the new bit led to the founding of the Sharp-Hughes Tool Company, and after Sharp's death in 1912 the name was changed to Hughes Tool Company.

The company continued develop-ment of the roller cone bit and in 1933 two Hughes engineers invented the tricone bit. This bit had three conical

rollers equipped with steel teeth. Drilling was accomplished by trans-ferring a pulldown force to drive the teeth into the hole bottom. The three roller cones turned as the drill string was rotated, and the teeth crushed and spalled the rock.

While tophammer drills could be used for small blast holes in rock, this method was not suitable for large hole diameters; for these rotary drills were

the best alternative. However, as drill-ers sought to use the rotary system for progressively harder rock formations so the feed force (pulldown) available had to be increased. Roller cones with long steel teeth were used in softer forma-tions for gouging the formation while roller cones with shorter teeth were used for crushing and spalling harder formations.

The US patent for a dual roller cone bit was issued to Howard Hughes Sr. in 1909.

The Secoroc Tricone bits are now regarded as the ultimate blasthole bit solution.


TalkingTeChniCally

A parallel development of the tri-cone bits made it possible to use these high loads on bits. To extend the life of the bits in hard and abrasive rock the steel teeth were replaced by cemented tungsten carbide inserts. Tungsten carbide inserts have significantly increased the number of blast holes that the roller cone bits are able to drill. Improvements in materials have continued to increase the life of the bearings so the cutting structures can be fully utilized. While the geometry of the roller cone bit is much the same as the original bit pat-ented in 1933, the material and technol-ogy currently utilized is cutting edge.

DownholedrillingtechnologyMeanwhile, manual lightweight pneu-matic drills had also underpinned the expansion of bench mining in open cut mines and quarries. But in the 1930’s downhole drills (DHDs ) were intro-duced for drilling deeper holes. The main initial development of this technology took place in Belgium and the United States. Atlas designed a downhole unit in the mid-thirties that was used with

good results in two Swedish limestone quarries until the 1950s but the company then ceased further DHD development, only re-entering the market in 1969 with the COP 4 and COP 6 down-the-hole hammers.

In 1955 Ingersoll-Rand introduced a new downhole drill design and started to establish downhole drilling on a truly commercial basis. The Tandematic, which at the time was claimed to pro-vide the highest drilling speed ever attained by a downhole drill, was sup-plied in two standard sizes – the DHD 275 for 4¾* inch and 5 inch holes and the DHD 1060 for 6 and 6½ inch . This later enabled the company to build drill rigs adapted to be used either for rotary drilling or with downhole hammers. The main difference is that downhole drill-ing requires more air, and consequently these drill rigs had to be equipped with a larger capacity compressor and a more powerful diesel or electric engine.

Downhole drill technology went through rapid change in 1960’s and 70’s. In fairly rapid succession I-R developed the DHD 325 ( their first 6" hammer), DHD 325A, DHD 16, DHD 1060, DHD 1060 A and B models, DHD 360 (all 6"

drills) and corresponding larger and smaller models, up to the current line of DHD’s. Probably the most significant change in DHD technology was the advent of the valveless DHD. Drill effi-ciency and life dramatically improved with the elimination of the flapper valve. Of course higher pressure and volume air from the air compressor advance-ments produced the performance one sees today. Re-entry to the downhole drill market at 6 bar** in 1969 also ena-bled Atlas Copco to take advantage of improved air compressors and develop more and more powerful downhole hammers, reaching 18 bar in the early 1980s and more recently 25 bar and 30 bar in the larger current hammer sizes.

Drillrigs

The mobilization of rotary and down-hole drills was linked to significant post-war changes in rotary drilling technology. Up until then rotary drill-ing had been used in water well drilling and surface mining using fluid circu-lation to clean cuttings from the hole. Coal mines were using rotary drilling in soft overburden, removing the cuttings with augers. In the late 1940’s it was rea- lized that air was an effective flushing medium with considerable advantages over water, doing a better cleaning job, protecting the bits and eliminating the difficulties of supplying water.

Experience also proved that air flu-shing improved the penetration rate of rolling cutter bits such as tricone bits and extended their life. By using effi-cient air flushing to keep the bottom of the drill hole free from cuttings the rock breaking process became more efficient.

In 1948, Ingersoll-Rand entered the large-diameter blast hole market by launching the Quarrymaster. It really was not a rotary drill, but a large self The Quarrymaster from 1948 was equipped with a huge 8" bore drifter.

Secoroc downhole hammer (DHD), also named Down The Hole hammer (DTH)

* 1 inch = 25.4 mm, ** 1 bar = 14.5 psi, *** 1 lb = 0.45 kg


TalkingTeChniCally

propelled mounting in the 40,000 lb weight range, designed with on board air and a long drill tower to drill 6 inch to 8 inch diameter holes for mining and quarry applications. The original Quarrymasters were equipped with a huge 8" bore drifter, know as the QD8. This was a piston drill with the drill steel attached directly to the drifter piston. The blow frequency was in the range of 200-300 blows per minute. The drifter used a large rifle bar rota-tion system. Achieving decent wear life between the rifle bar and rifle nut was sometimes a problem in tight ground. This was a single pass drill system, hole depth was limited by the tower length. The steel system was a heavy wall tubular product, in the range of 4" OD, and was extremely heavy. Since there was no steel change, the weight didn’t seem to be much of an issue.

Quarrymasters were used in some large iron mines in Canada and the Atlantic City Iron Ore Mine in Wyoming. Numerous Quarrymasters were used in the rock excavation for the St Lawrence Seaway in Canada.

In the same year also Atlas intro-duced its first mobile rubber tired drill wagons for top hammer drilling, but these were not equipped with any tram-ming machinery and were intended for considerably smaller hole diameters. I-R development work with downhole drills in the early 1950’s brought about changes to the drill mounting business. First, the Quarrymaster was equipped with the newly developed QRD rotary head, and this along with the new DHD 325 down hole drill, made for a produc-tive but heavy and bulky package.

The Drillmaster design, a somewhat smaller rotary drill, was introduced about 1955. It produced the same perform-

ance as the Quarrymaster in a smaller and less costly package. Upgraded versions of the Drillmaster, the DM-1, DM-2 and DM-3 followed in quick succession. Originally equipped with sliding vane air compressors up to 900 cfm*, all were updated to the screw compressor design. The Drillmaster line was equipped with the DRD and later DRD 2 rotary head to provide drill string rotation. As with the QRD rotary head the DRD was powered by a vane air motor and several steps of gear reduction. All of these drills only used hydraulic power, from an engine driven hydraulic pump off the cam shaft, to operate the jacks, tower raising cylin-ders, break-out wrench, and dust collec-tor drive motor. Neither rotary head was very useful in supplying straight rotary power for tricone bits, hence the future development of the T-4 and DM-4 with hydraulic powered rotary head for straight rotary drilling. I-R’s first truck drill was called the Trucm package. The drill frame package was mounted on a customer provided truck, often a used Mack truck. However, none of the standard truck designs proved very successful. The normal channel truck frames were not sturdy enough, result-ing in many cracked and broken truck

frames. I-R’s answer to this problem was to join hands with Crane Carrier Corp of Tulsa, OK, and mount the drill components and tower directly on an I-beam chassis frame, often used for mounting construction cranes. This product became the TRUCM-3 and the same style mounting carried over to the T-4 and T4W introduced in 1968.

A major new stimulus for blasthole drilling rig development generally was the introduction in the 1950’s of mil-lisecond delay blasting. This allowed

Big picture; Airpowered DM-3 with a DRD-2 Rotary head from the late 1950's. Inset; Tractor mounted Drillmaster, air powered with a DRD Rotary Head from the early 1950's.

Rotary table and Kelly bar concept.

The truck mounted T4BH was introduced in 1968.

* 100 cfm = 47.2 l/s


TalkingTeChniCally

blasters to design multi-hole large volume blasts that could be used for mass production techniques in open cut drill and blast mines. In turn this required the introduction of large, mobile drilling rigs able to drill large diameter holes using tricone bits, as well as the formulation of cheap bulk mining explosives based on ammonium nitrate and nitro-glycerine. These and other developments helped the mining industry to keep the costs of bench drilling substantially unchanged during the 1950s and 1960s, despite increasing wage costs.

The Quarrymaster and TRUCM machines were made progressively more self-contained through the 1950s. By the end of the decade the air supply was up to 10 bar and the marketing slogan “Pressure is Productivity” was promoted. The drill rigs and rock drills were sold together to maximize revenue but this did encourage other manufactur-ers to build competing rock drills.

hydraulicstechnologyaddstodrillersoptionsThe similarities between the air require-ments of rotary and downhole drilling

made the design of rigs able to do both an economically attractive proposition. In 1965-66 Ingersoll-Rand started work on the switch to hydraulic powered rotation for rotary and downhole drilling, launching first the truck-mounted T4W for water well drilling in 1968. In the same year this rig was modified to make a truck-mounted blasthole rig with a 5-rod carousel, the Drillmaster T4BH, which could drill holes of up to 7⅞ inch diameter and was successfully offered for coal mine drilling through-out the 1970s. The designers also used the power unit, tower and other com-ponents to create the crawler-mounted Drillmaster DM4 blasthole drilling rig. This machine was designed from the ground up for both rotary and downhole drilling. A 36 ft* high tower incorpo-rated a hydraulically indexed carousel housing seven 25 ft rods. The rotary head featured an axial piston hydrau-lic motor and single-reduction worm gear for rotation, providing 5.6 kNm of torque and rotation speeds from 0 – 100 rpm. There was a choice of diesel engine or electric motor for the spring mounted f loating power pack and a range of diesel or electric compres-sors, enabling use of either rotary or downhole drilling with the company’s DHD-15, -16 or -17 downhole drills. The excavator style crawler undercar-riage had tracks with 22 inch triple bar grousers driven by hydraulic motor through a planetary gear drive and chain reduction.

In the marketplace the DM4 com-peted with the more powerful electric top drive blasthole drilling rigs. The late 1960s and 1970s saw heavy take- up of the DM4 rig by the Appalachian coal mines in the United States. And the combination of patented rig, drill and drill rod technology was very profitable for Ingersoll-Rand. The use of hydraulic power for rotation and non-drilling functions meant that more air could be made available for rotary and, especially, for downhole drilling. This engendered an “air race” in the late 1960s and 1970s. The independent downhole drill manufacturers were able to build machines that could drill at 130 ft/hour in the 6 – 8 inch diameter hole range – faster than a rotary drill could achieve in this hole size range,

particularly when drilling in harder rock types.

The development of screw compres-sors to supply air for drilling rigs at up to 20.6 bar led to the 1970s introduction of an airend to supply both low pres-sure and high pressure air. These units were used in portable air compressors and also onboard drilling rigs, where they enabled downhole drills to outper-form rotary drills in the 6 - 8½ inch hole sizes in hard rock mines. However, rotary drills were still better for rock compressive strengths up to medium hard limestone.

The higher pressures were also very beneficial for water well drilling, in which air pressure must be sufficient to evacuate the ground water pressure from the hole while drilling.

expansionoftheDrillmasterrangeSignificant corporate developments and one major product launch impacted the Ingersoll-Rand drilling business in the mid-1970s. Firstly, in 1973 the company acquired DAMCO (Drill And Manu-facturing Company) in Dallas, Texas, who built mechanically driven pre-split drilling machines for quarrying and light coal stripping. These expanded the Drillmaster range down to the 20,000 lbf* bit weight class. The rigs also used the rotary table drive and kelly bar concept, which lightened the tower structure sufficiently to accommodate rod long enough to drill 40 – 50ft holes in a single pass if required. Ingersoll-Rand added their own compressors to create the DM20, DM25, DM25-SP (single-pass), DM35 and DM35-SP rotary rig models. Then, in 1975, the company bought the Sanderson Cyclone Drill Company in Ohio, USA, adding 12 models designed for the water well market.

The next extension of the size class range came with the launch of the Drillmaster DM50 with 50,000 lbf of weight on the bit. In this machine the diesel engine drove the hydraulic power pack from one end of the crankshaft and the compressor was directly coupled to the other. This concept was also used on the next two drills to be launched. The first one was a new crawler mounted

The DM50 could use bit loads up to 50,000 lbf and was launched in 1970.

* 1 ft = 0.304 m** 1,000 lbf = 4.44 kN = 453 kilogram-force


TalkingTeChniCally

rig for rotary or downhole drilling, the DM45 with 45,000lbf weight on bit. This was followed by a conceptually similar top drive rotary or DHD model, the DM30 and a specialized rotary table variant, the DM-35I, which was intro-duced in the 1980s for drilling underwa-ter in phosphate mines. It featured a dual kelly system that allowed explosives to be charged through the annulus between the outer and inner kelly. The inner kelly would then be removed for blasting. Later the DM 40SPi was developed for drilling and shooting deeper holes.

DevelopmentoflargeblastholedrillsTowards the end of the seventies, the company started designing drill rigs more specifically aimed at the base metal mining market, using power pack concepts developed for deephole drilling. So far, neither air-powered nor hydraulic drive rotary nor downhole drills had challenged the electric motor top drive rotary rigs manufactured in the United States for the 12 – 15 inch diameter hole market. These machines by now had very high weights on bit in the range 100,000 – 120,000 lbf, partly due to the weight of the electric motor for the rotary head, but were not suitable for live tower operation. Ingersoll-Rand’s first response was in 1979 with the development of the Drillmaster DM70, able to drill 10 inch diameter holes in metal mines and up to 12½ inch holes at coal mines using 8.6 bar air for rotary drilling. And in 1979 the company launched the DM-H (Drillmaster – Heavy), the first truly modern large blasthole drilling rig to be used for low pressure rotary drilling of 9 7/8 - 12 1/8 inch holes with bit loads up to 90,000 lbf.

The DM-H used hydraulics for both drilling and non-drilling functions and featured a hydraulic propel excavator type undercarriage with easily replace-able grouser pads and in-line compo-nents on the deck. It was equipped with a rotary screw compressor and a “live” tower with patented angle drilling system. The tower pivot point was flush to the drill deck and within the dust curtain, reducing the length of unsup-ported drill rod. It was an all-purpose

machine, with a single-pass version added in the mid-1980's. The machine has been upgraded over the years al-though replaced by the Pit Viper 351 for hard rock applications.

At much the same time the company started to offer electric powered ver-sions of the DM 45 and other models if customers wanted them, for instance for use in open pits where the other key equipment was electric powered. However, although these machines had electric motor power packs they retained the hydraulic rotation system. The first electric drill rig was the DM7B delivered to Clarksburg in 1977, followed a year later by the DM100 delivered to Rock Springs.

After recovery from the recession of the early 1980’s, Ingersoll-Rand launched a medium range Drillmaster, the DM-M designed for rotary drill-ing of 9 7/8 inch holes with bit loads up to 60,000 lbf. Three of the first four DM-M's went into operation at Peabody Energy's new North Antelope & Rochelle Mine in the Wyoming Powder River Basin, now one of the two larg-est coal mines in the world. Now, over 25 years later, the prototype DM-M is still in operation. The machine featured a carriage feed system with wire rope cables, resulting in a lighter tower and lower center of gravity.

In 1989 this model was upgraded to the DM-M2 on which maximum bit load was increased to 75,000 lbf and the hole size capability extended up to 10 5/8 inch. Stability was improved as well. In 1990-91 the company intro-duced the DML for multi-pass drilling to 180 ft hole depth.

This new model could drill from 6 to 9 7/8 inch (200 – 250 mm) diameter holes in rotary mode, and 6 – 8 7/8 inch using a downhole hammer. Following a development project based on a customer consultation exercise the DM-M3 was launched at MINExpo 1992. Designed primarily for deep drilling of overbur-den for cast blasting in large coal mines, the first production DM-M3 went into operation in 1993 at Arch Coal's Black Thunder Mine, one of the largest coal mines in the world.

For this new model, the designers raised bit load to 90,000 lbf and the hole diameter range up to 12 ¼ inch while a

Milestones in development

Year Model Load on bit

1948 Quarrymaster drifter

1955 DM3 30,000lbf

1968 T4BH 30,000lbf

1969 DM4 40,000lbf

1970 DM50 50,000lbf

1979 DM-H 90,000lbf

1983 DM-M 60,000lbf

1990 DML 60,000lbf

1992 DM-M3 90,000lbf

2000 PV-351 125,000lbf

2004 PV-270 75,000lbf

2008 PV-235 65,000lbf

The DM-H, launched in 1979, could be used with bit loads up to 90,000 lbf (400 kN).

The first Pit Viper 351 was launched in 2000 and used at the Morenci copper mine in Arizona.


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new patented cable feed allowed the use of 40 ft long drill rods.

ThelaunchofthePitViper

Although difficult market conditions restricted investment in the mid-1990’s, during 1997 the company started work on a new generation blasthole drilling rig design.

To differentiate this new range from the Drillmaster series, which initially was designed for drilling large holes in coal mining and soft rock, this new series was - from the very beginning - specified and designed for produc-tion drilling of large holes in hard rock conditions.

The first one out was the Pit Viper 351, which was successfully launched at MINExpo 2000. Weighing 170 tonnes, measuring 53 feet long, and equipped with a CAN-bus control system with seven on-board computers, the new Pit Viper 351 was at that time the largest and most advanced drill rig of its kind. The advanced control system allowed the drill pattern to be transmitted to the drill rig via a radio network, and it also featured production monitoring, rock recognition and a GPS navigation system.

A few months after the Minexpo show, in April 2001, the PV-351 was put to work at the Morenci copper mine in Arizona for final testing and evalu-ation. The mine had a fleet of 16 drill rigs from a variety of manufacturers, so in addition to the new rig being used for drilling in the hard igneous rock condi-tions, this was an excellent opportunity for benchmarking the PV-351 with the other brands.

The application required 12 ¼ inch diameter single pass drilling of 57 ft deep blastholes using up to 90,000 lbf weight on bit (of the 125,000 lbf capac-ity). The test was successful: the PV-351 drilled some 2.2 million feet by August 2004 at a recorded average rate of 60,000 feet per month and in some months even more than 80,000 feet per month.

Later the same year the multi-pass Pit Viper 275 was launched at MINExpo 2004. Based on the experience from the PV-351, combined with customer con-sultations, a project had been initiated for development of the PV-270 series. These drills were specified for a 75,000 lbf bit load capacity and were featured a similar cable feed system and auto-matic cable tensioning to that on the larger PV-351. The multipass version PV-275 with a 195ft depth capacity was

delivered for a test in December 2003 at Peabody's Kayenta coal mine in Arizona where it was used for cast blast drilling for removal of the overburden. This first machine is still in use there and, as a result of the good performance, the mine decided to invest in several addi-tional units. One of these is prepared for quick change between a multi-pass and a single-pass tower as an option to be adapted for different applications at the mine.

The first mine to use the single pass version, the PV-271, was the Barrick Goldstrike mine near Elko, Nevada. Since the PV-271 arrived at the mine in April 2004 it has been problem-free, and holds an impressive track record with an average penetration rate of 199 ft per hour. The long component life and also the automatic tensioning adjustments for the cables are much appreciated by the mine.

Following this tradition of product launches in Las Vegas, the latest addi-tion to the Pit Viper series - the PV-235 - was shown at MINExpo 2008. This is an advanced midrange drill for bit loads up to 65,000 lbf, with the RCS Rig Control System available as an option.

acknowledgements

Editors: Kyran Casteel and Ulf LinderContributions: Guy Coyne, Ron Buell, Kenneth Moff itt, Brian Fox, John Stinson, Dustin Penn, Gunnar Nord, Sverker Hartwig, Jim Langford, Diane Norwood, Darwin Hollar, Ewald Kurt.

Big picture: The electric PV-351E at the Boliden Aitik Mine. Inset: The workplace of today with RCS control and automated functions.

The Pit Viper 235 shown at MINExpo 2008.


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ergonomicsandsafetyforoperatorsToday much has changed with regard to operators, machines and machine interfaces. Twenty years ago the indus-try took a macro view of an operator’s ability to complete a shift without tiring or having an accident. Today designers work to a micro requirement; neither a hand nor a finger must be injured over a 30-year career doing the same func-tion.

In the past the requirements were for gauges and levers to be properly placed to avoid human strain during the work shift. Now engineers analyze site paths, a process of ensuring that natural hand motions are used to operate equipment. The drive for safety and efficiency are integrated.

Not only does the manufacturer look at drilling as the sole function of an operator. A multi-skilled operator may also manage drilling consumables, complete basic maintenance and report de-tails of bench conditions. These new roles also must be designed into the machine interfaces.

Also with regard to improved ergo-nomics and safety, Drilling Solutions engineers work to design systems that eliminate or reduce the hazards. In the late 1990s when the United States Mining and Safety Administration imposed stric- ter silica exposure limits for operators, engineers found that improved air qu-ality could not be achieved without removing the concentration levels in cer-tain applications. The drive then became to manage the dust rather than improve air quality through expensive filtration.The goal of Drilling Solutions is to allow the operator to do what comes naturally and to create a work environ-ment that provides superior comfort and safety.

OperatorcabinsandmachineinterfacesA rotary drill is recognized as one of two pieces of surface mining equipment that sits and works in its waste, heat and dust. The other piece is the shovel or excavator. The operator’s cabin, or cab, is the device used to protect the operator, a design factor not seriously considered as late as 1995.

Nearly everyone would agree today’s automobiles are safer, quieter, offer a smoother drive and are very user fri-endly. The automobile is becoming the acceptable standard in industry when looking at operator cabins. The visual look of an operator cab has also become a design criteria, as personnel equate past operator cabs with a metal box that induces high fatigue. An automotive’s structure and safety systems keep passengers safe. Likewise today’s drills are engineered to protect an operator against hazards that once injured or killed operators.

Reference dust management improvement.

ergonomicsandsafety

MachinedevelopmentsinanewdecadeErgonomics today has taken on a broader meaning with the advent of safer work rules, higher work efficiencies and superior design tools. Today engineers can study and design machines that are effi-cient to operate, maintain, build and transport. Engineering tools, new materials, improved indus-try standards and new technol-ogy allow a designer to model a machine and actually simulate operation under safer operating conditions. During this decade not much has changed with the technical perfor-mance of drilling as cutting struc-tures remain the same. Rather the design emphasis has been on efficiency, fewer accidents and ease of operation. Globalization of mi-ning to a higher level is also driv-ing changes. The HIV epidemic in Africa is reducing the workforce at an unheard of rate. New deposits in arctic regions require a new emphasis. This article highlights the advances Atlas Copco Drilling Solutions engineers have made to meet these new challenges.


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The image above shows a rock fall that the operator survived without injury. Using proper de sign techniques and better materials. Atlas Copco engineers have delivered an operator cab that reduces interior noise levels signif-icantly below the industry benchmark

of 80 dBA. For example, the Pit Viper 351 with 1500 hp was measured below 70 dBA when drilling.

Like automotive climate control sys-tems are developed to maintain opera-tor comfort more efficiently, today’s systems direct the cooling effort on the operator. The systems are also used to defrost windows in cold weather cli-mates just as automobiles do. Drilling Solutions engineers also are working to advance the cleanliness of the air the operator breathes.

Engineers can use computer models to quickly improve line of site. Cabs now feature more window space, which improves visibility, due to glass and insulation technology. Camera technology

allows an operator to watch the areas where visibility is restricted. The com-bined effect is to give operators a full view from the operator’s chair.

The operator chair and flooring play active roles in reducing drilling vibra-tions, which add to operator fatigue. Now an operator’s chair is often referred to as an operator’s pod, and is adjust-able to fit a variety of shapes, sizes and weights. All machine interfaces are now within the operator’s reach.

Technology can also play a role in protecting the operator from dangerous work conditions. Drilling Solutions engineers, working with suppliers, are creating a system that allows limits of operation to be defined and to give an operator feedback when an unsafe condition exists. As drilling conditions change within the pit, the machine can be easily reprogrammed to fit the new situation.

The result of this combined effort is to deliver a safe, comfortable work environment that is suited for the long shifts required in surface mining.

Maintenanceergonomics

Nearly unheard of a decade ago, in-dustry standards now require safe, rou-tine and easy access to all maintenance points. In the 1990s the Australian New South Wales MDG-15 Act gave guide-lines for maintenance ergonomics that have become the accepted standard in industry today, and these standards, in addition to factors such as fatigue and safety, drive the machine design effort.

For example, Australian studies showed a very high incident rate for person-nel getting on and off machines. These results drove the international market to look at alternatives. As a result, placement of key maintenance points could only be in a zone from waist to shoul-ders, based on measurements for 90 percent of the population. Until fairly recently, operator comfort and safety were only afterthoughts – if they were considered at all. Now, what was once “out of sight, out of mind,” is a critical requirement at the forefront of design innovation.

JohnStinson

Operator survived rock fall.

Comfort combined with ease of operation in one package.

The image shows digital readouts of weight on bit, rotation speed, torque and rate of penetration. It also can be programmed to give an operator visual feedback.

The image shows a digital leveling device on which the background can change colors, sound an alarm or remove power when an unsafe angle of operation is experienced.


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anincreasingdemand

Today, the population of the world stands at about 6.5 billion people. In simple terms, this means that every year approximately 10 tons of material is extracted using surface mining tech-niques for every person in the world.

If one looks to the future, the UN esti-mates that in 20 years (2038) the world’s population will have reached about 8.5 billion people. By simply applying the current utilization rate of 10 tons/person, one would expect the amount of material extracted yearly by surface mining techniques to climb to 85 billion tons. One must keep in mind, however, that today about 95% of the population growth is in the developing countries of the world. Based on their expecta-tions for improved living standards

in the future, the actual estimate of materials mined using surface mining techniques in the year 2038 is 138 billion tons (Bagherpour et al, 2007).

The ability of the earth to meet this type of demand is not really a question of resources, since they are clearly there, but rather a matter of price and cost. In looking at the mineral resource base, one must conclude that, in gener-al, the mining conditions will be significantly more difficult than today. In addition, ever-increasing environmen-tal and health and safety conditions are expected to be in place. This means that the entire mining process from pro- specting to exploration to development to extraction and finally to reclama-tion will have to become much more advanced. In many places of the world today, mine closure must be fully and satisfactorily addressed before a surface mine can be opened. This translates into requirements for applying first rate

engineering and technology for meet-ing today’s requirements and especially those of the future. Atlas Copco is at the forefront in producing the equip-ment and technologies required today and for addressing the challenges of the future.

abriefsynopsisofquarryingandopenpitminingThis introductory chapter will focus on those surface deposits that require the application of drilling and blasting techniques as part of the overall extrac-tion process. Excluded from the discus-sion will be strip mining, the mining of sand and gravel deposits and the quarrying of dimension stone.

As indicated, large quantities of raw materials are produced in various types of surface operations. Where the pro-duct is rock, the operations are known

Photo: Copper mine in the southwest USA.

anintroductiontosurfaceminingThewealthofnationsA well-accepted principle is that the wealth of a nation comes from the earth. In the world of mining, a corollary to this is that “If it can’t be grown, it must be mined.” Surface mining techniques are the principal means used to extract minerals from the earth. The yearly rock production yielding metals, non-metals and coal in the world totals 16.6 billion tons*. Of this, the production from surface mines is about 70% or 11.5 bil-lion tons. Crushed rock, sand and gravel - the fundamental materi-als required for construction - are largely produced using surface mining techniques. Their yearly production rate totals 23.5 billion tons. To this must be added the materials needed for the produc-tion of cement, another 2.3 billion tons. Finally, the amount of waste that must be moved in the process of extracting the valuable materi-als is estimated at 30 billion tons. Summing, one finds that the total amount of material extracted per year using surface mining tech-niques is of the order of 67.3 bil-lion tons (Bagherpour et al, 2007). * 1 ton = 907 kg


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as quarries. Where metallic ore or non-metallic minerals are involved, they are called open pit mines. There are many common parameters both in design and in the choice of equipment.

When examining a deposit for poten-tial mining and even when expanding a current operation, one often employs a process called circular analysis. As

shown diagrammatically in Figure 1, the process consists of five components. Although the figure applies specifically for the open pit mining of ore depos-its, a similar procedure is followed for quarries.

One naturally begins with a descrip-tion of the deposit and using some as-sumed costs a preliminary pit design

is obtained. By adding the desired pro-duction rate into the model a production schedule is generated. Based on the schedule, one determines the required equipment fleet, staffing, etc. to satisfy the schedule. This leads allows one to calculate the capital requirements and the operating costs. With these now-estimated rather than assumed costs, the ore reserves are re-examined and design alternatives evaluated. Eventually, an overall financial evalu-ation is performed. The double-headed arrows indicate the highly repetitive nature of the process.

Quarries

A rather simple but useful definition of a quarry is a factory that converts solid bedrock into crushed stone. Quarries can be either of the common pit type or, in mountainous terrain, the hillside type. Pit type quarries are opened up below the level of surrounding ter-rain and accessed by means of ramps (Figure 2). The excavation is often split into several benches depending on the minable depth of the deposit. When the terrain is rough and bulldozers cannot provide a flat floor, a top-hammer con-struction type drill rig can be used to establish the first bench. Once the first bench is prepared, production drilling is preferably carried out using DTH- or COPROD techniques.

The excavated rock is crushed, scre- ened, washed and separated into differ-ent size fractions, for subsequent sale and use. The amount of fines should bekept to a minimum. Not all types of rock are suitable as raw material for crushed stone. The material must have certain strength and hardness characteristics and the individual pieces should have a defined shape with a rough surface. Igneous rock such as granite and basalt as well as metamorphic rock such as gneiss are well suited for these purposes. Soft sedimentary rock and materials which break into flat, flaky pieces are generally unacceptable. The final prod-ucts are used as raw material for chemi-cal plants (such as limestone for cement manufacturing, the paper and steel industries), building products, and for concrete aggregates, highway construc-tion, or other civil engineering projects.

Financialoptimization

1. Capital and operatingsummation2. Revenue

3. Cash flow statement4. Marginal ore utilization

5. Rate of return

Ore reserveanalysis

1. Break-even analysis2. Drill-hole evaluation

3. Pit design4. Marginal analysis

Productionscheduling

1. Preproduction costs2. Working room

3. Stripping ratios4. Sequencing5. Reclamation

6. Operating schedules7. Financial

8. Constraints

Equipment andfacilities

1. Capital intensive2. Equipment selection

3. Operating costs4. Capital depreciation

5. selective mining

Refined ore reserves1. Cutoff grade

2. Marginal analysis3. Design alternatives

Figure 1. Financial optimization using circular analysis (Dohm, 1979).

Figure 2. A diagrammatic representation of a quarry operation.


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Quarries are often run by operators who sell their products to nearby contractors and road administrators. Because the products are generally of relatively low value, they are transport cost sensitive. Hence, wherever possible, quarries are discreetly located as close as feasible to the market. Special measures are required to minimize adverse environmental impacts such as noise from drilling, vibrations from blasting, and dust from crushing and screening to the neighbor-ing areas.

OpenpitminesTwo major differences between open pit mining and quarries are the geological conditions and the demands placed on the characteristics of the blasted material. For quarries, a majority of the rock products eventually delivered to the customers has only undergone crushing and screening in order to obtain the desired size fractions. An open pit metal mine, on the other hand, attempts to deliver the ore as pure as possible via crushers to a concentrator consisting of mills, separators, flota-tion and/or biochemical systems, etc. The resulting concentrates/products are eventually sent for further process-ing before emerging as a final product. For certain metals, this latter process involves smelting and refining. The deposits mined using open pit meth-ods have a variety of sizes, shapes and orientations. Sometimes the distinction between the valuable material and the waste is sharp such as shown in Figure 3 and in other cases the distinction is more subtle - based upon econom-ics. As in quarries, the minerals are extracted using a series of benches. If the orebody does not outcrop, the over-lying material must first be stripped away to expose the ore. As the initial pit is deepened, it is widened. The pit geometry is controlled by a number of factors including orebody shape, grade distribution, the stability of the slopes, the need to provide access, operating considerations, etc.

For the geometry shown in Figure 3, a significant amount of waste must be removed (stripped) to access the next bench of ore at the pit bottom. Without jeopardizing slope stability, it

is of prime importance to keep the pit slope angle as steep as possible, thereby keeping the excavated waste to a mini-mum. There becomes a point where the quality of the material contained in the next “ore” bench is not sufficiently high to pay the costs of the associated waste. At this point in time either the open pit mine closes or, if conditions are

favorable, continuation may proceed using some type of underground method.

Figure 4 shows the Aitik copper/gold mine in northern Sweden. It is Europe’s largest copper mine producing 18 Mton of ore per year. Currently at a depth of 480 m it is expected to reach of depth of 800 m before decommissioning. The Bingham Canyon mine in Utah (Figure 5)

Figure 4. The Aitik mine in northern Sweden (www.Boliden.se).

Ore

body

Waste

Good fragmentation needed

Good slope stability

Pit slope 45o

Bench slope 72o

Figure 3. General principles of open pit mining.


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has been in production since 1906 and is one of the largest man-made struc-tures in the world, measuring 1200 m

deep and 4400 m across the top. It has produced more copper than any other mine in history and has many years remaining. With respect to waste

removal, the fragmentation demands are simple. Since, the material is not required to pass through a crusher, the maximum size is controlled by the limitations imposed by the equipment used to load and haul the material to the waste dump. On the other hand, good fragmentation of the blasted ore offers great savings in the total costs of the mineral dressing process.

Someforwardthinking

Extraction of the valuable mineral whether in quarries or open pits requires a number of unit operations. Generally, the rock is drilled, blasted, loaded, hauled to a primary crusher and then transported further to a plant of some type for further processing. Figure 6 shows a schematic of the process.

Often, mines are organized so that the individual unit operations are se-parate cost centers. Although there are advantages to this approach, one result, Photo: Blasthole drilling of 40 ft (12 m) benches at Newmont's Phoenix mine, Nevada, USA. See page 91.

Drilling

Blasting

Loading

Hauling

Primary crushing

Secondary crushing

Grinding

Mine

Orebody

Further treatment

Ove

rall

frag

men

tatio

n sy

stem

Mill

Figure 6. Diagrammatic representation of the overall mine-mill fragmentation system and the mine and mill subsystems (Hustrulid, 1999).

Figure 5. The Bingham Canyon copper mine near Salt Lake City, Utah, USA. (www.kennecott.com)


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unfortunately, can be that the individual managers look at minimizing the cost of their center rather than on the overall objective of overall cost minimization. In reviewing the components in Figure 6, it can be shown that they can be replaced by two operations, fragmen-tation and transport. In the simplified view shown in Figure 7, there are five different stages of fragmentation each with a different energy – product pro-file.

One must carefully examine the best opportunities for applying fragmenta-tion energy in the various stages on the final product cost. For example, increased fragmentation energy can be relatively easily introduced in the mine by modifying the drill patterns and explosive characteristics. This action may provide an inexpensive alternative to adding the fragmentation energy in the grinding circuit. This process of considering all elements of the frag-mentation system, logically dubbed “mine-to-mill” is a recognized part of

mine-mill optimization. In addition to production, there are some other important customers for blast engi-neering. One is termed the “Internal Environment” and the other the “Ex- ternal Environment.” These are shown in Figure 8.

Both for safety and economic rea-sons, it is important to preserve the integrity of the pit wall. Large diam-eter blast holes, energetic explosives and wide patterns will be used in the production blasts which will be subse-quently loaded out using large excava-tors and haulage units. Near the pit wall, much more precise techniques involving smaller diameter holes, specially designed explosives, and special timing procedures are employed to minimize wall damage (Figure 9). Unless great care is taken, large loading equipment can easily spoil the results of the trim blasting. The result is that special loading and hauling fleets may be required. Failure to protect the pit walls, translates into the need for flatter slopes

and additional waste removal and/or the loss of reserves. These, in turn, translate into higher overall costs for the mining operation. In carrying out an evaluation of the appropriate drilling and blasting practices, emphasizing mine-to-mill aspects without taking into account the care of the slopes can result in lower production costs but at the sake of higher investment (capital) costs due to greater stripping or lost reserves. Therefore care must be taken to include all the costs when making the analysis. The “external environment” component falls into the category of a potential “show-stopper” since if proper meas-ures are not taken to fully comply with standards, the operation could very well be shut down.

Finalremarks

Atlas Copco has the advantage of long experience in all types of surface drill-ing operations, with a product range to match. With its history of innovative

DrillingSpecified Drill Pattern

External environmentMinimum: Flyrock, noise,airblast, ground vibration

Loading & HaulageGood: Fragmentation,Pile shape, diggability

Primary crusherHigh throughput andbridging preventation

Secondarycrushing & grindingEfficient crushing and

grinding feed

Internal environmentMinimum wall damage Blast Engineering

Drilling

Blasting

Loading & Haulage

Primary crushing

Conveyor

Secondary crushing

Grinding

Insitu

Further treatment

Frag

men

tatio

nTr

ansp

ort

Figure 7. The mine-mill system represented as fragmentation and transport unit operations (Hustrulid, 1999).

Figure 8. Simplified view of the five different stages of fragmentation, each with a different energy - product profile.


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ReferencesBagherpour, R., and Tudeshki, H. 2007. Material handling in world-wide surface mines. Aggregates International. Pp 10-14. June.

Dohm, G.C., Jr. 1979. Circular ana-lysis – Open pit optimization. Chapter 21 in Open Pit Mine Plan-ning and Design (J.T. Crawford, III and William A. Hustrulid, editors). AIME. Pp 281-310.

Hustrulid, William. 1999. Blasting Principles for Open Pit Mining. A.A. Balkema, Rotterdam.

Fernberg, Hans 2002, New trends inopen pits, Mining and Construction 1-2002

engineering, the company tends to think forward, and is able to advise the user on improving design elements of the operation that will result in overall cost savings.

WilliamhustrulidhansFernberg

Photo: Blasthole drilling and haulage at a mine in the southwest USA.

Figure 9. Near the pit wall more precise tech-niques are employed to minimize wall damage.


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acompleterange

With the acquisition of Ingersoll-Rand’s Drilling Solutions, Baker Hughes Mining Tools (BHMT) and Thiessen Team businesses, Atlas Copco has a complete range of products to offer to large quarries and open pit mines. Much of the world’s mining output begins through drilling of holes with rotary

drills. Ingersoll-Rand built air-powered rotary drills for many years prior to the introduction of their first fully hydrau-lic unit, the T4, in 1968.

aboutrotarydrills

It is important to note that rotary drills are capable of two methods of drilling. The majority of the units operate as pure rotary drills, driving tricone or fixed-type bits. The fixed-type bits, such as claw or drag bits, have no moving parts and cut through rock by shea- ring it. Thus, these bits are limited to the softest material. The other method utilized by rotary drill rigs is down-the-hole (DTH) drilling. High-pressure air compressors are used to provide com-pressed air through the drillstring to drive the DTH hammer (see illustration page 20). The primary difference between

rotary drilling and other methods is the absence of percussion. In most rotary applications, the preferred bit is the tricone bit. Tricone bits rely on crush-ing and spalling the rock. This is accomplished through transferring downforce, known as pulldown, to the bit while rotating in order to drive the carbides into the rock as the three cones rotate around their respective axis. Rotation is provided by a hydraulic or electric motor-driven gearbox (called a rotary head) that moves up and down the tower via a feed system. Feed sys-tems utilize cables, chains or rack-and-pinion mechanisms driven by hydraulic cylinders, hydraulic motors or electric motors. The preference at Atlas Copco is to use cables for pulldown, as they are lightweight and inexpensive, and allow easier detection of wear to help avoid catastrophic failures.

Atlas Copco’s largest drill, the Pit Viper 351E, operates on a blast pattern at an open pit copper mine. Rotary blasthole drills are the predominant method of drilling 9 inch (229 mm) diameter holes or greater.

Puttingrotarydrillingintoperspective

MiningprosperityAtlas Copco offers a complete range of rotary as well as DTH and top-hammer drill rigs for most types of open pit mining and quarrying applications. But how do these technologies complement each other and how do drillers know which method to choose, and when?


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Pulldown

Pulldown is the force generated by the feed system. The actual weight on bit,or bit load, is the pulldown plus any dead weight such as the rotary head, drill rods and cables.

Moreweightwithrotary

It only takes one look to see that the biggest DTH and tophammer drill rigs are very different than the biggest rotary blasthole rigs. In fact, the Pit Viper 351 rotary drill rig weighs in excess of nine times that of Atlas Copco's largest DTH hammer drill rig, the ROC L8. Yet the Pit Viper 351 is drilling a hole that is generally only twice the diameter. Take a typical medium formation tricone bit with a recommended maximum loading of 900 kg/cm of bit diameter (5000 lb per inch of diameter). With a 200 mm (7-7/8 in) bit, you could run about 18,000 kg (40,000 lb) of weight on the bit. The laws of physics dictate that for every action, there is an equal and opposite reaction, meaning that if you push on the ground with 18,000 kg (40,000 lb), the same force will push back on the unit. There-fore, the weight of the machine must be over 18,000 kg (40,000 lb) at the location of the drill string to avoid the machine “lifting off” the jacks. To achieve a stable platform through proper placement of the tracks and levelling jacks, the distribution of weight results in an overall machine weight that approaches or exceeds twice the bit load rating. This weight does add cost to the machine, but the size of the components also translates to long life. Even smaller rotary blasthole drills are built to run 30,000 hours of operation, and some of the large blasthole drills have clocked over 100,000 hours of use.

Rigdesign

With the exception of one model, the rubber-tire mounted T4BH, Atlas Copco’s rotary blasthole drills are mounted on excavator-style undercarriages. Power-ful hydraulic-drive systems allow the machine to tram over a variety of ground conditions, though rotary blasthole drills should always operate on firm, flat benches.

Principle:The hammer is situated down the hole in direct contact with the drill bit. The hammer piston strikes the drill bit, resulting in an efficient transmission of the impact energy and insignificant power losses with the hole depth. The method is widely used for drilling long holes, not only for blasting, but also for water wells, shallow gas and oil wells, and for geo-thermal wells. In mining it is also developed for sampling using the reverse circulation technique (RC drilling).

TONS

Principle:Rotation is provided by a hydraulic or electric motor driven gearbox, called a rotary head, that moves up and down the tower via a feed system, generating the pulldown required to give sufficient weight on the bit. Flushing of drill cuttings between the wall of the hole and the drill rods is normally done with compressed air.

The tower supports the drill string during drilling as well as the rotation head and feed system.

Down-The-holemethod Rotarydrillingmethod


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The key component of a rotary blasthole drill is the tower, which is some-times referred to as the derrick or mast. Atlas Copco towers are four main mem-ber, open front structures in which the rotary head slides up and down via a guide system. The length and weight of the tower ultimately dictates the size of the mainframe and undercarriage.

Most drilling functions are hydrauli-cally driven. Powering these hydraulic systems, along with the air compressor, is a diesel engine or electric motor. Most rotary drills are diesel powered for good mobility. Electric powered units offer some advantages such as lower power cost (in most areas), no diesel emissions, no refueling requirement and less maintenance. However, some operations are not setup with the pro-per electrical infrastructure or staffing to run electric units. Even when elec-tric power is available, many custom-ers avoid electric drills as the trailing cable used to provide power makes it harder to move the unit between holes or patterns. Generally, electric power

is preferred on large single-pass units used in major open pit metals mines where electric shovels are employed, though electric power is now available on smaller units such as the Atlas Copco Pit Viper 271, Pit Viper 275 and DML.

Theimportanceofair

A key parameter of rotary drilling is flushing the cuttings from the hole. Inmost rotary blasthole drills, cuttings are lifted between the wall of the hole and the drill rods by compressed air. Sufficient air volume is required to lift these cuttings. Many types of tricone bits have been developed to meet vari-ous drilling needs. Softer formation bits are built with long carbides with wide spacing on the face of the bit. This design yields large cuttings which increase drill speed and reduce dust. It is important to have sufficient clearance between the wall of the hole and the drill rods in order for such large cuttings to pass. If this clearance, known as annular area, is not sufficient, the cuttings

The drilling platform is supported by a crawler undercarriage except during drilling when it is raised up by hydraulic jacks.

The ability to carry long drill rods up to 70 feet provides more time for drilling.


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will be ground between the wall of the hole and the rods or by the bit itself (called regrinding) until they are small enough to exit the hole. This results in excess dust and accelerated wear on the bit and drill rod.

Bailingvelocity

A traditional rule-of-thumb is a mini-mum of 1,525 m3/min (5000 cfm) of uphole velocity, the speed at which air exits the hole. The actual amount of air required will vary widely based on the density of the material and the size of the cuttings. Dense cuttings as found in iron ore mines will settle much quicker than lightweight overburden in coal mines and thus need more air coming up the hole to lift them; 1,525 m3/min (5000 cfm) may not be enough. However, har-der material is generally drilled with hard formation bits that utilize shorter cutting structures, thus yielding smaller chips. Conversely, some soft material can be drilled effectively with only 915 m3/min (3000 cfm) uphole velocity. Unfortunately, many operations have tried to increase uphole velocity by in-creasing the diameter of the drill rod. This is obviously much easier than get-ting a larger air compressor by retrofit-ting or purchasing a new machine. In some conditions, this strategy works, but more often, the reduced annular area results in increased wear and dust, and the drill rate may even drop. Whatever the application, it is critical to have pro-per bailing air.

Dustcontrol

A necessary evil created by the air compressor in drilling operations is the generation of dust. To control the dust, the area surrounding the hole is en-closed by a dust hood. Dust hoods are sealed on the sides by dust curtains, and where the rod comes through the deck by a rod wiper or dust seal. A dust control system must be used in con-junction with the dust hood and cur-tains. The two most popular types of dust control are dry dust collectors and water injection. Dust collectors are essentially large vacuum cleaners that pull the dust away from the dust hood and run it through a collection of filter

Rotary drilling with tricone bits is the most cost efficient method for large hole diameters.

Large diameter holes produced by rotary drills, such as this Pit Viper 275, yield blast patterns with wider burden and spacing, resulting in fewer holes drilled.

To control the dust, the area around the hole is surrounded by a dust hood.


TalkingTeChniCally

elements. Water injection systems inject a fine amount of water into the air stream. Water injection is the more effective solution for ensuring dust is minimized, but the introduction of water into the hole can slow down the drilling process by increasing the den-sity of the cuttings at the bottom of the hole that the air compressor must move. Water injection systems require fre-quent refilling of the water tanks, and in freezing conditions, elaborate heat-ing systems must be used. Dust collec-tors offer a productivity advantage, but they can become plugged if not turned off when wet material is encountered. This is particularly a problem if the wet material freezes in the system.

Whenrotaryisbetter

Every drilling application is different, so we cannot say that there are parti-cular breakpoints where you should transition between drilling methods.

Generally, drilling below 152 mm (6 in) is best accomplished with tophammer units. Above this diameter, it is typi-cally done with a rotary rig, although tophammer units are doing some of this work effectively with the introduction of larger platforms and more powerful rock drills. For harder material, say above 100 MPa (15,000 psi), unconfined compressive strength (UCS), DTH is often faster than pure rotary drilling if provided there is enough air pressure on board. Simply looking at our product range (see above) gives an indication of which methods are com-monly used for the different diameters found in construction and mining.

There are certain limitations imposed on each method of drilling. With tophammer percussive drills, the power of the rock drill itself limits the ability to transmit adequate force to larger diameter bits, especially at dee-per depths when percussive energy is successively reduced with each new rod

connection. Down-the-hole (DTH) tools solve this energy loss problem, but their maximum hole diameter is limited by the volume of air. To build the air pressure that translates directly to impact energy, a certain volume of air is required. Take for example a Secoroc QL80 203 mm (8 in) DTH hammer that is designed to operate at 25 bar (350 psi). Even with our largest high pressure compressor 686 41 m3/min (1,450 cfm), the pres-sure will only build to 23 bar (325 psi), thus providing less impact energy. In real terms, each blow of the piston is about 45 kg (100 lb) less than it is designed for. In some cases, this method will still outperform rotary drilling. For most large diameter blasthole drilling, there is simply not enough air on-board for a DTH to be as cost effective as rotary drilling with a tri-cone bit. Rotary drilling is still the pre-dominant method of drilling 230 mm (9 in) diameter or greater. This is driven primarily by the current limitations of

Rotary drilling with tricone bits is the most cost efficient method for large hole diameters.

DML

ROC P55

CM 351

ECM 720

1"

ROC L630

ROC P65ROC L7CR

ROC L825

CM 785

Pit Viper 271

ECM 585

ECM 660ROC F9/F9CROC F9CR

ROC D9/D9RRC/D9CROC D7/D7RRC/D7CECM 590/592

ROC T15BVB 25

ECM 580CM 470

ROC D3ROC 203

DM25-SPROC L830

406mmPit Viper 351

381mm305mm127mm 152mm 178mm 330mm

CopperIron

16"15"13"25mm 51mm 76mm 102mm 356mm279mm

11"203mm 229mm

12"254mm

8" 9" 10"

Industrial minerals (Cement & Limestone)Gold

Coal

2" 3" 4" 5" 6" 7" 14"

Dimension Stone IndustryConstruction

Aggregate

DTH

COPROD

Tophammer

Tophammer / fully pneumatic

DTH / fully pneumatic

Rotary / DTH

Rotary

CM 765ROC L625

CM 348

Atlas Copco large rotary andDTH drill rigs are included

in this book. For information about the range of smaller surface rigs

visit www.surfacedrilling.comor contact your Atlas Copco

representative

ROC L740ROC F6BVB 25 DTHROC 203 DTH

Pit Viper 275 DM-M3

DM30T4BH

DML-SP

Pit Viper 235

DM45


TalkingTeChniCally

tophammer units and rig air systems. Tricone bits also become more cost ef-fective as the larger bits are equipped with larger bearings which in turn can handle higher loads. These higher loads translate to improved drill rates. An- other advantage of rotary rigs is the length of the drill rods that can be car-ried on board. Longer rods mean fewer connections. Smaller rotary blasthole machines utilize 9.1 meter (30 ft) length rods, while larger units are capable of running 10.7 meter (35 ft) or 12.2 meter (40 ft) rods. By comparison, topham-mer or DTH crawler drills use drill steel that is generally 6.1 meters (20 ft) or less in length. Further, some rotary rigs are large enough to handle a long tower that enables drilling of the entire bench height in a single-pass. At the largest open pit mines, rotary units are drilling 20 m (65 ft) deep holes in a single-pass to match the bench heights dictated by the large electric shovels that can dig a 17 m (55 ft) bench.

Productivityversuscost

Studies have shown that pure penetra-tion rate will increase linearly with increased pulldown. The same has also

been said of rotation speed. So why doesn’t every operation use more of each? Unfortunately, higher pulldown and rpm usually results in increased vibration and lower bit life. The vibra-tion causes increased wear-and-tear on the rig, but more importantly, it creates a very unpleasant environment for the operator. What invariably happens is that the operator reduces the weight or rpm until the vibration returns to a comfortable level. Some operations limit bit load and rpm even if there is no vibration in order to improve bit life. This is often the wrong strategy as the overall drilling cost per unit, also known as Total Drilling Cost (TDC), should be considered. TDC is calculated using the bit cost per meter/foot and the total rig cost per hour. The unit cost per hour includes labor, maintenance and power, and possibly capital cost. The drilling speed really doesn’t impact this cost-per-hour figure. What it does impact though is the cost per unit produced (cost/meter/foot, cost/ton, etc…).

You generally want to push the rig harder to reduce the cost/foot, but there will be a point where the rig overloads the bits (see diagram).

largeversussmall

There are some drawbacks to rotary rigs. Smaller crawler rigs are more flexible with many advantages such as articulating and extendable booms and guides that allow drilling at many different angles. Unlike crawler rigs, the components on rotary rigs are often not enclosed. They are mounted onto the frame in an open layout that makes them extremely easy to service. Large electric units normally have a machi-nery house to protect the electrical drivecomponents, and newer midrange sized blasthole units such as the Pit Viper 235 have the option of a machine enclosure. The general trend for 165 mm (6-1/2 in) or less is towards the smaller, more flexible units. However, many large scale quarries and small mines still favor the durability, life and simplicity of the larger rotary rigs for these small diam-eters. For the large scale open pit opera-tions that yield a high percentage of the total worldwide mineral production, it is anticipated that rotary drilling will remain the primary method for years to come.

BrianFox

0

2000

4000

6000

8000

10000

12000

14000

$-

$1,00

$2,00

$3,00

$4,00

$5,00

$6,00Footage/24 HoursBit Life (ft)Overall Cost/Ft

299 ft/hour, 1500' bit lifeHigh Production

74 ft/hour, 12,000' bit life

Great Bit Life

218 ft/hour, 5300' bit lifeLowest Cost

Foot

age/

24 H

ours

& A

vera

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it Li

fe

Tota

l Dril

ling

Cost

/Foo

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TotalDrillingCost(TDC)relatedtobitlifeandproductivity


TalkingTeChniCally

introduction

Atlas Copco has introduced a number of new drill rigs for the Drilling Solutions Division using a common technology platform. This approach allows devel-opment of new functionalities for the drill rigs, which experience has shown in both underground drilling and haul-age as well as surface drilling. The cur-rent generation of machines is designed for high productivity, quality drilling and a comfortable working environment for the operator. Drilling a hole constitutes a small amount of the direct cost and time of mining, but has a major impact on the other production processes because it affects fragmentation, back-break, underbreak, wall control, load-ing, haulage and processing. Although great attention is paid to penetration rate and wear of drill steel and bits, Atlas Copco is also interested in what drilling can do to improve rock excava-tion overall. The inputs to this ongoing process come from customers and from research projects where new technology is applied to drilling operations.

A H

OLM

BE

RG

200

7

PC-card

CCI module AP module Resolver module I/O module

Atlas Copco's Technology Platform.

automatedsurfaceblastholedrilling

UtilizingthetechnologyplatformThe current series of Atlas Copco Pit Viper drill rigs is based on the latest, well proven computer and information technology. These drill rigs are of modularized design in both hardware and software, so upgrades of the latest technology are available for older models. Se- veral options are available to faci- litate quality drilling. Atlas Copco has applied the same new automa-tion technology for other underground drilling equipment such as Simba production drill rigs, Boltec rockbolting rigs, and ROC surface crawler rigs. For the customer, this means commonality of compo-nents and training, leading to a better understanding of both the capability and the maintenance of Atlas Copco products. For the company, it allows continuous product development, which can be applied straight across the range.

PV-275 cabin with RCS provides an excellent operator s environment and improved drilling performance.


TalkingTeChniCally

RigControlSystemThe automation platform for Atlas Copco blasthole drilling equipment is the Rig Control System (RCS), which is based on standard PC-computer tech-nology. The new generation of RCS rigs has taken a quantum leap forward with respect to logging capabilities, service-ability and drilling accuracy. CAN-bus technology provides the backbone of this new rig control system. It is flexible and easily expandable, allowing new units to be added anywhere along the data bus by cable.

The electronic modules are all developed solely for the RCS rigs, and are ruggedized and protected from externalmagnetic and electric influences. For

surface blasthole machines, the flex-ibility of the system is highly utilized and can be adapted and configured for all different types of products. Cus-tomers can start at a low level of automation and, as their requirements change, can upgrade. New functionality can be added without major rebuilding of the machines.

Commonautomation

All Pit Vipers can be equipped with RCS Basic, which provides a number of safety and interlock features and a series of options– Autolevel, Autodrilling, GPS hole navigation, Rig Remote Access (RRA) and communication, wireless remote tramming, Measure While Drilling

(MWD) data log files, and International Rock Excavation Data Exchange Sy- stem (IREDES).

Safetyfeatures

The RCS Basic provides the machine with additional standard interlocks compared to the electric-over-hydraulic machines. A few of the interlocks cre-ated with the software are:• Hole depth indicator – displays the

rotary head position as well as the depth of the hole drilled;

• Pipe in hole tram interlock – rotary head must be in a safe position to allow tramming;

• Jack interlock – pipe in the hole will disable jack functions to protect the machine and reduce bending of rods;

• Rod support interlock – prevents damage of the rotary head and rod support by not allowing feed with rod support not in the stowed position;

• Carousel no-bump – prevents damage to the carousel by limiting pulldown pressure with the carousel not in the stowed position;

• Breakout wrench protection – prevents damage to the breakout wrench by disabling pulldown with wrench not in the stowed position;

• Engine and electric motor informa-tion displayed over the touch screen maintenance screens;

• Low fuel, lube and water level mes-sages; and

• Tram interlocks, so a trigger must be activated to allow tram function.

RCS cabin on a PV-351. The control system replaces the electric/hydraulic joystick and console layout pictured here.

RCS cabin on a PV-270 series.


TalkingTeChniCally

autolevel/autodelevelTo increase the quality in setup of the drill, leveling the machine on the jacks is performed automatically. This will help an average operator to close the gap to the skill level of an expert opera-tor. Installation of this feature will reduce wear and tear on the machine structure by limiting torsional effect on the mainframe and tower while leveling. This function's performance, of course, depends on ground condi-tions, but for a normal bench flatness, the results are that leveling is done in less than 35 seconds with an accuracy in pitch and roll to 0.2 degrees. Well

structured and integrated fault handling is vital for Autolevel/Autodelevel. This is to avoid unwanted tip over of the drill in case of uneven ground conditions or internal component faults.

autodrillingIn many cases there are several types of rock conditions within one blasthole, and an operator must be alert at all times to react to these varying ground conditions. With Autodrilling, computers are now the operators reacting to feedback from the machine’s gauges.

Atlas Copco's autodrill feature has reproduced the expert operator's reac- tions into an automatic drill control. When activated, this function will detect the rock when the bit touches the ground, and start your air, water, rota-tion and feed to collar the hole. After the collared distance has been met, then this module will adjust air, water, rota-tion and feed to a drilling setting. This feature will apply optimal pulldown and rotation to try and drill as fast as possible without stalling the rotation or getting stuck. Once the target depth has been hit, the autodrill feature will clean the hole or flush the hole, shut off the air and water and then return the bit to a tramming-safe position.

This feature provides the consistency of drilling to the correct hole depth, and a consistent water flow to maintain the hole so it does not collapse. Currently this is available for single-pass drill-ing and multi-pass drilling, although a manual rod change must be made at this time.

Start Rock contact detection Collaring Drilling

Hole building

Finished

Anti-jamming / vibration control

Hole cleaning

autodrilldiagram

This diagram is valid for a single-pass drill. For multi-pass drills a rod handling system sequence is added to the Autodrill sequence, which is currently not developed for rotary drills.

2. Using multilever rocker switch. Auto-levels up for switch up. Autodelevels for down in drill mode.

3. Autodrill. Drills to predefined depth and returns head to propel safe position. Anti-jam, void detection and so on in drill mode.

4. Future option. Auto tramming or auto-nomous operation.

1. Auto interlock button. Press and hold this first and then choose one of the following auto functions.

Onthepanel

GPS navigation screen.

Drill dashboard - drilling screen.

Leveling screen.

Settings screen.

RCS Automated Function Buttons.


TalkingTeChniCally

gPSholenavigation

To ensure the blasthole is precisely po- sitioned where the mine engineer has designed the blast pattern and is drilled to the correct depth, GPS hole navigation has been developed for the RCS platform. This hole navigation system uses antennas mounted on the tower rest and radio antennas on the cab to produce an accurate bit position. Drill plans designed with the local mine co-ordinates are imported to the system, and the bit position is provided in real time. The bit position is very accurate and is calculated by taking into con-sideration the variability on the bench, providing the operator with the correct depth to drill each specific hole. This feature also provides a moving map display with zoom functions as the rig is trammed closer to the desired blasthole location. The dominant system for positioning of a rotary drill on a blasthole drill plan is with satellite naviga-tion based on GPS or GPS and Glonass. Accuracies up to ±10 cm are possible to reach depending on installation and number of available satellites. The integration of the GPS receiver to the control system is via a standard RS serial link. Protocol used is preferably the stan-dardized NMEA0183. The advantage ofhaving the GPS system as a positioningsensor enables customers to choose pro-ducts of any brand (Trimble, Leica, Topcon) depending on the preferred standard in the actual mine.

RigRemoteaccessandcommunicationThe Rig Remote Access (RRA) system from Atlas Copco gives a customer the ability to connect the drill rigs to a standard computer network on a work site. The RRA system allows access information on the drill rigs from any authorized point in a network. The RRA system basically consists of a commu-nication server onboard the drill rig and a network adapter. The server supplies the user with three functions: a web server that can connect to any standard web browser, an FTP server to enable transferring of data (files) to and from the drill rig, and a server process that enables any data to be integrated into the user's administrative systems.

If a commercially available "office" network is used on the work site, which is easy to install into the existing infrastructure, it restricts the RRA func-tionality to only remote access, and does not permit remote control. Standard communication equipment is also used that makes the RRA easy to upgrade and adapt to new and more effective equipment when available. The system also utilizes standard communication protocols such as PPP or TCP/IP. With a wireless network connection to the drill rig, a number of working procedures in the mine are simplified and several new features are available to the mine planning organization. The basic mine planning and control functions can be

simplified substantially by having a direct link to the machines. Advanced work orders that previously were distributed at the beginning of each shift can now be distributed instantly. This leads to a more flexible and adaptable production organization. Computer designed drill plans and work orders that earlier had to be loaded manually with a PC card can now be downloaded directly from the office computer where they were created. This saves time and personnel and also allows last minute changes in order to adapt to variations in geology and ore geometry. Log files generated during drilling, also previ-ously transferred from the rig with a PC-card, can now be collected from any computer connected to the network. This means that information carried by the log files, e.g. production data, geological and geomechanical data (strata recognition) is available for the entire organization as soon as the drill completes its hole/pattern. Manual shift reports stating number of holes, drilled depth, etc. can now be completed automatically from data logs without human involvement. RRA is also a tool for more advanced service and mainte-nance procedures. The operation of the rig can be followed remotely and moni-toring of drill rig status can be made online using a standard web browser on a remote PC. “Web pages” are set up similar to the native RCS display on the rig. Troubleshooting can be done remotely using the built-in menus in the

Remote Rig Access and communication . Wireless remote control, compact portable package.


TalkingTeChniCally

RCS system. This can also be done by specialized technicians and engineers at Atlas Copco's product companies. Furthermore, entire replacement of the RCS software has been done remotely from Örebro, the Rocktec office. The RRA system has been introduced to a number of underground mines and construction sites since 2003, which has eased implementation in surface mining operations.

Wirelessremotetramming

The wireless remote tramming function allows the operator to tram a Pit Viper from the bench within a 60-meter dis-tance. This will allow an operator to walk all the way around the machine and tram the rig to avoid any blind spots or next to a highwall or berm to prevent damage to the machine. This controller is also equipped with safety triggers, so the operator must have control of the unit with his hands to tram the machine. The function has an emergency stop button and engine speed control as well, and can be equipped with additional functions when available.

iReDeS

The data that is transmitted to and from a drill rig or any other mining equipment is arranged in a specific format. Often different equipment suppliers use their own specific format, allowing data communication only between their own equipment. For a mining company or a contractor, an industry standard will simplify integration of equipment fromdifferent suppliers. Atlas Copco was one of the originators of the InternationalRock Excavation Data Exchange Stan- dard (IREDES) initiative in 2000. A positive and open attitude between the IREDES members has led to data profiles for the different processes in the rock excavation process – drilling, loading and blasting. Atlas Copco is fullycommitted to the IREDES standard andthe rotary drilling product line is IREDES compliant.

MeasureWhileDrilling

Measure While Drilling (MWD), strata logging, logs several drill parameters

during production drilling, and the data can be used for prediction of geologi-cal and geochemical variations within drill patterns on a bench. This can help determine the strength of that specific rock type. A rock mass is also intersec- ted by fractures and faults that strongly influence the conditions of the rock mass and, therefore, engineering aspects such as charging and blasting of the drill pattern. This data, when integrated with the blasting plan, should influence the explosive charging and specific density applied throughout the pattern, which will in turn influence the load-ing, hauling and processing of the ore.

Teleremoteoperation

This feature uses the mine's wireless network, either 2.4 or 5.2 GHz frequen-cy, and allows an operator to utilize the machine functions from a remote location including, drilling leveling, tramming, and GPS hole navigation. A dedicated communication channel that guarantees bandwidth and latency times for real time control of the drill is required. The package can be equipped with a four-camera system that is com-pressed to limit bandwidth for viewing of the machine from remote locations. This module also includes a dedicated safety system independent of the RCS package. If communication is lost between the remote station and the ma-chine, then it will shut down. Additional safety systems like personnel detection

systems or systems detecting when people enter the working area should be combined with the mine's specific safety instructions.

autotramming

Autotramming is a feature in the deve-lopment stages and has been tested on a machine at the Garland, Texas, factory. This component utilizes the GPS hole navigation system or can be deployed with an augmented GPS using the standard NMEA string to tram a ma-chine between holes on a blasthole pattern. This pattern is interpreted by the path planner, which is in communica-tion with the drill regarding direction and track speed to tram the machine at an ideal speed to the exact location. This module can reduce wear and tear on the machine structures as well as undercarriage by reducing spot turning and planning a correct path to the next hole. The current requirement for this feature is a "flat" bench, which must be verified by a mine engineer, to allow this machine to stay within its limits. A combination of any or all of these features are available for deployment to fulfill a specific mine's needs for automation. Additional feedback will be required in the future to further en-hance the automation package, but the RCS is Atlas Copco Drilling Solutions' platform for automation.

DustinPenn

Teleremote office installation.


TalkingTeChniCally


TalkingTeChniCally

RotarytriconebitfundamentalsRotary tricone bits consist of several basic parts:• Three “roller cones” that hold the

cutting structure on their external surface, and the bearings in their interior

• The “cutting structure” consisting of either Tungsten Carbide Insert teeth, or milled steel teeth.

• Three “lugs”, each of which has the bearing “journals” which match up with the cone bearing “bore”.

• Inner and outer roller bearing ele-ments.

• Ball bearing elements.These basic parts are then assembled into bit thirds, and three ‘thirds’ are then assembled into a “tricone” (three cone) bit.

Once completely assembled into a finished bit, the bit “pin connection” is threaded with the appropriate connec-tion size and type for the bit diameter.

The figure at right illustrates the assembled components of a tricone bit and presents a ‘cut away’ of one lug/cone assembly to show the internal component arrangement.

Note that this figure shows air pas-sages from the bit interior into the bit bearing areas. This is an “air bearing”

bit. Other types of bearing configura-tions are “open” (or fluid) bearing, and “sealed” bearing.

“Open” bearings do not have any in-ternal air passages, and the back of the cones are ‘open’ to the external drilling environment.

“Sealed” bearings are completely enclosed, with no internal air passages. The bearings are sealed off from the external drilling environment, and are filled with pressurized grease.

Rockbreakage

Contrary to popular opinion, rotary tri-cone bits do not drill by “crushing” rock. Instead, they actually drill by a mecha-nism called “spalling”. A European gentleman named Hertz originally defined this method of rock breakage back in the 1880’s. If a force is applied to an “indenter” in contact with a rock

surface, stress fields are set up under that indenter. As the loading force on the indenter is increased, the stress fields extend outward and downward from the point of contact and loading. The applied load creates fractures (cracks) that propogate along the stress field vectors, seeking a “free surface”. When these stress vectors find the free surface, the crack is completed, and the rock above the stress vector breaks free. A rock “chip” or “cutting” is created, and must now be removed.

Because tricone bits apply this force to several inserts simultaneously on each cone, the cones must constantly be rotated to new “indenting” positions in order to advance the hole. It would do no good to simply continue to apply weight to the bit without rotation. Nothing would happen. The bit must be rotated to bring new teeth into position for loading and rock breakage.

Elements of a rock bit.

TriconerotaryblastholedrillingRotarytriconebitelementsRotary tricone bits consist of se-veral basic parts: Three “roller cones” with the bit ‘cutting struc-ture’ (tungsten carbide inserts or milled steel teeth) on their exter-nal surfaces; “bearing races” ma-chined inside each “cone bore”; three sets of bearing elements consisting of small “inner” rollers, ball bearings, and large “outer” roll-ers; and three “lugs”, each having inner, ball, and outer bearing races that match the cone bore races and hold the different bearing elements.


TalkingTeChniCally

Drillholecleaning/cuttingsevacuationOnce the “cuttings” are created, they must be evacuated. If the cuttings are not removed from the hole, the bit will be ‘eroded’ by the abrasiveness of the rock chips, and the teeth will quickly wear down and/or fall out, rendering the bit ineffective. In blasthole drilling, hole cleaning is done with compressed air.

The rotary bit is either attached directly to the “drill pipe”, or one of a number of other drilling accessories, (bit adaptor subs, bit stabilizers) are used to attach the rotary bit to the drill pipe. The exact attachment method depends upon the drilling situation.

In any case, a large volume of com-pressed air is directed down through the drill pipe (also called the drill string) into the bit. The flow of compressed air is intentionally restricted at the tri-cone bit by the use of “jet nozzles”, in order to create ‘back pressure” and a “pressure drop” through the bit. This ‘back pressure” forces air into the bear-ings of an “air bearing” bit, to keep the bearings cool and clean, and to prevent contamination from entering the bit. Secoroc wants to achieve an actual pressure inside the bit of 45 psi (3.1 bar) or higher. This will direct from 15% to 25% of the air into the bearings for bearing maintenance, while the remain-ing majority of the air creates a “jet blast” against the face of the hole to blow newlyformed cuttings away from the bit.

The following figure shows the bit’s internal air path in yellow. Jet nozzles are shown in purple.

Rock density (specific gravity) varies greatly, depending on what material is being drilled. Coal for instance has a SG of around 1.6, while some iron ores have a SG greater than 3.8. Most rock we drill has an in situ SG of between 2.4 and 2.8. If there is a lot of natural ground water, this can wet the cuttings, increasing the cuttings SG by about 0.1 SG. Secoroc recommends a minimum air “Bailing Velocity” of 5,000 - 7,000 feet/minute (1524 - 2134 meters/minute) for light and dry materials, and 7,000 - 9,000 feet/minute (2134 - 2744 meters/minute) for rock materials that are wet or have a high density.

Drillingparameters

Secoroc tricone bits generally conform to the IADC rock type classifications. IADC is the International Association of Drilling Contractors, who set many “standards” and “conventions” for the general drilling industry. Secoroc has adapted certain IADC concepts to its tricone bits.Tungsten Carbide Insert bits fall into five IADC classes: • 4-1 to 4-4 - very soft to soft• 5-1 to 5-4 - soft to medium• 6-1 to 6-4 - medium to medium hard• 7-1 to 7-4 - hard to very hard • 8-1 to 8-4 - very hard to extremely

hardIn general, decades of bit manufac-turing, and product development and application experience gives us the following operating guidelines:For 4-1 to 4-4 IADC type bits:• 50 to 150 RPM• 1000 to 5000 pounds of applied load

per inch of bit diameterFor 5-1 to 5-4 IADC type bits: • 50 to 150 RPM• 3,000 to 6,500 pounds of applied

load per inch of bit diameterFor 6-1 to 6-4 IADC type bits:• 50 to 120 RPM• 4,000 to 7,000 pounds of applied

load per inch of bit diameterFor 7-1 to 7-4 IADC type bits:• 50 to 90 RPM• 4,000 - 8,000 pounds of applied load

per inch of bit diameterFor 8-1 to 8-3 IADC type bits:• 40 to 80 RPM• 6,000 - 9,000 pounds of applied load

per inch of bit diameterAs the rock gets harder, it is adviseable to apply slower RPM. As more load is applied to a bit it is adviseable to apply slower RPM.

“Strong” rocks may need ‘time’ for the indenting teeth to create sufficient stress in the rock fabric to cause it to crack, and the crack propagate. Thus, in ‘strong’ or ‘hard’ rock it is suggested that lower RPM is used. “Weak” rock does not need as much time to react to the indenting teeth. Higher RPM can be used effectively in “softer” ground.

These are general guidelines, and are intended as suggestions only. Every rock type is different, and every specific

Air circulation through nozzles and bearings.


TalkingTeChniCally

rock type exhibits a wide variation in mechanical properties at an individual site. Individual mines should determine optimum operating parameters for each rock type and drill type at that specific site.

Thevalueofabit

What is the “value” of a bit? What determines how ‘good’ a bit is? Ask around, and you will probably get one of these four answers to the question of ‘value’:• Low price• Long service life• High penetration rate• Low operating costSecoroc believes the highest “value” a tri-cone rock bit can have is “low operating

cost”. Considering that the cost of owning and operating a modern rotary drill rig can approach US$400 or more, bit performance needs to be judged on what the total cost of operating the drill is. This then, goes hand in hand with a high penetration rate, and is accompa-nied by a ‘good’ service life.Consider this example:• Drill operating cost per hour =

US$300• Penetration rate of Competitors bits

= 30 meters/hour• Penetration rate of Secoroc bits = 45

meters/hour• Hole depth = 15 metersThe “Operating Cost per Meter” iscalculated by:• OC/m = Drill Operating Cost /

Penetration Rate

Thus, it is easy to see that for a 15meter drilled depth hole:• Competitors Operating Cost / meter

is US$300 / 30 = US$10.00• Secorocs Operating Cost / meter is

US$300 / 45 = US$6.66The faster drilling Secoroc bit saves the mining company US$3.37 for every meter drilled. That is value.

Bitrecordkeeping

Without keeping track of bit perform-ance, there can be no way to measure one bit type against another, and one bit supplier against their competition. Secoroc can provide the templates for two types of “Bit Record Book” to re-cord bit performance.

Compilation of product performance histories creates a valuable tool for the sales person and bit manufacturer. Dif- ferent bits can be compared at a mine-site. Performance of the same bit at different minesites can be compared. How does one drill type compare against an-other drill type? If a new mine is being opened, you need to have an idea of what products to offer, and what per-formance can be expected.

Secoroc has a global product per-formance database available in Lotus Notes. Product performance from mines around the world can be com-pared. Sales people easily generate a variety of reports for their monthly bu-siness reviews and sales calls. Below is an example of a report generated by Perform v6, for two bit types compared over a five month period:

ClarenceZinkPerformance comparison for distance, of two bit types, over time.

8-1 to 8-4

7-1 to 7-4

6-1 to 6-4

5-1 to 5-4

4-1 to 4-4

10000 20000 30000 40000 50000 60000 70000

IADC vs. Rock UCS

IAD

C C

lass

Rock UCS (PSI)

1000

36000

42000

22000

28000

6000

10000

70000

48000

56000

0

IADC vs. Rock UCS Chart showing comparison of IADC classifications to rock hardness.


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Closeattention

When developing a rotary drilling system, most of the attention is usually given to the drill rig, the capital equip-ment that requires significant invest-ment and hence a planned payback. The second priority in the system tends to be choice of rotary tricone drill bit – the Tricone. However, to utilize the full power and capacity of the rig and the bit, and at the same time increase serv-ice life and productivity, considerationshould also be given to the entire drill string. The optimal drill string includes a shock absorber at the top, a rotary deck bushing to centralize the drill string as it passes through the deck of the rig, strong and straight drill pipes and final-ly a hole stabilizing roller stabili-zer or bit sub-adaptor to optimize the per-formance. Giving the necessary atten-tion to every part of the drill string will lead to the lowest total operating costs in rock excavation and fragmentation.

Therotarydrillstring

The primary purpose of the drill string is to transmit the rotational torque and weight from the power source – the rotary head of the rig – to the rock breaking drill bit. As for every rock drilling method, the power must be transmitted as efficiently as possible, and return as few vibrations as possi-ble, as these cause unnecessary wear on the rig and reduce penetration rates.

When selecting components for the drill string, attention must be given to the different roles of the support tools in the string. The aim can be to:

• reduce wear and tear on the drill rig• absorb damaging vibrations travelling

back up the drill string• improve transmission of energy from

the rotary head to drill bit• centralize the drill bit within the hole• longer bit life• reduce friction as the drill string

passes through the drill rig deck• stabilize the hole wall to prevent hole

caving• increase penetration rates and lower drilling costs• achieve blast hole accuracy for im-

proved blasting efficiency• improve the end result – the frag-

mentation of the blasted rock.

ShockabsorberAt the very top of the drill string – between the rotary head and drill pipe – a shock absorber is commonly used. As the name indicates, the intention of this tool is to reduce the negative effects of harmful vibrations that travel back up the string as a result of the drilling process.

The benefits of using a shock absor-ber include:• improved torque control• increased drilling penetration rates• better drill rig availability and exten-

ded drill rig drive head and mast life• longer service life of drill bits

Giving the necessary attention to the drill string components will pave the way for quality drilling and lower total operating costs.

OptimizingtherotarydrillstringMoneyinthebankIn rotary drilling, the careful selec-tion of every drill string component is vital to achieve accurate holes, optimal rock fragmentation and operational efficiency – parame-ters which affect total operational costs.


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Deckbushing

To guide the drill string and reduce the risk of wobbling, a rotary deck bushing is utilized at the drill rig deck opening. The deck bushing guides the pipes to prevent reduction of rotary head torque and assists with the final straightness of the hole.

The deck bushing contains an outer housing with a top flange that allows it to fit perfectly into the deck opening. A series of roller bearings allow the inner sleeve to rotate with the drill string. Wear of the deck bushing occurs pri-marily on the inner sleeve as cuttings are blown upwards, between the drill pipe and the inner sleeve.

Drillpipe

The role of the drill pipe is to transfer sufficient amounts of rotational torqueand weight to the drill bit. The goal is to establish an optimal rate of penetration

while still achieving an acceptable life of the Tricone bit. The use of a strong and straight alloy drill pipe is one of the best ways of preventing wobbling of the drill string and hole deviation. Drill pipe is subjected to a severe and abrasive environment, due to the rapid evacuation of drilling cuttings through the annulus of the hole, causing a sand-blasting effect on the drill pipes. It is logical, therefore, to utilize only the best alloy steel for both the threaded connections and the body of the drill pipe. Special wear protection material is applied to the most critical areas of erosion at the bottom of the drill pipe. The drill pipes can, in most cases, be refurbished to prolong service life.

Bitsubadaptororstabilizer

To connect the bit to the drill pipe, a wearprotected bit sub adaptor is gener-ally used when the rock formation is relatively competent, and not in need

of stabilization within the hole. In some softer, fractured rock formations, it is worthwhile to consider the use of a sta-bilizer as an alternative. The roller sta-bilizer contains three roller assemblies which provide support against the hole walls, serving to both guide the drill bit in a straight direction and pack the wall of the hole to prevent caving in. The use of either straight or spiral-bladed stabilizers is strongly discouraged as this causes excessive friction when these blades are at full gauge diameter, while they also lose gauge diameter rapidly rendering them virtually useless as a stabilizer after only a few shifts. In addition, the spiral-bladed stabilizerslows down the evacuation of the cut-tings. So, to achieve improved hole straightness, hole wall integrity, and at the same time increase the effective life of the stabilizer, only stabilizers with rollers fitted with cemented carbide inserts are recommended.

All in all, when you consider the significant amount of capital invested in a rotary blasthole drill rig and the annual investments in Tricone drill bits, the selection of the best quality rotary drill string tools that are suited to the application, is critical to the eventual success of the drilling program. The rotary drill string tools should not just be considered as mere support tools, but rather as an essential, integrated part of the total rotary drilling system.

The following basic criteria should be considered when deciding which rotary drill string tools will best opti-mize overall drilling performance and cost effectiveness:• are quality materials and innovative

design used to address specific drill-ing problems?

• can the tools be refurbished for an economical second run?

• does the supplier of the tools offer application and follow-up service?

In conclusion, straight blast holes drilled exactly to the pre-planned hole bottom positions, pave the way for lower total operating costs, taking into account the entire process – drilling, blasting, secondary breaking, loading, haulage and crushing/screening.

RickMeyer

WLS

ODID

Welded strapmethod

Square drive flange method

Smoothdrill™shock absorbing

sub

Smoothdrive™shock absorbing

sub

Threadsaver sub

Full length repairableTeamalloy™

body drill pipe(box-box optional)

Centeroll™rotary deck bushing

(repairable)

Duralloyª bit sub

Secoroc Tricone bits

Duralloy™bit sub adaptor

EZ-Drill™roller stabilizer

AB

CE

D

The optimal drill string includes a shock absorber, a rotary deck bushing, strong and straight drill pipes and finally a hole stabilizing roller or bit sub-adaptor.

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Qualityholes

In the hole range 100-254 mm, DTH drilling is the dominant drilling method today. The main features of DTH drill-ing in this hole range are: excellent hole straightness within 1.5% devia-tion without guiding equipment; good hole cleaning, with plenty of air for hole cleaning from the hammer; good hole quality, with smooth and even hole walls for easy charging of explosives; deep hole drilling capacity, with con-stant penetration and no energy losses

in joints; and efficient energy transmis-sion, with the piston striking directly on the bit. The COP 34-64 series of ham-mers was introduced from 1992, and immediately became the benchmark for productivity within DTH drilling. Over the years, the increase in aver-age drilling pressure, from 17 bar to a current market standard of 30 bar, has improved hammer performance, and productivity has increased proportion-ally to air pressure. The introduction of the Atlas Copco ADS and SDE series of high-performance, high-pressure DTH rigs gave another boost to the sales of

hammers. The flexibility, productivity and maneuverability of these rigs, when equipped with a COP hammer, make them the most productive combination on the market today.

COPgoldseries

The increase in drilling pressure also had some negative impact on the inter-nal components of the DTH hammer, as the increased stress promoted the risk of premature failures. So, in 1998, Atlas Copco Secoroc decided on a long-term strategy to improve reliability, while

DThgrowinginpopularityThe DTH drilling method is grow-ing even further in popularity, with increases in all application seg-ments, including blasthole, water well, foundation, oil & gas, cool-ing systems and drilling for heat exchange pumps. DTH competes favourably with rotary drilling in open pit mines, mainly thanks to increased productivity and flexibil-ity. Open pit mining has adopted smaller holes where rotary drilling has either been replaced by DTH, or where DTH has been introduced to create a better finish to the pit wall, as the method is also perfect for pre-splitting and smooth blast-ing, which avoids back-cracking. DTH drilling offers increased pro-ductivity, and is favoured by con-tractors for production drilling. In larger quarries, the optimum hole size is 110-165 mm. With today’s demands for strict hole control for safe blasting in populated areas, DTH drilling is a popular choice among quarry operators.

increasedproductivitywithDThdrilling

New Secoroc hammer and bit ready for action on an Atlas Copco drill rig.

Cutaway section of Secoroc COP 64 Gold.

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retaining the benchmark status of the COP DTH hammers.

Stage One of this strategy was the development of the second generation six-inch hammer, COP 64.2, introduced in October, 2000, which incorporated newly-designed steel disc spring and lower buffer. Performance was vastly improved, thanks to a drastic reduction in the number of internal failures. It was also possible to rebuild the hammer without diminishing its performance, making it even more attractive.

Stage Two was the introduction of the third generation COP 64 hammer, COP 64 Gold, which was unveiled in August, 2001. This version offers sustained performance and improved longevity of the external parts. The COP 64.2 resolved internal component reliability, while the COP 64 Gold has experienced a dramatic drop in the number of cylinder failures.

COP 64 Gold also boasts improved sustainable efficiency, maintaining an average of 96% of original performance throughout its service life, which is a further improvement on COP 64.2.

Durability improvements, thanks to the higher tensile strength of the new steel grade, are especially noticeable when the cylinder approaches mini-mum thickness limits. COP 64 Gold enjoys a greater durability margin than its predecessor.

The high demand for COP 64 Gold hammers, particularly in applications where performance and reliability are major considerations, has led Atlas Copco Secoroc to add the COP 54 Gold and COP 44 Gold to this increasingly successful range.

In July 2004 COP 54 Gold was re-leased with the same features as the COP 64 Gold and improved perfor-mance thanks to a heavier and modified piston and a 12 spline bit shank.

Now the COP 44 Gold will be released in Q3 2009. As the other ham-mers in the Gold Series It will have improved longevity of the external parts thanks to the “Gold” cylinder. Internally it is improved with a heavier piston that will increase the perfor-mance and with modified buffers and a steel disc spring the lifetime of internal

parts is extended. And finally a new 12 spline bit shank with 19% more area than DHD340A minimize shank fail-ures in soft or unconsolidated rock.

hammercylinder

The new cylinder has been redesigned in a number of important ways. COP Gold boasts a cylinder made of lowalloy wrought and toughened steel, a new grade with a higher combined Molyb-denum and Vanadium content (4.8%) than its predecessor. The result is great-er impact strength and higher wear and temperature resistance. All in all, this means greater resistance to breakage, impact, temperature and wear for the new hammer cylinder.

Thanks to the new steel grade, cylinder properties have been greatly improved. Wear has been reduced, both internally and externally. Cuttings and moving parts no longer cause the problems they once did. In effect, the service life of the cylinder has been extended considerably.

Rebuilding

With the introduction of COP Gold Series, hammer life will increase sub-stantially. Less internal and external wear, together with a reduced minimum cylinder wear limit, are key contribut-ing factors. As a rule of thumb: If the hammer has reach it’s external wear limits before 5000 drill meters use an

Table 1 Comparison of COP 64.2 and COP 64 Gold steel.

COP 64.2 steel COP 64 Gold steel Improvement

Yield point ReL(Mpa) 700 1400 100%Breaking strength Rm(Mpa) 1000 1950 95%Hardness (HRc) 32 42 31%

Table 1 reveals not only that the yield point for the new steel grade is twice as high, but also that breaking strength has been almost doubled.

Secoroc COP 54 Gold Express.

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Economy Kit and rebuild the hammer, between 5000 and 10 000 drill meters consider to rebuild the hammer and with more than 10 000 drill meters the internal parts could be subject to fatigue failures.

Ultimately, this means customers can look forward to increased drill rig availability.

The sum total of these improvements shows COP Gold Series to have more than 50% greater service life, in abra-sive rock conditions, than its predeces-sors.

The customer benefits from lower cost/metre drilled, thanks to less down-time and greater abrasion resistance, and 30-50% longer life of external parts.Higher availability results from less

breakage in the threads of top sub and chuck-ends of the cylinder, and there are fewer stoppages for service and maintenance. Improved penetration rate and higher efficiency are a result of reduced friction of the piston, and a greater life cycle penetration rate is the overall reward.

To sum up, the customer can drill more holes per hammer than previ-ously.

applications

COP Gold Series is high-pressure ham-mers, where performance is related to air pressure. A lower limit of 12 bar for deep hole applications is a good rule of thumb. The hammer is designed for

the same types of application as COP STD Series, with special focus on high-pressure applications.

In abrasive formations, performance will be up to 15-50% better than COP STD, in what is an ideal application for COP Gold hammers.

In soft unconsolidated rock drill-ing, the 12-spline chuck concept and the improved durability make COP Gold the perfect hammer. High pres-sure yields higher productivity, and drilling pressures of 28-30 bar are not unusual.

The COP Gold hammer concept offers customers a tool to meet the most exacting requirements.

leiflarsson

Increase in service life of COP 64 Gold, which has a 50% longer life than its predecesssor.

Totalimprovement

Duetowearresistance

Duetowearlimitchange

Duetolesscylinderfailure

Results of comparative tests with COP 64.2 and COP 64 Gold. The COP 64 Gold drilled 50% further.

NewMaterialOldMaterial

16000

14000

12000

10000

8000

6000

4000

2000

0146 145 144 143 142 141 140 139 138 137 136 135 134 133 132 131 130 129 128

Dri

ll m

etre

s

Cylinder OD (mm)

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Relevantapplications

QuarryingCompanies producing in non-abrasive rock formations should consider ham-mers such as Secoroc Quantum Leap or Secoroc COP. Both are time-tested and field-proven designs offering good productivity and ease of service.

Producers demanding the highest productivity and/or drilling in abrasive formations should consider either the Total Depth or Secoroc COP Gold hammers. These incorporate the latest technology

Quarrying application.

SelectingtherightDThdrillingtoolsCoveringeveryapplicationAtlas Copco Secoroc now has the most comprehensive range of DTH hammers, bits, and related equipment of any supplier in the world, backed by the strongest support network in the industry. Whether the call is for reliable hammers to keep investment to a minimum, or for the highest productivity to ensure maximum rig output, Atlas Copco Secoroc has the solution. The company is the only manufacturer to offer both first and second choice solutions in almost all typical DTH applications on a price vs performance basis. For premium performance and advanced technology, Total Depth and COP Gold hammers are offered. For an optimum blend of features and cost, COP and Quantum Leap can be the solution, and for high reliability at economical price, no-thing beats Fusion hammers. Total Depth, COP Gold, Quan- tum Leap, and COP and Fusion hammers are also energy efficient, consuming less fuel and with lower energy cost per drilled metre than other DTH hammers. This enormous choice of DTH drilling tools is backed by a reli-able network of distributors and customer centres that offer a complete range of parts, service and support.

Changing a Secoroc bit.

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and are the most reliable and produc-tive hammers on the market. For cus-tomers who are happy with rebuilds, Total Depth is recommended, while for those who typically run hammers until they wear out, Secoroc COP Gold has unbeatable wear resistance and will be the first choice.

Dimensional stone quarrying demands consistent hole straightness, and such operations typically use smaller size holes of 85-90 mm in limestone,

granite and marble. Here the TD 35 and COP 32 hammers are the best choice.

MineralexplorationMineral exploration generally occurs in very remote locations, requiring robust hammers capable of running high pressures, in sometimes dirty environments.For true reverse circulation drilling with face collection in mineral exploration and in-pit grade control, the Secoroc RC50 Reverse Circulation Hammer,

incorporating the Quantum Leap cycle, performs particularly well.

Geotechnical Environmental moni-toring applications will appreciate the Secoroc Fusion, or possibly the Secoroc Quantum Leap or COP hammers.

Drilling of holes for foundation, an-choring or drainage demands reliable, inexpensive hammers like the Secoroc Fusion range.

OpenpitminingMining operations typically have high equipment utilization, drilling up to 80% of the working day with DTH. The typical applications are normal 130-203 mm-diameter blast holes, 140- 165 mm buffer holes, or 115-140 mm pre-split holes. Companies should con-sider either the Total Depth or Secoroc COP Gold hammers. These incorporate the latest technology, and are the most reliable and productive hammers on the market. For customers who are happy with rebuilds, Total Depth is recom-mended, while for those who typically run hammers until they wear out, Se- coroc COP Gold will be the first choice.

Selectingtherighthammer

The optimum range of hole size for DTH drilling is 90 mm to 254 mm. Smaller holes are generally drilled using tophammer, and larger holes generally use rotary machines. However, DTH has an expanding position in the larger hole sizes up to 750 mm. As a rule of thumb, the smallest hole diameter a DTH hammer can drill is its nominal size. A 4 inch hammer will drill a 4 inch (102 mm) hole. The limiting factor is the outside diameter of the hammer, because, as hole diameter reduces, air-flow is restricted. Maximum hole size for production drilling is the nominal hammer size plus 1 inch, so for a 4 inch hammer the maximum hole size is 5 inch (127-130 mm).

Choosing the right hammer is largely determined by hole size and type of rock formation. Ideally, the size of the hammer should match the required hole dimension as closely as possible, leaving just enough space for cuttings to evacu-ate the hole. Secoroc hammers are purpose-matched for all rock types and applications. Where high performance

ROC L8.

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is the main criterion, Secoroc COP Gold and Secoroc Total Depth ham-mers are recommended.

In deep hole drilling applications, the Total Depth hammer has proven superior performance and adaptability to different air requirements, thanks to the Air-Select System.

Where proven technology is required, the Secoroc COP and Quantum Leap hammers are known for their reliability and longevity, and for a reliable work-

horse, the Secoroc Fusion is practically bullet proof, with a 30 year history of continuous improvement.

The Standard design for COP 54 and COP 64 Gold hammers can be used down to a depth of 330 ft (100 m) using a Standard bit size, making it useful for production drilling in quar-ries, shallow waterwell drilling, and underground blasthole drilling. HD is si-milar to Standard, but with heavy duty chuck and wear sleeve, and a top sub

fitted with tungsten carbide buttons for wear protection in harsh and abrasive conditions. These also protect the top sub from excessive wear when rotating out of the hole through broken rock.

highestperformanceThe Secoroc COP Gold and Total Depth hammers are designed for the most demanding drilling conditions and for those applications requiring premium performance. These hammers feature

Soft rock Medium hard rock (220 Mpa/32000 psi) Hard rock

Flat front HD

SpeedBit

Convex/Ballistic

Concave

Concave DGR

Rocket bit ballistic

Rocket bit spherical

Bit designs and rock types.

DM45 Blasthole Drill.

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state-of-the-art technology and deliver both maximum productivity and profit.

SecorocCOPgold• Superior longevity and reliability.• Easy to service and rebuild.• Best suited for production drilling because of its excellent external wear resistance and longevity.• Internal components coated for wear and corrosion protection. Permits multiple rebuilds.• Three start chuck thread for easy bit changes.• Bit replacement possible without using drill rig break-out chains and wrenches.• Unique air cushion reduces wear and tear on drill string and rig.

SecorocTD70,80and85• Provides the industry’s highest power output.• Best suited for deep hole applications.• Industry-leading simplicity and serviceability, resulting in very low operating costs.• Features modular components, snap-in cylinders, a reversible casing, backhead saver sleeves, and many options.• The hybrid valved/valveless design maximizes air compressor productivity.

Selectingtherightbit

Atlas Copco Secoroc has a comprehensive range of DTH drill bits to match all conceivable applications. Each bit is made from quality alloy steel, and has been precision machined to produce a perfect body, heat treated to the required hardness, given surface com- pression for fatigue resistance, and fitted with precision buttons manufactured in- house.

Five basic designs are available: CV Bit, FF Bit, SpeedBit, CC Bit, and Rocket Bit.

These are designed for specific applications for all rock types, hardnes-ses and conditions. Bit life and rate of penetration are the most important criteria in selecting the right bit for a particular application.

In most cases, the focus is on pro-ductivity,so the fast cuttings removal

Bitdesigns Facts

Convex/Ballisticfrontdesign Convex front with large cutting grooves and ballistic gauge and centre buttons. For soft to medium hard non-abrasive formations. The bit is designed for maximum penetration rate. Also, an alternative in hard abrasive formations, if high penetration rate is called for.

SpeedBitFlat front design/ballistic centre buttons. Flat front with spherical gauge buttons and ballistic centre buttons. For high penetration in medium hard to hard abrasive formations.

Flatfrontdesign–hDFlat front with large spherical gauge buttons for hard and abrasive formations. Also, front flushing grooves for effi-cient cuttings removal.

ConcavefrontdesignConcave front with spherical buttons Perfect choice for medium hard to hard, less abrasive, fractured formations. Minimizes effect of hole deviation.

Concavefrontdesign–hDConcave front with spherical buttons, with larger gauge buttons. Ideal for medium hard to hard, abrasive and frac-tured formations.

ConcaveDgRfrontdesignConcave front with double rows of spherical gauge buttons. Only available for 8 in bits and larger. The rein- forced gauge gives superior protection in medium hard to hard, abrasive and fractured formations.

RocketbitSuper high penetration in soft to medium hard formations with low silica content. The Rocket bit also handles difficult formations with clay intrusions where other bit designs will not work.

TheSecorocrangeofDThbitsensuresthateverydrillercandemandasolutionforeveryapplication.

TalkingTeChniCally


features of the SpeedBit and Convex/Ballistic designs are preferable, to ensure the buttons are cutting clean, with the minimum of re-crushing.

In hard and abrasive formations, however, the flat front (FF) HD design offers best bit life, having strong gauge rows with large spherical buttons which are easy to regrind and maintain. The SpeedBit offers improved productivity with the same gauge as the FF HD, but with ballistic buttons in the front for faster penetration.

An alternative is the Concave design with spherical buttons. The Rocket Bit can be dressed with ballistic buttons for use in soft to medium hard formations where fractured rock can be expected, or can be supplied with spherical buttons for hard and abrasive formations.

Bits are manufactured to match all diameters of all Atlas Copco Secoroc hammers.

Selectingtherighttube

Key features of a high quality DTH tube are durability, accuracy and man-ageability. Atlas Copco Secoroc tubes are made from cold drawn tubing, providing a superior surface finish and tole- rance compared to conventional tubes made from hot rolled tubing.

This drastically reduces the risk of scaling from the tubes entering the hammer, a major cause of premature ham-mer failure.

The joints are friction welded to achieve maximum strength, and the threads of the end-pieces are heat treated for optimum durability and strength of the thread profile. This not only ensures long thread life, but also makes cou-pling and uncoupling quick and simple, reducing drilling time.

Tube diameter should be close to the hammer diameter to provide opti-mum flushing, re-ducing the chances of getting stuck.

In most applications, Atlas Copco Secoroc standard API threads will be the best choice.

Atlas Copco Secoroc also offers a wide range of subs and crossover subs to meet an array of demands, all manu-factured to the same standards as the tubes.

Quality Standard End piecesAPI grade N-80 tubes and adapters

Loweryieldlimit N/mm2 min550 min550

Tensilestrength N/mm2 min650 min700

ElongationA5 min% 18 21

Corehardness HB 190–230 210–250

Surfacehardness HRC 58–62

Drill tube Wall 23/8" 23/8" 27/8" 27/8" 31/2" OD (mm) (mm) RD 50 API Reg API IF API Reg API IF API Reg

70 3.6 ■ ■

76 3.6 ■

76 5.6 ■

89 3.7 ■

89 5.7 ■ ■ ■

102 5.7 ■

114 4.3 ■ ■

114 5.7 ■

114 7.9 ■

Secoroc COP 54 Gold Express - the production driller s best friend.

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COPBackhammer

The COP Backhammer is a tool that can save and recover a drill string stuck in a hole. It can be easily fitted in a suitable tube joint between the drill support and the rotation head to provide an effective combination of back-ward hammering and vibration to loosen stuck drill strings.

ServiceandsupportAtlas Copco Secoroc service, support and training follows every purchase,

to ensure that customers extract maxi-mum productivity from their drilling operations. Having a knowledgeable and available Secoroc drilling engineer on site or on-line makes the difference be-tween going it alone and tapping the experience and know-how of a world-class partner. For example, Secoroc knows that using higher productivity bits reduces the cost of each drilled hole, and the simplest way to cut costs is to drill holes faster. This has been a focus of product development, and is at the core of Secoroc technology, ensur-ing that every generation of products

drills faster and more efficiently. It takes a support team to apply this knowledge, so that customers can be assured they run a profitable and efficient drilling operation in an increasingly competi-tive business climate.

The bottom line is that the customer can count on Secoroc service and sup-port, supplied by the largest, most de-dicated manufacturer of DTH drilling tools in the world.

leiflarsson

With on-site support, the choice of DTH equipment is even easier to make.


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longertowers

The drilling of large diameter holes, generally considered to be greater than 9 inches in diameter, is done predomi-nantly with rotary blasthole drills. One of the reasons for this is that larger diameter tricone bits allow for large bearings to handle high pulldown forces to drill through hard rock quickly. These high pulldown loads require a heavy tower structure to transmit these pulldown forces to the drill bit. Further, this high pulldown must be offset by sufficient mass to keep the drill rig from lifting off the ground. The resulting rig is therefore quite heavy.

With a heavy, durable rig already dictated by a large hole diameter, drill designers are able to take advantage of the large platform to offer longer towers capable of drilling benches in one pass. This often drives a change in structural design and supporting components such as undercarriages, but the basic rig en-velope doesn’t change. Drilling a hole in one pass has many advantages.

eliminationofrodchangingtimeAdding a rod may take 45 to 60 sec-onds depending on the size of the rig, and taking the rod back off may take

60 to 90 seconds. The extra time for removing a rod is due to the extra cycle required to lower the head to pick up the next rod.

The effect of rod changing time is more dramatic in soft material, as shown in Fig 1. Surprisingly, it is the large metals mines that pioneered the use of single-pass drills, even though they may see limited productivity benefit. In extremely hard rock such as that encoun-tered in taconite, the single-pass benefit might only be 3 percent. At the other extreme would be very soft coal overburden. This material can be drilled with claw-type bits at rates of 400 meters/ hour or more. In this situation, a single- pass drill would yield an overall pro-ductivity gain of over 25 percent.

Simplifiedoperation

Even in situations where the productiv-ity gain from eliminating rod changes is relatively small, there are benefits. Operators don’t have to worry about the rod changing operation, which consists of 10 actions to add a rod and 13 actions to remove a rod. Eliminating these tasks during each hole reduces the chance for errors such as cross-threading the tool joints on the drill rods or dropping a rod. Tasks such as changing a bit in the middle of the hole or reaming the hole to clear out cuttings are much simpler when you don’t have to add or remove rods. These factors could increase overall productivity by a few more percent.

Takingadvantageofsingle-passdrillingTheeasywaytogetmoreblastholesperdayLarge rotary drills have been in use for years around the world in mining applications. In many open pit operations, these large drills were equipped with electric power and long towers for drilling benches in a single pass. Today, these features are being added to smaller equipment. Let’s look at the benefits of single-pass.

Fig 1. Comparison of single-pass and multi-pass drilling, = Time lost for rod adding and rod removal, = Lost productivity for multi-pass drilling.

Fig 2. Single-pass Pit Viper rigs

Rig PV-235 PV-271 PV-351

Hole range 152-251mm(6-97⁄8") 171-270mm(6¾-105⁄8") 270-406mm(105⁄8-16")

Single pass depth

12.2m(40ft) 16.8m(55ft) 19.8m(65ft)

0

10

20

30

40

50

60

70

80

90

100

0 2 4 6 8 10 12 14

Drill depth in metres

Ove

rall

prod

uctio

n ra

te in

met

res/

hr1

130 ft

30 ft

40 ft

40 ft2

2

40' Single-pass,

50 MPa Rock*

30' Multi-pass,

100 MPa Rock*

40' Single-pass,

100 MPa Rock*

30' Multi-pass,

50 MPa Rock*

(12.2 m)

(12.2 m)

(9.1 m)

(9.1 m)

* Compressive strength


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lessmaintenanceThe carousel and wrench systems used routinely in multiple-pass operation are high wear items due to the nature of their operation. While they may still be used on single-pass drills, especially for changing drill bits, they see a much lower duty cycle. As mentioned above, tight drill tool joints can be a problem. Improvements in breakout wrench sys-tems have helped address these issues, but it is still common to see joints that can’t be broken by onboard wrench systems.

Given the advantages above, why wouldn’t every drill be built as a single- pass? Obviously, it isn’t practical to build a unit to support a 70 meter hole in coal overburden. It may be possible, but you’d end up with a unit with a mast as long as a dragline boom. The expen-se of such a unit would probably never be recovered with the operating cost savings.

SafetyfactorsAs towers grow in length, the support-ing mainframe and undercarriage must grow as well. To maintain the structural life and reliability of smaller multiple-pass units, proper safety factors must be used in the design. The result is a larger and more expensive machine than cus-tomers are willing to buy. An example would be the move from the DM-M2, a multiple-pass unit with 35-foot drill rods and a gross weight of about 57 tons, to the single-pass Pit Viper 271 for 16.7-meter holes. The Pit Viper 271 weighs in at around 80 tons.

Many smaller rotary drills operate on slopes that could not be considered firm and flat. While single-pass drills might be capable of operating on a minor slope (less than 10 percent), they will generally have a higher center of gravity than their multiple-pass equiva-lent, reducing the stability of the unit. This is often the operator’s perception

as the unit may be capable of slopes that might be substantially more.

However, many factors must be taken into account when determin-ing whether to operate on a particular slope. Ground conditions are rarely a single plane. Instead, they are com-pound angles of widely varying rock size and type. Most operators err on the side of limiting the slope they will attempt to navigate. Thus, single-pass drills are viewed as being limited to flat benches only.

As we say at Atlas Copco, we are committed to our customers’ superior productivity. We will continue to deve-lop single-pass units for smaller diam-eter operations. While we have several smaller units already capable of single-pass (the DM25SP and DML-SP), they are rotary table drive units. They utilize lightweight towers on relatively small base units by locating the feed and rota-tion mechanisms towards the bottom of the tower. The drawback of this design is that rotation is accomplished through a rotary table drive that engages a fluted kelly bar, driven mechanically by drive pins. The kelly bars are very expensive due to the fluting milled into them, and if the material is abrasive, they wear quickly and result in high operating costs. However, in soft applications, they are a great option.

As most of our applications involve harder, abrasive material, we are look-ing to develop tophead-drive units with longer towers. Adding to our fleet of large single-pass units, as outlined in Fig 2, we are testing the new Pit Viper 235. It is equipped with 40-foot drill rods and can single-pass drill 12.2-meter holes, which is ideal for many metals operations. In designing this unit, the engineering team strived to address the perceived stability issue that turns some mines away from single-pass. The result is a unit that is more stable than our DML with 35-foot drill rods and a 9.5-meter capability. We encour-age our customers to look at single-pass drilling as it is one of the easiest ways to get more holes per day.

BrianFox

Committed to superior productivity: Single-pass Pit Viper drill rigs such as these at Phoenix Mine, Nevada, will continue to be developed for smaller dimension drilling.


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Principles

When properly initiated, commercial explosives are rapidly converted into gases at high temperature and pressure. When detonated unconfined, a liter of explosive expands to around 1000 litres of gas in milliseconds. When confined by rock, expanding explosion gases re-sult in extremely high stresses in the rock. The gas energy released during detonation acts equally in all directions but tends to escape through any path of least resistance. Therefore, blastholes should be charged and stemmed so that the gases are confined for sufficient time to provide optimum breakage, displace-ment and looseness of the blasted rock.

The majority of explosives used in today’s surface metal mines are primer-sensitive explosives. Under normal conditions of use, a primer is required to initiate them reliably.

All primer-sensitive explosives cotain the following essential components:

• An oxidizer: a chemical which provides oxygen for the reaction. Am- monium nitrate is the most common oxidizer;

• A fuel: which reacts with oxygen to produce heat. Common fuels include fuel oil and aluminum powder;

• A sensitizer: which provides voids that act as “hot spots” where the reac-tion starts during detonation. Sen- sitizers are generally air or gas in the form of very small bubbles, some-times encapsulated in glass micro-balloons (GMBs).

An explosive is classified as detonator-sensitive if it can be reliably initiated in an unconfined state by a #8 strength detonator (which has a base charge of 0.46 g of PETN). Detonator-sensitive explosives may or may not contain in- gredients that are themselves explo-sives.

Propertiesofexplosives

The physical characteristics of the vari-ous types of explosives differ markedly. For example, ANFO type explosives are loose, free-flowing, granular composi-tions, whereas emulsion explosives have a consistency that varies from that of

syrup to firm putty. There are also vari-ous blends of emulsion and ANFO type explosives, notably so-called heavy ANFOs. Watergel (slurry) explosives are also used in some countries.

The physical properties of the explo-sive can dictate the handling system used to charge the explosive into blast-holes.

WaterresistanceThe water resistance of explosives varies considerably. Emulsions have ex-cellent water resistance; heavy ANFOs have some water resistance while ANFO has negligible water resistance.

DensityThe in-hole density of explosives has a significant effect on the energy per meter of charge length. Higher-density explosives generate more energy. Ex- plosives are supplied in different densi-ties to enable the shotfirer to control the total energy released in a blasthole to suit the particular blasting conditions and to achieve the desired result.

SensitivitySensitivity is a measure of the ease with which an explosive can be initiated by

Blasting at the Aitik Mine in northern Sweden.

BlastinginopencutmetalminesexplosivesSince blasting was introduced in mining as part of the production process, blasting technology and blast management have been inter- connected. Explosives have been the primary method of break-ing and loosening rock since the introduction of black powder. Over the years, however, blast-ing technology such as the physi-cal properties of explosives and types of detonators has evolved. The same holds true for the pro-cess of blast management – from design principles for production blasts that are cost-effective and optimize mining operations, to safety and accident prevention during every step of the drilling and blasting process. Drilling and blasting results have a major impact on many processes in a mine. Therefore, it is important to find the right combination of drill pattern, explosives and blast design to contribute to the eco-nomic success of the total mining operation.


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heat, friction impact, or shock. The trend in commercial explosives is towards lower sensitivity to initiation without detracting from detonation efficiency.

CriticaldiameterThe critical diameter of an explosive is the diameter below which a stable deto-nation does not occur. To ensure reli-able initiation under normal conditions of use, explosive suppliers recommend a minimum diameter for each of their products. To ensure reliable results under most conditions, the recommended minimum diameter is larger than the critical diameter.

DesensitizationMost explosives become less sensitive at higher densities. Desensitization can occur at excessive hole depths due to the static head of pressure. It is also possible for explosives to be dynamically desensitized by nearby earlier firing charges.

Velocityofdetonation(VOD)VOD is the speed with which the deto-nation propagates through a column of explosive. Two explosives having the same strength but different VOD may perform quite differently in a blast. As a general rule, the higher the VOD, the greater the shock energy and the lower the heave energy. However, it is important not to correlate shock energy directly with fragmentation energy.

The VOD of explosives used in sur-face metal mines vary between about 3000 m/s and 7500 m/s. The VOD of many explosives increases with charge diameter and confinement. Because of their high degree of refinement and effi-ciency, emulsion explosives can maintain very high VOD even with poor confinement and in small diameters.

energy/strengthThe energy of an explosive expresses the ability of the explosive to do work. An explosive with greater energy will be able to do more work on the surrounding rock. Energy produced by an ex-plosive can be calculated using thermo-dynamic codes and measured using a variety of techniques.

Shockenergy,gasenergyandheaveenergyFollowing detonation, high-pressure gases compress and crush the rock im-mediately surrounding the explosives. This results in an increase in the size of the blasthole and will vary according to the characteristics of the rock. The energy that is released by the explosive can be partitioned into two main types, the shock energy and the heave energy. The shock energy that is delivered to the rock is related to the extent and the rate of the borehole expansion to a so- called equilibrium state and includes the effects due to sub-optimal initiation. The energy delivered thus far is termed “shock energy,” which is primarily

responsible for conditioning the rock and initiating mechanisms that gener-ate fractures.

The “gas energy” or “heave energy” is delivered during the later expansion of the explosive products into the crack network of the rock. Once a fracture network is established the gas is able to expand into the network, both extend-ing the fracture process and causing movement of the rock. As this happens, the gas pressure drops until it vents to the atmosphere.

Primer-sensitiveexplosivesPrimer-sensitive explosives have rela-tively low sensitivity to shock, friction and impact, resulting in excellent safety and handling characteristics. The reli-able detonation of primer-sensitive ex-plosives requires initiation by a primer (e.g. Pentex™) that is in good contact with the charge. Ammonium nitrate is the major ingredient of most primer sensitive explosives.

Detonator-sensitiveexplosivesDetonator-sensitive explosives include Pentex™ boosters and Senatel™ pack-aged emulsions, which can be reliably initiated by a single #8 strength detona-tor or by a strand of 10 g/m detonating cord.

initiatingsystemsInitiating systems are used to safely initiate charges of explosives at pre-determined times by carrying a firing signal from one place to another, using chemical or electrical energy.

Drilling at the Aitik Mine, northern Sweden.


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Modern initiating explosives incor-porate various explosive and inert components, which are partly or wholly consumed in the blast. Small quantities of signal tubing or wire often remain in the muckpile.

Non-electric initiating explosives use pyrotechnic compositions or explosives to store and transmit energy by control-led shock waves, detonation or burning. Electric initiating systems require an ex- ploder to generate an electrical charge, which is transmitted along wires. Blast timing is usually controlled by pyro-technic (burning) delay elements lo-cated inside detonators.

Non-electric initiating systems based on a signal tube are currently the most widely used for blasting in surface metal mines. Most mines now use non-electric detonators inside blastholes, with remote initiation of blasts using a non-electric firing system.

Electronic blasting systems are be-coming more common, and differ from electric and non-electric delay systems in that the delay time is controlled by a programmable integrated circuit, resulting in very precise timing. The accuracy and programmability of elec-tronic detonators allows for blast timing to be tailored to the geometry, geology and unique requirements of any blast-ing operation to more effectively use explosives energy.

BulkexplosivesSpecialized equipment and tools are required to safely and effectively mix and charge explosives in surface metal mines. Most of the equipment and tools used in blasting operations are subject to statutory regulations.

A Mobile Manufacturing Unit (MMU®) is effectively an explosivesfactory on wheels. Each MMU® is de-signed to produce and deliver specified bulk explosives from a manufacturing unit based on a conventional truck chassis. Orica MMU®s are able to carry large quantities of non-explosive raw materials to the mine site, avoiding the need to carry explosives on public or mine roads. The bulk explosives are manufactured at the blasthole collar and accurately delivered into blastholes at high discharge rates. MMU®s are pro-ducedin a variety of configurations to Orica Mining Services offers a total loading service to its customers.

Examples of initiating systems produced by Orica (MMU ®) services.


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meet specific needs. The complexity of the onboard manufacturing facility de-pends on the type and number of explo-sives required. The truck on which thisis mounted is selected to suit the ma-terial to be carried and the terrain on which it will operate.

explosivesselection,primingandchargingPriming and charging of blastholes is one of the most important parts of a successful blast. Blastholes must be accu-rately primed and charged to the design specified by the blast designer.

The objective when selecting a combination of explosives is reliable per-formance, which will ensure the lowest overall operating costs without sacri-ficing safety. When selecting explosives, the principal considerations are:• Ground water conditions;• The properties of the rock being bla-

sted, i.e. strength, structure, etc.;• The diameter and depth of blast-

holes;• Drilling costs and drilling capacity;• The relative explosives cost per unit

of effective energy;• The fragmentation and heave char-

acteristics of the explosives;• Shelf life;• Desired results.

ANFO has proven to be the most cost-effective method of blasting dry blastholes. ANFO has relatively low

fragmentation energy, high heave en-ergy, and is extremely effective in all but the toughest, most massive rock types. Wet blastholes ideally should be charged with a water-resistant explo-sive, either an emulsion or a watergel. The explosive will displace the water up the hole, which may flow into adja-cent dry blastholes.

Other options that may be considered are:• Dewater the holes using in-hole

pumps, compressed air or other means, and then treat them as blast-holes containing nuisance water by charging with water-resistant bulk or packaged explosives to above the original water level, then continuing with ANFO.

• Charge the wet blastholes with pack-aged explosives until above the water level. Then charge with ANFO.

Blastdesign

When starting to work a new mine or a new area of an existing mine, it is necessary to develop one or more initial designs for production blasts. In this situation, some “rules of thumb,” derived over many years of relevant practical experience, should be used for develop-ing these designs. If a detailed assess-ment of rock mass properties has been carried out, computer modeling can be used to assess the suitability of the designs developed, and possibly to

indicate alternative superior designs.Initial blast designs must then be progressively improved to optimize mining operations and costs. Optimum designs help to produce the required fragmenta-tion, muckpile looseness, muckpile pro-file, toe conditions and grade control. In some cases, blast designs must also minimize flyrock and control ground vibrations and air overpressures.

Designvariables

Bench height normally lies in the range of 5-18 meters The selected bench height is influenced by:• Statutory regulations (excessively

high benches are unsafe and, there-fore, not permitted);

• Rock mass properties;• The type and size of digging equip-

ment;• Grade - control requirements;• The need to maximize the overall cost

efficiency of drilling and blasting.

Increasing bench height decreases total drilling consumption of primers and initiators, the labor required for firing, and the number of mining cycles. Op- timum blasthole diameter increases with bench height. In general, an increase in blasthole diameter decreases the total cost of drilling. Drilling accuracy be-comes more critical in higher benches and drill deviation can produce costly consequences.

BlastholediameterOptimum blasthole diameter is greater for higher benches and for larger dig-ging, hauling and crushing equipment. Large diameter blastholes are less suitable in strong, massive rock; when minimal broken rock movement is required; or where it is very important to control blast vibrations.

At large surface mines, the total cost of mining is usually minimized by drilling large diameter blastholes. Larger diameter blastholes reduce costs for drilling, primers and initiators and labor. They usually need higher powder factors than small diameter blastholes to give the same fragmentation, espe-cially in strong rocks. Smaller blast-holes give better distribution of energy in the rock mass.

The Mobile Manufacturing Unit on site (MMU ®).


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FreefacesForward displacement of blasted rock occurs if a blast shoots to a free face (Figure 1). Some movement of the rock mass is necessary to allow for crack propagation. Increased movement assists crack propagation and can improve fragmentation. This may not be the main objective in some operations (e.g. blast-ing in ore) so free faces may be limited (choked) to restrict ore dilution.

BlastholeangleVertical blastholes are usually used in surface metal mines because:• Angled blastholes are more difficult

to set up and drill;• Some drills do not have an angled

drilling capability; and• Drilling accuracy is greater with

vertical blastholes.

In free-face blasting, vertical front-row blastholes often leave variable and excessive burdens between the top and bottom of the charge (Figure 2). This variation is greater in high- or shallow-dipping faces and can cause hard, immovable toe. Front row blastholes collared near the crest to control the toe burden can cause explosion gases to blow out prematurely in the face. (See Figure 3 and 4)

This blow out creates noise, airblast and flyrock and reduces blasthole pres-sure near the bench floor level, which may prevent adequate breakage and movement of the toe. This may neces-sitate the use of some angled blastholes in front rows. (Figure 5)

SubdrillinganddrilledlengthofblastholeEfficient excavation needs toe condi-tions that suit the digging equipment. Toe conditions are affected strongly by the amount of effective subdrilling. Subgrade or subdrilling is the length of the explosive charge, which lies beneath the designed bench floor level.Unavoidable fallback of drill cuttings and small rock fragments reduces the effective subdrilling to less than that originally drilled. It is good practice to drill a certain extra distance (which is longer for higher benches and weaker rocks) to allow for unavoidable fall-back.

PrimingThe overriding concern in priming is to locate the primer in the explosives column and ensure operational safety and efficiency. The primer is generally placed at or near grade level. Some operators place the primer at a known dis-tance above or below bench floor level to ensure that, should a misfire occur, the excavator operator does not dig directly into a primer.

This may be a valid reason for notplacing the primer at bench floor level.

Bottom priming has several advan-tages over top priming. They include:• Improved fragmentation, displace-

ment and muckpile looseness;• Reduced toe problems, better floors,

and cleaner faces;• Reduced noise, airblast, flyrock and

surface overbreak; and• Fewer cut-offs and misfires.

ChargedistributionDistribution of the explosive charges in the rock mass is an important

Effective free face

Fig 1. Effective free face.

ExcessiveBurden

RequiredBurden

Fig 2. Variable burdens, vertical holes.

Caution!

Flyrock

Airblast

Fig 3. Excessive blasthole angles cause problems.

Caution!

Flyrock

Airblast

Fig 4. Problems with variable burdens.

CorrectBurden

Fig 5. Angled holes increases rock breakage.


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consideration when determining blast geometry. Crater blasting to a horizontal rock surface has a less efficient charge distribution but is preferred in shallow ore deposits where quality control dictates low benches, despite a higher explosives consumption.

BlastholepatternBlasthole patterns depend on blasthole diameter, rock properties, explosive properties, bench height, and the results needed. Operating experience and blast modeling results have shown that, in massive rocks, better fragmentation and productivity are obtained with staggered patterns than with either square or rectangular patterns. Equilateral triangu-lar patterns provide optimum distribu-tion of explosion energy in the rock. While staggered patterns give the best theoretical performance, the initiation sequence can alter the geometry and re-sults of blasts on square or rectangular patterns.

Spacing-to-burdenratioBurden and spacing are related to blast-hole diameter, depth, rock type and charge length. Blasthole spacings con-siderably smaller than the burden tend to cause premature splitting between blastholes and early loosening of the stemming.

This can cause premature release of explosion gases to the atmosphere and considerable overbreak. Loss of heave energy reduces breakage and produces large rock slabs in the muckpile.

On the other hand, a spacing-to-burden ratio that is too large can cause the face midway between back-row blast-holes to remain intact, especially near bench floor level. This results in tight digging and possibly unbroken toe.

Front-rowblastholesSpecial attention should be paid to the position of front-row blastholes. If the burden on front-row charges is exces-sive, it will not be broken by the time second-row charges detonate. Restric-tion of motion at the beginning of the blast can prevent optimum blasting results throughout the blast. Where burden is too small, explosion gases burst rapidly through the face, causing noise, airblast and flyrock.

(c) Paddock blast – rectangular

(b) Paddock blast – square

(a) Paddock blast – staggered







Fig 6. Blasthole patterns.

d) Square – Fired on Echelon


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ChangingburdenandspacingChanges in burden generally affect fragmentation, muckpile looseness and toe much more rapidly than changes in spacing. If enlarging a blast pattern for improved economy, it is more common to increase the blasthole spacing in steps before altering the burden.

StemmingStemming enhances fragmentation and rock displacement by reducing prema-ture venting of high-pressure explosion gases to the atmosphere. (Figure 7)

Dry granular materials are best for stemming because they have inertial resistance and high frictional resistance to ejection. Materials that behave pla- stically or that tend to flow are not suit-able for stemming, e.g. water, mud, wet clay. Stemming length can be reduced significantly if effective stemming is used, resulting in better explosive dis-tribution and improved overall frag-mentation. Optimum stemming length depends mainly on blasthole diameter, stemming material, and surrounding rock properties. Inadequate stemming increases collar rock breakage, but decreases overall fragmentation and displacement because explosion gases vent to the atmosphere more easily and rapidly. It also creates more flyrock, sur-face overbreak, noise and airblast.

Long stemming lengths ensure good confinement of explosion gases, but fragmentation of collar rock becomes coarser.

SizeandshapeofblastsMost oversize rocks come from the back, sides and top of blasts. Boulders are created by open fractures in the free face, irregular burdens and by back-break around the perimeter. Damage from previous blasting around the peri-meter opens fractures which define rocks isolated from the rock mass. These rocks are not fragmented by ex-plosion-generated strains and cracks, but are merely pushed forward into the muckpile. In addition, large rocks that have been torn loose or dislodged can slide from the new faces into the muck-pile. Increasing the blast size reduces the proportion of large rocks from the blast perimeter, and therefore improves overall fragmentation.

allocationofdelaysThe sequence in which blastholes are initiated and the time interval between successive detonations has a major in-fluence on overall blast performance. The performance of production blasts can only be optimized when charges detonate in a controlled sequence at suit-able discrete, but closely spaced, time intervals.

Optimum delay allocation for a blast depends on many factors, which include:• Rock mass properties (strength,

Young’s modulus, density, porosity, structure, etc.);

• Blast geometry (burden, spacing, bench height, free faces, etc.);

• Diameter, inclination and length of blasthole;

• Explosive characteristics, degree of coupling, decking, etc.;

• Initiating system (surface or in-hole delays, type of downline, non-electric or electronic, etc);

• Type and location of primer;• Environmental constraints (air and

ground vibration levels and fre-quency); and

• The desired result (fragmentation, muckpile displacement and profile etc.).

It is not possible to determine optimum delay allocations from first principles, but blast monitoring, analysis and inter- pretation have led to a greater under-standing of the mechanisms and signi-ficance of blasthole interaction.

DelayalongrowsThe delay time between adjacent blast-holes in a row is sometimes called the intra-row delay. Firing a single row of blastholes with the optimum delay be-tween holes produces:• Optimized fragmentation for that

particular blast geometry;• Forward displacement, which is less

than that for an instantaneous single-row blast; and

• Reduced overbreak.

DelaybetweenrowsThe delay time between the initiations of rows of blastholes is sometimes termed the inter-row delay. The delay between rows can be as important as the delay along rows in controlling overall blast performance. Multi-row blasts are fired using a time delay between the detonations of successive rows of blastholes. The burden on each blast-hole needs time to move after the deto-nation to create an effective free face. Dependent blastholes then fire towards this new free face developed during the blast. (Figure 8)

hole-by-holeinitiationIn many situations the simplest method of blast initiation hook-up is to fire blastholes row by row or simultane-ously along echelons. This will rarely produce optimum blast performance, especially in terms of fragmentation or ground vibrations. The end result can be improved by introducing hole-by-hole

(a) ExcessiveAirblast & Flyrock

(b) Goodbreakage & displacement

(c) Poor fragmentation

Fig 7. Effect of correct and incorrect stemming.


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firing, where every blasthole is initiated in sequence at a unique time. Where appropriate delays are selected, hole-by-hole initiation exploits the positive benefits of blasthole interac-tion while avoiding most of the nega-tive effects. This leads to improved fragmentation and muckpile looseness, reduced overbreak, lower ground vibra-tions, and better control over the final muckpile position and profile.

FinalwallblastingAt most open pit mines, the final slope of the pit affects profitability appreci-ably. Steep stable pit walls can be formed by smoothwall blasting tech-niques, which include cushion blasting, presplitting and postsplitting. But with each of these techniques, the combined cost of drilling and blasting is relatively high. In some cases, stable pit walls can be formed without smoothwall blasting.

Careful blast design is the key to producing clean, safe pit walls at minimum cost. The blast design needs to consider the rock conditions in the area, the likely amount of backbreak from this blast, and the design location of the final pit limit. Key factors to consider in final wall blasting are:• Geology – Rock properties have the

greatest influence on the effect of blasting on pit walls. Heavily jointed rock often produces overbreak along joint planes.

• Blasthole location – The location of the back row of blastholes is critical to the location of the final pit limit. The back row of blastholes needs to be drilled in front of the final pit limit to allow for backbreak behind the blastholes. The correct location depends mainly on previous experience in the pit and trial and error, par-ticularly if the amount of backbreak is variable. If the standoff distance

between the back row and the pit limit is too small, there will be too much overbreak into the final face. If the standoff distance is too large, digging back to the design final face will be difficult, expensive and may need a bulldozer. (Figure 9)

• Blasthole depth– If blastholes are drilled into the berm below then the succeeding wall will be dam-aged. Sufficient standoff distances need to be maintained to designed crests.

SmoothwallblastingtechniquesCushion blasting, postsplitting and pre-splitting are the three common blast-ing techniques used to produce stable final walls. Postsplit and presplit blasts are often used alone to produce stable walls.

Cushion blasting is frequently over- looked when designing final-wall blasts, but can be the most versatile and useful method of the three techniques. The back-row blastholes in a cushion blast contain lighter charges than the production blastholes, and are drilled on a correspondingly smaller pattern. Cushion blastholes are usually the same diameter as the production blastholes in front of them.

Charge weight is commonly reduced by about 45 percent, and both burden and spacing by about 25 percent. The energy factor is therefore essentially the same throughout the final wall blast.

A postsplit blast consists of a row of parallel, closely spaced blastholes drilled along the final face. These blastholes are charged with a light, well-distributed charge, and fired after the production blastholes in front have detonated. Postsplit blastholes split the rock web between the blastholes to produce a sound smooth face with minimal overbreak.

Presplitting requires a row of closely spaced blastholes drilled along the design excavation limit, charged very lightly, and detonated simultaneously before the blastholes in front of them.

SpecialblastingtechniquesWhile the main emphasis in surface metal mines is on production blasting,

(b) Insufficient "Relief"

1 32

13 2

(a) Good "Relief"

Fig 8. Burden relief.


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there are times when special blasting techniques are required. These include:• Opening up new benches using

either drop cut or ramp blasting • Mining of weathered and fresh rock• Dilution control• Choke blasting• Blasting ore and waste together• Steeply dipping multi vein orebodies• Shallow dipping narrow vein ore-

bodies• Flat or bedded orebodies• Selective ore blasting• Separate ore and waste blasting • Deck charging • Secondary blasting and popping• Plaster blasting• Floor and toe blasting

SafetyandaccidentpreventionSafe and cost-efficient blasting requires all mine operators and supervisors to understand and follow correct proce-dures for handling and using explosives. Most mines now have on-site induction training to develop skills for specific jobs, including blasting. Many mines have written work procedures, which specify the method, tools and equip-ment to be used for each job. These procedures, combined with local mine rules and statutory regulations, are designed to maintain the health and safety of all people working in the mining en-vironment.

Blasting requires the use of special tools and equipment, which are usually subject to statutory regulations. All tools and equipment used for charging and firing explosives should be prop-erly maintained, regularly checked and correctly used.

There should be no improvisation or substitution, as this can cause injuries and accidents.

There are many hazards when work-ing in and about a mine. The additional hazards associated when using explo-sives that need to be mitigated are:• Electrical hazards that can affect the

use of electric detonators. The sources of electrical current are static, stray currents from machinery, light-ning and radio frequency energy.

• Heavy impact on initiating explo-sives

• Vehicles driving over explosives• Hot and reactive ground

• Misfires• Fume• Walking on rough ground and

around blast holes• Vehicle and pedestrian congestion

on the bench

ChargingblastholessafelyBefore charging commences, the bla-sting area should be barricaded and marked with cautionary signs and lights. All unnecessary tools, equip-ment and people not involved with bla-sting should be removed from the area. Smoking must not be permitted near explosives or charging operations.

The quantity of explosives deliv-ered to the job should not far exceed immediate requirements, and any unused explosives must be returned to the magazine when charging has been completed.

Explosives and detonators must be kept apart in separate containers until charging commences. These containers should be located in a safe place, clear of equipment, and marked by appropri-ate signs or lighting.

Electric detonators must be kept clear of all sources of electricity and all

potential conductors of stray currents. Electric detonators should be kept coi- led, with the lead wires shorted toge-ther, until they are used.

All blastholes should be cleared of obstructions and checked for length before charging. Drilling sludge and loose rocks should be washed or blown out before charging.

economicsandbenefits

Cost effectiveness of drilling and blast-ing can be defined in many ways, but the “bottom line” is that these operations must contribute to the best overall economic result for the total mining operation. Drilling and blasting influ-ences many different processes in a mine, with the benefits of a cost-effec-tive blast being felt anywhere from digging to maintenance, hauling, crushing and milling, ore recovery to labor utilization and secondary breakage. Therefore, decisions on drilling and blasting need to be made in the overall con- text, and should not generally be based on short-term economic factors.

The development and introduction of bulk explosives and efficient delivery

Maybe SmallerDiameter

Final Limit

Could be PresplitProductionBlastholes

Final Limit

ReducedEnergy per m

No Subgrade

Fig 9. Placement of blastholes along final pit limits.


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systems has provided a quantum step forward in blasting efficiency and has allowed cost reduction through econo-mies of scale.

The factors contributing to economic production in mines include:

Productivity• Overburden/waste removal• Primary raw feed/mine production/

sales tonnage• Mobile equipment capacity/type and

availability• Fixed plant capacity/type• Ore grade control factors• Maximizing reserves through struc-

tural stability• Minimizing stripping ratio: waste/

ore

Mineconditions• Type and extent of overburden/

waste• Rock type and geology• Height and inclination of operating

benches• Ground water conditions• Environmental constraints

laborforcecompetence• Training• Motivation and numbers

OperatingcostsvsfragmentationDrilling and blasting results have a major impact on each part of a mine's

operations. The optimization criteria for mine production operations can be expressed as finding the right combi-nation of activity costs, and managing them in order to minimize the overall production costs (Note: this does not mean that reducing any particular parameter in isolation will necessarily result in a lowering of overall costs). Figure 10 schematically represents the activity costs as a function of maxi-mum fragmentation size. The relation-ship between these activity costs varies from mine to mine.

The curve is divided into three zones – A, B and C. Zone B is where the total costs are minimized within a control-lable and acceptable range. In zones A and C the unit costs of one or more activities make the overall production cost excessive. In this case, the cost effectiveness of blasting does not necessarily increase with a decrease in blasting costs, and changes can oftenbe counterproductive.

The best time to break rock is undoubtedly during the primary blast–the aim being to achieve desired and predictable fragmentation, muckpile looseness, and a suitable muckpile profile for ease of digging. During the evaluation, other key issues may be: • To modify fragmentation to suit

excavator or crusher specifications;• To make blasting more environmen-

tally acceptable;• To improve labor utilization allo-

cated to blasting;

• To reduce blasting costs, particularly in wet areas;

• To protect pitwalls or control over-break damage; and

• To maximize recovery of product ore.

The process of optimizing blasting must be done in a controlled manner so that the inf luence of changes on blast performance can be measured and evaluated. It is most important that changes are made one at a time, and that a thorough analysis of the total cost and the blast performance are made to enable any benefits to be identified and quantified.

acknowledgements

Article produced by Orica Mining Services, the world's largest provider of commercial explosives and blasting systems.

Fragmentation

Zone ofMinimumTotal Costs

TotalCosts

Secondary

Crushing

Load & Haul

Cost perTonne

Drill& BlastUn

it Co

sts

($)

A B C

Fig 10. Costs versus fragmentation.

The PV-351 can drill blastholes up to 16 inches in diameter.


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TheRussianexperience

For rotary drill rigs the key base mate-rials adversely affected by low tempe-rature operation are steel, rubber and lubricants.• At lower ambient operating tempera-

tures steel becomes brittle, creating possible earlier fatigue failures. For heavy equipment designers, the task is to select steel with proper material properties, to reduce the load or to reduce the loading cycles. Through the combination of the three factors, structural integrity can be equalled to equipment running in non-arctic conditions.

• With any rotating equipment, seals and hoses are used to retain fluids. Like steel, the newer generation synthetics lose f lexibility, becoming brittle. With arctic conditions, the key is again through material selec-tion to keep equipment doing its primary function without the aid of artificial heat sources. In an arctic

application the use of natural rubber or silicon is better than synthetics.

• To maintain acceptable component life in arctic conditions effective lubrication is essential. Typically this will require using the standard addi-tives with a base lubricant that will f low at the ambient temperatures and at the viscosities specified for the application.

Beyond making necessary changes to base materials, subsystem redesign may be required to meet the low temperature challenge. Engineers must decide if the material can be changed, heat be added or in some cases the part be eliminated to achieve 5,000 to 6,000 operational hours per year.

Exposure and constant ground con-tact subject the crawler undercarriage to particular abuse in low temperature, icy conditions. Many components either rotate or articulate (rollers, idlers, drive sprockets and track chains). Again the driver is to upgrade the base material, steel and rubber, where necessary. Some applications may require heat-ing the drive elements to keep seals soft and pliable.

Similarly, for a diesel engine power-ing the rotary rig in these conditions, special attention must be given to start-up and lubrication. Atlas Copco has designed a series of heater packages for lubricants, the engine block and batter-ies. All these packages are powered by

Exposure and constant ground contact subject the crawler undercarriage to particular abuse in low tem-perature, icy conditions, requiring careful selection of materials. Some applications may require heating the drive elements to keep them working.

DrillinginarcticconditionsCopingwithclimaticextremesThe spread of mining to inhospi-table parts of Mother Earth has posed a major challenge for mining equipment design engineers in terms of both basic machine functions and operator well being. Ope- ration at high latitude or high alti-tude requires a significant degree of redesign. Available coal and mineral resource geography has intensified, first with exploration and then mining activity, in the Arctic and sub-Arctic central con-tinental regions of North America and Asia. In parallel the ability to build equipment that can operate economically at temperatures around -55°C has become increas-ingly important. Similarly, the development of mines at high alti-tudes requires machines that can cope with low atmospheric pres-sure as well as low temperature.


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110, 240 or 380 V AC electricity pro-vided by the mine electrical grid or a diesel generator. If getting electrical power to the drill is impossible, a diesel- powered block heater is another option available. Likewise if low ambient fuel is not available use of 24 V DC fuel heaters is yet another option available.

Lubrication systems pumping grease over long distances can be impossible, and it may be best to redesign with a component that has impregnated oil bushings or closed bearings. To prevent the pump from cavitating, the lubricant will either have to be heated or replaced by a special blend that maintains vis-cosity through the ambient temperature range.

Dust suppression is most difficult in low ambient climates. The synthetic rubber normally used in dry dust col-lectors becomes brittle in extreme cold, and articulated components such as hoses and dust curtains will fail. If the drop out chute does not close properly the system fails to back flush. Also moi- sture entering the collector will freeze when it enters the cold dust collector chamber. Vibrators can be used to pre-vent material collecting on the dust collector body.

Another option under development is a wet dust control system. To keep the system from freezing is a design challenge. In this case short hose con-nections with diesel fired pre-heaters create enough energy to keep the system in operation.The benefit with wet systems is the reduced number of moving parts.

Given that the time limit for human exposure to very cold air is 15 min-utes, the cab for artic rigs must be big enough for two operators and their cold weather clothing. Additional insulation, heating and defrosting capability are also essential.

The marriage of low temperature solutions and advanced technology on Atlas Copco Drilling Solutions rotary blasthole drills has been successful. Today over 150 Drillmaster and Pit Viper class rigs work in coal, gold, copper, diamond and iron mines where temperatures can drop below -40C.

JohnStinson

Atlas Copco has designed a series of heater packages for lubricants, the engine block and batteries.

Watermist closed.

Proheat closed.

Wiggins closed.

Watermist open.

Proheat open.

Wiggins open.


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efficiencyandproductivity

The Pit Viper 235 has a weight on bit of up to 65,000 pounds (29,500 kg) and is designed for rotary or downhole (DTH) drilling of 6-inch to 9 ⅞- inch (152 – 251 mm) diameter holes. Competitive per-formance and excellent long-term reli-ability have been key marketing points for the Atlas Copco Drilling Solutions range of drilling rigs for a long time. The PV-235 is specified and fabricated to maintain this reputation, with particular attention having been paid to the reduction of horsepower demand and non-drilling time. The cab and control technology have been significantly upgraded and the diesel engine options are Tier II and Tier III units.

Atlas Copco Drilling Solutions has again placed great emphasis on flex-ibility in application, and the PV-235 is available with any one of three towers to drill 30-foot (9.1 m), 35-foot (10.7 m) or 40-foot (12.2 m) clean 230-mm holes. The new machine can be configured in a surprising number of ways to offer an optimal match to a mine’s particular operating method and environment.

Like the PV-351 and the PV-270 models, the PV-235 will be available with either a choice of diesel engines or an electric motor. And it retains the

hydraulic systems, including the rotary head, that have consistently been pre-ferred by the Atlas Copco design and engineering team for many years.

lessmass,moreoptions

Starting at ground level, the Pit Viper 235 has a newly designed platform. It is built with two-speed hydraulic excavator style Caterpillar 330 under-carriages – the 330L for units with the 30-foot tower and with the 35-foot

tower, and 330EL when the 40-foot tower is fitted. The dimensions for the PV-235 version with tower up is 34 feet 2 inches long and 14 feet 6 inches wide (10.4 x 4.4 m) A high speed lock-up operates with the tower raised.

The plate steel frame is new to blast-hole drill construction and was desig-ned using finite element analysis. The material thickness is one third that of an equivalent welded plate construction and has a better fatigue life. The frame accommodates the 450- and 600-gallon

Pit Viper 235 is capable of dilling a single pass 40 ft clean hole.

ThenewmidrangePitViper235

ThestarofMinexpo2008The new ultra class haul trucks in the Central Hall arguably may have achieved the greatest visual impact at MINExpo 2008, but sur-face mine drillers attending the record-breaking Las Vegas show hailed their own new star in the North Hall – the Atlas Copco Drilling Solutions Pit Viper PV-235 at the Atlas Copco display. This PV-230 class machine thus fol-lowed in the tracks of the first Pit Viper model, the PV-351, which was launched at MINExpo 2000, and the PV-270 series models in-troduced at MINExpo 2004.


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fuel and water tanks, which are ISO block, three-point isolation mounted. An additional 400-gallon water deck tank can be fitted if no dust collector is used.

For safer, easier and quicker trouble shooting and maintenance, the Grip Strut open mesh deck provides excellent access to the superstructure elements, in-cluding ground level battery and starter isolators, deck level access for the serv-ice points on most systems, and quick fills at waist level. An optional bolt-on drum deck on the drill end adds extra space for lube and other fluids storage tanks, and cleans up the deck area to allow 300° of access and improved serviceability. Other optional fittings include a central lubrication system, fire suppression equipment, a jump start receptacle and a spring-assisted ladder.

For mounting on this platform, Atlas Copco Drilling Solutions has decided to offer customers a wider choice of power system options than on previ-ous models. The structure is similar to that designed for the Pit Viper 351, with an independent sub-structure and three-point mounting. But there is a wider choice of Cummins or Caterpillar engines, covering the range 540 – 800 hp at 1,800 rpm with the Cummins QSX 15 to QSK 19 or Cat C15 to C27 engines, all meeting Tier III regulations.

There is also a wider choice of air compressors, as either single-stage asymmetrical oil flooded Atlas Copco or Ingersoll-Rand rotary screw units are available for low pressure (1,200 – 1,900 CFM, 100 psi) rotary drilling, and the two-stage equivalents for high pressure (1,250 or 1,450 CFM, 350 psi) downhole drilling. A new Electronic Air Regulation System (EARS) allows low load starting.

The hydraulic system has been further refined with load sensing and other features to reduce horsepower de-mand. The heavy duty Funk gearbox is driven by a drive shaft from the front of the engine. There is one piston pump for rotation; one load sensing piston pump for the feed, set-up and auxiliary functions; and one pressure-compen-sated piston pump for the fan circuit. The propel function uses the feed and rotation pumps and there is an in-cab

For angle drilling the PV-235 uses a pivot at the base of the tower with adjustments from vertical to 30 degrees in 5-degree increments, while keeping the deck level.

The hydraulic automatic cable tensioning cylinder is a time saver for maintenance .

The enclosure option will reduce noise and provide cold weather protection; full-length doors offer easy service access.


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switch to select the diverter valves. The valve rack is centrally located for easy service access, at the same time simpli-fying hose runs and control wiring. The pressurized hydraulic fluid tank has a capacity of over 100 gallons and the filters are serviced at waist level.

To allow operation at ambient temperatures up to 125° F (52° C) the cool-ing system features oversized radiators. Variable speed control helps to reduce fuel consumption and noise and improves cold weather performance. The low fan speed also lowers noise emissions. Available as an option is a very smart enclosure that further reduces noise, provides cold weather protection and has full length doors for service access.

TowersThe open front structure of the three towers available is similar to that used on the other Pit Viper models – fabricated from rectangular steel tubing by certified welders and having four mainvertical members. The 40-foot (12.2 m),35-foot (10.7 m) and 30-foot (9.1 m) holedepths mentioned previously are the distance from ground level to the bottom of the hole, while the top of the bitbasket is 5 feet above ground level. Using a starter rod and the updated four-rod carousel, the 40-foot tower can be used to multi-pass drill to a maximum depth of 200 feet (61 m). The carousel features a spur indexing drive and a parking brake.

The PV-235 is fitted with a standard single-speed direct drive rotary head that requires less maintenance than other designs. Operating at 0 – 130 rpm this unit provides a torque of 7,800 lbf-ft (10.6 kNm) while the 200 rpm option delivers 5,200 lbf-ft (7.0 kNm) of torque. Alternatively there is an optional two-speed head delivering either 4,250 lbf-ft (5.7 kNm) at 200 rpm, or 8,800 lbf-ft (11.9 knm) at 100 rpm. These rotary heads are fitted with adjustable wear guides. The spur gear head design used on the present DM45 and DML rigs is an option. The single cylinder cable feed designed for the PV-235’s 40-foot tower provides a hydraulic pulldown force of 60,000 pounds and a further improvement in non-drilling speeds. The sheave diameter: cable diameter (D/d) ratio

is 22:1 and reverse bending of the cables,which can create excess fatigue and shorten cable life, is eliminated. The pull-down rate is 140 ft./min. with the 40-foot tower and 193 ft./min. for the 35- and 30-foot towers. Retract is 202 ft./min. with the longest tower and 195 ft. /min. for the other two. Auto-tensioning of the cable, necessary to counter the loss of tension caused by cable stretch, is by means of a single cylinder with exclusive balancing yoke.

For angle drilling the PV-235 uses a pivot at the base of the rig tower, proven on the earlier Pit Vipers, with adjust-ment from vertical to 30° in 5-degree increments. But the rear telescopic support legs provided on the larger rigs are unnecessary. This single pivot design reduces non-drilling time significantly, with tower raising and lower-ing improved. The rig has a new two- cylinder impact slide wrench for drill string breakout that has replaced the single-cylinder deck fork used on previous models. The rear jacks are

incorporated into the new tower rest, as are the exhaust mounts, air cleaners and lights. The arch-shaped rest adds torsional stiffness to the frame and riser arms secure the tower when it has been lowered, reducing wear during tramming.

evenbettercab

Together with the power system en-closure, if fitted, the most distinctive feature of the latest Pit Viper is the cab. The cantilevered pod-type FOPS design is a further advance on the progress achieved with the PV-270 series ma-chines in terms of both capabilities and appearance. Visibility is enhanced not only by the shape of the cab and large glass area, but also by tinted windows, improved wiper/washers and six Nordic integral lights (which also consume less power than conventional ones). The integrated air conditioning system - with hydraulically powered compressor, evaporator and condenser

The RCS option provides various levels of automation.


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– is mounted under the cab rather than on the side. The Atlas Copco engineers worked with the cab supplier to achieve further noise reduction. For easier “housekeeping” there are fitted floor mats and a sweep-out door at the non-drill end. Optional offers are a safety camera system and a radio/CD player for the cab.

The standard controls are electric over hydraulic, with push buttons and in-seat joysticks – one for each hand – operating the key drilling and tramming functions. Adding the proven Atlas Copco RCS computerized network rig control system, which is an option, provides various levels of automation, in common with the rigs manufactu-red by the company’s surface and under-ground teams in Sweden. For the PV-235 these options include remote tramming, auto leveling and GPS navigation, all

of which can help minimize non-drilling time, and also measure-while drilling logging technology. (See page 25 for RCS explanation.) Prospects for the new Atlas Copco Drilling Solutions model are good

if the Pit Viper 235 enjoys the same level of success as its predecessors.

DustinPenn

The FOPS designed cab offers excellent visibility and comfort.

A two speed excavator style undercarriage.


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lowcenterofgravity

Clearly an essential quality for this market is f lexibility, though the design engineering team could not ignore the across-the-board industry requirement for maintenance convenience and cost effectiveness. These two characteristics are evident from the PV-270 crawler tracks through to the choice of single- pass or multi-pass drilling.

The PV-270 machines offer a choice of proven Caterpillar and Atlas Copco undercarriages to enhance their com-patibility with other mine fleet members. The PV-271 is built with the extended version of either the CAT 345SL or the Atlas Copco GT3400, while the PV-275 can have either the standard 19-foot 6-inch (5.9 m) CAT 345SL with GFT110 final drive or the ACGT 3400 tracks, with two-year track and 30,000- hour side frame warranty.

The design and testing process used for the PV-270 main frame was gener-ally similar to that for the Pit Viper 351. To ensure long frame life without re-builds, the I-beam used is 24 inches thick with a cross section of 162 lb./ft. – smaller than the PV-351 frame but almost twice the size used on the DM-M3 rig. The structure achieves a low center of gravity for good stability

and reduces drilling vibration.Single- pass stability ratings, adjusted for dynamic conditions, are 5° with cab facing downhill and 8° tramming across the slope, both with tower up, and 10° with tower down, cab facing uphill. The equivalent multi-pass figures are respectively 11°, 13°, and 16°. The rigs also offer the customer a choice between a standard three jack configuration and four, with the rear jacks tied as on the Pit Viper 351.

Poweroptions

The power system setup for the PV-270 series machines is structurally similar to that on the Pit Viper 351 but includes a choice of matched engines and com-pressors suitable for the rotary or downhole drilling options. The engines offe-red, which are Tier II compliant, are the 760 hp (567 kW) Cummins QSK 19, the 800 hp (597 kW) Caterpillar C27, and the larger 950 hp (709 kW) Cater-pillar C32. There is a single side-by-side hydraulic/compressor/radiator cooler package.

The Ingersoll-Rand compressor op-tions are a 1,900 CFM (900 l/s) unit or a 2,600 CFM (1230 l/s) supplying 110 psi (760 kPa), plus a 1,450 CFM (680 l/s) air compressor delivering air at 350psi

(2,400 kPa) for downhole drilling. The CAT C32 engine is fitted on those rigs using the 2,600 CFM compressor. A lot of customers prefer the combination of CAT undercarriage and CAT engine for easily organized and reliable dealer support.

The electric power pack option com-prises alternatively a 700 hp (520 kW) WEG 6808 motor running on 6,000 V AC/50 Hz current and coupled with an 1,800 CFM/50Hz Ingersoll-Rand air compressor, or a 900 hp (671 kW) WEG 6811 motor running on 4,160 V AC/60 Hz power that is coupled to the Ingersoll-Rand 2,600 CFM/60 Hz air compressor. An electric powered ver-sion for downhole drilling is available for the DM-L rig, and a similar unit could be developed, if required, for the PV-270 machines, albeit limited to 1,070 CFM and 350 psi for 50 Hz appli-cation. The motor is totally enclosed and is cooled by a fan with the highest rating in the industry, which allows the unit to operate without a machinery house. An oil-immersed non-flammable 40 kVA transformer protects the motor, providing 380 V AC for the extensive heating package used for all the reser-voirs. The high voltage safety circuit and the operator controls run on 110 V AC that is converted to 24 V DC so that

Pit Viper 275 used for blasthole drilling in South African coal mine.

DevelopmentthroughinteractionSingle-ormulti-passdrillingThe medium scale Pit Viper 270 series drilling rigs provide 75,000 lbf (340 kN) force on bit and can be equipped for either rotary or down-hole (DTH) drilling. They combine structural features of the PV-351, components successfully used on the DM45, DM-M2 and DM-M3 models, and some new ones, in-cluding Tier II engine options. These features were incorporated as a result of extensive discussions with customers already using the Drilling Solutions equipment range and with other professionals inter-ested in the application of the Pit Viper concept at this scale of rig.


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the electric machine can use the same components as the diesel-driven rigs.

Experience shows that electric mo-tors typically last 20,000 – 30,000 hours before replacement or rebuild in this ap-plication, as compared with the 10,000 – 14,000 hour life usually attained by diesel engines. This is one reason why there is growing interest in the electric Pit Vipers, to which Atlas Copco has also responded by matching the electric power pack to a mine’s available power supply. For example, four PV-275 rigs have been delivered to the Moroccan phosphates producer Office Chérifien des Phosphates (OCP) for operation at 5,500 V AC.

Like that on the PV-351, the hydrau-lic system for the 270 series utilizes a leak-free, clean specification. However it has the single gearbox and three pumps configuration used on the DM-M3 rig, albeit with larger units; using fewer components has proved to reduce operating cost. There are two main pumps for feed, rotation and pro-pel, while the double pump supplies the auxiliary functions.

The air cleaners are similar to those on the PV-351, with one provided for the Cummins engine, two for the CAT, one for the 1,900 CFM air compressor and two for the 2,600 CFM unit. These and the other serviced units are easily accessed from the PV-270 deck, which is designed on similar lines to that of the PV-351, while retractable ladders are also available.

Threetowers

The two machines comprising the Pit Viper 270 series are primarily differen-tiated by their towers. These are of sim-ilar construction to those on the PV-351 but are new designs, not stretched or lighter weight versions of the existing design.

The PV-271 live tower is dimen-sioned for 55-foot (16.7 m) clean hole single-pass drilling. Like the PV-351 it does have a two-rod changer, in this case for 25-foot rods enabling drilling to a total depth of 105 feet. With a four-rod carousel holding 40-foot pipe, the PV-275 is designed for multi-pass drill-ing to a maximum depth of 195 feet. There is also a 65-foot clean hole tower

The PV-275 can be used for angle drilling with 0 - 30° adjustment in 5° increments.Photo from an Australian coal mine.

The PV-271 live tower is dimensioned for 55-foot single-pass drilling, there is also a 65-foot clean hole single pass drilling tower option where the rotary head and tower has to be down when moving the drill rig.


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option, but with this unit one drill pipe must be racked and the rotary head brought down in order to lower the tower for relocation.

Like the power pack, the vari-able displacement rotary head for the PV-270 rigs is very similar to the proven design used on the DM-M2 machine. Equipped with two motors the 188 hp (252 kW) rotary head deliv-ers up to 8,700 foot pounds (11.8 kNm) of torque. Maximum speed is 150 rpm. Internal spur gear speed reduction gives better torque on rough ground and in other circumstances where the head stalls later than other designs. The hydraulic rod support with automatic actuation is essentially the same as that proven on the DM-M3 rig. There is also an upper fixed rod catcher.

Again like the PV-351, the Pit Viper 270 series drilling rigs use the cable feed system introduced on the DM-M3, however with some redesign to achieve

faster feed speeds. The feed rate is 127 ft. /min. (38 m./min.) and the retract rate is 158 ft./min. (48 m./min.). The automatic tensioning is derived from the PV-351 system which has proved problem-free to date. The pipe handling system on the PV-271 is similar to that on the PV-351, and the PV-275 is similar to the DM-M3. The PV-270 series machines also use the same patented system for angle drilling as the Pit Viper 351, with 0 - 30° adjustment in 5° increments for the multi-pass PV-275 and 0 - 20° adjustment in 5° increments for the single pass PV-271. These rigs are quite widely used for angle drilling, both in coal mines and in metal mines for toe blasting.

Cabcommonality

The cab fitted to the Pit Viper 270 series rigs is essentially the same single

piece design as that used for concur-rent DM45 and DM-L machines. It meets the FOPS requirements of ISO 3449 Level 2, is thermally insulated and pressurized, and has adjustable vents for climate control. The air con-ditioning unit is side mounted, which, along with other detailed features, makes this cab easier to service so no roof access is required. The sound damping has been tested down to 70 dB(A).

The operator enjoys excellent vis-ibility over the ergonomically designed wrap-around console. The controls are predominantly electric-over-hydraulic sticks.

Options

As well as the four jack system, options available for the PV-270 series rigs when they were introduced included a dry dust collector with 9,000 CFM blower,

The Pit Viper 271 cab offers the operator excellent visibility and the sound damping has been tested down to 70 dB(A).

The PV-271 Rotary head.


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four-camera system with LCD monitor, buddy seat, water injection, fire suppres-sion, cold weather package, a central fast service system, high intensity Nordic lights, and a hydraulic test station (that is now standard) and many more options.A new option is the Atlas Copco computerized RCS control system (See article page 25.) Several PV-270 machines have been delivered with RCS.

Rapidacceptance

The Pit Viper 270 series rigs were rap-idly accepted. It was a machine that got it right in terms of all the parts work-ing together perfectly, and customers seem to agree. In only four years the sales of the PV-270 series surpassed the accumulated 14-year sales record of its predecessor, the DM-M2.

Barrick was one of the first mines to use a PV-271 at their Goldstrike operations, and the company now has nine of them. Newmont was another early customer, buying four PV-271 machines for the Yanacocha gold mine in Peru, and now has 17 of these rigs. Copper mining customers include Freeport-McMoRan which now has over 20 machines. Most recently, the PV-270 series has broken into the Australasian coal and metals markets.

Many of the PV- 270 series rigs have been ordered for coal applications mainly in South Africa, Russia and the USA. The other major applications are in copper and gold, mostly in the Americas, and iron ore mines in Africa, Latin America, Russia and Ukraine. Almost all of the PV-275 machines are equipped for rotary drilling, but a significant number of the PV-271 units have ben configured for downhole drilling, mainly single-pass drilling of 8-inch diameter holes at gold mines.

Since the first PV-275 was shipped for testing at Peabody’s Kayenta coal mine in 2003 and the 2004 MINExpo launch of the new models, more than one hundred fifty PV-270 series rigs have been shipped to customers.

DustinPenn

PV-271 working in copper mine.


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Powerplatform

From the ground up, the Pit Viper 351 is a robust and highly capable drilling rig. The undercarriage is a hydraulically driven custom version of the Caterpillar 385 excavator unit. At 26 feet 10 inches (8.18 m) in length this is the largest undercarriage used for a rotary drilling rig. Maximum tramming speed is 1.1 mph (1.77 km/h).

The main frame was designed using finite element analysis and was subjected to dynamic strain gauge testing. To ensure long frame life without rebuilds, the I-beam used is 30-inches thick with a cross section of 326 lbs./ft. It supports three inboard mounted tanks – one 900 gallon (3407 liter) water and two 600 gallon (227 l) fuel – as well as the forward jacks and rear tower support and jacks assembly. There are four levelling jacks with 10-inch (254 mm) bore and 72-inch (1829 mm) stroke. The rear jacks are cross linked to minimize frame twisting.

Power for the multiple hydraulic systems and air compressor used on the Pit Viper 351 comes from either a diesel engine or an electric motor. Either dri-ves the hydraulic power pack via a drive shaft and the air compressor directly. A floating power pack sub-base iso-lates the components from vibration. Two coolers allow operation up to an

ambient temperature of 125°F (52°C). Two 12-cylinder diesel engines with electronic monitoring systems that meet the EPA Tier I standard are offered – the Cummins QSK 45, rated 1500 hp (1119 kW) at 1800 rpm, and the

Caterpillar 3512, rated at 1650 hp (1230 kW) at 1800 rpm.

The 1400 hp (1044 kW) electric power unit comes with a rear access plat-form and, optionally, a 1500-foot (457 m) capacity cable reel for 2-inch (51 mm)

The diesel powered PV-351 can be offered with Cummins or CAT 12-cylinder engines.

largediameterdrillingPitViper351The giant Pit Viper 351 is a flexible rotary drill rig with a weight on bit of 125,000 pounds (56,700 kg), and the ability to drill 10 5/8-inch to 16-inch (270-406 mm) diameter holes to a maximum depth of 135 feet. However, at MINExpo 2000 many customers commented: “It’s set up to single-pass drill a 65-foot-deep hole.” The PV-351 is ruggedly constructed with an operating weight of 385,000-415,000 pounds (175-188 tons). However, it takes only touch screen controls and a joystick to operate.


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cable. The WEG 6811 squirrel cage motor normally runs on a 50 or 60 Hz, 4160 – 7200 V AC power supply. The machi-nery house for the electric unit, containing the majority of the main components, is hydraulically pressurized and has two access doors and removable roof panels. Some 80–85 percent of the components used in the rig are the same in the diesel and the electric versions.

The hydraulic system has a 350 gallon (1325 l) tank with three-micron filtra-tion. To ensure reliable operation, the designers made extensive use of hard piping with Stauff clamps for hoses, O-ring face seal fittings and two quick change filters. There is a single gear-box and five pumps. The main Parker Denison variable displacement pumps control the propel motors and drill feed/rotation. Other pumps run various aux-iliary functions. The use of integrated circuit blocks reduces the number of hose connections.

The well-proven Ingersoll-Rand asym-metrical screw compressor features twin rotors in parallel, variable volume elec-tronic control and lubrication pumps that minimize load during startup. It delivers up to 3,800 CFM (107.6 m3/minute) of air – the highest rate ever available on a blasthole drill – at 110 psi (758 kPa), a pressure that ensures im-proved bit life. The air cleaners employ an innovative three-stage system in which the elements are easy to access and easy to change. Quick release co-vers make for easy operator mainte-nance.

The Pit Viper 351 is designed to be a maintenance friendly machine. The superstructure is laid out to allow safe, easy movement and good access to service points. The rig has standard Wiggins Quick Fills for programmed maintenance and daily refilling. The spool valves are located above the deck and all the filter elements are easy to reach. The stand-ard decking to the rear of the tower and the tower access ladder enable service personnel to inspect the rotary head and other tower components while the tower is down.

Versatiletower

Like the main frame, the tower for the Pit Viper 351 was designed with the aid

of finite element analysis and tested by dynamic strain testing. The tower is of open front construction, fabricated by certified Drilling Solutions weld-ers using rectangular steel tubing, and has four main vertical members. The design retains the unique “live” design used for the Drillmaster towers, which enables the operator to raise and lower the tower with the rotary head at the top and the rods in place, a capability that typically saves 4 – 10 hours work when moving a rig.

The tower is dimensioned for drill-ing 65 feet (19.8 m) in a single pass. Using a longer starter rod, the operator can drill 70 feet (21.3 m) in a single pass but the tower cannot be used live. There is also a two-rod carousel with key lock retention for 35-foot (10.7 m) long and 8⅝-inch to 13⅜-inch (219 – 340 mm) diameter drill pipe so the PV-351 can to drill to a depth of 135 feet.

Drill rotation uses the hydraulic drive rotary head system that the Garland team has preferred to an electric motor drive for a long time. It is the compact size and light weight of this design that makes possible “live” tower operation of the PV-351 and preceding Drillmaster rigs. The variable displacement rotary head on the big Pit Viper has two 14- cubic-inch motors that deliver 340 hp (254 kW) and a maximum torque of 19,000 foot-pounds (25,759 Nm). Maxi- mum speed is 170 rpm. Simply adjusted extended head guides maintain align-ment during descent and a separate lube pump improves motor spline life. A rod support system, actuated automatically by detection points at the rotary head, supports the pipe at its mid-point when-ever the rotary head is near to the top of the tower.

Another important feature of the Atlas Copco Drilling Solutions rig design is the patented cable feed pull-down and pull-back system developed in-house and introduced on the DM-M3. It is low-cost, four times lighter and much quieter than a chain feed, but offers good buckling resistance. The cables absorb the loads transmitted by drilling before they reach the rotary head so that drilling is smoother and bit wear is reduced. As well as providing 120,000 pounds (54,446 kg) of pulldown and 125,000 pounds (56,700 kg) of bit load, the dual

Pit Viper 351 “live” tower.

Weg motor – 1400 hp.

Valve stand offering excellent accessibility for maintenance.


TalkingTeChniCally

cylinder system delivers 70,000 pounds (31,752 kg) of pull-back and retract speed is 140 FPM (42.7 m/min). The system also improves rig safety as the operatorcan detect dangerous amounts of wear,whereas a chain feed can fail catastro- phically. The downside is that stretch-ing in use results in a loss of cable tension, but this has been countered by an automatic tensioning system that uses independent hydraulic motors and jack screws to tension the pull-down cables and hydraulic cylinders to tension the pull-back ones. The system maintains tension, ensuring accurate rotary head alignment, and eliminates maintenance hours for tensioning.

The break-out system may not be the most technically sophisticated piece of equipment on a rotary drilling rig, but from the operator’s point of view, its effectiveness is very important in terms of the physical effort required and the non-drilling time involved. On the Pit Viper 351 primary break-out is achieved simply and effectively by a slid-ing fork and reverse rotation. A patented self-adjusting hydraulic tong wrench, already proven on the

DM-M3 rigs, is used for auxiliary break-out. Neither operation transmits shock loads to the tower. The PV-351 has a patented system for angle drilling between vertical and 30°, in 5° incre-ments. The same system is used on the DM-M3 rig. There is a short, independ-ently supported pivot point and hydrau-lic cylinder at the base of the tower, and two telescoping rear legs are attached to the tower close to the rotary head’s uppermost position and to the tower rest at the rear of the rig. Locking pins are remotely activated. This configura-tion allows the tower to pivot at deck level, minimizes the amount of unsup-ported drill pipe, and gives the operator a better view of the deck. The hole to be drilled can be collared within the Pit Viper’s dust hood.

newgenerationcab

The operator’s cab designed for the PV-351 represented a major step forward for rotary drilling rigs. Structurally it incorporates FOPS protection meeting the ISO 3449 Level 2 standards, floor-mounted air conditioning with adjustable

vents, and sound damping to 75 dB(A). The cab is raised to improve forward visibility and provides a good direct view of the rig deck as well. The wind- screen has wiper/washers as standard; there is a pressurizer, and sun shades are optional. The operator’s ability to maintain high productivity through a shift is further enhanced by an adjustable, swiveling suspension seat that is optimally placed for using the touch screen machine interface and the multi-function stick controls for feed, rotation, propel, and tower raising. The sticks for jack operation and tramming have safety triggers. Auxiliary func-tions are push-button operated.

The Pit Viper 351 has a control sy-stem that utilizes five computers and provides integrated drill technology options. It was designed to work with the GLOBAL positioning and monitor-ing system and to provide a platform for future automation. The rugged infrared touch screen displays data from the rig’s central computer, including all pertinent drill information, using internationally recognizable symbols. The screen is not affected by dirt and can be used by

The optional cable reel for 1600 feet of 2-inch cable.

Comfortable cabin with excellent visibility.

Automatic cable tensioning – pull-down cables jack screws.


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operators wearing gloves. The PV-351 rigs being supplied to Boliden’s Aitik copper mine in Sweden are equipped for Remote Rig Access, enabling Atlas Copco to check the drilling perform-ance, maintenance requirements, etc. from distant locations. Aitik already uses this technology to good effect for other major equipment units. This includes the RCS (computerized Rig Control System page 25), GPS posi-tioning, MWD (Measurement While Drilling) data collection functionality, Autodrill, Auto levelling and wireless data transfer.

Options

A number of equipment options are available for all the Pit Viper models. These include fire suppression systems and computer-controlled central lubrication.

Specific options developed for the PV-351 include a cold weather package for operation in ambient temperatures down to -40° C, a four-camera LCD vision system and attention horn, and a wireless remote propel control. Remote controlled tramming with the operator off the rig is mandatory in certain situations under some regulatory authori-ties. Additional options are a Hiab crane

for loading and unloading bits and accessories, hydraulic retractable stair- case, tower ladder and much more. Op-tional equipment for electric Pit Vipers includes a 5-by-8-foot cable reel for 1,600 feet of 2-inch cable, a load break switch, a power factor correction system, a machinery house pressurizer, and a 2,100 gal (7,950 l) water injection system.

extensiveexperience

It is now almost eight years since the first Pit Viper 351 started drilling at the then Phelps Dodge Morenci copper mine. This prototype machine has now operated for more than 40,000 hours. A second field follow machine went to Northgate’s Kemess mine in May 2003. Atlas Copco decided to invest consider-able amounts in production facilities, and this enabled the Drilling Solutions division to step up marketing efforts as mining industry investment in new equipment began to increase.

Commercial deliveries of the Pit Viper started in 2005-6 and the first PV-351 units headed south to Codelco’s Chuqui- camata copper mine in Chile and to the Anglo Platinum Potgietersrust opera-tion (now called Mogalakwena) in

South Africa. Codelco reported excel-lent results with the first machine and ordered a second rig that arrived at Chuqui in September 2006. Soon after, another PV-351 started operating at Codelco’s Radomiro Tomic mine and Andina or-dered electric powered machines. The first two Pit Viper 351 rigs at Anglo Platinum now have a fleet of nine electric machines.

There are now PV-351 fleets work-ing for Vale at Sossego in Brazil, at the Penasquito precious metals mine in Mexico, and at the Los Pelambres and Spence copper mines in Chile. Anto-fagasta chose a mix of diesel and electric rigs for Los Pelambres and Rio Tinto has done the same at the Rössing ura- nium mine in Namibia, southern Africa. Antofagasta minerals has ordered electric PV-351 units for its Esperanza pro-ject in Chile, while a fleet of PV-351s entered service in Western Europe at Boliden’s expanding Aitik copper mine in northern Sweden.

DustinPenn

Operators panel with the RCS touch screen.

Excellent view of the drill deck from the cabin.


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TheDRillCareportfolio

Developing valuable service and ma-intenance programs that provide high quality care for customers using new Pit Viper and other drilling rig models around the world has involved a number of key steps:• alignment with a proven, traditional

approach to parts and service provi-sioning already practiced within the Atlas Copco group;

• taking into account the global spread of the drilling rig fleet;

• achieving the highest possible level of competence within Atlas Copco Customer Service Centers around the world;

• providing top quality materials, parts, services and documentation necessary for optimal drilling rig operation and maintenance; and

• state-of-the art distribution center.

Atlas Copco Drilling Solutions parts and services team has built a customer care program for direct delivery to the mine site. The DRILLCare™ program is designed to ensure continued reliability and highest possible availability of drilling equipment, yielding to the custo-mer superior productivity and the lowest total cost of ownership. Every ele-ment in the DRILLCare™ portfolio of products and services was designed and launched with customer care in mind.

• DRILLCare Genuine Parts• DRILLCare Oils & Lubricants • DRILLCare Extended Warranty• DRILLCare Service Agreements • DRILLCare Innovative Solutions

genuineparts

DRILLCare™ Genuine Parts are manu-factured to the same quality standards as the components used for drill rig ma- nufacture. They undergo the same en-durance testing and quality assurance process. Consequently, these parts are warranted between scheduled machine services and will maintain the reliabil-ity, availability and performance of the drilling rig.

In addition to individual parts, Atlas Copco Drilling Solutions packages comprehensive service kits containing all required components for specific tasks. The prices for these kits are always more favorable compared to the individual component costs; they reduce inventory size and administration as well as

minimize service time. To support cus-tomer needs, our 129,000-square-foot climate controlled distribution center in Allen, Texas, processes and ships over 1,000 line items daily. The facil-ity is staffed by more than 75 dedicated employees ensuring quick, accurate order fulfilment to a 24/7 global drill-ing fleet.

Oils&lubricants

Formulated by specialist suppliers to exacting Atlas Copco Drilling Solutions specifications, the DRILLCare™ range of oils and lubricants are, like the ge-nuine parts, subject to rigorous quality assurance procedures. Their use en-sures extended warranty eligibility as well as helps to minimize downtime and optimize service life.

extendedwarranty

Designed to offer additional protection against unscheduled component failure

Atlas Copco DRILLCare TM is designed with customer care in mind. For more information go to:www.atlascopco.com/drillcare

PeaceofmindFocusonuptimeA large and growing number ofcustomers count on the econo-mic advantages of involving Atlas Copco in the servicing of their equipment throughout its opera-tional life. They know that quali-fied service and maintenance are the most important factors in maximizing efficiency and mini-mizing downtime. Atlas Copco continues to harness technologyand improve skills to deliver com-prehensive parts and services to meet those needs.


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for a three-year period with unlimited operating hours, the DRILLCare™ Extended Warranty offers fair, simple coverage with no small print. It covers the air compressor, rotary head, hy-draulic pumps and motors, hydraulic feed and jack cylinders, main frame and tower, and Atlas Copco approved undercarriage.

To meet warranty conditions, the customer is responsible for following the Atlas Copco service schedule and planned audits, and must use genuine parts, selected oils and lubricants. Following these procedures allows the customer to focus on production while assuring rig

reliability. The extended warranty can also be linked to DRILLCare™ Service Agreements.

Serviceagreements

Taking the quality of care up a level, DRILLCare™ Service Agreements provide customized protection plans for drilling operations. These service solutions feature total maintenance, preventative maintenance, fixed-price repair and parts-only plans. They utilize genuine Atlas Copco parts and materi-als so that the extended warranty period is secured. They minimize unplanned

downtime and they help customers achieve lowest total operating cost for their drilling equipment.

innovativesolutions

To enhance the value of DRILLCare™, Atlas Copco continues to develop prod-ucts that increase the effectiveness and efficiency of drilling and maintenance operations. In addition to premium quality air and hydraulic hoses, the com-pany has introduced a Hydraulic Hose First Aid Kit and filter carts for both hydraulic fluid and diesel fuel.

The portable, environmentally fri-endly Hydraulic Hose First Aid Kit contains drill rig specific hoses and adap-tors with complete instructions and accessories. This enables the user to achieve a first-time fix at the job site in the fastest possible time and with spill-age control. On site mobility can be in-creased by wheel or truck mounting.

The Hydraulic Filter Cart is designed to provide a new level of fluid integrity through superior contamination control when pre-filtering new hydraulic fluids or cleaning existing systems. The three-wheeled cart is highly mobile, although it can be fixed to a service vehicle or drilling rig. The unit is built with high quality components that can be config-ured in a number of ways. It provides multi-stage 3-micron filtration with magnetic removal of metal contaminant particles, and spin-on genuine replace-ment elements. There is a high pressure cut-out. Using the cart avoids the need for a contamination bypass, meets spe-cific flow requirements and prevents secondary failures. The Hydraulic Filter Cart will improve safety and reliability, while simultaneously saving time and money. The same sturdy base unit can be configured as a high efficiency tool for diesel fuel contamination control.

Atlas Copco trained service person-nel shall be on-hand at mines around the world, providing support and ensur-ing continued operation. Their mission is to add value to every process, pro-vide solutions and optimize each visit to help our customers improve drilling productivity.

JeffRose

Hydraulic Hose First Aid Kit - Provides an immediate replacement for every hydraulic hose on our drill rig.

Hydraulic Filter Cart - A superior contamination control device with maximum protection in mind.


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grindingmethods

There are two different methods of bit grinding to restore the buttons. The preferred method uses a diamond coated profiled wheel, and the other, a grinding cup.

The profiled wheel provides a smooth and efficient grinding oper ation, which,

throughout its life, maintains the cor-rect button shape and pro trusion. It features correct centring on all buttons, producing a high quality cemented car-bide surface, with no risk of cemented carbide nipple. Long bit life, and higher penetration rates, will result from good grinding quality.

Disadvantages of using the grinding cup are that it may produce an incorrect button shape and protrusion. It is dif-ficult to centre the grinding cup over the gauge button, and there is also a risk of producing a sharp cemented carbide nipple on the button, and a possibility of scratches due to the larger diamond grain used. Reduced bit life will result from poor grinding quality.

Several tests have been carried out to find which method gives the best bit performance. The grinding wheel gives the correct shape to the button, regardless of the amount of wear on the wheel, ensuring that the bit will achieve

Totalbitlifedrillmetres

700

600

500

400

300

200

100

010 20 30 40 50 60

10regrindingsperdrillbit

Grindingintervaldrillmetres

TheeconomiccaseforroutinebitgrindingCuttingholecostsThe button bit was originally de-veloped to do the job of an insert bit, without the necessity for fre-quent grinding. However, it was soon found that the service life of a button bit increased consider-ably if the cemented carbide but-tons were ground. Nowadays, it has become ex-tremely important to grind button bits at proper intervals, in order to extend the service life of the rock drilling tool, maintain penetration rates, and drill straight holes and lower the total cost. In all rock excavation opera-tions, the cost is usually ex pressed in cost per drilled metre (cost/dm), in cost per cubic metre (cost/cu m), or in cost per tonne. The cost to produce a hole de-pends on how fast it can be drilled, and how many tools will be con-sumed. The cost to produce a cubic metre of rock is dependent upon the cost of the hole, and the cost of blasting. If the blasthole is of poor quality, then more explosives will be consumed in blasting the rock. Unsharpened bits very often give a poor quality hole with deviation. Grinding constitutes around 2% of the costs of the entire drill-ing operation. To run the business without grinding could multiply this cost, with up to 100% added when production losses are taken into account. Labour and mate-rial are the highest costs, while the machine investment cost is low when utilization is high, with a large number of bits to be ground.

Diagram 1: Typical bit life grinding at different intervals.

The Secoroc Grind Matic BQ2 grinding machine can handle drill bits up to 127 mm in diameter.


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standard penetration rate throughout its entire life. It has also been shown that bit life is increased considerably when grinding wheels are used, rather than grinding cups. Wheels also excavate steel around the button, simplifying the grinding task, and giving the bit a more exact profile.

Bitlife

With so many parameters involved, it is difficult to estimate bit service life. First, a proper grinding interval must be established, preferably at the stage when the button has a wear flat of one third of the button diameter. When

the number of drilled metres to reach this stage has been established, then a calculation of bit life can be made, by multiplying by the number of times it can be reground. As a general rule, a bit can be reground 10 times, but smaller bits may achieve slightly less than this figure, while larger bits may achieve more. So, if the grinding interval has been established as 60 drill metres, then the average bit life will be 660 drill metres (diagram 1). If a bit is overdrilled, and the wear flat is more than half of the button diameter, there is a tendency towards cracked buttons. There is always a sharp edge created on the button, and this becomes sharper the more the bit is overdrilled. This sharp edge, especi ally on ballistic buttons, is very brittle. Once the edge cracks, pieces of cemented carbide break away and circulate in the hole, causing secondary damage to the but-tons.

When a bit doesn’t show any vis-ible wear flat, it may be suffering from micro cracks on the cemented carbide surface. This is known colloquially as snakeskin, and can be clearly seen when using a magnifier. In this case, the surface has to be ground away, oth-erwise the micro cracks lead to more severe damage on the buttons.

Likewise, buttons which protrude too much must be ground down to avoid damage (diagram 2).

Penetrationrate

When the right bit has been chosen for the rock condition, it will provide maximum penetration rate, along with acceptable hole straightness. In rock conditions like Swedish granite, with a compressive strength of around 2,200 bar, the bit gets a wear flat after just 10-20 drill metres, accompanied by a small drop in penetration rate. When it has a wear flat equivalent to one-third of the button diameter, the penetration will have dropped by 5%. If the bit is used further until it has a two-thirds wear f lat, the penetration will have dropped more than 30% (diagram 3). When a bit has a heavy wear flat it tends to deviate, and, by the time it reaches the bottom of the hole, it will have devi-ated far more than planned. As a result,

Diagram 2: Risk of total loss when a bit is overdrilled.

Diagram 3: Penetration rate drops as the button profiles flatten.


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the blast will produce coarse fragmenta-tion, and much secondary blasting may be required.

In slope hole drilling, it is of utmost importance that the holes are straight. If the holes deviate, the slope walls will be uneven, making rock reinforcement more difficult than expected.

Rock formations with different layers and joints are often characterized by heavy hole deviation, putting extra stress on the remaining rock tools in the drillstring. A sharp bit always cuts better, and will prevent both deviation, and its disadvantages.

grindingmachines

Two parameters guide the selection of the right grinding machine: the number of bits to be ground; and whether the machine should be portable or station-ary. Several kinds of grinding machines are available to satisfy these parameters. In most cases, a simple machine will suffice for a small operation, grinding only a few bits.

The semi-automatic machines are more suitable for larger operations, such as mines and construction sites, where the machine can be stationary, and the rocktools can be brought to it. Secoroc Grind Matic HG is a water or air-cooled handheld machine for grinding cups. Both spherical and ballistic cups are available. The machine is driven by up

to 7 bar compressed air, and is suitable for a small grinding operation.

Secoroc Grind Matic Manual B is an air-driven portable grinder using diamond-coated grinding wheels for spherical and ballistic buttons. The machine is mounted in a box fitted with wheels and handles for easy set up. It is mainly for threaded button bits, but small down-the-hole bits can be ground in this machine. A steel spring is mounted in the profile of the grinding wheel, where it functions as a centring device, allowing for easy grinding.

Secoroc Grind Matic Manual B-DTH is similar to the Secoroc Grind Matic Manual B. It is mainly intended for down-the-hole bits and COPROD, but

can also be used for threaded bits with a special bit holder. As an optional acces-sory, the machine can be equipped with a belt grinder for gauge grinding.

Secoroc Grind Matic BQ2 is the latest semi-automatic machine, with many features such as auto-indexing device, timer control, automatic feed, and an automatic centring arm. These features, coupled to an ergonomic design, ensure high productivity, and the machine is designed to handle large volumes of threaded button bits. Cooling water is recycled after the waste pro-duct has been separated in a container. Secoroc Grind Matic BQ2-DTH is the latest grinding machine for mainly down-the-hole and COPROD bits. It

Cost of grinding reduces dramatically with volume.

Annual grinding volume – buttons.

Figuresontheleftsideofthediagram

showcostperbuttoninSEK.

9

8

7

6

5

4

3

2

1

0

Labourcost

Grindingmaterialcost

Machinecost

500

0

1000

0

2500

0

5000

0

7500

0

1000

00

Diamond grinding wheels. Secoroc Grind Matic Manual B.


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can also be used for threaded bits with a special bit holder. The machine has the same features as Secoroc Grind Matic BQ2, and can grind bits up to 180 mm (7 in) diameter.

grindingadvice

The Secoroc Grind Matic machine’s secret of success is that both the grind-ing table and the diamond grinding wheel rotate. The result is perfectly ground button surfaces, regardless of whether the buttons are spherical or ballistic.

In addition, the machine’s unique diamond grinding wheel is designed to ensure even wear on its grinding surface, while still retaining its profile. This, in turn, guarantees the button shape throughout the life of the wheel.

Secoroc’s advice is to use Secoroc Grind Matic grinding machines, with profiled diamond grinding wheels, for grinding button bits. It is the only solu-tion able to consistently deliver perfect-ly shaped buttons on customers’ bits.

Correct grinding is important for every drilling operation, particularly in these days of cost consciousness and fierce competition. It can make a world of difference to the bottom line.

BoPerssonComparison of grinding wheel with grinding cup.

Secoroc Grind Matic Manual B-DTH. Secoroc Grind Matic BQ2-DTH.


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Development

Atlas Copco Secoroc has gained extensive knowledge and experience of regrinding large volumes of button bits with stationary grinders, such as the Secoroc Grind Matic BQ2 and Secoroc Grind Matic BQ2-DTH. These, together with previous generations of si-milar grinders, have all used profiled diamond grinding wheels for working on spherical and ballistic buttons. However, onboard grinding machines have always been fitted with diamond grinding cups, which have proved to be less efficient than profiled diamond grinding wheels.

The new Secoroc Grind Matic Jazz grinder, which is equipped with profiled diamond grinding wheels, will consistently deliver the same perfectly shaped spherical and ballistic buttons after regrinding. This is increasingly important in relation to ballistic but-tons, which are becoming more and more popular.

SecorocgrindMaticJazz

The air-driven Secoroc Grind Matic Jazz helps optimize the performance

of the rock drill and drill string, without the bit leaving the rig. It is user friend-ly, is designed for economy of air consumption, and can easily be retro- fitted to most rigs in current use. It is delivered with an attachment for bol- ting on to existing rigs, which allows the operator to fold away the grinder when not in use. It will also be available through the sales companies as an option on new Atlas Copco drill rigs. To make the grinder ready for work, it is simply a matter of hooking up the air hose, connecting the electricity, and filling up the water tank for the mist cooling.

The low air consumption of the Secoroc Grind Matic Jazz makes it possible to grind bits without interrupt-ing drilling operations. The grinder is semi- automatic, and features an auto-matic centring device for placing each button in the correct position under the grinding wheel. An indexing bit holder is used for the gauge buttons, and there is a handy time relay for setting grind-ing time.

Secoroc Grind Matic Jazz is a very flexible grinder that will have a bene-ficial influence on drilling economy. It will grind spherical and ballistic buttons,

SecorocgrindMaticJazz

RigmountedgrinderIn today’s world of professional rock drilling, where ever more powerful drill rigs and hammers are used, it has become extremely important to give the drill string all the necessary care and mainte-nance needed if optimum drilling productivity is to be achieved. Regrinding the cemented car-bide buttons of the bit at proper intervals increases the service life of the whole drill string. This, in turn, helps maintain penetration rates, while ensuring that holes are drilled straight and true. Quick and efficient grinding of button bits in surface drilling applications, where the rig is con-stantly on the move from one job site to another, has been an elu-sive goal. However, Atlas Copco Secoroc has now come up with the solution, by developing a rig-mounted semi-automatic grinder. The Secoroc Grind Matic Jazz, equipped with a profiled diamond grinding wheel, achieves the same quality of grinding onboard the rig as that previously associated with static workshop models.

Secoroc Grind Matic Jazz for correct and professional grinding.


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on threaded or tapered button bits, as well as big DTH - and COPROD bits from 35 mm (13⁄8 in) to 254 mm (10 in) in diameter.

Grinding the button bit in a profes-sional way makes sense, because grind-ing accounts for only a fraction of the cost of the entire drilling operation.

When a drilling programme is carried on without correct service of the bits, drilling output and produc tivity will be significantly lower, and costs may escalate.

BoPersson

Secoroc Grind Matic Jazz

Technical Data

Airpressure,maximum 7bar(102psi)

Airpressure,minimum 6bar(87psi)

Airconsumption 25l/sec

Coolantcontainer 3l

Airtooloilconsumption 1.8cl/hour

Output,spindlemotor 1kW

Speed,spindle 15,000rpm

Voltage 24V

Weight,exclusiveofpacking 90kg(198lbs)

Transportdimension 800x500x700mm

Grinding Capacity

Maximumdistancebetweenbitholderandgrindingwheel 250mm(97⁄8")

Maximumdiameterofdrillbit 254mm(10")

Minimumdiameterofdrillbit 35mm(13⁄8")

Minimumdistancebetweenbuttons 3.5mm(9⁄64")

Button bits should be reground when the penetration rate drops, or if any of the cemented-carbide buttons are damaged (fractured buttons should be ground flat). It is both practical and economical to redress the buttons when the wear flat reaches about 1/3 of the diameter of the button.

lookoutfor“snakeskin”

Donotgrindawaytoomuchcementedcarbide

alwaysgrindbrokenbuttonsflat

avoidgrindingthegauge

If microscopic fatigue cracks – so called “snake skin” – begin to appear on the cemented carbide buttons, the cracks must be ground away. In any event, bits should be reground after 300 metres of drilling at the most. This should be done even if there are no visible signs of wear and the penetration rate continues to be good. If snake-skin is not removed, the cracks will deepen and ultimately result in button fracture.

Do not grind too much on the top of the buttons. Let a few millimetres of the wear flat remain on top of the button.

A drill bit can remain in service as long as the gauge but-tons maintain the diameter of the bit. Fractured buttons must always be ground flat to prevent chips of cemented carbide from damaging the other buttons.

If necessary, remove some of the bit-body steel below the gauge buttons, so that a clearance (taper) of 0.5 mm is maintained. If the flushing holes start to deform, open them up with the aid of a rotary burr or steel file.

Whentoregrind

1

Gauge button anti-taper has to be removed by grinding, although excessive reduction of the bit diameter should be avoided. Leave about max 1 mm of the wear flat.

grindinginstructionsforbuttonbits

Secoroc Grind Matic Jazz can easily be set up on the drill rig, here the Grind Matic Jazz is ready for grinding.


SWeDen,COPPeRMiningaTaiTik

aitik36ontrack

New Boliden, Sweden’s major inte-grated non-ferrous mining and metals producer, is the third largest copper metals supplier and the third largest zinc metals supplier in Europe. The com-pany operates primary zinc production facilities at Kokkola in Finland and Odda in Norway, a copper smelter and refinery at Harjavalta and Pori in Finland, and the Rönnskär complex at Skelleftehamn on Sweden’s Baltic coast, which treats various concentrates and scrap to yield refined copper, lead, precious metals and zinc clinker. The largest supplier of copper concentrates to Rönnskär is Boliden’s Aitik open- pit mine near Gällivare, 400 km by rail from Skelleftehamn. The Aitik 36 project is designed to keep this feed stream cost competitive. “The invest-ment will make Aitik one of the most efficient mines in the world, and will substantially improve its competitive-ness. This will, in turn, generate the preconditions for healthy profits and cash flows in the future,” says Boliden s President and CEO Jan Johansson at the time the project was approved.

When Boliden started mining at Aitik in 1968, it was one of the world’s first large, very low-grade ore copper mines to be developed in a high-wage econo-my. As well as utilizing the most cost- effective technology available, Boliden has raised capacity on several occa-sions in order to contain concentrate

production costs. Aitik 36 is by far the largest of these expansions. From an ini-tial 2 Mt/y the company had raised ore production and treatment capacity in stages to 18 Mt/y by 1998; by 2012 the present project will take it up to 36 Mt/y. Aitik 36 involves a largely new in-pit crushing and conveying system and a completely new state-of-the-art concen-trator facility that will replace the exist-ing one after a short period of combined operation. The new facilities are sched-uled to start up in 2010 and, although Boliden has reduced copper production this year in response to market condi-tions, the company has kept Aitik 36 on the original time track, good news for the several companies supplying and/or working on the project.

There has been no major new ore di- scovery and this massive expansion will not necessitate development of a new mine at this stage. What mainly made the expansion feasible was a new state-of- the-art and larger scale concentrator,

which will be able to improve the operation’s economics while treating even lower ore head grades than the 0.44 per-cent copper, 0.22 g/t gold and 3.61 g/t silver that Aitik milled in 2005. Helped by positive exploration results in the pit area, this new parameter tripled proven and probable reserves from 219 to 630 Mt. As of December 2006 proven ore reserves totalled 520 Mt, grading 0.29 percent copper, 0.2 g/t gold and 2.0 g/t silver, while probable reserves were 110 Mt and the overall resource stood at approximately one billion metric tons. The ore available also includes recover-able amounts of molybdenum. Boliden initiated the Aitik 36 Project in 2007.

At present the open pit is 3,000 meter long, 1,100 meter wide and 405 meter deep. However, to achieve the necessary ore extraction rate, Aitik must cut back the mine boundary in a numberof places, including the area where someof the office and workshop facilities are located. This, in conjunction with the

BolidenmineseconomiesofscaleDoublingcopperoutputTo maintain cost-effective copper production Boliden AB is under-taking the Aitik 36 project. This will double concentrator capacity at the Swedish operation and re-quire a proportionate increase in mined ore output. Atlas Copco is supplying a fleet of four Pit Viper PV-351E drilling rigs, two of which are already operating.

The Aitik 36 project will raise ore production from 18 Mt/y in 1998 up to 36 Mt/y by 2012. The investment will make Aitik one of the most cost-sefficient mines in the world.

BOliDenMineSeCOnOMieSOFSCale


age of some of the machines in use at the time, has required a considerable outlay on new mining equipment. Boliden undertook a thorough evalu-ation of the options for this purchase program in 2007.

SwitchingtoatlasCopco

This exercise led the Aitik mine man-agement to increase loading and haul-age capacity by buying new models from the companies that had supplied the existing fleets. But, when it came to drilling rigs, the evaluation persuaded Boliden to switch manufacturer.

Like the rope shovels and the hydraulic excavators in use, the drill rigs would use the mine’s electric power supply network. In deciding how to replace the four electric drive rotary head rigs then in use with four new ones, Boliden’s criteria also included the ability to sin-gle pass drill 311-mm diameter holes to a depth of at least 19 meter. In addition, Aitik looked for good built-in safety and productivity enhancing features such as finger-tip joystick controls, programmable automatic drilling modes, GPS-based hole navigation, an opera-tor-friendly cabin, ease of raising and lowering the tower for tramming, and the ability to drill angled holes.

With an operating weight of 185 tonns and offering single-pass drilling to 19.8 meter and hole diameters from 270 - 406 mm, the electric version of the hydraulic drive rotary head Pit Viper (PV-351E) that Atlas Copco offered ticked Boliden’s boxes. This was not a new model; several of these rigs had been supplied to customers in South Africa and Chile. However, it did now have Atlas Copco’s Rig Control System technology with touch screen in-cabin display and a choice of three automatic drilling modes, plus the manufacturer’s Rig Remote Access system for main-tenance problem-solving. Accesses are safe and four cameras that display dif-ferent views on a screen in the cabin provide good visibility where there is no sight line. In particular the 45-foot tower can be lowered in a few min-utes, enabling much quicker relocation times than some competing rigs can achieve. The up to 30-degree angle drilling option is relatively expensive

Boliden undertook a thorough evaluation before deciding to invest in four new Pit Viper 351E rotary drill rigs. Boliden’s criteria included the ability to drill 311 mm holes to a depth of 19 meter. In addition they looked for safety and productivity enhancing features.



but Aitik calculated that having it fitted to just two of the four rigs would achieve the degree of operational f lexibility required. A very significant factor was that the operators participating in the different evaluation tests endorsed the joystick control system, said Patrik Gillerstedt mine manager.

During 2008 Boliden and Atlas Copco started to prepare for the staged delivery of the PV-351E rigs. Technical s,upervisor Stefan Kuoppa, who has been with Atlas Copco since 2001 and is normally based at the Atlas Copco CMT Sweden branch in Kiruna, vis-ited the ADS headquarters in Garland, Texas for intensive training on the assembly and maintenance of the rig. He moved into Aitik during November 2008. Two Boliden operators spent almost three weeks in Garland to famil-iarize themselves with the rig, and Atlas Copco has also trained present Boliden operators to train new ones.

The first two units – the ones fitted with the angle drilling option – were delivered to the mine on several trucks, and assembly of the first Pit Viper was completed in January 2009. Kuoppa’s local Atlas Copco team worked with Aitik engineering personnel under the

guidance of ADS experts from Garland. Not surprisingly assembly of the second rig took a good deal less time than the first. The rigs are maintained by Aitik staff, supervised by Stefan Kuoppa who commented that they had not experi-enced any significant problems when working on the Pit Vipers.

When we visited Aitik, Stefan Kuoppa and Emil Nyström had recently started work on the third Pit Viper with the Aitik technicians, but without any staff from the United States. The team was ready to lift the tower into place. Emil would supervise the job while Stefan went on vacation.

hands-onexperience

At Aitik, Boliden divides the produc-tion drilling workload between a major Swedish contractor, NCC Roads, and its own drilling team. NCC does the presplit drilling with a fleet of Atlas Copco ROC L8 DTH rigs and Boliden does all the rotary blasthole drilling.

For bench blasthole drilling the typical hole spacing is 7-by-9 metres and the rigs drill 200 – 300 holes for a blas-ting round designed to yield around700,000 tons of rock. Orica is contracted

to charge each hole with about a ton of Fortis Advantage emulsion explosive. The constituents are stored in Gällivare and mixed at the mine. The explosive is delivered and charged by purpose-built truck. Drilling patterns are transmitted from the mine office to the Pit Vipers using the mine’s W-LAN network but Aitik intends soon to use the Minestar system installed in 2007-8.

By early July the first PV-351E to be assembled had been working for 2,100 hours and the second for nearly 1,400 hours. Drilling with the Pit Viper is a one-person operation but the operator of a hired-in wheel loader does the cable shifting when moving between benches. As well as the Atlas Copco rig being very heavy and very large (16.4 meter long, 8.1 meter wide and 31.4 meter high with tower up), the hydraulic drives, cable feed system and rig control tech-nology make the PV-351E quite differ-ent to operate from the rigs already in use. Nevertheless, according to driller Gerd Martinsson, the PV-351E is rather easy to handle. She has been working at Boliden since 1995, and as a drill operator for the last three years.

Even more experienced is Johnny Holmlander, one of the Aitik operators

The PV-351 could offer features like finger-tip joystick controls, a comfortable cabin, ability to drill angled holes, and ease of raising and lowering the tower for tramming.

The typical hole spacing for the PV-351E is 7 x 9 m, drilling vertical holes to a depth of 19.5 m using two 9.9 m drill pipe in a single pass.



who visited Garland for training. He has been drilling for 34 years and has worked at Aitik since 1979. We joined him in the cabin as he was about to navigate the PV-351E close to the bench edge, ready to drill Hole 72. Equipped with two 9.9 meter drill pipes and 311-mm bit, the Pit Viper was to drill

this hole to a depth of 19.50 meters in a single pass. Holmlander commented that more typical depths were in the 17 – 18 meter range. He explained that the rig can drill at a penetration rate of 40 cm per minute in the upper part of this bench but the rate can drop to 9-10 cm/min in the harder rock types at Aitik. The operator’s sight lines to the tower and drill table unit are good, and the automatic drilling modes work very well in consistent rock, as well as the auto leveling feature that reduces wear and tear on the machine structure. The bit diameter is around 1,000 m, he said.

Meanwhile, NCC Roads, a contract driller working at the mine, ordered two new ROC L8-30 Mk II rigs, which are currently up and running at the mine, replacing older rigs. The Atlas Copco ROC L8 does not have the RCS system yet, points out Stig Fredriksson, the sales engineer based at Atlas Copco CMT Sweden branch in Luleå. But he hopes that when Aitik production is

running at 36Mt/y ore there will be more L8-30 rigs at the mine, and they will probably have the RCS-system.

Futureoptions

So far, Patrik Gillerstedt says, he is sat-isfied with the PV-351E rigs’ progress. Now that Aitik management and opera-tors have a clear idea of the PV351’s capabilities and characteristics in operation, they are assessing the possi-ble use of further technical options that are available, such as auto tramming, and teleremote control.

Meanwhile, Boliden is planning development of a new supplementary open pit, Salmijârvi, a short distance southeast of the present Aitik pit.

acknowledgements

Kyran Casteel, a contributing editor for Engineering & Mining Journal and Coal Age, visited the Aitik mine in July 2009.

The drill rigs drill 200 – 300 holes for one blasting round and the penetration rate can vary between 0.4 m/min in the upper part and 0.1 m/min in the harder rock types. Orica is contracted to charge each hole with about a ton of Fortis Advantage emulsion. Drilling patterns are transmitted from the mine office to the Pit Vipers using the mine’sW-LAN network.

The Atlas Copco RCS touch screen in-cabin display.


USa,BUTTe,MT

Thecontinentalpit

Today, many cities that saw their rise in the late 19th century offer a skyline of Victorian architecture and brick high rises, but not many also have head frames jutting out amidst their skylines. In its heyday, Butte’s population was nearly three times its current size, num- bering over 100,000 inhabitants. Every-one was focused on building fortunes in a growing metals market or offering services to the mining industry.

A dozen antique head frames now mark the former underground activ-ity, like monuments to an unforgotten period of history. One of the country’s leading mining institutions, Montana Tech at the University of Montana, still keeps a decline active so tomorrow’s geologists and engineers can learn from the past.

Underground mining ceased in 1975 and large scale open-pit mining began in 1955 with development of the Ber-keley Pit, which closed in 1983. The Continental Pit opened in 1980 and is currently 7,320 ft long, 3,640 ft wide and 380 ft deep. Projected dimensions are 8,000 x 6,000 x 800 ft.

Mining in Butte today takes on a very different look. Montana Resources bought the property from Atlantic Richfield in 1986 and reopened the Continental Pit. The company stopped mining in 2000 due to high electricity costs and resumed in 2003.

From 1986 to 2006, the Continental Pit has given up 1.4 billion pounds PV271's team up to quickly finish holes on a blast pattern.

PitVipersbeatthechillPitVipersfitforcoldclimateThe city of Butte, MT, was once one of America’s biggest mining regions. Named "the richest hill on Earth," its underground opera-tions eventually extended to some 12,000 miles of drifts. Today it is the Continental Pit mine that do-minates the landscape and, since 2005, two Pit Viper drill rigs that feed production.

PiTViPeRSBeaTTheChill


of copper and 163 million pounds of molybdenum from 285 million tons of milled (dry) ore.

According to Wikipedia, from 1880 through 2005, the mines of the Butte district have produced more than 9.6

million tons of copper, 2.1 million tons of zinc, 1.6 million tons of manganese, 381 thousand tons of lead, 87 thousand tons of molybdenum, 715 million troy ounces of silver, and 2.9 million ounces of gold.

acityonahillFrom the top of the west ridge, on the impressive campus of Montana Tech, one looks out to a grand view of a city that slides away to the valley below. The active Continental Pit nips at the city’s edge, cresting at the far eastern ridge. As the older Berkley Pit grew over the years and the city has shrunk in population, hundreds of homes have been sacrificed to the growth of the mine.

On a daily basis, 102,000 tons of rock are mined from the pit with 52,000 tons of ore milled. To keep the three shov-els and 170- and 240-ton haul trucks moving, Montana Resources uses two Atlas Copco Pit Viper Series PV271 drills, which were acquired in May of 2005 to replace four older drills.

In the past Montana Resources had used electric drills, but because diesel provided mobility and convenience with no electric power cables, “the decision was made to purchase diesel drills,” says Gary Hayes, maintenance supervisor for Montana Resources mobile fleet.

“They’ve done really well for us,” says Hayes. The availability for the month was at 94 percent, with year to date being 85 percent. The goal for availability is 90 percent, but staying ahead of the shovels is what counts.

Coldpackage

Because cold is an issue in Montana, the mine has had to make accommo-dations for the weather. Each drill is outfitted with a 40 kW generator to run the cold package, which includes heat blankets and heaters for the hydraulic tanks, batteries, separator tank …etc. The engine is kept warm when not in operation with a ProHeat system. The mine is currently in the process of rout-ing engine exhaust through the water tanks to keep the drilling water from freezing during the winter. Previously alcohol was used as freeze protection but as costs rise, the mine wants to utilize the drill’s spent energy to keep costs down.

“The key is to keep going,” says Hayes. Shutting down means heating up the system to get started again.Cold package solution with heater blanket mounted on air receiver tank.

From left, Gary Hayes and Clint Byington discuss outfitting the rig with tank heaters.



growingthemine

Montana Resource’s driller Brian Lankford likes operating the PV271, commenting on benefits such as how the speed of the bit can be changed and about the drill’s maneuverability. “Having no cable is a plus, but simply turning it is better with this drill,” says Lankford.

“Changing the bit and bushing takes about 22 minutes with this drill. Our old drills took three hours,” explains the operator. The mine bench where this PV271 is working is seven holes wide with 22 ft x 22 ft spacing. The bench is

over a hundred yards long with holes 48 ft deep. Lankford says the rock nearest the high wall is harder, taking 28 minutes to drill the 9⅞ inch holes. But further out, holes take as few as 12 minutes to drill.

Staminaandlongevity

Since the drills went into production in 2005, they have had few issues. The first drill is due for a complete rebuild in December. “If you run a piece of equipment 24/7, things start wearing out,” the operator remarks. “We have had no structural issues, as of yet.”

Montana Resources works closely with their dealer, Modern Machinery, which keeps a complete supply of parts to cover any standard issue. Hayes says they really rely on Modern Machinery. “Modern has a couple guys who can walk right to a problem if there is one, and they have done a great job working with our guys to educate them on the drills,” says Hayes.

“When we reopened in 2003, 70 percent of our employees were new to mining,” states Hayes. “We put six guys with Modern technicians and had class-es to educate them on the maintenance and operation of the drills.”

Once called the “richest hill” on Earth, mining is showing no sign of slo- wing around Butte. Although there are 12,000 miles of underground mine wor-kings under Butte, it is up to Montana Resources to change the landscape of Butte, and the PV271 is a big part of that future.

acknowledgements

This article first appeared in Atlas Copco Mining & Construction maga-zine No 3 2007. Story and pictures by Scott Ellenbecker, Ellenbecker Communications.

Drilling on the Continental Pit in Butte, Montana.

Brian Lankford finds the control console easy to monitor in order to make adjustments.



Brian Lankford takes measurements of a 9 7⁄8-inch hole to 28 feet deep.


USa,elkO,neVaDa

Productdevelopment

Atlas Copco has a creed that is stated in most internal and external commu-nications. “We are committed to your superior productivity through interac-tion and innovation.” These are not just marketing words tossed about lightly, but rather a promise of conviction to each customer. However, unlike most marketing statements recited to customers, this statement is also a reminder for employees as to why they are here and what makes Atlas Copco better.

If you have looked at purchasing a PV-271, you may have met or talked with Jim Owen. Atlas Copco’s Western US district manager, Jon Torpy, said that just about every company that has purchased a PV-271 in the United States, and several outside of the US, has first visited with Jim Owen about the drill. “Jim has been a great resource for other mines dealing with similar drilling conditions.” For Barrick Goldstrike, Owen is an important part of the rig’s daily operation. Owen said, “I’m re-sponsible for everything below the tophead: shocks, subs, steel, bits, bush-ings, and preventative maintenance on the drills – whatever is needed. I just keep the drills moving.”

Barrick’s Goldstrike mine has four PV-271 rigs and holds claim to the first PV-271 ever built. “After 27,113 hours, two compressors and two rotary heads,”

Owen said, “it is still our best perform-ing rig with no cracks in the tower or frame. Where it counts, all is good.” Since it arrived at the mine in 2004, the original rig has been problem free. Other than the replacement of wear items and preventative maintenance, “the first rig went to work the day it was taken off the lowboy and has been drilling ever since,” said Owen.

To put that in perspective, that’s a whopping 58,856 holes for a total of 2,671,217 drill ft. Over that period of time the PV-271 has had an average penetration rate of 199 ft per hour. “The rate has stayed constant over the life of the rig, faster when starting a layback and reducing when we go deeper,” said Owen.

Owen is impressed with component life, too. On the first rig he got 10,000 hours totaling 1.2 million drilled feet on the first rotary head and so far 17,000 hours on the second rotary head. Design has had much to do with this. “I really like these drills,” said Owen, emphasizing his personal reason that, “they save me so much work!” He com- plimented the rig’s smooth operation stating, “It is even easier on bits because not having to add a rod, there is no air loss which sometimes results in back reaming.”

One of the features that Owen really likes is the Automatic Tensioning Ad- justment for the cables. “As you drill the cable stretches and slackens up. With a smaller drill you’re manually adjusting

After consulting with customers, Atlas Copco developed the PV-271 to meet their requirements to increase productivity in open-pit, hard rock mining.

innovationthroughinteractionFirstPV-271everbuiltWhen the Pit Viper 271 drill was developed, Atlas Copco’s engine-ering and marketing staff worked closely with customers to design a rig for greater efficiency when the truck and shovel mining me-thod is used. Jim Owen works at Barrick Goldstrike Mine near Elko, NV. He is not a driller or mechan-ic, but his day-to-day responsi-bilities give him the experience to know the PV-271 better than just about anyone.

innOVaTiOnThROUghinTeRaCTiOn


about once a month or so,” said Owen, who is glad this is not necessary with the longer cables on the PV-271. The task of manually adjusting the tension requires lowering the tower which takes time. With the automatic tensioning feature on the PV-271 the work is done automatically.

interactionfromthebeginningThe PV-271 was developed to increase productivity in open-pit, hard rock mining. Not only was the entire drilling process examined, but also how it fit with mining operations as a whole. To ensure they hit the mark, Atlas Copco turned to Goldstrike and worked clo-sely with the Goldstrike operations team, which included Jim Owen. Interacting with Goldstrike and other customers during the development of the PV-271 ensured that Atlas Copco developed a drill that met the mining industry’s exact requirements, not just what they THOUGHT was required. For Goldstrike

that meant the drills needed op-timum footage, but they also needed to drill to the shovel’s optimum perfor-mance. “A 50-ft bench would work great for the shovel, but this size drill is per-fect with a 40-ft bench,” said Owen.

Increasing the footage rate was a result of completing a full hole without adding or removing drill steel. Effi-ciencies came with more time over the hole and reduced setup and tram-ming time. Goldstrike uses two 25-ft steel and one 10-ft sub for a total of 55-ft. Including the ground to rotary head space when jacked up, this gives Goldstrike the required 40 to 46 ft of clean, straight hole.

Production drilling at Goldstrike is done with 9⅞- and 8¾- inch bits for trim and presplit work. Owen said, “We changed the breakout wrench because the drill was designed for 7⅝- inch pipe, but we use 7-inch pipe because it’s a better fit for the 9⅞- and 8¾- inch bits – and it’s also cheaper.” Pipe could be an expensive item but because they are not making connections, drill steel

lasts them about eight months. He said when they are finished with the pipe, there is nothing wrong with it other than its diameter is reduced. The wall thickness on the bottom of the 10-ft sub is 2½ inches for extra strength above the bit.

Owen said he doesn’t know a guy who would complain about the PV-271 – including drillers and mechanics. “Mechanics can be intimidated with electronics over hydraulics, but it’s so much easier to work on. And once a guy works on it, they find it’s better, not much more difficult than the wiring on your boat trailer,” he said with a chuckle.

“I have no problem bragging up the PV-271,” said Owen. “It’s faster, more reliable and the factor of safety…every-thing just came together on this rig.” When talking about the rate of drilling, Owen said, “I’ve seen one driller get 5,500 ft in one shift.” Today Goldstrike is all rotary drilling with a tricone bit. Owen said, “13,000 ft on a bit is not uncommon and hammer drilling isn’t necessary.” Because the rigs at Gold- strike use tricone bits, a 1900 cfm 110 psi low pressure compressor is all that is needed. Many compressor options are available on the rig, depending on the type of drilling.

“Innovation through interaction” are big words describing how the PV-271 came to be. It was mostly guys who use drills sitting down with guys who make drills and saying, “We need a drill that is perfect for what we do.” For those at Barrick Goldstrike, that started with a hole size, required depth and a need to mine gold more efficiently. A couple of years ago, Goldstrike reached a mile- stone of 30 million ounces of gold mined. “That’s the largest gold removal from any one pit in the world and we’ve mined a couple million since then,” commented Owen. So it’s safe to say the PV-271 is doing its job.

acknowledgements


Jim Owen, Drill Supervisor, plays an important role in the rigs' daily operation and is responsible for everything needed to keep the drills moving.


USa,BaTTleMOUnTain,neVaDa

hammerdrillingwithPV-271Mine manager Mark Evatz said, “Any-thing that touches Phoenix rock wears fast. The rock fights back here. The Pit

Viper is big and bad and can take it.” Evatz is talking about Atlas Copco’s Pit Viper 271 (PV-271) blasthole drill. Because of the hardness of the rock, drilling at Phoenix requires hammer drilling and the mine uses tough Atlas Copco TD65 hammers with 6¾-inch bits. The mine’s PV-271s are outfitted with a single 1450 cfm, 350 psi oil-flooded air compressor.

Phoenix has six Atlas Copco PV-271 drill rigs plus an Atlas Copco DML and a DM45 midrange blasthole rig. The mine’s goal is to keep four million tons of muck in inventory to stay ahead of the shovels and support needed operational flexi-bility (ore control related).

Drilling efficiency has been a con-tinuous point of improvement since operations began at the mine. The single-pass depth capability of 55 ft (16.5 m) on the PV-271 helped with that. Origi-nally, the plans called for 20-ft bench heights, supported by 23-ft drill depths, but time spent moving from hole to hole was eating up productivity. Drilling on

that plan resulted in drilling an aver-age of 47 ft an hour. When depths were changed to 44-ft drill depths, support-ing blasting of 40-ft benches, they were able to utilize the single pass capacity of the PV-271, and performance increased to over 60 feet an hour. Although the drill depth change largely supported the improvement, other aspects of continuous improvement associated with increased knowledge of the Pit Viper drills helped as well.

“We are below our budgeted drill costs,” said Evatz. “This is partially because the best cost- per- foot comes from hammer drilling when in hard rock.” Pat McAmis, maintenance planning general foreman, concurred with this. “You can try to put more drills on the bench, but space and costs don’t make that practical.”

The mine focuses on maximizing blast-induced fragmentation while maintaining the integrity of the ore zones (minimal dilution). Although the crusher can handle 30-inch boulders,

Unforgivingground

improvementandteamworkarethekeystosuccessatPhoenixMineThe formation in Newmont’s Pho-enix Mine near Battle Mountain, NV, contains high levels of abra-sive quartzite but also contains precious gold, copper, and silver. Newmont started mining opera-tions at Phoenix (formerly Battle Mountain Gold) three years ago and the planners knew they were working with a challenging geo-logical formation. But as it turned out, it was more challenging than anticipated.

Biting through the hard and abrasive quartzite in the Nevada desert, the single pass Pit Viper 271 gives the Phoenix Mine a clean, 45-ft hole.

UnFORgiVinggROUnD


McAmis said, “The goal is to maxi-mize what you’re digging – keeping a methodical approach.”

At the Phoenix mine, “drills are top priority machines and we mine to feed the mill,” said McAmis. He is pleased with the performance of the PV-271 and has no major concerns, complimenting the support from Atlas Copco and his distributor, Cate Equipment. “We’re all in it to make money and you have to be fair, but I would say we work well together.”

DaytodaycontactDrill operator Clinton Riddle started in mining in 1976 and has seen a lot of technology advancements over the years. “For me, things really started to change the last couple of years.” He cited that these advancements include the speed of drilling with air, computerized con-trols, and automation on the rigs.

Depending on the formation and area of the mine, Riddle said a 45-ft hole can take 5 to 45 minutes. As he drills, he watches his computer monitor, which tells him the hardness of the rock, the drilling rate, and performance statis-tics such as time per hole, torque and rotation. The color-coded block on the right of the screen shows red for harder rock formation and yellow or green for softer formation. This helps him antici-pate what changes may be required in the hole. He said the color bar is nice to have, but it’s still just a guide.

Riddle said the average shift com-pletes about 18 45-ft holes, but there are some eight- to 12-hole days and he’s seen as many as 50 a day. Atlas Copco’s Western Region manager, Jon Torpy, has been in mines all around the world. About the rock at Newmont, Torpy said, “We, as Atlas Copco, have only seen a handful of locations that have the difficult drilling conditions found at Phoenix,

and the PV-271, coupled with the TD65 hammers, are the best tools for the job.”

Maintenance superintendent Walt Holland is responsible for the entire mine’s equipment maintenance at New-mont’s Phoenix Mine. He said that he looks at mining equipment like a three leg stool – drills, shovels, trucks – and all have to be working to keep things moving. Because of the hardness of the rock, “drill maintenance is very impor-tant at Phoenix,” said Holland. Other Newmont properties may drill 120 to 130 ft an hour, but at Phoenix, they are now up to 60 ft per hour. “The rock hardness at Phoenix is unique to the world,” he pointed out. “What I like about the Pit Viper rig is its quality. I am getting 92.5 percent availability and that is really good.” The operators were given additional training required for the single pass rig and they feel very com-fortable operating them now. “We have a great history with Atlas Copco and have worked right through any issues that have come up,” Holland said.

In recent months, productivity at Phoenix has increased and Holland credits this in part to good communica-tion between operations, maintenance, and engineering. “Phoenix is success-ful because we don’t get conflicting missions. We work well together and challenge each other. The ground is unforgiving at Phoenix and it takes a team approach to be successful. When mechanics and operators are talking, you know you’re winning,” he said with conviction.

Mark Evatz echoed this sentiment. “There had to be a steep learning curve at Phoenix,” he said. Since operations began, the most recent quarter was the best at Phoenix from an operation standpoint. “More revenue at a reduced cost has had a lot to do with technol-ogy and the application of the Pit Viper rigs,” said Evatz.

For Evatz, continuous improvement is a large part of the success at Phoenix. “We had 96 of 100 points right when we started up Phoenix,” he said. A lot of the original planning decisions came from the best practices used at other Newmont Nevada mines, such as the Lone Tree Mine. “We looked at the hardest rock at Lone Tree as a comparison

Single pass drill of 40-ft benches with PV-271 rigs.

UnFORgiVinggROUnD


when beginning operations. Basing equipment estimates and mining prac-tices on Lone Tree’s numbers, our drill production was half of Lone Tree’s,” Evatz said. For another equipment example, Evatz said dozer grousers require replacement three to four times faster at Phoenix than Lone Tree. Although the overall mining rates were comparable at ~150k tons per day, the rock hardness/abrasion at Phoenix is substantially greater.

Major consumption items such as down-the-hole hammers and bits are a large ticket item when hammer drilling, but necessary in very hard rock. The mine uses about a dozen TD65 ham-mers a month and hundreds of 6¾-inch bits. To maximize performance, Atlas Copco has placed a full-time Product Support Sales Representative (PSSR) in the mine to support and develop the use of consumables. His responsibili- ties include everything from evaluat-ing bit and hammer performance, maintaining hammers, and sharpening bits to flipping a casing in order to maximize hammer life. Jim Wheeler, Atlas Copco senior area manager for consumables in the Intermountain Region, said, “Having someone on-site is all about continuous improvement.” An example of this was a recent insert change on the 6¾-inch hammer bit’s gauge row, which has increased bit performance. Having someone there watching the performance of all consumables ensures that all pieces are working together, reducing drilling costs and improving productivity.

Maximumproductivity

The TD 65 is a robust, high-powered down-the-hole hammer designed for maximum productivity in combination with large drill rigs. At Phoenix Mine it is equipped with 165 mm (6¾ in) button bits but will also take bits up to 216 mm (8½ in). The TD 65 also ranks as the most powerful hammer on the market,delivering 2,160 blows per minute at the maximum air pressure of 30 bar (435 psi). Jim Wheeler, Atlas Copco’s senior area manager, said it was chosen for its high penetration rate and that it has been living up to expectations since delivery. “The hammer has been

in daily operation since the Pit Viper arrived at the site and everything is going well. We are getting a penetra-tion rate of 60 to 180 feet (20-50 m) per hour.”

About 150 bits are used per month, and in these extraordinarily abrasive conditions, regrinding is not considered an option. However, in order to reduce bit consumption as much as possible, Secoroc has changed the carbide in the buttons to a tougher grade. Wheeler said, “Back in 2007, Newmont Phoenix was testing several hammer and bit manufacturers. They chose us becauseour equipment drills faster and lasts longer. They also agreed to use only Secoroc consumables on the under-standing that we would take the respon-sibility for the on-site service and maintenance. The mine is very positive to this arrangement and definitely sees the benefit of this kind of service.”

At the site, Tony Silva, who is re-sponsible for stocking the spares and rebuilds the hammer when required, uses the Secoroc rebuild kit to replace the backhead, hammer case and chuck.

Other hammers previously used at the site did not stand up as well to the abrasive conditions, particularly the outer parts which are usually the first to wear down. However, on the TD 65, the backhead, hammer case and chuckare all designed using a thicker mate-rial. Replacement parts are required.

In addition, the TD 65 has a revers-ible hammer case so when the lower end becomes worn (most of the wear occurs from the bottom up), it can simply be disassembled, flipped over and drilling can continue.

Atlas Copco estimates that the ham-mer can normally be rebuilt two to three times before the outer parts need to be

A PV-271 coupled with TD65 hammers have proven to be the best tools for the job.

UnFORgiVinggROUnD


replaced. Other features designed to give increased productivity include a special “hardbody” chuck, a patentedQuantum Leap air cycle which powersthe piston to more than 80 percent of the stroke, and a patented Air Select regulation system which enables the air consumption of the hammer to be more precisely matched to the air output of the compressor.

ThehammerthatwonthebattleofPhoenixrockWhen the Atlas Copco Pit Viper 271 was put to work at the Phoenix Mine, the down-the-hole hammer was a crucial part of the overall solution. Drilling con-ditions in the region known as the high desert in northern Nevada are among the most challenging in the world. The

quartzite encountered here is notorious for its hardness, and nowhere is it more abrasive than at the Phoenix Mine, lo-cated just south of Battle Mountain.

“Anything that touches Phoenix rock wears out fast. Here the rock fights back,” stressed Mark Evatz, mine manager.

Evatz added that incorporating someone from Atlas Copco onto his team has allowed them to share the successes and failures, and has helped fix issues as they come up – the first time. There is no finger pointing, just solutions for Evatz.

Despite the tough geological condi-tions at Phoenix Mine, Atlas Copco was confident that the Pit Viper 271 and, in particular, Secoroc’s Total Depth TD 65 down-the-hole hammer were up to the task. When Newmont began operations at Phoenix, it was estimated that $205

million would be necessary to build and start up the mine. After two years, those numbers were closer to $230 mil-lion due to escalated construction labor and material prices. Although mining took time to reach the desired produc-tion levels, it has been achieved.

Evatz concluded, “We looked at an aggressive ramp-up with Phoenix. We can accelerate problem solving by wor-king together with Atlas Copco and Cate Equipment, which makes us all more successful.”

acknowledgements


Helping Pheonix to maximize performance: Jim Wheeler, Atlas Copco’s Senior Area Manager, says: “The TD65 has been in daily operationsince the Pit Viper arrived and we are gettinga penetration rate of 60-180 feet per hour.”

Cutting backheads – cemented tungsten carbide inserts – protect the hammer and case against wear. They also help to prevent the hammer getting stuck in the hole.

Robust and high-powered: These TD 65 hammer components prevent exceptional wear in abrasive rock.


geiTa,TanZania

DMlhigh-pressuredrilling

As Tanzania’s most well known mining operation, Geita Gold Mine, an Anglo Ashanti property, constantly tries to increase productivity as it manages its three-pit operation.

At one time, Geita utilized only crawler drill rigs using Atlas Copco’s ROC L8. That evolved to incorporate

Atlas Copco DML low-pressure blasthole rigs in 2006 to improve produc-tivity in non-ore producing formations. Today, the mine continues to use cra-wlers, but is stepping up its use of the DML – now using high-pressure air and Secoroc COP 64 Gold hammers – to increase productivity in the ore body.

Powder factor is calculated by taking the mass of explosives divided by the total volume of rock moved per hole. This volume is from the burden, or the distance from the blasthole to the free face, spacing which is the distance between holes, and hole length. Blasting engineers at Geita use this equation to determine the proper amount and type of explosives necessary to reach the desired fragmentation of the rock.

Two different explosive emulsions are used at Geita. P400 is a 20 percent ammonium nitrate to 80 percent emul-sion; P700 is a 35 percent ammonium nitrate to 65 percent emulsion. The P400 offers more shockwave energy,

whereas the P700 offers more gas or heave energy. The P400 is used in hard rock and ore for maximum fragmenta-tion because the shock energy reflects back into the formation, increasing breakage. P700 is used when opening the pit as this is primarily mechanical energy.

For Geita, the mine’s different explosive techniques mean workers have to consider what they’re doing to maxi-mize productivity of the f leet at all times. Currently the crusher at Geita has a capacity of 15,000 tons per day. The

increasingholediameteratgeitagoldMine

DoingmorewithlessAs the pits at the Geita Mine ma- tured, the need to increase ton-nage took on a priority. Cut 4 on the main pit was too large to complete in the appropriate time using an Atlas Copco ROC L8 fleet. Mine planners worked with the Atlas Copco Drilling Solutions staff to expand the bore hole diameter and select the drilling fleet to meet these challenges. The result: increasing the hole diameter and pattern spacing led to increased productivity at a re-duced cost.

The DML drill pattern with 8-inch or 9-inch hole diameters gets blasting engineers the fragmentation they want.

By increasing hole diameter, spacing and burden, the number of drill rigs could be substantially reduced (photo from May 2005).

inCReaSinghOleDiaMeTeRaTgeiTagOlDMine


goal of the drilling and blasting engi-neers − led by Gerhard Engelbrecht with calculations coming from engi-neers Zebedayo Mumusi and Mavindi Edward − is to keep the tonnage up with fewer holes drilled. “Drilling is more expensive than explosives,” poin-ted out Engelbrecht.

With an average of 85,302 feet drilled per week, the month of May produced a total of 331,365 feet for a total of 1.9 million banked cubic meters (BCM) drilled. The ore body density at Geita is 2.7. (BCM is the total volume of rock moved per one blasthole.)

Geita operates two shifts, measuring availability on 17 hours per day of drill time with five hours for maintenance. The operators work through lunch, eating at their station. The average BCM per day is 64,000. Interestingly, when the workers were given a break for lunch, the productivity dropped to 58,000 BCM per day. Zebedayo Mumusi equates this drop in productivity to the anticipation of taking a break, resulting in a reduction in efficiency.

increasingholediameter

Today the mine operates six DML rigs and plans to add two more. This will

result in a reduction in their crawler rig numbers. The DML drills 9-inch or 8-inch hole diameters using a Secoroc COP 64 Gold 6-inch hammer. The crawlers, on the other hand, drill a 4-inch hole. Increasing the hole diameter has allowed the mine to increase the pat-tern spacing resulting in lower costs. Mumusi said, “The increased size eq-uates to a 5-percent reduction in costs for blasting materials alone.” The smal-ler rigs operate on a pattern of 12 feet for burden and 14 feet for spacing. The large DML operates on a 15-foot x 18- foot pattern in the ore body in the Star and Comet pits and 16 foot x 19 foot in the Geita Hill and Nyankanga pits. In overburden and surface work the pattern is increased to 23 feet x 26 feet and 20 feet x 23 feet in transition areas. Currently the bench depth is 36 feet, but Mumusi said the plan is to increase the hole depth to 49 feet. This is not a prob-lem for the DML as it uses a 35-foot drill steel with a 21-foot starter pipe.

“The plan is to concentrate on larger hole sizes – bigger holes and fewer holes translates to better performance at a reduced cost,” said Engelbrecht. Mumusi agreed, “My goal is to have fewer holes and continue getting the same fragmentation; the DML lets me

do that.” Currently the crawler rigs drill an average of 59,055 feet and the DML rigs drill 29,528 to 36,089 feet per week. But Mumusi said, “I get much more BCM with the DML.”

Geita will continue using two sizes of drill rigs, utilizing the smaller craw-ler rigs for situations such as trim shots and inner-face drilling locations where a small rig can maneuver better. How-ever, the DML rigs will be the work hor-ses for production drilling. The DML high-pressure blast hole rigs were origi-nally purchased for overburden and sur-face work, but are quickly becoming the big production machines and are a major factor in increasing productivity at Geita.

acknowledgements

This article was written by Scott Ellen-becker after a visit to the Geita Gold Mine in July 2009.

Big hole blasting at the Geita gold mine.

A worker changes the bit on the Secoroc COP 64 Gold DTH hammer.


gUeRReROSTaTe,MexiCO

highpressuredrillingwithDM45This region of Mexico has never had a large-scale open pit mining opera-tion before. “We’re setting a precedent here,” says Roberto Díaz Colunga, manager of the Los Filos Project. “In two years this will be the largest gold mining operation in the south of Mexico. The project already provides more than 1,200 direct and indirect jobs, and once we reach our steady production rhythm, we’ll be able to refine over 300,000 ounces of gold per year.”

The Los Filos Project is located 8 km from the village of Mezcala, approxi-mately 200 km southwest of Mexico City in Guerrero State. The project is owned by Luismin SA. de CV, a Mexi-can company fully owned by Goldcorp of Canada. Goldcorp is investing USD 232 million to bring the project into production.

A fleet of Atlas Copco equipment is already working at the site, with more units due to arrive. Seven DM45HP blasthole drill rigs and two CM760D crawler drill rigs have been acquired by Luismin. The project’s main con-tractors, Materiales La Gloria and Desarrollos ROD, also use Atlas Copco equipment on their key pre-production tasks.

“Before entering commercial pro-duction, Los Filos will have had two years of pre-production development and Bermejal one. This is a key phase for the project and it’s important that

Two of the 15 ECM 350 drill rigs belonging to Desarrollos ROD, which is in charge of constructing the leaching pad at Los Filos.

goingforgoldinguerrerolargescaleminingprojectFilos and Bermajal – collectively known as the Los Filos Gold Project – are set to become the largest gold mining operations in Southern Mexico. Preparation work to reach the deposits, an estimated 5 million ounces of gold, is already under way.

gOingFORgOlDingUeRReRO


we have the right type and quantity of equipment in place,” says José Caracheo Brunel of Los Filos Mine Planning Department.

Twodeposits,oneproject

The project comprises two separate gold deposits, Los Filos and Bermejal, which

are found in adjacent hills approxi-mately 1,200 m above Mezcala.

A feasibility study was originally completed in 2005. This study was re-cently expanded to include the adjacent, and subsequently acquired, Bermejal deposit. The Los Filos and Bermejal deposits will be developed as a twin open-pit, heap-leach operation, using

two different ore processing methods depending on grade.

The mine reserves and resources total over 5 million ounces, of which 4.5 million ounces are in the proven and probable reserve categories. Higher grade ore (1.50 g/t of gold) from the Los Filos deposit will be crushed to 80 percent at –19 mm and agglomerated before being conveyor stacked and heap leached, whereas lower grade ore (0.55 g/t of gold) from the Los Filos and Bermejal deposits will be hauled from the open pit directly to the leach pad to be bulk heap leached. The recovered solution will be treated to obtain a final gold ore product on site.

Exploration drilling continues on pit extensions and, in particular, on identi-fying higher grade areas.

200-milliontonsofore

The mine development plan calls for a sequence of five mining phases over a 10-year period for both deposits. Under the plan, a total of 200 million tons of ore will be mined with an average gold grade of 0.69 g/ton and an overburden strip ratio of 1.5 to 1. The stripping will entail the removal of 300 million tons of overburden to access the gold bearing ore.

The project will process 24 million tons/year of ore. A pre-production of 14 million tons/year is required for each deposit. To develop the ore bodies, conventional open-pit mining methods will be employed using 12–15 cubic-meter capacity loaders and shovels and 91- to 146-ton capacity trucks. The pit design for both deposits incorporates 12-meter high waste benches and 6- meter high production benches. Final average slope angle will be 48–52 de-grees depending on the type of rock.

“We expect almost all the material will require blasting; the reason for blasting the ore on 6-meter benches is to provide better ore control and limit dilution,” explains Caracheo Brunel.

The operational cycle will start with the drilling of 175-mm and 114-mm diameter blast holes in the waste and mineral strata respectively. To achieve this, Luismin has ordered a total of seven DM45HP blasthole drill rigs. The DM45 is a high pressure, crawler

M E X I C O

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DOMINICANREPUBLIC PUERTO

RICO

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The Los Filos project is located some 200 km southwest of Mexico City.



mounted, hydraulic tophead drive, multi-pass rotary blasthole drilling rig specifically designed for production blasthole drilling. Operation of the drill is performed using electric-over-hydra-ulic controllers, ergonomically located so that the operator faces the drill cen-tralizer bushing while drilling.

Two of the seven units ordered were delivered in 2005 and are already hard at work on the site, equipped with Secoroc ballistic button bits. A third unit arrived in May with two more units arriving in June and then two more in August. “We only ordered the last five machines once the Bermejal deposit was acquired. Some of these units will work in the Los Filos deposit and some at the Bermejal deposit,” says Caracheo Brunel. “We acquired the DM45 model because it is the ideal size and capac-ity for the production volume we’ll be managing here.”

Demandingtopography

The two CM760D crawler drill rigs with DTH hammers were delivered in 2005. “These machines are very useful. They are currently working on bench development but later we plan to use them for pre-splitting,” says Caracheo Brunel.

Díaz Colunga, project manager, adds, “We had seen the CM760 working before; they have the versatility needed to access this demanding topography, which doesn’t offer many possibilities of large spaces during the opening of the benches. Because of this, they are ideal for preparation tasks. Also, we required a machine able to conduct detailed work such as presplitting and road construction. These units are good for these jobs.”

Díaz Colunga continues, “We have also chosen these machines, both the DM45 and the CM760D, because of Atlas Copco’s proven experience. This reassures us of the equipment’s good performance to guarantee the drilling, which is the first, most important step in the whole production cycle.”

About 25 contractors are at work on the project. Materiales La Gloria – the main contractor – is a regular Atlas Copc o customer, and its fleet of equip-ment at Los Filos includes T4BH,

Specifically designed for production blasthole drilling: one of seven DM45HP drill rigs used at Los Filos to keep the project on schedule.



ECM350 and ECM590 drill rigs. Re- cently, the company ordered two CM780D crawlers with DTH hammers. Meanwhile, another major contractor, Desarrollos ROD, has a f leet of 15 ECM350 rigs operating at Los Filos.

Asked about the performance of the Atlas Copco equipment, Díaz Colunga says, “So far we are satisfied as their performance has matched our plans and expectations.” He notes that the project hasn’t yet reached a normal production rhythm. “We believe we will be more satisfied with the drilling results if we together look after two very important factors – the discipline in the operat-ing habits that we transmit to our personnel, and the meticulous respect for the preventive maintenance pro-gram. Other factors are covered by engineering design and Atlas Copco’s experience, in which we have complete faith.”

Specialistsupport

Madisa, the local Atlas Copco distri-butor, is responsible for technical support at Los Filos and is supported by spe-cialists from Atlas Copco’s Mexicana

office. Juan Carlos Gómez, Atlas Copco product manager, explains that upon delivery of a new drill rig, an Atlas Copco specialist will train operators on the use of the rig. “At the same time, Madisa sends its mechanics and instructors so they can participate in training and become even more familiar with the machine.”

This training is now even more im-portant for Madisa, which has secured a full maintenance and repair contract at Los Filos. Operators of the recently delivered DM45 and CM760D rigs are trained in a three-week program and technical visits help to reinforce their know ledge.

Javier García Adame and Rosalino Carreia Soto are two of the operators of the DM45HP rotary rigs. García, who has been working for the project for over a year, had been operating the DM45 for nearly four months when Mining & Construction visited the site. “It was a comprehensive training process but easy to take on,” he says. “I have no problems with the machine and feel I know it quite well now.”

Carreia, who has been working at the project for six months, is still going

through the training process. “There are lots of things to learn but it is not complicated at all. And the specialist giving the training is good too. I’m looking forward to finally operating the machine all by myself!”

Díaz Colunga reaffirms the impor-tance of the training. “We have had the benefit of the specialist training that Atlas Copco instructors have given to our operators. “I am convinced that in the future this link will be crucial to strengthening the success of our opera-tions.”

The project is at an advanced stage of development. Construction is well underway and is expected to be com-pleted by the end of 2006 with com-mercial production planned to start in the second quarter of 2007. Commercial production for that year is expected to be 200,000 ounces of gold, rising to 350,000 ounces by 2008.

acknowledgements

This article first appeared in Atlas Copco Mining & Construction magazine No 2. 2006.

5 m5 m

5 m

5 m6 m

ø 6"ø 11-12 ¼"

72 º

15 m

The drilling and blasting pattern at the Los Filos mine showing the angle of the drill holes.

Berm

Backbreakholes Production

holes


eaSTeRnaUSTRalia

Multi-seam,multi-pitminingCoal production and export is a very serious business in the Hunter Valley, New South Wales. Normally one train passes through Muswellbrook carrying coals to Newcastle, Australia’s major coal shipping port in 2008, every 20 minutes, said Robert (Rob) Swan. Muswellbrook (pronounced Musselbrook) lies pretty central to the main Hunter Valley coal mines; it is where the Atlas Copco office and service facilities for the area are located and where Rob, who is the Regio- nal Manager – Eastern New South Wales, is based. It is also quite close to the Hunter Valley Operations (HVO) “which has proved very convenient for us”, said Dale Radnidge, the HVO Main- tenance Supervisor, whom we met at an office complex known as Cheshunt Bathhouse located in the southern sec-tion of the HVO.

Located 24 km northwest of Single- ton, the Hunter Valley Operations, are100% owned by Coal & Allied Indu-stries Ltd, which in turn is managed by Rio Tinto Coal Australia. Rio Tinto describes the Operations as a multi- seam, multi-pit open cut mining operation. HVO comprizes: part of the Howick mine, now known as the West Pit, which started operating in 1968; the Hunter Valley No. 1 mine, where production began in 1979, and the Lem-ington mine, which commenced coal-ing in 1971. Coal & Allied merged the Howick and Hunter Valley mines in 2000 to create Hunter Valley Operations

and included Lemington when it was acquired in 2001. The company will approximately produce between 10.5 and 13.5 Mt/y.

In addition to the Hunter Valley Ope- rations, the Coal & Allied portfolio includes the quite new Bengalla strip mine 4 km west of Muswellbrook and the integrated Mount Thorley Warkworth open cut mines 15 km southwest of Singleton.

PurchasefactorsDale Radnidge explained that there had been various reasons why Coal & Allied (C&A) wanted to buy the Pit Viper 275. For one thing, it would be fitted with the Cummins QSK 19 Tier 2 compliant engine that will meet the relevant Austra-lian environmental impact regulations for some time to come. C&A had good previous experience with the Pit Viper’s predecessor rig, the DM-M2, which was bought in 1995. This has always been a very cost effective machine for the company, with very good life cycle costs – despite the fact that the rig has had to operate for periods in

ambient temperatures of over 50° C. Dale had also had positive feedback from Pit Viper owners concerning the steps taken by Atlas Copco Drilling Solutions to improve features that had been weak points on the older rigs.

At the crunch, Atlas Copco quoted a competitive purchase price and the com-ponent life cycle costs were acceptable.

Atlas Copco also offered to pro-vide a maintenance technician for 12 months: previously an Ingersoll-Rand Drilling Solutions rig owner himself, this technician has also helped the Atlas Copco team at Muswellbrook to iden-tify maintenance issues.

Regulatoryissues

However, life is not too simple for eq-uipment purchasers in Australia, espe-cially in New South Wales where the government guidelines on equipment specifications, primarily designed for machinery operating in coal mines, are the most stringent in Australia. Rio Tinto Coal Australia management also has very strict rules covering equipment specifications and it was necessary to

In the Hunter Valley, New South Wales, Coal and Allied Industries mines a multi-seam, multi-pit operation.

CoalminingineasternaustraliahunterValleyShipping 260 million tonnes in 2008, Australia is the world’s larg-est exporter of black coal. Roughly one third comes from coalfields in New South Wales, two thirds from those in Queensland. Pit Viper 275 rigs are contributing to pro-duction from the Hunter Valley in New South Wales and the Bowen Basin in Queensland.

COalMiningineaSTeRnaUSTRalia


have the standard version of the PV-275 modified in a number of respects. Dale Radnidge, the maintenance electrician and maintenance fitters at HVO were involved and so was the unit’s produc-tion trainer.

The order was placed late in 2007, not too long after the AIMEX mining equipment show in Sydney, and Atlas Copco was able to deliver the PV-275 that had been displayed - in yellow and black livery – to the Muswellbrook workshop.

C&A also ordered a new Atlas Copco DML rig that required rather more modification than the Pit Viper. Mr

Radnidge explained that a major aim of purchasing these two rigs was to start to create a unified fleet of different size drills with a common cabin design so that each operator can easily switch from one model to another when neces-sary. The DML rig has replaced an existing competitor machine, whilst ano-ther elderly competitor machine had been put on stand-by when the PV-275 started work.

Modifications

The HVO maintenance team were able to inspect the Pit Viper at the Atlas Copco

workshop. They could therefore make recommendations as to the changes to be made in addition to those modifica-tions necessary for regulatory reasons. These additional alterations were in-tended to make it easier to maintain the PV-275.

Meeting NSW electrical equipment requirements necessitated taking out the whole electrical system and install-ing a different one. Some of the hydrau-lic system components also had to be changed.

Operation

The mines presently use a walk meter and laser depth indicator in conjunction with mine survey data for drill positi-oning as the hardware needed to use the GPS system on the PV-275 is not in place yet. The DML has the Aquila sy-stem fitted for use with HVO’s Modular Mining Dispatch f leet management system. Dispatch is also being used to monitor the availabilities being achieved by the two new Atlas Copco drilling rigs. At the time of the visit, the Pit Viper was being used with five rods to drill 54 m holes in overburden for blasting and stripping by either dra-gline or shovel. However, the drilling requirements range from 10 – 60 m depth although the bulk of the benches are drilled with 30 – 40 m vertical holes. Hole size is 7⅞ in for coal and partings and 10⅝ in for overburden. Pre-split holes are drilled at either 10 m or 80 m spacing, in both cases at a 15° angle. Approximately 20 – 25% of drilling time is spent on the pre-splits. All nine drilling rigs working at HVO use Secoroc tools provided through a separate supply and service contract that has been in force for six years.

HVO has two Bucyrus International draglines (1 x 1370, 1 x 1570), six P&H electric shovels and a Terex-O&K RH70 hydraulic excavator. As well as the Atlas Copco drilling rigs there are six older ones from other manufacturers. Mr Radnidge explained that this mixed fleet was built up as a result of the merging of the mines that are now part of the Hunter Valley Operations. C&A has been using the maintenance plan-ning tools in the SAP software portfolio since May 2008. The Coal and Allied Ltd Pit Viper 275 is fitted with a Cummins QSK 19 Tier 2 compliant engine.

HVO Maintenance Supervisor Dale Radnidge (right) with Atlas Copco’s Rob Swan.



Summarizing, Dale Radnidge said that not only was the deal which Atlas Copco offered sound but the working relationship that C&A has established with the Atlas Copco team has been good too. C&A is comfortable with the purchase. Indeed, HVO had planned to buy two more rigs, which had been shipped to Australia. However, in the current economic climate this will not be possible during 2009.

Queensland–DrillproServicesThe vast Bowen Basin coal deposits in mid-Queensland extend from the area west of the coastal city of Bowen to south of the Tropic of Capricorn in an area which lies west of Gladstone. The mines are connected by rail lines to five major ship loading Coal Terminals: Abbott Point near Bowen, Hay Point and Dalrymple Bay near Mackay, and the RG Tanna and Barney Point terminals

near Gladstone. The Bowen Basin accounts for roughly half the world’s sea-borne trade in metallurgical (coking) coal.

Drillpro Services is a drill services and drilling contracting company formed by John Anderson, who had previously worked in a senior position for a major Australian equipment dealer handling machines competing with the Atlas Copco Drilling Solutions range. Having started out selling drill rig parts and doing rig rebuilds, Drillpro bought its first rig for contract drilling in 2001, followed by two more each year after that. For some time the company used the rigs John Anderson had previously sold, but later Drillpro experienced problems with a particular model so Mr Anderson decided to try the equi-valent Pit Viper 275. He is now an enthusiastic customer and advocate.Cur- rently the company has two Pit Vipers working at widely separated mines in the Bowen basin. The first to be delivered

C&A intends to create a fleet of different size drills with a common cab design so that each operator can switch easily from one model to another.

The HVO Pit Viper was being used to drill 54 m holes in overburden, using five rods.

Hole sizes are 7 7/8 in for coal and partings, 10 5/8 in for overburden.



is at the Curragh operation between Blackwater and Emerald, one of several mines lying close to the Tropic, and the second about 300 km further north at the Coppabella mine.

Curraghnorth

Operated by Wesfarmers Curragh Pty Ltd, which is wholly owned by Wes-farmers Ltd, the Curragh mine was first

developed by an ARCO-led consortium mainly to supply thermal grade coal to the Stanwell power station near Rock-hampton in Queensland. Subsequently metallurgical coal production has grown and the company exports this grade together with surplus thermal coal. Target export tonnage for the Financial Year July 2008 – June 2009 was 7.0 Mt while 4.0 Mt would go to Stanwell.

Production from the original Cur-ragh mine has been supplemented by the development of the Curragh North extension. There are three dra-glines working at Curragh and two at the extension, where there are also hy-draulic excavators loading Caterpillar trucks (793 and 789 models). Both types of coal are mined from this extension: one grade is taken to the coal prepara-tion plant at the original mine by a belt conveyor, the other is hauled by large high-sided truck-trailer units. The plant also washes coal from Yarrabee, some 25 km to the north.

Thiess has the overburden stripping contract at Curragh North, with Drillpro doing the drilling and other specialist firms, including Orica, carrying out the blasting. The overburden is mainly sand and gravel. John Anderson explained that Drillpro Services has worked at Curragh for 11 years. Under the current three-year contract the company operates and maintains two drills that belong to the mining company as well as the one PV-275 and one DM-M3 that Drillpro owns itself. The Pit Viper is working at the Curragh North extension.

From January 5 to January 18, 2009 Drillpro had drilled 51,000 meters, as compared to the mine’s target of 25,000 m/week. This requires a penetration rate of 850 m per 10 hours drilling per shift. However, Curragh was looking to increase the rate to 30,000 m/week. From early August 2008, when the PV-275 started work, up until the time of our visit on January 20, 2009, the rig had drilled 130,000 meters. The rig was still using the original drill rods and had thus far achieved 98% availability, Mr Anderson said. Both this Pit Viper and the one at Coppabella drill 270 mm holes. However, the Curragh machine has a Cummins QSK engine while the Coppabella PV-275 has the Cat C27 option.

Drillpro Services deploys one of the company’s two PV-275 rigs at the Wesfarmers Curragh Pty Ltd Curragh North extension.

Phil Smith finds the Curragh Pit Viper easy to use.



Usually Drillpro uses a DM-M3 for drilling 25° pre-split holes and 20° bench holes for cast blasting. Some-times, commented John, Drillpro gets held up because the pre-split holes are not blasted soon enough. However, the area we visited had a soft wall so pre-split drilling was unnecessary. We watched Phil Smith operating the PV-275. He drilled the A/O hole to 51m and the holes H11 to A11 to between 47 and 50 m.

Phil Smith has 17 years’ experience in exploration drilling followed by 3½ years of production blasthole work, including drilling with the DM45 and the Driltech D75 rigs. He told us that the PV-275 is better than both of them: it is easier to use and has more feel for the drilled rock. The cabin’s perforated blinds were very helpful in the bright Australian sun, eliminating glare but providing sufficient visibility for Phil to move the rig from one hole to the next drilling position. John Anderson remarked that he would like to have a window in the cabin roof to provide a view of the mast, but the design of the FOPS cab makes this impossible. Instead there is a camera system which the operators took some time to get used to, but now find perfectly satis-factory.

Modifications

As in New South Wales, though to a slightly lesser extent, some modifications are essential to meet the Queensland government guidelines, explained Don Emery, who is Atlas Copco’s Regional Manager, Mackay. And although John Anderson could not have his roof window, he did get several substantial modifications that he asked for.

The Curragh Pit Viper was shipped into Brisbane, trucked to the Mackay workshops where it was modified, trammed into the Queensland Mining Exhibition held from July 24-27, 2008 and then delivered straight to the mine site. In carrying out the altera-tions Atlas Copco was considerably assisted by an adjacent firm of boil-ermakers which could generate the required drawings and do some of the fabrication.

In addition to rewiring according to Queensland standards, the main

modifications and additions included: a modified walk-up ladder; one plat-form in front of the cabin and another to provide high level access to the

mast; a Hiab crane, with its own power supply mounted under the cabin, to help with drill tools handling; addition of a Chubb fire suppression system on

The second Drillpro PV-275 works at the Coppabella & Moorvale JV’s Coppabella mine.



a rail around the engine; two lifting hooks; and a microwave and fridge. Several of the standard features were relocated for greater convenience, such as the isolators, which were moved to the back end of the frame to be within reach from ground level, the Wiggins fast fill unit and the lube drums. Phil Smith was particularly enthusiastic about the Hiab crane which makes his life a good deal easier, he said.

The Coppabella machine was deliv-ered with the lift hooks pre-fitted, an upgraded engine fire suppression system and greasing access for the driveline to the pump. In addition, extra tanks were fitted for dust suppression so that refilling is required after two shifts. As well as a Hiab crane and extra platforms like those on the Curragh Pit Viper, there is an access to the mast and the camera on the mast via the top of the cabin.

Coppabella

The overall operation and the mining operation at Coppabella are managed by Macarthur Coal (C & M Management) Pty Ltd – working on behalf of the Cop- pabella and Moorvale Joint Venture. The Joint Venture comprizes Macarthur Coal Ltd (73.3 % stake held via Coppabella Coal Pty Ltd); CITIC (via CITIC Au- stralia Coppabella Pty Ltd), Marubeni Corp. (via Mapella Pty Ltd), and Sojitz Corp. (via Winview Pty Ltd) each holding a 7 % interest; JFE Shoji Trade Corp. (3.7 % held via KC Resources Pty Ltd); and Nippon Steel Trading Co. Ltd – 2.0 % held via NS Coal Pty Ltd. The coal han-dling and preparation plant has a capac-ity in excess of 6 Mt/y raw coal and is operated by the Sedgman Coppabella Joint Venture.

The mining lease was granted on June 1, 1998, overburden removal start-ed in July 1998 and the first coal was mined in October 1998. By April 2007 Coppabella had yielded 40 Mt of run of mine coal. Macarthur Coal’s attrib-utable production in 2008 was 2.57Mt. Proven and probable reserves totalled 67 Mt as at 30 June 2008.

The operation is located adjacent to the Peak Downs Highway, 140 km southwest of Mackay between Nebo and Moranbah. It mainly produces a 9% ash,

low volatile PCI grade metallurgical coal that is railed to the Dalrymple Bay Coal Terminal near Mackay. But, in response to market trends, Coppabella has revised its mine plan in order to mine thermal coal and reduce PCI grade output, demand for which has fallen sharply. This also meant that 140 people were laid off in mid-December 2008.

John Anderson’s son Matt joined Drillpro Services in 2003 and now man-ages four contract sites in the area. Of these Coppabella, where Neal Torresan is the company’s site supervisor, is the largest but the other clients are pre- stigious – BHP Billiton Mitsubishi Alliance (BMA), whose Poitrel mine is operated by the contractor Leighton; Vale Australia’s Broadlea; and Peabody’s Eaglefield, where the main contractor is Macmahon. Drillpro was also bidding for work at BMA’s South Walker Creek mine, where Thiess is the mining con-tractor.

At Coppabella, overburden removal is primarily by dragline, coal mining by large excavators loading trucks. Orica is responsible for blasting the holes Drillpro drills under the terms of an 18

month contract. There are presently three producing pits; East, Southern and Johnson. Drillpro has the PV-275 and one other rig operating, one spare machine and one parked unit, all of these being of other make. (When bidding for new contracts having idle machines can help, commented Matt Anderson.)

The Coppabella PV-275 rig drills 20° angle, 18 meter pre-splits and 12-18 meter main bench holes, of which some are angled at 20° but most are vertical. The coal is 13-14 m thick in places at a depth of approximately 37 meters below surface. Jason Camielleri was operating the drill during our visit to the Johnson Pit South.

Routine servicing of the Coppabella machine’s Cat C27 engine is done by Drillpro but any guarantee work is done by the Caterpillar dealer. At the time of our visit the machine had done about 1000 hours.

acknowledgements

Kyran Casteel, a Contributing Editor for Coal Age and Engineering & Mining Journal, visited the New South Wales and Queensland coalfields in January 2009.

Drillpro’s Pit Viper 275 rig at the Coppabella mine, seen here in the Johnson Pit South, is equipped with the Caterpillar C27 engine option. The machine drills 20° angled pre-split holes and either 20° or more often vertical main bench holes.


RUSSia,SOUTheRnSiBeRia,kUZneTSkBaSin

TheDMlexpectance

The Kuznetsk Basin (Kuzbass) is well known for its huge coal resources, half of which, some 693 million tons, are coking coals, the main commercial fuel for smelting iron. Today, more than 100 underground coal mines and open pits are in production with, 17 coal clean-ing plants producing different grades. Annual production of power station and coking coals is some 1.5 billion tons.

Drill-and-blast contractor Azot-Chernigovets Ltd. offers blasted material preparation for the open pit Chernigovsky mine with an annual production of some 6 Mt.

“In our f leet there are only for-eign rotary blasthole drill rigs,” says Vladimir Bornev, site supervisor. “We drill blocks with five rigs, three of which are Atlas Copco DML rotary blasthole rigs.”

The plan for 2007 was to achieve 1.1 million drillmeters and by the 11th month, the company was well on track to meeting this goal. Comparing the DML rigs, the most popular in Kuzbass, with their domestically manufactured counterparts, Bornev says that the Atlas Copco rigs are very productive and maneuverable, with the powerful diesel engine and compressor productivity among the main benefits. “Local rigs achieve a maximum of 10,000–11,000 drillmeters per month, while the plan for our DML is 20,000–22,000 drill-meters per month,” he says. “In fact, one of our drill rigs has broken all records at the mine; in August it drilled 30,500 meters. The DML rigs are built much better, quality-wise, and the design is more sound and reliable.”

Victor Yarkov, operator of the record-breaking DML, says, “The cabin is well insulated, with good visibility and ope-rating lights. Also, the control levers are comfortably located.” Yarkov has worked here for almost 20 years and says good teamwork also contributes to the successful drilling.

At Chernigovsky, tricone drill bits are used for the 203 mm and 270 mm blastholes with 9-meter pipes to depths of 5-15 meter. The performance of the rotary head is 100 rpm at 10.575 Nm and the compressor capacity is 34 m3/min at 758 kPa.

“Water in the coal beds is about 50 percent, and in some sectors even more,” says Vadim Khlebunov, deputy chief engineer of Azot-Chernigovets. “This, combined with fissuring, often makes drilling and blasting a problem. However, the rig performance is excel-lent and if you follow the manufac-turer’s recommendations, there will be no problems at all.”

The contractor produces and uses two types of emulsion explosives for dry and wet holes. “We provide a com-plete technology process,” comments Khlebunov. “We sell fully prepared cubes of rock mass and run operations

both at Chernigovsky and at a number of other open pits.” The set task per shift for the DML is 400-500 drillmeters, so it achieves 800–900 drillmeters per day over two shifts. Says Khlebunov, “We hold a record of 1,300 drillmeters per day. Our success is the result of co-ordinated efforts by all those involved. We want to prove what the drill rig and the enterprise is capable of.”

Bachatskyopenpit

At the Bachatsky open pit, owned by Kuzbassrazrezugol, the average thick-ness of the coal seams is 32 meters. Here, too, the main goal is to increase pro-ductivity at minimal cost. The rig fleet has been completely renewed; the previous 14 electric drill rigs have been replaced with four diesel and two electric rigs. Two DM-M2 and two Pit Viper 271 rigs are in use and the miners are happy with the equipment.

Alexander Bogatiriov, deputy technical director, says, “Though the rigs belong to different classes, I think they are equal in terms of productivity. Ope- rators hold the same opinion; the DM-M2 is not second to the Pit Viper. Competition between the rig operators

The successful Azot-Chernigovets team at the Chernigovsky open pit: (From left) Vladimir Klimov, operator, Oleg Grebenshikov, operator assistant; Dmitry Kuznetsov, foreman; Vadim Khlebunov, deputy chief engineer; Vladimir Bornev, drill site supervisor; Victor Yarkov, operator and team leader; with Yury Dolgov of Atlas Copco.

BoostingSiberianenergyStandfirstEconomic growth in southern Si- beria is increasing year-on-year and at the Kuznetsk Basin coal field, new mining enterprises are appearing and existing operations are introducing the latest equip-ment to boost their productivity.

BOOSTingSiBeRianeneRgy


produces such great results with the DM-M2 as 30,600 drillmeters per month and with the PV-271 37,000 drillmeters per month, which can be com-pared with a performance of some 8,000 drillmeters per month for the conventional Russian drill rigs.

Single-passcapability

The first drill rig was commissioned in 2004 and was the second such drill rig in Kuzbass. To increase productiv-ity, the management decided it wanted single-pass drill rigs and the Pit Viper proved to be the ideal choice. “We have practically reached the maximum theoretical productivity capabilities of the rigs,” says Bogatiriov. “As for mainte-nance, we observe Atlas Copco factory recommendations. Earlier, the lifetime of the locally manufactured machines was five to seven years, but with the new machines, we expect 10 to 12 years.”

Atlas Copco’s local distributor, Mi- ning Solutions, is responsible for staff training and maintenance of the rigs.

Engineer Vladislav Grebnev, deputy general director, says, “We have had people on this site from the start, work-ing hand-in-hand with the customer to steadily boost the productivity of the equipment.

“The operators traditionally believe that productivity increases depend so-lely on torque. Pulldown force was not taken into account. We worked together as a team and the rigs started achieving 18,500 meters per month. That was the start of the productivity increase.”

The company provides three types of service contracts: a complete serv-ice, including night duty; setting up, diagnostics, parameter monitoring; and emergency call-out. Today, 40 units of Atlas Copco equipment are covered by the service contracts and practically all customers extending their contracts choose the full-service option. Service contracts are applicable to all rotary drill rigs including DML, DM45, DM-M2 and Pit Viper 271s in the region.

acknowledgements

This article first appeared in Atlas Copco Mining & Construction No. 1 2008

A winter’s day at the Bachatsky open pit: The Atlas Copco drill rigs DM-M2 and Pit Viper 271 help to produce coal for both the domestic and international markets.


USa,WyOMing

PowderRiverBasin

Under the rolling grasslands of north-east Wyoming, massive seams of low-sulfur, sub-bituminous coal are mined on a scale unmatched anywhere on earth. The Powder River Basin (PRB) is home to 13 major open-pit coal mines, all of which would be considered large in their own right. Combined, these mines tallied 451 million short tons (410 mil-lion metric tons) of coal production in 2008. Individually, the PRB is home to the 10 largest coal mines in the United States, and quite possibly the five larg-est in the world. Two mines, Peabody Energy’s North Antelope/Rochelle Mine and Arch Coal’s Black Thunder Mine, each produced over 88 million short tons (80 million metric tons) in 2008.

The key to the success of these mines is the thick coal seams, which can ex-ceed 80 feet (24 meters) high. While the geology may seem very favorable, strip ratios continue to increase as mining progresses. Many of the mines now average 3 cubic yards of waste to 1 ton of coal. This translates to overburden cover in excess of 300 feet (91 meters) in many areas. Therefore, to meet the

high coal production, an enormous amount of overburden must be moved.

Draglineoperations

When moving this amount of material, mines turn to the lowest cost equipment available. Many of the PRB mines uti-lize large walking draglines as their

primary stripping tool. Draglines are very cost-efficient earthmovers as they utilize massive buckets (up to 160 cubic yards, or 122 cubic meters), and deposit their material directly without need for haulage units or conveyors. Unlike a shovel or loader, which has a limited digging height that dictates the bench height (usually less than 60 feet, or

hiddentreasurebeneathamerica'swesternprairieMulti-passdrillsmeetdemandMuch of the world relies on coal for electricity generation. This is especially true in the United States, where coal is responsible for over 50 percent of the power produced. To meet this need, over 1 billion tons of coal is mined on an annual basis. The proven DM-M3 and now the PV-275 are the drills of choice in large scale mining operations in Wyoming. These robust drills, with their ability to drill large deep holes at an angle, have be-come the standard in the Powder River Basin.

Massive amounts of overburden - up to 300 ft (91 m) - are removed to reach the seams of coal that can exceed 80 ft (24 m) thick. Powder River Basin coal is treasured because of its low sulfur content.

hiDDenTReaSUReBeneaThaMeRiCa'SWeSTeRnPRaiRie


18.3 meters), a dragline is capable of deep digging depths beyond 100 feet (30.5 meters).

While the dragline is a very effective earthmover, the overall cost of overburden removal can be reduced through cast blasting. Cast blasting is a method of drilling and blasting that uses high explosive energy to throw a sizeable portion of the bank into the adjacent empty pit where the coal was previously removed. This method often results in casting 30 percent or more of the bank overburden material to its final resting place, known as the “effective cast” or “cast to final.”

As dragline operations require a flat bench, large track dozers with special wide blades (sometimes referred to as carrydozers) push the cast material down and build a bench at a set height above the coal seam. The dragline will then uncover the coal seam. This mining

Draglines are effective earthmovers, removing overburden and depositing directly into spoil piles as shown here. In the foreground, casted material can be seen filling the empty pit, while dozers work to build a dragline bench.

A dragline digs on the spoil side of the pit. Draglines move in small steps via a cam-type walking mechanism.



method allows for the excavating of a large vertical block of material ranging from 100 feet (30.5 meters) to 200 feet (61.0 meters) or more in depth, compared to the 50-foot to 60-foot (15.2 to 18.3 meter) vertical benches taken by truck/ shovel methods. A challenge of the dragline method is maintaining stability of the face (known as the highwall) after excavation, especially when water is present in the material.

Drilling for cast blasting applications generally involves deep depths (up to 235 feet or 71.6 meters), large diameters (up to 12 1/4 inches, or 311 mm) and angles up to 30 degrees from vertical. Large diameters result in wider drill patterns, reducing the number of holes drilled. Because of the size of the dragline buckets, large fragmentation size from the blast is not a concern. How-ever, some operations have found that smaller diameters such as 11 1/4 inches (286 mm) yield better blasting results with the tighter spacing.

Deep blasthole drilling has its chal-lenges. Foremost is the amount of cuttings generated by the large diameter, deep holes. A 12 1/4-inch (311 mm) hole to 200 feet (61.0 meters), assuming a swell factor of 30 percent, would yield 7.9 cubic yards (6.0 cubic meters) of cuttings. This is a very large pile that smaller drills simply cannot containunder their dust hoods. Even though asmall unit might have sufficient pulldown, rotary torque and air to drill a hole, it wouldn't be effective due to excess cuttings falling back down the hole after the hood area is filled.

Most of the drilling for dragline operations is done at angles between 20 and 30 degrees. The angle drilling serves two purposes. First, the angle can be set to roughly the same angle as the desired highwall. This is done to help keep a consistent face-row burden to improve the effectiveness of the cast shot. In simple terms, the burden at the top of the highwall (the crest) should be similar to the burden at the bottom of the highwall (the toe). Second, angle drilling can help shape the direction of the cast shot. As the blast projects perpendicularly from the bore hole, an angled hole gives a vertical component to the blast, helping lift the mate-rial and therefore throw it further. It is

important to remember that the drilling depth increases as the angle increases. For example, if mining a 200-foot (61.0 meter) bench, the drilling depth at 30 degrees would be 231 feet (70.4 meters).

Some mining regions are fortunate to have soft material, which yields extremely fast drilling rates and less wear on buckets, tires and truck beds. The PRB is in this class, with much of the material having a compressive strength of less than 5,000 psi (34 MPa). The

material is so soft that tricone bits are rarely used. Instead, aggressive claw-type bits are the standard. Contrary to the general belief that soft material calls for as high a rotation speed as possible, these claw bits rotate at lower RPM (100 or less), but their design allows them to shear through the material at rates exceeding 1,000 feet/hour (305 meters/ hour).

To handle the high penetration rates, large air compressors must be used. This is especially true in the PRB as these

Drilling at an angle then blasting the bank into the adjacent empty pit results in casting 30 percent or more of the bank overburden material.

Drillers on the DM-M3 appreciate the clear view of the breakout wrench and easy access to controls.



drills often use smaller diameter drill rods to increase the annular area (the gap between the wall of the hole and the drill rod) to allow the larger cuttings generated by the claw bit to exit the hole without having to be reground to a smaller size. High volume compressors of up to 2,600 cubic feet per minute are used, and it is important to have suffi-cient air pressure (100 psi, or 6.8 bar, or more) available to prevent plugging bits. Because of the light weight of the over-burden (approximately 3,000 pounds per cubic yard, or 1.04 tons per cubic meter), bailing velocities may dip below the 5,000 feet per minute (1,524 meters per minute) recommendation that the industry would normally prescribe, yet still effectively clean the hole.

BuildingDrillsforthePRBAtlas Copco’s DM-M3 and Pit Viper 275 (PV-275) are ideal for coal mining in the Powder River Basin and the DM-M3 was, in fact, first designed for mining the overburden in the PRB. Jon Torpy, a regional manager for Atlas Copco, said, “The DM-M3 is in a class of its own with the right balance of air, rotary head performance, bit load, and depth capacity. The PV-275 has taken these strengths and added to them. The DM-M3 was designed to drill the Powder River overburden so it can drill the deep angle holes required to reach the coal.”

Walt Schroeder is a product support sales representative for Atlas Copco, but prior to working for Atlas Copco,

Schroeder was a driller. He has operated many drills including seven years on a DM-M3. Schroeder said, “I have never had a bad word to say about the DM-M3 and it’s always the truth. Ask anyone who has operated one. There is no other drill that can mast over to 30 degreesand drill 240 feet – all day, every dayand never even grunt!”

Schroeder added, “When this rig was designed there were definitely miners involved. There isn’t a more comfort-able rig to operate; they got it right when they engineered this rig. I’d say this is the most ergonomic drill on the planet and I’ve never run a rig that I like more.”

Schroeder’s confidence speaks to durability, too. Availability is critical according to Schroeder. “There is not a drill made that has the air, power and overall drilling performance at this depth and angle that can match the availability of the DM-M3. I know guys you wouldn’t let operate your lawnmo- wer who are drilling with the DM-M3 – this rig is tough!”

acknowledgements

Story and pictures by Brian Fox and Scott Ellenbecker. Portions of this article first appeared in Mining & Construction USA, No. 1, 2009.

Good highwalls are a result of proper drilling and blasting and bench preparation. The dragline seen here is using the spoil side stripping method as this pit nears completion.

The 235-ft drill depth of the DM-M3 allows the dragline access to the deep coal in one blast. The DM-M3 can drill at an angle of 30 degrees, which maintains the angle of the highwall and helps shape the direction for the cast shot.


USa,VanSanT,Va

VirginiadrillingIn 1998, partners Verlo Stiltner, David Hale and Mike Sheets started the contract drilling company Virginia Drilling to diversify the existing blast-ing business, Austin Sales, owned by Hale and Stiltner.

The company began as a contract driller on construction applications with Ingersoll-Rand ECM 490 and ECM 690 crawler rigs. Today the company has grown to include 28 Atlas Copco DM45’s, nine Atlas Copco DML’s and seven Atlas Copco crawler drills in various sizes, including one ECM 490 and one ECM 470 and two ECM 690’s and three ECM 720’s.

Virginia Drilling is the largest, if not the only, contract driller in the world focused primarily on the coal industry. Even the smaller construction crawler

drills are dedicated to road, reclama-tion and underground mine face-ups to a point that 85 percent to 90 percent of the work is for the coal mining com-panies.

Two years ago, the company’s co-founder David Hale passed away, but the business has continued to grow with strong leadership and committed em-ployees. Today the company has 18 drills on order and has a steady business growth plan slated for years to come.

gettingstartedBecause of the existing blasting busi-ness, Virginia Drilling knew everyone in the area. Founding partner and con-struction drilling manager Mike Sheets summed it up, “the coal industry in the region is a real fraternity.” Just over a year after starting the business, which

Movingmountains

afocusonthecoalindustryIn the southern Appalachian range of West Virginia, Kentucky, and Virginia, known as the Blue Ridge Mountains, the seam of coal flows through the ground at varying depths, sometimes just at the base of the mountain. To get the coal Virginia Drilling Company works with their coal company partners to shave off the moun-tains one 30-ft to 40-ft lift at a time. Virginia Drilling’s business philosophy has developed over time but has remained simple, says said founding partner and company president Verlo Stiltner. “We grow the business by focus-ing on what you do best and sur-round yourself with experts.”

Virginia Drilling now has over 50 Atlas Copco drill rigs in its fleet.

MOVingMOUnTainS


until that time had focused on construc-tion projects, Virginia Drilling partners were approached by a coal company who knew their blasting expertise and asked them to drill in the coal field.

The premise was to not waste blast-ing material on the bench, to work efficiently and maximize outside resources. The goal was to get costs below indus-try average and have higher drill uti-lization.

Partnerresponsibilities

From the beginning Virginia Drilling’s partners accepted that they were not drill experts. Admittedly, Virginia Drill- ing Chief Operating Officer Clinton Evans pointed out they had lots to learn and wanted to work closely with drill dealer Brandeis Equipment to develop a maintenance program.

“When choosing a drill it was really a no-brainer,” said Evans. They went with Atlas Copco because if its prod-uct reputation, but also they needed a strong dealer that would support every aspect of the drill including parts and support.

According to Brandeis branch ma-nager, Barry Justice, 40 percent of their parts inventory is for Atlas Copco Drills. “If the drills don’t run, the whole mi-ning process stops,” said Justice.

Brandeis has 19 service trucks in the field, running its parts department on a double shift and supplying 24/7 service to Virginia Drilling. All that attention equates to a higher performance on the drills. The oldest drill in the fleet is a 1999 DML with 22,000 hours. Typi- cally on a mine site the cost of drilling equipment is approximately 5 percent to 10 percent of the total expenditures. This is another reason why some mining companies don’t focus on their drilling.

Virginia Drilling knows that the excavation equipment can catch up to them but can’t pass them.

Atlas Copco regional sales manager Tom Borer said, “Virginia Drilling has drills with 20,000 hours on them that run better than drills owned by others that have 10,000 hours.”

There is no big secret here; it’s all in the preventative maintenance (PM) program. The main pumps, for example, average 7,000 to 8,000 hours for most, Two Atlas Copco DML drill rigs prepare for the next shot that will lower the bench to the coal seam.

MOVingMOUnTainS


while Virginia Drilling averages 11,000 to 12,000 hours. It’s not uncommon forVirginia Drilling to get 40 percent greater life out of their drill compo-nents because of the PM program.

Mike Sheets said, “It’s all about ta-king away problems.” Brandeis takes the burden of maintenance away from Virginia Drilling and Virginia Drilling takes away the burden of drilling and blasting from the coal companies.

He emphasized that his customers’ focus is to move material. They don’t want to worry about getting the shot right or all the liability that comes with explosives.

Sheets said, “If everyone focuses on the part of the business that makes them money everyone wins, and if we’re not drilling holes, we’re not making money.”

To ensure they are drilling holes they follow the PM program religiously. If a drill is close to a scheduled PM and a Brandeis truck is in the area, they will perform the service rather than let it get behind. As a contract driller for many mining operations in the area, Virginia

Drilling takes total responsibility for the drilling and blasting operation. The agreement with its customers is a win-win for everyone.

When this part of the business began and the deal was laid out for the custo-mer, he didn’t believe it. “He told us it seemed too good to be true,” said Sheets.

They proposed a sliding scale based on 50,000 to 1 million yards of shot material with discounts built in for vo-lume. Virginia Drilling guaranteed the product amount in the customer’s time-frame. They absorb most costs related to putting the product on the ground, from equipment to human resources to blasting material.

“When we finished making our proposal the first response was ‘where do I sign,’” said Sheets. Today Virginia Drilling s client list is long and growing.

Trainingequalssuccess

People are a critical part of making this work. At any one time Virginia Drilling has seven to eight drill trainees, with

that number going as high as ten. The training program has developed over time to what it is today, a well executed system. For the first two weeks they mostly watch and listen. They learn how to set up on the bench, put the mast up and down and terminology. They learn by watching and listening.

“We prefer they don’t even come in with experience,” said Evans.

They don’t want new employees to have bad habits and to learn drilling according to the company’s operation. After they have a couple weeks with the best drillers they come in for class-room work. They learn down pressure, rotation, penetration rates, bit perfor-mance and compressor and engine ope-ration, everything they need to know about the drill and what its responsibil-ity is for drilling the hole.

Then the trainees go back in the field with the experienced driller again to apply the classroom work. Every month drillers are evaluated to make sure they are getting optimum production, maxi-mum penetration and bit life

Shouldering the burden for the coal companies. From left: Mike Sheets, Clinton Evans and Verlo Stiltner of Virginia Drilling.

MOVingMOUnTainS


and overall efficiency. But, all the aspects of training come right back to keeping the drill working at its maximum performance rate.

“We expect to get 30,000 hours from our drills,” said Evans.

The drillers have to be doing their job correctly to ensure that level of equipment life.

Performanceforresults

Drill performance also factors into how Virginia Drilling bids a job. “Every-thing is evaluated when looking at the cost per foot,” said Sheets. “Because we look at all aspects of the drilling and blasting process, we know how to find our efficiencies.”

One drill site may run into five dif-ferent layers of sandstone in a mine. Laminated charts plot out the geology of the mine. The goal is to get the maxi-mum penetration in relation to the time in the hole.

“The bit is an integral part of the operation,” said Evans. Bits give you the data as to how the drill is performing. Weight and rotation is applied to the bit according to the situation. In this area a driller may expect to get a penetration rate of 6 feet a minute at 165 rpm and 15,000 lbs.

Although bits have an optimum ro-tation rate its only half the equation. “We are not willing to sacrifice a drill to drill faster,” said Clinton Evans. Vir-ginia Drilling looks to maximizing the relationship of down pressure to rota-tion rpm to ensure the life of the drill.

Using 7 ⅞-inch to 9-inch bits on its DML’s and 6 ¾-inch to 7 ⅞-inch bits on its DM45’s, operating between 2,500 to 4,000 hours a year, Virginia Drilling projects 2 ½ million yards of rock a month. It is expected that each drill is responsible for 500,000 yards. The DML’s are equipped with 6 ¼-inch x 30-ft pipe, while the DM45’s run 5 ½-inch x 30-ft pipe.

Virginia Drilling can move drills if needed, and to meet the required ton-nage they will run three to four drills per site at one time with a maximum of five.

Evans prefers the DML because it is beefier from the frame up, but the performance and hole sizes dictate what drills will be used. It goes back to blasting – try to make the pattern smal-ler but get the most value from the caps, primers and explosives.

Generally, hole spacing is on an 18-ft x 18-ft pattern. The 7 ⅞-inch hole can support 16-ft to 18-ft spacing, while the 9-inch hole can do a 19-ft to 21-ft spacing. Virginia uses a 70/30 ANFO emulsion blend as an explosive.

acknowledgements


Blasting off the top – benching down to the coal that can be seen at the base of the mountain.

DRillingMeThODgUiDe


ThetophammermethodInpercussivetophammerdrillingtheimpactenergyisgeneratedwhenthepistonisstrikingtheshankadapter.Thisenergyistransmittedfromtherockdrillviatheshankadapter,drillsteelanddrillbittotherock,whereitisusedforcrushing.Theentiresystemofrockdrill,drillsteel,drillbit,rotation,feedforceandflushingmustharmonizeformaximumdrillingeconomy.Thetophammermethodisprimarilyusedfordrillinginhardrockforholediametersupto5inch(127mm),andthemainadvantageisthehighpenetrationrateingoodsolidrockconditions.Handheldpneumaticrockdrillsareusedforsmallholediameterswhilerigmountedhydraulicrockdrillsarecommonlyusedforholediametersabove15/8inch(41mm).Heavyhydraulicrockdrillswithanimpactpowerofupto40kWareusedforlargeholediametersupto5inch.Tomaintaingooddrillsteeleconomyandholestraightnessheavyextensionrodsorrigidguidetubeswithlargeouterdiamerhavetobeused.

Thedown-the-holemethodThedown-the-holemethodisareliablewaytodrillbothdifficultandeasyrock.Therockdrillpistonstrikesthedrillbitdirectly,whilethehammercasinggivesstraightandstableguidanceofthedrillbit.Thisresultsinminimaldeviationandgreaterholewallstability,eveninfissuredorotherwisedemandingrock.Sincetheannulusbetweenthedrillpipesandtheholewalliscomparativelysmall,ahighflushingvelocityismaintained,whichcontributesfurthertoholequality.Goodholequalityenablestheburdenandspacingtobeincreased,whichsavestimeandmoney.Straightholesmakechargingeasierandenabletheamountofexplosivetobereduced.ThereliableDTHmethodisaneasywaytoproducedeep,straightholes.Fromanenvironmentalpointofview,thenoiseemissionsandvibrationfromDTHdrillingarecomparativelylow.Thisisofparti-cularadvantagewhendrillingindenselypopulatedareas.

Different applications need different kinds of drilling equipment and performance. The drilling method has normally been established for some time, and well proven techniques are seldom replaced by new methods. This guide is an at-tempt to start a discussion around the method and equipment that might provide the ultimate solution for an applica-tion. Below, we compare three different drilling methods on offer from Atlas Copco.

Drillingmethodguide

Principle:Inthesimplestofterms,thetophammerdrillingmethodgoesbacktomanuallyhittingtheendofadrillsteelwithasledgehammer.Asrecoilmakestherodjumpbackitisrotatedtoensurethattheholeisround.Inasimilarwaytheimpactenergyoftherockdrillpistonistransmittedtothedrillbitintheformofshockwaves.Drillcuttingsareremovedfromtheholebottombyairorwaterflushing.

Principle:Thehammerissituateddowntheholeindirectcontactwiththedrillbit.Thehammerpistonstrikesthedrillbitresultinginanefficienttransmissionoftheimpactenergyandinsignificantpo-werlosseswiththeholedepth.Themethodiswidelyusedfordrillinglongholes,notonlyforblasting,butalsoforwaterwells,shallowgasandoilwells,andforgeo-thermalwells.Inminingitisalsodevelopedforsamplingusingthereversecirculationtechnique(RCdrilling).

RotarydrillingmethodsTheprimedifferencefromotherdrillingmethodsistheabsenceofpercussion.Rotarycutting,usingfixedtypeclawordragbits,ismainlyusedforsoftrockwhichiscutbyshearing.Rotarycrushingusestriconebitsrelyingoncrushingandspallingtherock.Thisisaccomplishedbytransferringdownforce,knownaspulldown,tothebitwhilerotatinginordertodrivetheteeth(commonlytungstencarbidetype)intotheholebottomasthethreeconesrotatearoundtheirrespectiveaxis.Thesoftertherockthehighertherotationspeed.Thedrillrigsneedtobeheavytoprovidesufficientweightonbit.Generally,drillingbelow152mm(6inches)isbestaccomplishedbypercussivedrillingunlessprevailingrockconditionsaresuitedforrotarycutting.Rotarycrushingistheprimechoiceforlargediameterholes,above254mm(10inches)inopenpitmining,overburdenstrippingatcoalmines,anddeepwelldrilling.

TONS

Principle:Rotationisprovidedbyahydraulicorelectricmotordrivengearbox,calledarotaryheadthatmovesupanddownthetowerviaafeedsystem,generatingthepulldownrequiredtogivesufficientweightonthebit.Flushingofdrillcuttingsbetweenthewalloftheholeandthedrillrodsisnormallymadewithcompressedair.

SPeCiFiCaTiOngUiDe


SpecificationsguideFrom a pure technical point some readers may find the definitions and units used on the following pages con-fusing. Several of the terms and units have a history dat-ing back to the early days when drilling was based more on practical experience than on advanced engineering.

FeedForceFormanyusersandequipmentmanufacturersfeedforceiscommonlyreferredtoas“Weightonbit”(WOB),andexpressedinlb(pounds)orkg.SincethistermWOBiscom-monlyusedbymanydrillers,wedecidedtoincludeitinthespecificationspages.The“Weightonbit”isdefinedasthedownwardforceonthedrillbit,generatedbytheforcefromthepulldowncylinderscombinedwiththeforcegeneratedbytheweightofthedrillstring.

Fromapuretechnicalpointmassandweightaredifferentpropertiesandaforcecannotbemeasuredinpoundssincethatisaunitformeasurementofmass.Sincethe18thcen-turypound-force(lbf)hasbeenusedforlowprecisionmeas-urementofaforce.Amoreprecisedefinitionisthenewton(N),theamountofforcerequiredtoaccelerateamassofonekilogramatarateofonemeterpersecondpersecond.

Inthespecificationstablesyouwillalsofindtheforcegener-atedbyhydrauliccylindersexpressedasHydraulicpulldownandHydraulicpullbackspecifiedinlbfandkNunits.

Conversion table

Thisunit Times equals Thisunit Times equals Thisunit Times equals

length Ounce (US fluid oz) x 29.57 = ml mph (mile/hour) x 0.45 = m/s

mm (millimeter) x 0.001 (10-3) = m Pint (US liquid) x 0.4732 = l mph (mile/hour) x 1.61 = km/h

cm (centimeter) x 0.01 = m Quart (US liquid) x 0.9463 = l ft/s (foot/second) x 18.29 = m/min

dm (decimeter) x 0.1 = m yd3 (cubic yard) x 0.7646 = m3 ft/min (foot/minute) x 0.3048 = m/min

km (kilometer) x 1 000 (103) = m Force Frequency

in (inch) x 25.4 = mm kN (kilonewton) x 1 000 = N blow/min x 0.017 = Hz

ft (feet) x 0.305 = m kp (kilopond) x 9.81 = N kHz (kiloHertz) x 1 000 = Hz

yd (yard) x 0.914 = m kgf (kilogram force) x 9.81 = N rpm (rev/min) x 0.01667 = r/s

mile x 1609 = m Ibf (pound force) x 4.45 = N degree/second x 0.1667 = r/min

Power Torque(momentofforce) Pressure

J/s (joule/second) x 1 = W kpm (kilopondmeter) x 9.81 = Nm bar x 100 = kPa

Nm/s (newton meter/second) x 1 = W Ibf•in (pound-force inch) x 0.11 = Nm bar x 100 000 (105) = Pa

kW (kilowatt) x 1 000 = W Ibf•ft (pound-force foot) x 1.36 = Nm kp/cm2 x 0.98 = bar

hk (metric horse power) x 735.5 = W Mass(commonlybutincorrectlycalledweight) atm (atmosphere) x 1.01 = bar

hp (horsepower UK, US) x 745.7 = W g (gram) x 0.001 = kg psi (pounds/in2) x 6.895 = kPa

Volume t (tonnes, metric) x 1 000 = kg psi x 0.06895 = bar

l (liter) x 0.001 = m3 grain x 0.0648 = g area

ml (milliliter) x 0.001 = l oz (ounce) x 28.35 = g mm2 (square mm) x 0.000001 (10-6) = m2

dm3 (cubic decimeter) x 1.0 = l ozt (troy ounce) x 31.10 = g cm2 (square cm) x 0.0001 (10-4) = m2

cm3 (cubic decimeter) x 1.0 = ml lb (pound) x 0.4536 = kg in2 (square inches) x 645 = mm2

mm3 (cubic millimeter) x 0.001 = ml ton (long, US) x 1 016 = kg ft2 (square feet) x 0.0929 = m2

in3 (cubic inch) x 16.39 = ml ton (UK) x 1 016 = kg yd2 (square yard) x 0.8361 = m2

ft3 (cubic feet) x 28.316 = l ton (short) x 907 = kg Acre x 4 047 = m2

Imperial gallon x 4.546 = l Speed(velocity) Square mile x 2.590 = km2

US gallon x 3.785 = l km/h (kilometer/hour) x 0.2777 = m/s ha (hectare) x 10 000 = m2

Ounce (Imp. fluid oz) x 28.41 = ml m/s (meter/sec) x 3.6 = km/h

equals Dividedby Thisunit equals Dividedby Thisunit equals Dividedby Thisunit


BlaSThOleDRillS

RotaryblastholedrillsAtlas Copco offers the most comprehensive line of ro-tary blasthole drills in the industry. With a multitude of configurations to choose from, you can find the perfect solution for your needs. Many models can be configured for either rotary or DTH drilling, and our blasthole pro-ducts will drill holes from 4 inches to 16 inches indiameter.

Onthefollowingpages,youwillfindbasicspecificationsandbriefdescriptionsofthestandardandoptionalequip-mentavailableforeachmodel.Thedifferentconfigura-tionsofdrillrigsanddrillstringsmakeitpossibletofindhigh-performingsolutionsforavarietyofapplications.Safetyandergonomicdesignwithoperatorcomfortandwell-beinginmind,aswellassimplicityinmaintenance,havebeenafocusformanyyears–andarestilltoppriorities.

Whenselectingyourdrillrig,youmayhaveachoicebetweenhigh-pressurecompressorsforDTHdrillingor

low-pressureunitsforrotarydrilling,andbetweendieselorelectricpowerunits.Dependingonthedrillingpatternandbenchheight,youcanselectbetweendrillssuitableforangledrillingorsingle-andmulti-passdrilling.

Somerigmodels,liketheT4BHandtheDMseriesthatuseconventionalcontrolsystems,arewellknownthroughouttheminingcommunityfortheirruggedandreliabledesigns.ThenewerPitViperseries,withitsmoreadvanceddesigns,canbeequippedwiththeRCScom-puterizednetworkcontrolsystemasanoption,whichofferspossibilitiesfordifferentlevelsofdrillautomationandcommunication.

Thisisonlyabasicguide.Ourproductspecialistsaroundtheworldarepreparedtoprovideyouwiththeinforma-tionyouneedtoselectthebestdrillanddrillstringpackagetosuityourspecificapplication.


BlaSThOleDRillS


BlaSThOleDRillS

Technical data

DrillingMethod RotaryandDTH-Singlepass

HoleDiameter 4in-7in 102mm-178mm

HydraulicPulldown 25,000lbf 111kN

Weightonbit 25,000lb 11,300kg

HydraulicPullback 25,000lbf 111kN

Singlepassdepth 40ftor50ft 12.2mor15.2m

Maximumholedepth 40ftor50ft 12.2mor15.2m

Feedspeed 72ft/min 21.9m/min

Rotarytable,torque 3,500Ibf•ft 4.7kNm

Estimatedweight 62,000lb 28tonnes

Dimensions tower up (50 ft tower)

Length 30ft6in 9.3m

Height 74ft 22.6m

Width 12ft8in 3.9m

Dimensions tower down (50 ft tower)

Length 72ft 21.9m

Height 13ft 4.0m

Compressor range

Lowpressure,Rotary [email protected]/[email protected]

Highpressure,DTH [email protected]/min@24bar

Engine (Tier III)

Caterpillar C15 425HP@1800RPM(LP900)

Cummins QSX15 425HP@1800RPM(LP900)

Caterpillar C15 525HP@1800RPM(HP900)

Cummins QSX15 525HP@1800RPM(HP900)

Kelly specifications

Hole depth* Kellydiameter

Suggested bit diameters

Thread**size and type

40 ft (12.2 m) 27/8" (73mm) 4"-51/2" 23/8"IF

33/4" (95mm) 51/2"-7" 27/8"API

43/4" (121mm) 57/8"-7" 31/2"API

50 ft (15.2 m) 27/8" (73mm) 4"-51/2" 23/8"IF

33/4" (95mm) 51/2"-61/4" 27/8"API

43/4" (121mm) 57/8"-7" 31/2"API

*Cleanhole**Allkellyshavepinconnectionsonbothends

High pressure DTH drilling

Upto6"DTHhammerandmax.7"bitdiameter

Visitwww.atlascopco.com/blastholedrillsformoreinformation

DM25-SP

DM25

The Atlas Copco DM25-SP surface blasthole drill is designed for rotary and fast down-the-hole drilling in the hardest of rock. The heavy-duty gear drive on this tough drill delivers precise control at variable speeds without compromising power, while the hydraulic motor feed system provides smooth, continuous bit loading and rapid feed speeds to reduce drilling costs. The DM25-SP has the option for a 40 ft (42.2 m) clean hole tower or a 50 ft (15.2 m) clean hole tower.

Standardequipment• Spacious,thermalinsulatedandsound-attenuatedcab• Cabpressurizer/heater• Hydraulicallyretractabledusthoodwithskirting• Ninequartzhalogennightlightingpackage• Coolingpackageratedupto125°F(52°C)ambient temperature• Heavydutyenginesilencer/muffler• Separateairintakefiltersforengineandcompressor• Remotehydraulictowerpinning• Hydraulicallypoweredauxiliarychainwrench (DHDunitsonly)• 250-gallon(757l)fueltank• Hydraulicspurgearandplanetarydriverotarytable with0to170RPMandamaximumtorqueof3,500lbf•ft• Three48in.(1,219mm)strokelevelingjackswith18in. (457mm)pads• 68,000lb.(30,845kg)GVWratedexcavator-type undercarriage• 19.7in.(500mm)widetriplebargrousers• Separateairintakefiltersforengineandair compressor• Reinforcedrectangularsteeltrackframewith oscillationyokemounting• Fulllengthkellybarandkellysub• Deckservicecatwalkwithrailings• Backupalarm


BlaSThOleDRillS


BlaSThOleDRillS

DM30 Technical data

DrillingMethod RotaryandDTH-Multipass

HoleDiameter 5in-63/4in 127mm-171mm




Singlepassdepth 26ft 7.9m

Maximumholedepth 150ft 45m


Rotaryhead,torque 5,400Ibf•ft 7.3kNm


Dimensions tower up

Length 24ft4in 7.4m

Height 44ft4in 13.5m

Width 11ft10in 3.6m

Dimensions tower down

Length 42ft2in 12.9m

Height 14ft6in 4.4m

Compressor range



Engine (Tier III)





Drill pipe specification

Drill pipe diameter Suggested bit diametersv - rotary

Thread

4"(102mm) 5"–6" 27/8"API

4½"(114mm) 57/8"–63/4" 31/2"API

5"(127mm) 63/4" 31/2"APIorBECO


Upto6"DTHhammerandmax.6¾"bitdiameter


DM30

The Atlas Copco DM30 represents an ideal combination of versatility, economy, and power in blasthole drills. Atlas Copco drills have been hard at work serving the drilling community for over a century. Customers worldwide recognize Atlas Copco brand drills for quality, reliability, longevity and performance. The DM30 proudly carries on this tradition. Designed for quarrying and small mining applications, this versatile drill can be easily loaded onto a trailer and moved from one location to another.

Standardequipment• Spacious,thermalinsulatedandsound-attenuatedcab• Cabpressurizer/heater/ventilator• Hydraulicallyraiseddusthoodwithskirting• Ninequartzhalogennightlightingpackage• Auxiliaryhoistfordrillpipeandaccessoryhandling• Coolingpackageratedupto125°F(52°C)ambient• Heavy-dutyenginesilencer/muffler• Separateairintakefiltersforengineandair compressor• Remotehydraulictowerpinning• Powerindexedcarouselfortwo4,4½,or5in. ODx30ft.drillrods• Remotehydraulicforkchuckfordrillpipebreakout• Hydraulicallypoweredauxiliarychainwrench• 250-gallon(946l)fueltank• Rotaryheadwithsinglefixeddisplacementmotorwith 0to100RPMavailable,andamaximumtorqueof 5,400lbf•ft• Three48in.(1,219mm)strokelevelingjacks• 68,000lb.(30,845kg)GVWratedexcavator-type undercarriage• 19.7in.(500mm)widetriplebargrousers• Reinforcedrectangularsteeltrackframewith oscillationyokemounting• Deckservicecatwalkwithrailings• Back-upalarm


BlaSThOleDRillS


BlaSThOleDRillS

T4Bh Technical data

DrillingMethod DTHandRotary-Multipass

HoleDiameter 55/8in-97/8in 149mm-254mm




Singlepassdepth 22ft6inor27ft6in 6.8mor8.4m

Maximumholedepth* 147ft6inor177ft6in 45mor54.1m


Rotaryhead,torque 6,500Ibf•ft7,165Ibf•ft

8.8kNm9.7kNm



Length 28ft8in 8.7m


Width 8ft 2.4m



Height 13ft6in 4.1m

Compressor range




Engine (2TierII, 3Tier III)



Cummins QSK19C2 760HP@1800RPM(HP1250)


Drill pipe diameter Suggested bit diameters Thread

4" (102mm) 55/8"–6" 27/8"API

41/2" (114mm) 57/8"–63/4" 31/2"API

5" (127mm) 63/4"–73/8" 31/2"APIorBECO

51/2" (140mm) 63/4"–77/8" 31/2"BECO

61/4" (159mm) 77/8"–9" 4"BECO

7" (178mm) 9"-97/8" 41/2"BECO



*Maximumholedepthonlyachievedwithcertainpipesizesandwallthicknesses


T4BH

The Atlas Copco T4BH is synonymous with mobility, power, performance, and productivity. Mounted on a custom carrier, the T4BH is designed to perform in rough terrain and has been the leading blasthole drill in its class in the quarry and mining industries for over 35 years. The T4BH is a truck mounted, hydraulic tophead drive, multi-pass rotary drilling rig specifically designed for production blasthole drilling to depths of 150 ft. (45.7 m) with a 25 ft. (7.6 m) drill pipe change, optional 30 ft (9.1m) tower is also available with the 8 x 4 carrier option.

Standardequipment• Spacious,thermalinsulatedsound-attenuatedcab• Sixquartzhalogennightlightingpackage• Rectangulardusthoodwithskirting• Auxiliaryhoistfordrillpipeandaccessoryhandling• Coolingpackageratedupto125°F(52°C)ambient• Heavy-dutyenginesilencer/muffler• Separateairintakefiltersforengineandaircompressor• Powerindexedcarouselforfive4½inODx25ftpipe• Remotehydraulicforkchuckfordrillpipebreakout• Hydraulicallypoweredauxiliarychainwrench• 205-gallon(776l)fueltank• 4SV-2-10spurgear2-motorrotarytopheadwith 0to160RPM,andmaximumtorque6,500lbf•ft• Three48in.(1,219mm)strokelevelingjacks• Customdesigned3-axlecarrierwith380hp(283kW) dieselengine,10-speedtransmissionand16in. (406mm)wideflangeH-beamframe• Remotetowerpinning• Back-upalarm


BlaSThOleDRillS


BlaSThOleDRillS

DM45/DM50 Technical data

DrillingMethod RotaryandDTHMultipass

HoleDiameter 57/8in-9in 149mm-229mm




Singlepassdepth 27ft5in 8.5m

Maximumholedepth* 175ft 53.3m


Rotaryhead,torque 7,200Ibf•ft 9,76kNm

Estimatedweight 77,000lb-95,000lb

35tonnes-41tonnes

Dimensions tower up



Width 17ft2in 5.23m



Height 18ft 5.5m

Compressor range






Engine (Tier III)












Drill pipe diameter Suggested bit diameters

Thread

41/2" (114mm) 57/8"–63/4" 31/2"API

5" (127mm) 63/4"–73/8" 31/2"APIorBECO

51/2" (140mm) 63/4"–77/8" 31/2"BECO

61/4" (159mm) 77/8"–9" 4"BECO

7" (178mm) 9" 41/2"BECO

High pressure DTH drilling (DM45)

Upto61/2"DTHhammerandmax.8"bitdiameter



DM45

The Atlas Copco DM45 and DM50 are crawler mounted, hydraulic tophead drive, multi-pass rotary drilling rigs specifically designed for production rotary or DTH blasthole drilling to depths of 175 ft. (53.3 m) with a 30 ft. (9.1 m) drill pipe change.

Standardequipment• InsulatedcabwithFOPS80dB(A)• Cabpressurizer/ventilator/heater• Ninequartzhalogennightlightingpackage• Dusthoodwithcurtainsandhydraulicallyraising dustflap• Auxiliaryhoistfordrillpipeandaccessoryhandling• Heavy-dutyenginesilencer/muffler• Separateairintakefilterswithquickreleasedustdrop coversforengineandaircompressor• Gearindexingcarouselforfive4½in.x30ft.pipe• Slidinghydraulicforkwrenchfordrillpipebreakout• Hydraulicallypoweredauxiliarychainwrench• 350-gallon(1,324L)fueltank• 4SV-2-10twomotorhighspeedrotaryheadwith 0to160RPM,andamaximumtorque7,200lbf•ft• 30footdrillpipechange• No-bumprodchanger• Etherinjection• Jack-upindicatorlights• Three48in.(1,219mm)strokelevelingjacks• 23.6in.(600mm)widetriplebargrousers• Reinforcedrectangularsteeltrackframewith oscillationyoke• Walkwaysandrailings• Remotetowerpinning• Back-upalarm


BlaSThOleDRillS


BlaSThOleDRillS

DMl-SP Technical data

DrillingMethod RotaryandDTH-Singlepass





Singlepassdepth 50ftor60ft 15.2mor18.3m

Maximumholedepth 50ftor60ft 15.2mor18.3m

Feedspeed 100ft/min 60m/min

Rotarytable,torque 7,500Ibf•ft 10.2kNm

Estimatedweight 90,000-100,000lb 41-45tonnes

Dimensions tower up

Length(50fttower) 37ft6in 11.4m

Length(60fttower) 37ft6in 11.4m

Height(50fttower) 71ft7in 21.8m


Width 13ft10in 4.1m


Length(50fttower) 68ft 20.7m

Length(60fttower) 79ft 24.1m



Compressor range

Lowpressurerotary 1,200cfm@110psi/34.0m3/[email protected]



Highpressure,DTH 1,250cfm@350psi/35.4m3/min@24bar

Engine (2 TierII, 3 Tier III)






Cummins QSK192 755HP@1800RPM(LP1900)



Kelly specifications

Hole depth* Kellydiameter

Suggested bit diameters

Thread**size and type

50 ft. (15.2 m)or60 ft. (18.3 m)

43/4in.(121mm) 6"–63/4" 31/2in.Reg.

61/4in.(159mm) 77/8"–9" 41/2in.Reg.

7in.(178mm) 9"–97/8" 51/2in.Reg.

*Cleanhole**Allkellyshavepinconnectionsonbothends.


Upto7"DTHhammerandmax.87/8"bitdiameter


The Atlas Copco DML-SP is a crawler-mounted, hydraulic table drive, single-pass rotary drilling rig, specifically designed for production blasthole drilling to depths of up to 60 ft. (18.3 m) in a single pass without a drill pipe change. Nominal hole size range is 6 to 9-7/8 in. (152 to 251 mm) for rotary bit applications. The DML-SP has the option for a 50 ft (15.2 m) clean hole tower or a 60 ft(18.3 m) clean hole tower.

Standardequipment• InsulatedcabwithFOPS• Cabpressurizer/heater• Nine-quartz,halogennightlightingpackage• Rectangulardusthoodwithskirtingandhydraulically retractablefrontcurtain• Coolerpackageratedupto125°F(52°C)ambient temperature• Heavydutyenginesilencer/muffler• Separateairintakefilterswithquickreleasedustdrop coversforengineandaircompressor• Hydraulicallypoweredauxiliarychainwrench• 350-gallon(1,324l)fuelcapacity• Singlemotorrotarytablewithvariablehydraulic motor(0-100RPM)andamaximumtorqueof7,500lbf•ft• Hydrostaticmotorfeedsystem• Three48in.(121.9cm)strokelevelingjacks• 31.5in.(800mm)widetriplebargrousers• Reinforcedrectangularsteeltrackframewithoscillation yokemounting• Walkwaysanddeckrailings• Fulldepthkellybar• KellyRPMtachometeronconsole• Remotetowerpinning• Back-upAlarm• Etherinjection• Jack-upindicatorlights


BlaSThOleDRillS


BlaSThOleDRillS

DMl Technical data






Singlepassdepth 27ft5inor32ft5in 8.5mor10m

Maximumholedepth* 175ftor205ft 53.3mor62.5m

Feedspeed 146ft/min 0.7m/s


Estimatedweight 87,000-110,000lb 39.5-50tonnes




Width 16ft6in 5m



Height 17ft8in 5.4m

Compressor range




Highpressure,DTH(electricmotor) 1,050cfm@350psi/29.8m3/min@24bar


Highpressure,DTH 1,450cfm@350psi/41m3/min@24bar

Engine (2Tier II, 3Tier III )











Weg motor 6808 700HP@50–60Hz(LP1200orHP1050)



Thread

41/2" (114mm) 57/8"–63/4" 31/2"API

5" (127mm) 63/4"–73/8" 31/2"APIorBECO

51/2" (140mm) 63/4"–77/8" 31/2"BECO

61/4" (159mm) 77/8"–9" 4"BECO

7" (178mm) 9"–97/8" 41/2"BECO

75/8" (194mm) 97/8"–105/8" 51/4"BECO





The Atlas Copco DML is a crawler mounted, hydraulic tophead drive, multi-pass rotary drilling rig specifically designed for production blasthole drilling to depths of 175 ft. (53.3 m) with a 30 ft. (9.1 m) drill pipe change. An optional 35-ft. (10.7 m) steel change is also available to handle single pass drilling requirements. Various carousel capacities are also available for the 35-ft. (10.7 m) option.

Standardequipment• InsulatedcabwithFOPS• Cabpressurizer/ventilator/heater• Ninequartzhalogennightlightingpackage• Dusthoodwithcurtainsandhydraulicallyraisingdustflap• Auxiliaryhoistfordrillpipeandaccessoryhandling• Heavy-dutyenginesilencer/muffler• Separateairintakefilterswithquickreleasedustdrop coversforengineandaircompressor• Gearindexingcarousel• Slidinghydraulicforkwrenchfordrillpipebreakout• Hydraulicallypoweredauxiliarychainwrench• 350-gallon(1,324L)fueltank• 4SV-2-10twomotorhighspeedrotaryheadwith 0to160RPM,andamaximumtorqueof7,200lbf•ft• 30footdrillpipechange• No-bumprodchanger• Etherinjection• Jack-upindicatorlights• Three48in.(1,219mm)strokelevelingjacks• 33.5in.(850mm)widetriplebargrousers• Reinforcedrectangularsteeltrackframewithoscillation yoke• Walkwaysandrailings• Remotetowerpinning• Back-upalarm


BlaSThOleDRillS


BlaSThOleDRillS

PitViperPV-235

PV-235

The new Pit Viper series 235 blasthole drills offers several advanced options, like the RCS control system, remote tramming, auto levelling, and GPS navigation. The hydraulic system has been refined with load sensing and other features to reduce horsepower demand. There are several engine and compressor combinations available for either rotary or high pressure DTH drilling. The PV-235 can be supplied with any one of three towers - to drill 30 ft (9.1 m), 35 ft (10.7 m) or 40 ft (12.2 m) clean holes up to 9 7⁄8" (251 mm) in diameter.

Standardequipment• SpaciousthermalinsulatedcabwithFOPSandnoise abatedlessthan80dB(A)• Cabpressurizer/ventilator/heater• Twelvequartzhalogennightlightingpackage• Dusthoodwithcurtainsandhydraulicallyraising dustflap• Auxiliaryhoistfordrillpipeandaccessoryhandling• Heavydutyenginesilencer/muffler• Separateairintakefilterswithrubberdustevacuatorfor engineandaircompressors• Gearindexingcarouselfor5½inx30ftpipe• Slidinghydraulicforkwrenchfordrillpipebreakout• Hydraulicallypoweredauxiliarybreakoutwrench• 450gallonfueltank(1,700l)• 4SV-2-10twomotorhighspeedrotaryheadwith 0-160RPM,andamaximumtorqueof7,200lbf•ft• 30ftdrillpipechanger• No-bumprodchanger• Batteryandstarterlockablemaster-switcheswithjump startreceptacle• Jack-upindicatorlights• Four48in(1.2m)strokelevelingjacks• Triplebargrousers33.5in(850mm)wide• Reinforcedrectangularsteeltrackframewithoscillation yoke• Walkwaysandrailings• Remotetowerpinning• Back-upalarm

Technical data






Singlepassdepth 40,35,30ft 12.2,10.7,9.1m

Maximumholedepth* 240,210,180ft 73.2,64.0,54.9m

Feedspeed 140-193ft/min 0.7-1.0m/s

Rotaryhead,torque 5,200Ibf•ft7,800Ibf•ft

7.0kNm10.6kNm




Height 52ft8in 16m

Width 14ft6in 4.4m



Height 18ft8in 5.7m

Compressor range






Highpressure,DTH(electricmotor) 1,050cfm@350psi/29.8m3/min@24bar

Engine (3Tier III, 2Tier II)





Caterpillar C272 800HP@1800RPM(LP1900orHP1250)

Cummins QSK192 755HP@1800RPM(LP1900orHP1250)


Cummins QSK192 760HP@2100RPM(HP1450)

WEG 6808 700HP@50-60Hz



Thread

41/2" (114mm) 6"–63/4" 3"BECO

5" (127mm) 63/4"–73/8" 31/2"BECO

51/2" (140mm) 63/4"–77/8" 31/2"BECO

61/4(159mm) 77/8"–9" 4"BECO

7" (178mm) 9" 41/2"BECO

75/8" (194mm) 97/8" 51/4"BECO

8" (203mm) 97/8" 51/4"BECO






BlaSThOleDRillS


BlaSThOleDRillS

PitViperPV-271The PV-271 is designed to handle 6-¼" up to 8-5⁄8" drill rods. The cable feed system utilizes a dual rod/dual piston cylinder and offers high feed speeds for increased productivity. The PV-271 offers a 55 ft single-pass tower with a total depth capacity of 105 ft through a 2-rod carousel with 25 ft rods. It has an option to be delivered with the RCS computerized rig control system, incorporating functions like; remote tramming, auto levelling, auto drilling, and GPS navigation.

Standardequipment• Insulated,pressurized,airconditionedcabwithtinted glassandsuspensionoperatorseat• Caterpillar345XLundercarriagewithhydraulictrack tensioners• Hydrauliccylindersdrivencablefeedsystem• Hydraulicmotordrivenrotaryhead;maximum8,700lbf•ft torque;speedrange0-150rpm• Rotaryheadtachometeronoperatorconsole• Remotehydraulictowerpinning• Two-rodcarouselfor6¼"to8-5⁄8"drillrods• "No-bump"rodchanger• Hydraulicallypoweredbreakoutwrench(forkchuck)• HandsFreeauxiliaryhydraulicchainwrench• 8,000lb(3,629kg)capacityauxiliaryhoist• Hydraulicallyretractabledustcurtains• Coolingpackage• Separateairintakefiltersforengineandaircompressor• Wideflangestructuralsteelbeamframewithoscillation yokemounting• HydraulicTestStation• 12-lightnightlightingpackage-70watthalogen• Fulldeckservicecatwalksandrailings• Two48" (1.2m)andone60"(1.52m)strokelevelingjacks

Technical data

DrillingMethod RotaryandDTH–Singlepass






Maximumholedepth 105ft 32m




Dimensions tower up


Height 87ft 26.5m

Width 18ft4in 5.6m



Height 22ft1in 6.7m

Compressor range




Engine (Tier ll)






Weg motor 6808 700HP/671kW@50or60Hz




Thread

61/4" (159mm) 63/4"–9" 4"BECO

7" (178mm) 9"–97/8" 41/2"BECO

75/8" (194mm) 97/8"–105/8" 51/4"BECO

8" (203mm) 97/8"–105/8" 51/4"BECO

85/8" (219mm) 105/8" 6"BECO




PV-271


BlaSThOleDRillS


BlaSThOleDRillS

PitViperPV-275The PV-275 is designed to handle 6-¼" up to 8-5⁄8" drill rods. The cable feed system utilizes a dual rod/dual piston cylinder and offers high feed speeds for increased productivity. The PV-275 offers a multi-pass tower with 195-ft depth capacity through a 4-rod carousel with40-ft rods. It has an option to be delivered with the RCS computerized rig control system, incorporating functions like; remote tramming, auto levelling, auto drilling, and GPS navigation.

Standardequipment• Insulated,pressurized,airconditionedcabwithtinted glassandsuspensionoperatorseat• Caterpillar345SLundercarriagewithhydraulictrack tensioners• Hydrauliccylindersdrivencablefeedsystem• Hydraulicmotordrivenrotaryhead;maximum 8,700lbf•ft(11,800Nm)torque;speedrange0–150rpm• Rotaryheadtachometeronoperatorconsole• Remotehydraulictowerpinning• Four-rodcarouselfor6¼"to8-5⁄8"drillrods• "No-bump"rodchanger• Hydraulicallypoweredbreakoutwrench(forkchuck)• HandsFreeauxiliaryhydraulicwrench• 8,000lb(3,629kg)capacityauxiliaryhoist• Hydraulicallyretractabledustcurtains• HydraulicTestStation• Two48"(1.2m)andone60"(1.52m)strokelevelingjacks• Coolingpackage• 350U.S.gallon(1,325L)fueltank• Separateairintakefiltersforengineandaircompressor• Wideflangestructuralsteelbeamframewithoscillation yokemounting• 12-lightnightlightingpackage-70watthalogen• Fulldeckservicecatwalksandrailings

Technical data

DrillingMethod RotaryandDTH–Multipass






Maximumholedepth 195ft 59.4m




Dimensions tower up


Height 67ft 20.4m

Width 18ft4in 5.6m



Height 22ft1in 6.7m

Compressor range




Engine (Tier ll)










Thread

61/4" (159mm) 63/4"–9" 4"BECO

7" (178mm) 9"–97/8" 41/2"BECO

75/8" (194mm) 97/8"–105/8" 51/4"BECO

8" (203mm) 97/8"–11" 51/4"BECO

85/8" (219mm) 105/8" 6"BECO




PV-275


BlaSThOleDRillS


BlaSThOleDRillS

DM-M3 Technical data

DrillingMethod Rotary-Multipass






Maximumholedepth 200-240ft 61-73.2m




Dimensions tower up


Height 67ft 20.4m

Width 18ft11in 5.8m



Height 23ft9in 7.2m

Compressor range

Lowpressurerotary 2600cfm@110psi/73.6m³/[email protected]

Engine (Tier ll)

Caterpillar C32 950HP/709kW@1800RPM(LP2600)

Cummins QST30 950HP/709kW@1800RPM(LP2600)

Weg motor 6811 900HP/671kW@50or60Hz(LP2600)



Thread

75/8" (194mm) 97/8"–105/8" 51/4"BECO

85/8" (219mm) 105/8"-11" 6"BECO

91/4" (235mm) 11"–121/4" 6"BECO

103/4" (273mm) 121/4" 8"BECO


The Atlas Copco DM-M3 is a crawler-mounted, hydraulic tophead drive, multi-pass rotary drilling rig specifically designed for the blasthole drilling of 9-7⁄8 in. (251 mm)to 12-¼ in. (311 mm) diameter holes. The on-board depth capability is up to 240 feet (73 m) when using 8-5⁄8 in.diameter (219 mm) drill pipe and a 5-rod carousel. Standard drill pipe length is 40 feet (12.2 m). Hydraulic pulldown is featuring a patented hydrostatic, closed-loop system acting through twin, double-rod hydraulic cylinders and cable.

Standardequipment• Insulated,pressurizedFOPScabwithheater• Rotaryscrew2600CFM@110psiair compressor• CaterpillarC32dieselengine(950HPat1800rpm)• Six-light,70wattquartz-halogennightlightingsystem• Cabandladderaccesslightsplusdustcurtainlight• Coolingpackage• Remotehydraulictowerpinning• Auxiliaryhoistof8,000lb(3,600kg)capacitywithliftingbail• Hydraulically-actuated,drillpipecarouselinternaltotower for4drillpipeor5for8-5/8"in.diameter40ft.• Hydraulicslidingforkchuckbreakoutwithauxiliary hydraulicwrench• 650U.S.gallon(2,460L)fuelcapacity• Wideflangestructuralsteel"I"beammainframewith oscillationyokemounting• Separatethree-stageairintakefiltersforengineand compressor• Rotaryheadtachometer• Threehydrauliclevelingjacksand"jacks-up"indicatorincab• Hydraulicallyactuatedrodsupportarmtoaligndrillpipe duringrodchangingoperationsandwhenusingtheangle drilloption• Fullwalkwaysandrailings• 35.5in(900mm)wide,triplebarreplaceblegrouserpads

DM-M3


BlaSThOleDRillS


BlaSThOleDRillS

The Pit Viper 351 is a crawler-mounted, hydraulic tophead drive, multi-pass rotary drilling rig specifically designed for the blasthole drilling of 10-5⁄8" to 16 in diameter holes. It has a single-pass depth capability of 65’ (20 m) with total depth capability of 135’ (41 m). Its hydraulic driven cable feed system is capable of 125,000 lbf. (511 kN) of bit loading. Due to the light weight of the cable feed system the PV-351 can operate with a “live tower”. A patented automatic tensioning system is eliminating down time for cable adjustments. It has several advanced options like an auto drilling system, auto levelling, remote tramming, and GPS navigation.

Standardequipment• RCSrigcontrolsystem,computerizednetwork• Insulated,airconditionedcab• 3000CFM(84.9m3/min)@110psig(7.6bar)aircompressor• Caterpillar385Customundercarriagewithhydraulic propelandautomatichydraulictracktensioning• Hydrauliccylinderdrivencablefeedsystem• Hydraulicmotordrivenrotaryhead• Tworodcarouselfor8-5/8"to13-3/8"diameterx35’drillpipe• “No-bump”rodchanger• Hydraulicallypoweredbreakoutwrench(forkchuck)• HandsFreeauxiliaryhydraulicchainwrench• 12,000lb(5440kg)capacityauxiliaryhoist• Hydraulicallyretractabledustcurtains• Four72inch(1.83m)strokelevelingjacks• Coolingpackage• 1200U.S.gallon(4545L)fueltank• Separateairintakefiltersforengineandaircompressor• WideflangestructuralsteelI-beamframewithoscillation yokemounting• Fulldeckservicecatwalksandrailings• Automaticlubricationsystem• NordicNightlightpackage• Attentionhorn,propelalarm• Groundlevelshutdowns• Deckingintower(whenhorizontal)aboverodchanger

PitViperPV-351 Technical data

DrillingMethod Rotary-Singlepass

HoleDiameter 105/8in-16in 270mm-406mm


Weightonbit 125,000Ib 56,700kg



Maximumholedepth 135ft 41.1m

Feedspeed 127-158ft/min 0.6-0.8m/s


Estimatedweight 385,000lb-415,000lb

175tonnes-188tonnes

Dimensions tower up



Width 26ft81/2in 8.1m


Length 98ft 29.9m


Compressor range


Lowpressurerotary(electricmotor)

3,200cfm@110psi/90.6m3/[email protected]


Engine (Tier l)

Caterpillar 3512 1650HP@1800RPM

Cummins QSK45 1500HP@1800RPM




Thread

85/8" (219mm) 105/8"-11" 6"BECO

91/4" (235mm) 11"–121/4" 6"BECO

103/4" (273mm) 121/4"-13" 8"BECO

123/4" (324mm) 15"–16" 8"BECO

133/8" (340mm) 16" 10"BECO


atlascopco.com

PITVIPER 351


BlaSThOleDRillS

DRillRigOPTiOnS


electricpowerpack

Asanalternativetoadieselengineasthemainsourceofpower,severaldrillmodelscanbeconfiguredwithanelectricpowerpackage,consistingofanelectricWEGmotor,starterandtransformer.Electricver-sionsareusuallylesscostlytooperateduetofewerlubricants,havinganintegratedcoolingsystem,andnodieselfuelcosts.Insomecases,theoperatingcostadvantagewillinoneyearcovertheadditionalinvestmentcostfororderinganelectricversion.Theservicelifeofanelectricmotorisconsiderablylongerthanforanequivalentdieselengine,andhasquieteroperation.

Weg motor options are available for: DML,DM-M3,PV-235,PV-271,PV-275,PV-351

FourjackconfigurationStabilityinthesetupofthedrillrigisimportantforthedrillingoperations.Alldrillrigsareprovidedwithhydrauliclevelingjacks,asabasic“tripodarrangement”somemodelshaveanoptionofafourjackarrangementwherethetwonondrillingendjacksaretiedtogetheractingasoneoutrigger.

Available for:DML,DM-M3,PV-271,PV-275

StandardequipmentforPV-235andPV-351

DRillRigOPTiOnS


angledrillingpackageTheAtlasCopcoadvancedangledrillingpackageallowsthetowertobepositionedfromtheverticalinincrementsof5degrees.Allcontrolsforpositioningarelocatedattheoperatorscontrolconsoleinsidethecab.Thissystemchangesthepivotpointonthetowertodrilldecklevelandensuresthattheholewillalwayscollarwithinthedusthood.Thisdesignalsoprovidesforstabilityandensuresthataminimumlengthofthedrillpipewillbeunsupportedbetweenthecentralizerandthecollar.Goodstabilityandguidanceofthedrillstringduringcollaringanddrillingwillreduceholedeviation.Highprecisionindrillingandblastingwillimprovefragmentationandcontributetoloweringoverallproductioncosts

Available for:PV-235,PV-271,PV-275,DM-M3,PV-351

Variationsoftheangledrillpackageareavailableonallothermodels

Coldweatheroperation• Tosecuretrouble-freeoperationandapleasant operator’sworkingenvironment,thereareseveral coldweatheroptionsavailableincluding:additional cabheater,hydraulicoilanddieselengineheating, tankheaters,arctichosesandcoldweatherfluids.

• Awellinsulatedandheatedwaterinjectionsystemis available.

• Gen-setsareavailableforsomemodelsofdrillrigs

• Fullyutilizedtheseoptionsallowthedrillrigsto operateinarcticconditions.

DRillRigOPTiOnS


autothreadlubricationsystem

Centrallubricationsystem

Thesystemincludesacabactivatedbuttonthatinitiatesflowofgreasethroughapneumaticpumptoanozzle.Thenozzleislocatedonthedrilltable,andspraysthegreaseatthepipejointthreads.Thishelpstoextendthelifeofyourpipethreadswhenchangingrods.

TheQuicklubelubricationsystemisdesignedtoprovidearelativelysimpleandinexpensivemethodofcentralizingandautomatingthelubricationofmachinerybearings.

Thesystemdispensessmallmeasuredamountsoflubricantatfrequentintervalswhilethemachineisoperating.Withafullyautomatedsystem,thelubricantissuppliedbyaelectricpumpthroughoneormoredistributionblockstoeachpointcoveredbythesystem.Eventhosehardtoreachareassuredofbeingproperlylubricatedandpurgedofcontaminants.

Upto300lubricationpointscanbeserved,dependingonthelengthofthehose.• Reliablydistributedlubricantinpredetermined amounts• Deliverslubricanttotheconnectedlubricantpointsin asafemanner.• Eachlubricationcircuitisequippedwithasafetyvalve thatholdsthepressurewithinpermissiblevalues.• Ifthereisablockinalubricationcircuit,lubricantwill leakfromthesafetyvalve.• Worksthroughlubricationcycles(intervaltime, propagationtimeandloadtime)

Canbeusedincoldweatherapplicationsifspeciallowtemperaturegreaseisused.

DRillRigOPTiOnS


FiresuppressionsystemAdry-chemicalfiresuppressionsystemcanbeprovidedwithmanualactivationpoints.Thesystemisprovidedwithcanister(s)thatarelocatedonthedeckofthemachine.

Thefiresuppressioncanistercontainadrychemicalfiresuppressantwhichutilizesanitrogencartridgeforthepneumaticactuator.Severaldischargenozzleslocatedthroughoutthemachinewillspraythesuppressantwhenthesystemisactivated.ThisfireextinguisheragentsisratedforextinguishingtypeA(trash/wood),typeB(liquids)andtypeC(electricalequipment)fires.Thefiresuppressioncanistercanberechargedasneeded.

CentralhydraulicteststationThecentralhydraulicteststationallowsfortestingofcomponentpressures.Astandardtestfittinggaugecanbeusedandpluggedinintothedesiredportforreadingofthesystempressure.Thehydraulicteststationismountedonthedeckforeasyaccessibility.

Available for:T4BH,DM45,DML,PV-235,DM-M3StandardequipmentforPV-271,PV-275

(not required for RCS rigs - electronic sensors are included in the RCS system)

DRillRigOPTiOnS


WaterinjectionsystemThewaterinjectionsysteminjectsaregulatedquantityofwaterintotheairflowgoingtothedrillpipe.Thewatercontentintheair-flushingsuppressesthedustcreatedbythedrillingoperation.Thewaterinjectionsystemhasahydraulicmotordrive,andisoperatedfromthecabcontrolsystem.

Thereareseveralsizesofwaterinjectionsystemsavailable,andtheinjectiontanksareeithermountedwithintheframeoronthedecktoensurethedrillingwaterrequirementsaremet.

DustcollectorDifferentsized“novisibleemission”drydustcollectorsareavailable.Thedesignfeaturesapleatedpaperelementtypefan/filterunit.Intervalflushingiscontrolledbyanelectronictimer.Avacuumhoseallowsthefan/filterunittodrawthedustoutofthecollectionarea.Thedustisremovedfromtheairstreamastheairflowsthroughthepleatedpaperfilterelements.Heavycuttingsarecontainedaroundthehole.Operationofthedustcollectoriscontrolledfromthecabcontrolsystem.

DRillRigOPTiOnS


Fastservicesystem

groundlevelshutdown

Thefastservicesystemconsistsofgroundlevel,quickconnectfittingsforfillandevacuationoffuel,hydraulicoil,engineoil,compressoroil,enginecoolant,andwater(onsomemodels).

Allrigsareprovidedwithastandardemergencyshutdownbuttonmountedinthecab.Asanoption,oneorseveraladditionalgroundlevelshutdownbuttonscanbeprovidedformountingoutsideofthecab.Bypressingthegroundlevelshutdownbutton,thepowertotheengineisdisconnected.

RacorfuelfilterTheRacorfuelfilterisspecificallydesignedtoseparateoutanywaterthatmaybeinthefuellines,andaRacorfuelfilterwithheateroptionasshownisavailableforsomemodels.

DRillRigOPTiOnS


Remote control unit with cord connection.

Remotetrammingsystem

Videocamerasystem

Theoptionalremotetrammingsystemofferstheoperatortheabilitytomovetherigfromadrivependantwhichcanbewornontheoperator’sshoulders.Theremotetrampendantisconnectedtotherigbyacord,andisoperatedbysimilarjoysticksastheseusedontheoperator’spanelinthecab.

Available for:DM45,DML,PV-235,PV-271,PV-275,(nonRCSrigs),DM-M3

Information from the OU unit is radio transmitted to the RRC Machine Unit and executed by the RCS.

Forimprovedsafetyandvisibilityaroundthedrillriganoptionalvideocamerasystemcanbeinstalled.ThesystemconsistsofthreeorfourrigmountedvideocamerasandaLCDdisplayscreenmountedinsidethecab.Eachcamerahasamotorizedlenscoverforprotection,andcontainsaheaterwhichautomaticallyturnsonwhenthetemperaturefallsbelow50°F(10°C).Thecamerasareinstalledinwaterresistanthousings,completewithilluminatorsforlowlightconditions.Thecameraimagedeviceisaninterline–transfer0typeCDC,withapictureresolutionof270,000pixels(horizontalresolutionof380TVlinesandaverticalresolutionof350TVlinesThemonitorisa6.8"LCDscreenwithanautodimmer.Screenresolutionis270.000pixels,andscreencontrolsinclude:bright,contrast,color,tint,imageselectable,autoscantimeandscale(on/off)

Available for: PV-235,PV-271,PV-275,PV-351

Radioremotecontrol

The RRC radio remote control Operator’s Unit (OU unit) with all controls and indicators ( for drill rigs with RCS option).

WirelessremotetrammingfunctionallowstheoperatortotramaPitViperfromthebenchwithina60mdistance.

Available for: PitViperwithRCS(seepage25fordetailsonRCSpackage)

DRillRigOPTiOnS


StereoradiowithCDplayerTheoperator’scabcanbeequippedwithastereosystemwithAM/FMradio,CDplayer,mp3jackandspeakers.Thepackagealsoincludesabatteryequalizerfor24Vto12VDCconversion.

Available for: DM45,DML,PV-235,PV-271,PV-275,DM-M3,PV-351

enginepre-lubesystemSpecialenginepre-lubeassemblysystemsareavailablebothforCumminsandCATdieselengines.Theenginepre-lube,lubesthevalvezonepriortoenginestartup,givingthebenefitoflesswearandtearontheengineovertime

Available for: DM45,DML,PV-235,PV-271,PV-275,DM-M3,PV-351,

StandardequipmentforPV-351(Cummins)

TowingpackageTowhooksoratowbarmountedonthenondrillendoftherigallowfortowing.

Available for:DM45,DML,PV-235,PV-271,PV-275,DM-M3,PV-351

DRillRigOPTiOnS


Sodium240VoltnightlightpackageThe240VACnightlightpackageconsistsofadditional400Watthighpressuresodiumlightsandadditional150Watthighpressuresodiumlights.Theselightsareinstalledinadditiontothestandardlightpackageontherigandrequirepowerfromanexternal240VACpowersource(likeanoptionalgen-set).

Available for:DM45,DML,PV-271,PV-275,DM-M3

StandardequipmentforPV-351Electric

highintensitydischargelightsThehighintensitydischarge(HID)nightlightpackageconsistsofupgradingthestandardhalogenlightstoXenon24V,35Wattlamps.WiththisupgradetheHIDlampswillbemountedinthestandardlamplocations.TheHIDlampshavegreatluminousintensityandacolormimickingnaturaldaylight.Theselampsaredesignedspecificallyforforestry,miningandearthmovingapplications,andaredesignedtohavelowpowerconsumption.Lightscanbeturnedonwhentheengineisonoroff.

DRillRigOPTiOnS


Buddyseat

Torquelimitcontrol

Ifanadditionalseatisrequiredinthecab,afold-upbuddyseatcanbemountedinsideoneofthecabinwalls.

Available for:DM45,DML,PV-271,PV-275

Standardseat:PV-235,PV-351

Rotationaltorquelimitcontrolisstandardonhighpressuredrillrigs,andisanoptionavailableforlowpressurerigs.Thetorquelimitgaugeandcontrolleraremountedinthecabandoperateanelectricallycontrolledremotevalve.Torquelimitcontrolisusedtolimittherotationpressurewithintheclosedlooprotationcircuit.

Available for:DM25,DM30,DM45,DML,PV-235,PV-271,PV-275

CabsunshadesPulldown,fabricsunshadeslocatedonallwindowsareavailable.

Available for:DM45,DML,PV-235,PV-271,PV-275,DM-M3,PV-351

DRillRigOPTiOnS



ROTaRyDRillingTOOlS

Triconerotaryblastholedrilling Introduction

animpressivelegacyAtlasCopcoSecorocLLC.tracesitsbeginningsbacktoHowardHughes,Sr.,inventorofthefirsttwo-conerotarydrillbitforrockin1909.“Ourpurposeistoneverbesatisfiedbutwillcontinue,withthehelpofourexperi-encedengineers,toanticipatetherequirementsofthedrillingindustry.”ThewordsspokenbyMr.HughesarevalidatAtlasCopcoSecorocLLCtoday.HowardHughes,Sr.leftbehindanimpressiveinventor’slegacy,havingheld73distinctpatents.Thecompanycontinuedtobealeaderindevelopment,withtheintroductionofthefirstTriconeTMrockbitwithinter-fittingteethin1933,andthefirstTungstenCarbideInsertrockbitsin1951.

loweringourCustomersTotalDrillingCost(TDC)AtlasCopcoSecorocLLCisdedicatedtoreducingthecustomer’stotaldrillingcostswhilemaintainingthehigheststandardsofquality.AtlasCopcoSecorocLLChasrepeatedlyshowncustomersthatabetterbit,thoughmoreexpensive,actuallyreducesthecostofthedrilledhole.Whenaminingengineerorapurchasinggrouptakesintoaccountthetotalcostofoperatingadrill,itiseasytoseethatthebestwaytocutcostsistodrilltheholefaster.

Ourgoalisnottojustmeetyourexpectations,buttoexceedthem.Aspartofourcommitmenttocontinuousimprovement,weconstantlylookforwaystomakeourproductsdrillfasterandmoreefficiently.

TriconesorDTh?Howdoyoudecideonwhichdrillingmethodtouse,RotaryTriconedrilling,orDownTheHolehammerdrill-ing?Eachhasseveralfactorsinitsfavor.DTHdrillinginhardgroundgenerallyhashigherpenetrationratesthanTriconedrilling,andexertslesswearandtearonthedrillbecauseheavy“pulldown”forcesarenotusedwithDTH.Butitismuchmorelabor,consumables,andinventoryintensivethantriconedrilling.Insoftground,DTHdrill-ingtendstobeproblematic.DTHlosesitspenetrationrateadvantageat9to10inchdiameter(229-254mm)in“hard”rock.

TriconedrillingcanmovemuchmorematerialinagivenamountoftimethanDTHdrillingduetothegenerallylargerdiametersused,butTriconedrillingmaybealess“oregradesensitive”methodduetolargerbitdiametersandthereforegreaterholeburdenandspacingsused.

Ultimately,themine’s“productioncost”istheeconomicdriver:attheendoftheday,whichmethodgivesthelowestCOSTPERTONofmaterialblasted?

Let’sconsiderthisexample,forastraightforward“rockremoval”scenario:• 121/4”Triconebitandsuitabledrill• 100feet(30.5m)perhourpenetrationrate• 50foot(15.2m)benchheight,plussubdrill• US$300/hourdrilloperatingcost• 9”DTHandsuitabledrill• 50foot(15.2m)benchheight,plussubdrill• 125feet(38.1m)perhourpenetrationrate• US$200/hourdrilloperatingcost

Whichmethodhasthelowestcostperton?UsingtheHustrulidblastingcalculationspresentedinthevariousAtlasCopcoAcademysessions(whichcalculateburden,spacing,subdrill,andstemmingbasedonholesize,faceheight,androckandexplosiveSG),weseethefollowingproductioncosts:

Inthisexample,DTHdrillingisalmost50%morecostlythanusingTricones.Infact,ittakesanother17%in-creaseinRateofPenetration,to146feet/hour,fortheDTHmethodtoequaltheCostperDrilledTonoftheTriconemethod.

Dependingonthecommoditymined,thegeometryoftheminingbenches,thetonnageproductionrateneeded,etc.,itisadvisedthatrotaryTriconedrillingalwaysbeinvestigatedasamorecosteffectivewaytocorrectlyservethecustomer.

12¼"Tricone&Bigdrill

9"DTh&Smalldrill

$300 CPH $200

100 ROP 125

5676.9 Tons per hour produced 3970.2

1 Drill required for tonnage 1.430

$0.053 Op cost/ton/drill $0.050

$0.053 Actual cost/drilled ton $0.072


ROTaRyDRillingTOOlS

Triconerotaryblastholedrilling Elements of a rock bit


ROTaRyDRillingTOOlS

Triconerotaryblastholedrilling Bit elements

Cones

Conesmakeupthecuttingelementsoftherockbitandarecomprisedofthefollowing:

1. TungstenCarbideInserts-whicharepressedinto thesoftersteelmaterialwithinterferencefittohold iteminplace.

2. ConeThrustButton-Madeofawearresistant materialusedtotakeaxialbearingloads.

3. OuterConeShell-Insertland’sandconegrooves.

4. ConeBore-Internalballandrollerbearingraces.

CarbideinsertRows

A. NoseB. InnerC. NexttoGageD. GageE. GageBevel


ROTaRyDRillingTOOlS

Triconerotaryblastholedrilling Bit elements

lugs

Coupledinthrees,by120ºtoformthebitbodyandthepinconnection,thelugsaremachinedtoholdthenozzlesandajournal-bearingsurface.

nozzles

Nozzlesareusedtocreateback-pressureinthebittoforceairthroughthebearingairwaysandincreasethe“air-blast”forcetoremoveandflushcuttingsfromthebottomofthehole.Toolargeofanozzlewillcauseinsufficientvolumesofairtobedeliveredtothebearings,whiletoosmallofanozzlewillincreasetheback-pressureabovethecompressormodulationsetting.Whenthecompressor’smodulationsettingisreached,itwillthenreduceit’svolumeoutputcausingadecreasein(air?)volumegoingtothebit.


ROTaRyDRillingTOOlS

Triconerotaryblastholedrilling Tricone bit inserts

Inserts are the actual physical elements that spall and break the rock. Inserts are made from tungsten carbide pow-der and a cobalt binder material, which is pressed into the designed shape then sintered. Depending on the applica-tion, the tungsten carbide inserts in a given bit will have a shape and physical properties best suited for the rock being drilled.

ConicalTheconicalinsertisusedprimarilyinmedium/medium-hardrock.ItisdesignatedinthebitnomenclaturewithaC.

ChiselThechiselinsertisusedinsoft/medium-softrock.Itisthestandardinsertinsoftbits(40’s&50’s)andisdesignatedwithanFinthebitnomenclature.

OgiveTheogiveinsertisusedinareaswheretheaggressivenessoftheconicalinsertisrequiredwithadditionaltoughess.TheogiveisdesignatedasanOinthebitnomenclature.

SuperScoopThesuperscoopisusedinverysoftrock.Withthepatentedoffsettip,diggingandgouginghelppenetrateinstickymaterials.ThesuperscoopisdesignatedwithanSinthebitnomenclature.

RoundtopTheovoidorroundtopinsertisusedinthehardestformations.Itsbluntgeometrygivesitthemostfractureresistantdesign.Theroundtopisthestandardin-sertinhardbits(60’s70’s&80’s)andisdesignatedwithanNinthebitnomenclature.

SerratedflattopSerratedflattopinsertsareusedonshirttaillipsandalongthelugas“armor”toprotectagainstshirttailandlugwear.

WedgecrestedchiselWedgecrestedchiselinsertsareusedexclusivelyonthegagerowsofverysofttohardbits(40’sthrough60’s).Thisshapegivesafractureresistantinsertthatismuchtougherthanconcialorregularchiselinsertsongage.

90ºChiselortrimmerThetrimmerisusedspecificallyintheMAGNTproductline.Itenhancesthegagerowsabilitytocuttheboreholewall.TheMAGNTfeatureisusedinsofttomediumbrittlerockforma-tions.


ROTaRyDRillingTOOlS

Atlas Copco Secoroc LLC uses the IADC (International Association of Drilling Contractors) code along with the product line and added bit features to help describe the bit. The IADC code is a three numbered system to clas-sify the hardness and type for all roller cone rock bits.

Firstdigit–identifiesthebittypeandmajorhardnessclass:1–SteelToothforsoftformations

2–SteelToothformediumformations

3–SteelToothforhardformations

4–Insertforsoftformations

5–Insertforsoft/medium,formations

6–Insertformedium/hardformations

7–Insertforhardformations

8–Insertforextremelyhardformations

Seconddigit–Designatesthehardnesssubclassofmajorhardnessclass.Thisrangesfrom1to4,where1isclassifiedasthesoftestsubclassand4isthehardestsubclass.

Thirddigit–Designatesthebit’sfeatures:1–Rollerbearing

2–Rollerbearingair-cooled

3–Rollerbearingwithgagebevelinserts

4–Sealedrollerbearing

5–Sealedrollerbearingwithgagebevelinserts

6–Sealedfrictionbearing

7–Sealedfrictionbearingwithgagebevelinserts

8–Directional

9–Other

Example: IADC6-3-2 Thisisamedium/hardair-cooledroller bearing.

Example: 121/4MAGNT53CA 21/4–Size MAGNT–ProductLine 53–FirsttwodigitsoftheIADCcode (rockclass“5”subclass“3”) C–Inserttype(Conicalinserts) A–Fullarmoredlug

Triconerotaryblastholedrilling Nomenclature

Productlines:

• MAGNT–MaximumActiveGage(MAG)/New Technology(NT).Usedinsoft/mediumbrittle material.Featuresincludeenhancederosion resistanceandnewbearinggeometries.

• HDNT–HardDrilling(HD)/NewTechnology(NT). Mediumhardtohardformationbits,withnewcarbide grades,aggressivecuttingstructuresandenhanced bearings.• eM–epsilontechnologyevolvedfromtheMAG productline.Widevarietyofdrillingapplications usingstreamlinedlugsforgreaterbailingareaand allowingrapidevacuationofcuttings.Balancedcut tingstructuresforimprovedbearingloading,lowered carbidestressandhighercapacitybearingsforlonger life.

• eH–epsilontechnologyevolvedfromtheHDproduct line.Widevarietyofdrillingapplicationsusing streamlinedlugsforgreaterbailingareaandallowing rapidevacuationofcuttings.Balancedcuttingstruc turesforimprovedbearingloading,loweredcarbide stressandhighercapacitybearingsforlongerlife.

insert/ToothType:• C–Conical• N–RoundTop • O–Ogive• S–SuperScoop• F–Chisel• 1–ConventionalGageTooth• 2–TaperedGageTooth• 3–“T”GageTooth• 4–“L”GageTooth• 5–“Web”GageTooth

Ovoidsarestandardinserts anddonothavesuffixes.

lugFeatures:• A–Armor• B–Backreaming• ST–Shirttailprotectionintoothbits• L–Streamlinedlug• R–Regularcirculation

OtherFeatures:• H–HardNoseoncones• G–Gagebevelontoothbits• T–Toughcarbide(breakageresistant)• W–Wearresistantcarbide


ROTaRyDRillingTOOlS

Steeltoothbitselection

Softformationbits

TheTypeS,regularcirculationsteeltoothbitisdesignedforoptimumperformanceinformationsoflowcompres-sivestrength,suchassoftsandrock,calcite,shaleandclay.Theseformationsquiteoftencontainabrasivema-terialssuchassharpsandandmaybeinterspersedwithlayersofmediumandhardformations.

Softformationbitsaredesignedwithlongslim,strongteethtopermitdeeppenetrationintotheformationwithcomparativelylightweight.Also,bitgeometryisadjustedtogivemaximumdesirablescrapingactiononbottom.Sospecificrangeoffootageorpenetrationratescanbeusedasayardstickfordeterminingwhentostopusingthistypebit,duetowidevariationinweight,rotaryspeedsandformationvariationsencountered.However,ifexcessivetoothbreakageoccurs,youmightsafelyassumethateitherthecombinationofweightandrotaryspeedistoogreatorformationistoohardforthistypebit.

Normally,thesebitsarerunwithrelativelylightweights,rangingfrom1,000poundsto3,000poundsperinchofbitdiameter.Rotaryspeedsusuallyrangefrom120to170revolutionsperminute,dependingupontheweightappliedtothebit.

Mediumformationbits

TheTypeMandregularcirculationsteeltoothrackbitsaredesignedforabrasiveandnon-abrasivemediumfor-mations.Notethatthisdesigndiffersfromthe“softer”typesprincipallyintheprogressivestrengtheningoftheteethandchangeinbitgeometrytoprovidemorechipping-crushingaction.Thesebitshavemorecloselyspacedteethwithalargeincludedangleandmoregagesurfacetoresistthewearinharderandmoreabrasiveformations.Theyareparticularlyefficientinformationswhereshales,sandyshales,andlimestonesalternate.Weightcanbeappliedveryeffectivelytothesebitsduetothemoreruggedconstructionofthecuttingstructureandbearings.However,excessiverotaryspeedsshouldbeavoidedtoreducetheshockloadsinherentindrill-ingtheseharderformations.Thisisespeciallyimportantwhenformationsarebroken,causingroughoperation.Youshouldavoidcombinationsofweightandrotaryspeedswhichpromoteroughrunningtopreventpre-maturefailureofbearingsandcuttingstructure.Drillingweightscommonlyrangefrom1,000to5,000poundsperinchofbitdiameter,withrotaryspeedsfrom60to100revolutionsperminute,dependingupontherelativeweightonthebit.

0

Unconsolidated Sands

2,000 Limestone, Siltstone

Clay Stone, Mudstone

4,000

Marl, Chalky Limestone

6,000

Soft Shales

8,000

Consolidated Sandstones

10,000

Soft Marble, Dolomite

12,000

Tuff, Soft Schist

14,000Rock UCS hardness (Unconfined Compressive Strength) is only one factor contributing to the “drillability” of any rock. Other factors influencing drillability are fracture toughness, shear strength, Young’s modulus of elasticity, Poisson’s ratio of stress vs. strain & internal angle of friction. Any particular bit may be used in harder or softer rock than this chart indicates.

S series

M series

H series

SteeltoothTriconerockbittypevs.rockhardness

RockUCS(PSi) SteeltoothTriconebitseries RockType

Hard formation bits

TypeH,regularcirculationsteeltoothrockbitsarede-signedtodrillhardformationswhichcontainamountsofabrasivematerials.Formationsrequiringtheuseofthisbittypearethosehaving:

1. Highcompressivestrengthwithlowabrasivecontent suchasdolomite.

2. Highcompressivestrengthwithhighabrasivecontent suchasdolomiteandtraprock.

3. Mediumcompressivestrengthwithhighabrasive contentsuchasquartz,sandstoneandthecopper ores.

Comparedwiththesoftandmediumformationbits,thisbithashighercapacitybearingsandmorecloselyspacedteethwithincreasedtoothanglestoallowtheuseofheavierweightsrequiredtoeffectivelydrillhardforma-tions.Thegeometryofthisbitprovidesmaximumchip-pingandcrushingactionwithminimumscrapingaction.

Theoutermostrowofteethoneachconeisthedriv-ingrow;thatis,thisrowgeneratesarockgearpatternonbottom,whichinthecaseofthesestrongrocks,isnoteasilybrokenup.Becauseofthis,awebbedgagesurfaceisgenerallyusedonheelrowsofteethtokeepthepatternsbrokendown.

Tungstencarbidehardfacingisappliedtothe“webs”tostrengthenthegageagainstabrasivewear.

TypeHbitsarecommonlyrunwithweightsrangingfrom4,000to7,000poundsperinchofbitdiameterwithrotaryspeedsdecreasingfrom40to80revolutionsperminuteasweightisincreased.


ROTaRyDRillingTOOlS

Steeltoothbits Bit specifications

SSeries

TheSserieshaswidelyspaced,longtaperedteethwithbroad,axialcrestsforthebottom-holeactionnecessarytoachievehighpenetrationrates.Inter-fittedrowsofteethpreventformationpackingandfacilitatethecleaningaction.Thegagebevelishardfacedforwearresistance.TungstencarbidehardfacingontheothercriticalareasoftheSseriescuttingstructureprovidessuperiorabrasivewearresistanceandallowstheteethtoself-sharpen.

Applications:Softerformationssuchasclays,shales,softsandstones,andsoftlimestones.

Suggested Operating Parameters:WeightonBit–1,000to3,000lbspersquareinchofdiameterRPM–70to120IADCrange1-1-2to1-4-2

MSeries

Mseriesbitsaredesignedwithshorter,strongerteethtowithstandtheweightrequiredfortheseformations.TheMseriesshirttailisoverlaidwithtungstencarbidehardfacingforabrasivewearresistance.

Applications:Mediumformations,suchaslimestones,sandstones,anddolomites.


hSeries

Hseriesbitshaveaheavygagebevelandshort,closelyspacedteethtowith-standheavierimpactloads.Tungstencarbidehardfacingontheshirttailofferssuperiorwearresistance.TheHserieshasprovensuccessfulindrillingopera-tionsinwhichexcessivegagewearmustbeavoided.

Applications:Hardshaleformations,limestones,sandstones,anddolomiteformations.



ROTaRyDRillingTOOlS

FivebasicclassificationsofAtlasCopcoSecorocrockbitsareavailableforTCI(TungstenCarbideInsert)blastholedrillbits.Thesearedividedintothe40,50,60,70and80seriesrockbits.Theprincipaldesigndiffer-encesareintailoringthecuttingstructureofeachtypetomostefficientlydrillspecificformations.Forexample,60seriesbitsaredesignedfordrillingmedium-hardtohardformations,the70seriesforhardformationsandthe80seriesforthehardestformations.

Themodificationsincuttingstructuredesignfromseriestoseriesare:

1. Thespacingofinsertsorteethisgreatestforthe softerorweakerformationsanddecreasesasthe formationhardnessincreases.

2. Thenumberofrowsand/orthetotalnumberof insertsorteethperbitincreasesasformation hardnessincreases.

3. Thegroovedepthandamountofintermeshis decreasedasformationhardnessincreases.

4. Theinsertortoothprojectionabovethecone shellisgreatestforthesofterformationsandis decreasedastheformationhardnessincreases.

Specifications

40seriesThe40seriesbitsaretypicallycharacter-izedbylargediameterwidelyspacedsuperscoop,chiselorconicalinserts.Theconfigura-tionpromotesmaximumpenetrationratesinsofterformationsthathaveatendencytostickandballupthecuttingstructure.

Applications:Softformationssuchasshale,siltstone,softlimestoneandalluvials.

Suggested operating parameters:Weightonbit-1,000to5,000lbs/inchofdiameterRotationspeed-50to150RPM

TCibitselection Bit specifications

50seriesThe50seriesbitsaretypicallycharacter-izedbymoredenselyspacedchiselorconi-calinserts.Thiscon-figurationpromotesmaximumpenetrationratesinsoft/mediumformationsthatarefracturedorhavevary-ingdegreesofhard-ness.

Applications:Soft/mediumformationssuchassandstone,shale,graniteandsomemarble.

Suggested operating parameters:Weightonbit-3,000to6,500lbs/inchofdiameterRotationsspeed-50to150RPM

60seriesThe60seriesbitsaretypicallycharacter-izedbymoredenselyspaced,shorterpro-jectingchisel,concialorogiveinserts.Thisconfigurationpromotesmaximumpenetrationratesinmedium/hardforma-tions.

Applications:Medium/hardforma-tionssuchashardlimestone,hardshale,basaltandquartzite.

Suggested operating parameters:Weightonbit-4,000to7,000lbs/inchofdiameterRotationSpeed-50to120RPM


ROTaRyDRillingTOOlS

80seriesThe80seriesbitsaretypicallycharacter-izedbyverydenselyspaced,shortproject-ingovoid/roundtopinserts.Thiscon-figurationpromotesmaximumpenetrationratesinextremelyhardformations.

Applications:Extremelyhardformationssuchaschert,hematiteoreandquartzite.


TCi(TungstenCarbideinsert)bits Bit specifications

70seriesThe70seriesbitsaretypicallycharac-terizedbydenselyspaced,shorterprojectingconicalorogiveinsertswithaconicalorovoid/roundtopgageinsert.Thisconfigurationpromotesmaximumpenetrationratesinhardformations.

Applications:Hardformationssuchastaconite,bandedironandquartzite.


TechnicalData

Pinconnectionsizesandmake-uptorquesBitsizerange Connectionsize Torquerange

mm inch mm inch kilogram - force meter

pound - force foot

73 2 7/8 N-Rod* N-Rod* 277-346 2,000-2,500

95-114 3 3/4-4 1/2 60 2 3/8 415-484 3,000-3,500

117-137 4 5/8-5 3/8 73 2 7/8 622-760 4,500-5,500

143-171 5 5/8-6 3/4 89 3 1/2 970-1240 7,000-9,000

194-229 7 5/8-9 114 4 1/2 1660-2210 12,000-16,000

251-349 9 7/8-13 3/4 168 6 5/8 3870-4420 28,000-32,000

381-445 15-17 1/2 194 7 5/8 4700-5530 38,000-40,000

*Non-standard API


ROTaRyDRillingTOOlS

TCi(TungstenCarbideinsert)bits Bit selection

Triconecarbideinsertrockbitseriesvs.rockhardnessRockUCS

(psi) TungstencarbideinsertTriconebitseries Rocktype

0 Claystone, Mudstone

Chalky Limestone

4,000 Soft Shale

Loose Sandstones

8,000 Limestone, Siltstone

Solid Sandstones

12,000 Medium Shales

Tuff, Soft Schist

16,000 Andesite, Rhyolite

Quartzite (Sand, Silt)

20,000 Limestone, Marble

Monzonite, Granite

24,000 Gneiss

Diorite, Diabase

28,000 Hard Shale, Slate

Limestone, Dolomite

32,000 Basalt

Tactite, Skarn

36,000 Granodiorite

Taconite

40,000 Quartzite

Syenite

44,000 Gabbro

48,000 Banded Iron Formation

Taconite

52,000 Chert

56,000 Quartzite

60,000 Amphibolite

64,000 Hornfels

68,000 Hematite Ore

Higher “Lava”, Basalt, Biwabic, Quartzite

Rock UCS hardness (Unconfined Compressive Strength) is only one factor that contributes to the “drillability” of any rock. Other factors strongly influencing drillability are: fracture toughness, shear strength, Young’s modulus of elasticity, Poisson’s ratio of stress vs. strain, internal angle of friction. Any particular bit may be used in harder or softer rock than this chart indicates.

40series

4-1to4-4

50series

5-1to5-4

HD NTseries

MAG NTseries

Epsilonseries

70series

7-1to7-4

80series

8-1to8-4

60series

6-1to6-4


ROTaRyDRillingTOOlS

Whentochangeabit Tricone bits

Atmostminesthedecisionwhentochangethebitistypicallyleftuptothedriller,withverylittleguidancegiven.Thisresultsinmostbitsbeingchangedonlyaftertheyhavebeencompletelywornout.Webelievethatatypicaloperationcansave$000’sannuallybyapplyingsomesimplerules.

AttheendofaTriconebitslifethecuttingstructurebecomesineffectiveeitherthroughbreakageorwear,resultinginreducedpenetrationrate.UsingtheTDCfor-mula,“costeffective”bitlifecanbecalculatedandrelatedtopenetrationrate,givingthedrilloperatoraguideastowhentochangethebit.

This bit has too many broken teeth to be effective any longer.

Worn teeth cannot penetrate the rock, therefore productivity diminishes.

Analyzingatypicalbitrun,asshowninthetableabove,theoptimumpointintimetopullabitcanbeidentified.Itisseenthathadthebitbeenremovedonthe20thofOctober,therunwouldhavebeen$0.30permetermorecosteffectivethanonthe24thOctober.

Basedon250,000metersdrilledannually,theprojectedsavingswouldbe$75,000perannum.

analyzingatypicalbitrunRigcost:$200

Bitcost:$3,550

Date Meters hours ROP TDC/m

9-Oct 727 9 80.8 $7.36

10-Oct 1,597 20 80.7 $4.70

11-Oct 2,308 29 80.2 $4.03

12-Oct 3,106 38 81.6 $3.59

13-Oct 3,573 46 77.6 $3.57

14-Oct 4,078 54 76.1 $3.50

15-Oct 4,431 58 76.5 $3.42

16-Oct 4,753 62 76.7 $3.35

17-Oct 5,251 70 75.0 $3.34

18-Oct 5,662 76 74.7 $3.31

19-Oct 6,174 83 74.5 $3.26

20-Oct 6,774 91 74.6 $3.21

21-Oct 7,162 99 72.7 $3.25

22-Oct 7,459 107 69.9 $3.33

23-Oct 7,893 117 67.4 $3.41

24-Oct 8,295 127 65.2 $3.51

727

1597

2308

3106

3573

4078

4431

4753

5251

5662

6174

6774

7162

7492

7893

8295

$8.00

$7.00

$6.00

$5.00

$4.00

$3.00

$2.00

$1.00

$

MetersDrilled

Optimumtimetochangebit.LowestTDC=$3.21permeter

PenetrationRateTDC

-80.0

-75.0

-70.0

-65.0

-60.0

Pen

etra

tio

nr

ate

(m/h

r)


ROTaRyDRillingTOOlS

howarockbitdrills Rock failure

abrasionThisisanillustrationofthefirstphaseofrockfailure,calledtheabrasionphase.Thisistheresultofinsuf-ficientweightonthebit.Theinsertsarecontactingtherockunderverylowweightandtheresultingactionisverysimilartoplacingaknifebladeagainstagrindingstone.Thedrillercanveryeasilytellwhenheisintheabrasionphasebecausethecuttingscomingoutoftheholewillbefinedust.

FatigueHere,moreweighthasbeenaddedtothebitwithRPMthesameasinthepreviousillustration.Theadditionalweighthascausedsomepenetrationoftheinsertsintotheformation,butnotactualfailureoftherock.Thisiscalledthefatiguephaseandagain,thedrillercaneasilyrecognizethisphasebycheckingthereturns.Smallchipsandahighpercentageofdustwillbecomingoutofthehole.

Itshouldbepointedoutthatrockfailurecanbeaccom-plishedwiththistypeofloadingandinsertpenetration.However,itmayrequiremanyimpactsontheformationtocausetherocktofail.Thepenetrationratewillbecon-siderablylessthandesired.

SpallingHere,rotationspeed(RPM)isstillthesamebutsufficientweighthasbeenappliedtothebitformosteffectiveinsertpenetrationintotheformation.Notethattheshellofthebitisnotagainsttheformation.

Inthixsecondillustration,theinsertsareloadedundertheproperweighttocausetheformationtospall.Chipsareremovedbythecirculatingair,allowingthecuttingstructuretoadvance.Under“load”condition,thebitwilldrillatmaximumefficiency.Thedrillerwillnotealargeamountofchipswithverylittledustorfinesinthereturns.

Rock cutting, abrasion - vergy small cracks, insert grinds surface.

Rock cutting, deeper abrasion - deeper cracking, but does not connect. Next cone must crack rock between these teeth.

Rock cutting, spalling starts - enough weight applied to hard rock deeper. Cracks connect. Chips will come free with air blast.

Rock cutting, deep spalling - cracks connecting at deeper levels. Cracks connect bertween teeth and between rows.


ROTaRyDRillingTOOlS

MaximizeROPWiththebitdrillinginthespallingphase,itispossibletoincreasethepenetrationratebymaintainingtheproperweight,whileincreasingtherotationspeed(RPM).Theamountofincreasepossibleinthepene-trationrateisvariableandwillbedeterminedbytheexperienceofthedriller,thecapabilitiesofthedrillandtheformationcharacteristics.

MaximumdrillingefficiencyTheprecedingchartsillustrate:spallingweightplusrotationspeedequalspenetrationrate.Therefore,opti-mumdrillingefficiencymaybereachedasfollows:

AtasetRPM,determinebestweightonbit(WOB)toproducemaximumcutefficiency.

AttheWOBthatgivesmaximumcutefficiency,RPMshouldbedeterminedtoproducebestrateofpenetration.

Note:Highrotaryspeedsdonotnecessarilyproducehighpenetrationrates.

excessweightOncethespallingphasehasbeenachieved,applyingad-ditionalweighttothebitwillonlybeharmfultodrillingefficiency.Theadditionalweightwillcausetheinsertstoburythemselvesintheformation.Theresultisade-creaseinpenetrationrate.

MaximumcutefficiencyWithrotationspeed(RPM)fixed,thisillustrationshowstheeffectofweightincreasesontherateofpenetration.Aftertheformationhasbeen“spalled”additionalweightwillreduceornotincreasethedrillingrate.

howarockbitdrills Cutting efficiency

RPM

ROP

RPMvsROP

WeightonBit(Pulldown)

ROP

WOBvsROP

WeightonBit

ROP

MaximumDrillingEfficiency

RPM

Rock cutting, overpenetration - cuttings trapped betwween cone shell and rock. Cannot be blown out by air blast from nozzles.


ROTaRyDRillingTOOlS

importanceofrecords Tricone bits

Drillinghours

Keepingcompleteandaccuraterecordsofblastholebitperformancecannotbestressedtoomuch.Acare-fulstudyofbitrecordscanbeofconsiderablehelpindeterminingtheproperbittypesandbestoperatingconditionstouse.Themetersdrilledbyabitandthepenetrationratehavelongbeenaccepted“yardsticks”forevaluatingtheperformanceofarockbit.However,thesearetwodifferentunitsofmeasureandmanyer-roneousconclusionshavebeendrawnfromthesetwofactorsalone.Itisthereforenecessarytocombinethesetwounitsofmeasureintoone,knownasTotalDrillCostpermeterorTDC/meter.

TheTotalDrillingCostisthen,thecostofthebitplusthecostofoperatingthedrill.

Thesimplisticcost/mwouldusebitcost/metersdrilled,indeedthismakesuponehalfoftheTDC/mequation.Thespeedatwhichthebitdrillsisincludedbydividingthecostofthedrill/hourbythepenetrationrateofthebit.

Hence:TDC$/m=Bitcost Rigcost/hour Bitmeters Bitdrillingspeed

ItmaybeseenintheTablebelowthatthreebitsoftypeAwererunalternativelywiththreebitsoftypeB.Therecordindicatesthattheformationdrilledwasrelativelyuniform.TypeAaverage1418metersin27.8hours;typeBaveraged1577metersin33hours.WhichbitwasmosteconomicifbitcostswerethesameatUS$3000andrigrateperhourwasUS$120/hour?

TypeAbitTDC$/m=$4.47TypeBbitTDC$/m=$4.57

NowthebitscanbecomparedandTypeAisthebetterbitwiththelowerTDC$/m.

Typicalbitperformancerecord

Bittype

Meters drilled

Hours run

Rate M/hr

Weight in Kg

Rotary RPM

Premium product

Soft Med. Hard

a 1907 38.1 50.1 40000 70/90 X

B 1913 39.5 48.4 40000 70/90 X

a 1303 23.9 54.5 40000 70/90 X

B 1485 32.3 46.0 40000 70/90 X

a 1044 21.3 49.0 40000 70/90 X

B 1334 27.3 48.9 40000 70/90 X

avg.a 1418 27.8 51.1

avg.B 1577 33.0 47.7

Bitselection

Acarefulstudyofbitperformancerecordscanbeofgreathelpindeducingoperationcoststhroughselectionofthemosteconomicalbittypesandoperatingcondi-tions.Anactualcaseinwhichtheperformancerecordsandbitselectionweregivenfullattentionisillustratedinthefollowingexample:

Analysisofthestandardproduct,indicatedthatgagerowcuttingstructurewasworn,leadingtoshirttailwearandfailure.Thepremiumproduct,withenhancedtungstencarbideinsertfeaturestoallowmaximumpenetrationratewastried.

UsingtheTDC$/mequationintroducedearlierandperformancedatafromabove,abreakevengraphcanbeconstructed.

Bittype

Standardproduct Premiumproduct

Bitcost US $2500 US $2875

Meters/bit 5400 5000

Meters/hour 28 32

Rigcost/hour 120 120

Weight 25000 kg 25000 kg

RPM 80-100 80-100

TDC/meter 4.75 4.33

Summaryofaverageperformancedata

+


ROTaRyDRillingTOOlS

importanceofrecords Tricone bits

Drillinghourspremiumbitbreakevenperformance

Step1 Premiumbitcost Rigcost/hour

2875 120

*PlottotheleftofzeroontheXaxis

Step2 Premiumbitcost StandardTDC$/m

2875 4.75

Step3 DrawastraightlinethroughpointsAandB

Bitperformanceabovethelinewillreturnaprofitfortheadditionalinvestmentinthepremiumproduct.

=Hours(pointA)

=24

=Meters(pointB)

=605

5500

5000

4500

4000

3500

3000

2500

3000

1500

1000

500

-25 25 50 75 100 125 150 175

-24step1(pointA)

Met

ers

dri

lled

156hours

BreakevenCosts

605mstep2(pointB)

Hours

Rotary Tricone Blasthole Drilling

Rock Type Allrocktypes,allrockstrengths

Hole Sizes 55/8"-171/2"(143mm-445mm)

Hole Depth 10ft-250ft(3.04M-76.2M)

Rate of Penetration, Hole-to-hole Soft(coaloverburden):100-300M/hr Hard(ironore):20-60M/hr

Straightness of holesVerygoodintypical10-20meter“benching”operations

Suggestusingdrillstringrollerstabilizerinlongholesforcastingor“deepbenching”operations

Production Capacity, Typical Tons/ Shift per drill (10 hrs.)

Coaloverburden,77/8"(200mm)bit:75,000tons IronOre,121/4"(311mm)bit:30,000tons

Low Fuel Consumption, Ltr/Hr 75-90l/hrsmalltomediumdrill(0.01-0.012ltr/t) 100-120ltr/hrmediumtolargedrill(0.03-0.04ltr/t)

Economic Drill String Life, M 300,000meters/pipe,nonabrasiverock 40,000meters/pipe,highlyabrasivepipe

Low Drill String Investment Yes,relativetosizeandholedepth

Suitable for Difficult Drilling Conditions Yes

Suitable for Good Drilling Conditions Yes

Operator Friendly Yes,largerdrillcabs,moreroom,moreavailableamenities

Flushing Flexibility1000to4000CFM,(28.3-113.3cuM/min)dependingondrillandbitsize.Abletoadjustbitairpressurewithdifferentnozzles.Compatiblewith“highpressure”(350psi/24barandhigher)aircompressors.


ROTaRyDRillingTOOlS

Whenever‘standard’airvolumesarecalculated,sealevelatmosphericpressure,14.7psia,mustbeaddedtogaugepressure.

gaslawPhysicsBoyle’s Lawstatesthatataconstanttemperature,thevolumeofagasvariesinverselywiththeabsolutepres-sure:P1xV1=P2xV2Charles’ Lawstatesthatataconstantpressure,thevol-umevariesdirectlywiththeabsolutetemperature:V1xT2=V2xT1

Amonton’s Lawsaysthatataconstantvolume,theabso-lutepressurevariesdirectlywiththeabsolutetempera-ture:P1xT2=P2xT1

Inourwork,Boyles’,Charles’,andAmontons’lawsallinteractthroughtheCombinedGasLawequation:

P1xV1=P2xV2T1T2

airDensityandatmosphericPressureAsaltitudeincreases,theambient(local)atmosphericpressuredecreases.Thecolumnofairabovethatparticularpointontheearth’ssurfaceisnotasdeep,thereforeitweighsless,andexertslesspressureonthatpoint.Thisallowsthe“contents”ofaSCFtoexpanduntilequilibriumwiththenewatmosphericpressureisreached.Whatstartsoutasone(1.00)standardcubicfootofairbecomeslarger,becausetheatmosphericpressureconfiningitisless.

Atsealevel,atmosphericpressureis14.7psia.At5000feet,atmosphericpressuredropsto12.23psia.Thisallowsthesameweightofair,.07494lb.(containedinonecubicfoot)toexpandintoalargervolume.Becauseitnowhasalargervolume,thedensityisless.At5000feet,and70Deg.F,one(1)ambientcubicfootofairweighs.0623pounds.TheoriginalSCF,weighing.07494poundshasexpandedinto1.202cubicfeet:.07494lb/.0623lb=1.202.

Temperaturehasthesameeffectonairasdoesconfiningpressure(altitude).Astemperatureincreases,thedensityofairdecreases.Thiscanbeseenfromthegaslaws.Conversely,asaltitudedecreases,airbecomesmoredense.1.000SCFbecomes0.89SCFat-2,000feet,andhasadensityof.0834poundspercubicfoot.

Airisacriticalfactorintriconerotaryblastholedrillingperformance.Withoutproperairflow,triconerotaryblastholebitscannotbeoperatedefficiently.Bitbearingsarenotkeptcleanandcool.Cuttingsarenotblownawayfromthecuttingfaceofthebitandmovedupandoutofthehole.Theoperatingcostofdrillingaholeincreases.

keyConcepts

StandardairAirisacompressiblegas.Inaircompressordesign,aircompressorworkandairflowcalculations,thestandardunitofvolumeisthecubicfoot.Thestandardtempera-tureis70degreesFahrenheit,andthestandardelevationis0feet,orsealevel.Standardatmosphericpressureatsealevelis14.7psia.TheStandardCubicFoot(SCF)ofairhasastandardmassof0.07494pounds.(Stan-darddensityis.07494lb./cu.ft.)AllengineeringairflowcalculationsarebasedontheStandardCubicFootandstandardconditions:standardairmass,standardairtem-perature,andstandardatmosphericpressure.

actualair“Actual”airisthe“free”airoutsideofthedrillbitthatdoestheworkindrilling.Compressedairdoesnotmovecuttingsawayfromthecuttingfaceofthebit.Com-pressedairdoesnotmoverockparticlesuptheblastholefromthebittothesurface.Compressedairmustbereleasedto“atmospheric”or“ambient”or“actual”sitespecificconditionsbeforeanyworkcanbedone.

“Actual”airisderivedfrom“standard”airbyapplyingtheAltitude/Temperaturefactor:

absolutevs.gaugePressurePressuresarevariouslyreportedas“psia”and“psig”.Theendingletter,“a”or“g”,referstowhetherthepres-surebeingdiscussedis“absolute”pressureor“gauge”pressure.

“Absolutepressure”isthesumofthelocalambientat-mosphericpressureplusanypressurereadingonapres-suregauge.“Gaugepressure”isthepressureindicatedbyapressuregaugeintheairsystem.

Atsealeveland70oF,aCabgaugepressureof37psigisthereforeequivalentto51.7psia:37psig+14.7psiambientatmosphericpressure=51.7psia.At5000feet,and70oFthesamecabgaugereadingwouldbeequiva-lentto49.23psia:37psig+12.23psia(atmosphericpressureat5,000ft,70oF)=49.23psia.Ifno“a”or“g”appearsafterpsi,thepressureistakentomeangaugepressure.

airpractices Introduction


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airpractices Air requirements

altitude/TemperatureFactorTheA/Tfactorisusedtoadjust(“derate”)aircompres-sorintakeratingsinresponsetochangesinlocalaltitudeandambienttemperature;andto“expand”thecalcu-latedcompressedairoutputtolocalconditions.TheA/Tfactoralsohelpstocalculatethe%Capacityoftheaircompressorduringanaircompressorvolumetest;andusingthemeasureddeliveredSCFM(whichmaybequitedifferentfromthespecificationvolumerating)calculatestheBailingVelocity,ChipSettlingVelocity,andtheChipExitVelocity.

Forexample,theA/Tfactorfor5,000feetand70oFis1.202.(14.7psiastandardatmosphericpressureat0feet/12.23psiaambientatmosphericpressureat5,000feet=1.202.)

BailingVelocityThespeedoftheactualairmovingupablasthole.Ageometricalcalculationdependentonbitdiameter,drillpipediameter,andthevolumeofaircirculatedthroughthehole.BailingVelocitymustbehigherthanChipSettlingVelocityorcuttingswillnotbetransported.

ChipSettlingVelocity

Thevelocityarockchipfallingthroughairwantstoachieve.TheoreticalvaluesarecalculatedfromanadaptationofStokesLaw.Dependentoncuttingsdiameterandrockspecificgravity.

ChipexitVelocityThespeedthecuttings(chips)moveupthehole.ThedifferencebetweenBailingVelocityandChipSettlingVelocity:CEV=BV-SV.

TriconerotaryblastholedrillairrequirementsTherearetwothingsthatcleancuttingsfromarotarybl-astholeandmustbecombinedtomakedrillingefficient:airpressureandairvolume.

Airpressuredeterminestheforceofthejetnozzleairblastblowingagainstthebottomoftheholetomovecuttingsawayfromthefaceofthebit.

Airvolume,asbailingvelocity,liftscuttingsupoutoftheholeoncetheyaremovedawayfromthebitface.

Twootherfactorsthataffecttheairrequirementsarethemoisturecontentoftherockandcuttings,andtheincidenceoffracturesandjoints.Wetrock,duetogroundwaterorexcessivewaterinjection,willbeheavierthanthesamerockwhendry.Cuttingsfromwetrocktendtosticktogether,makinglargerparticlestobeblownfromthehole.Fracturedorjointedgroundwillrobairfromtheblasthole,causingtheactualbailingvelocitytobelowerthanthecalculatedbailingvelocity.Inbothoftheseinstances,theactualairvolumerequiredmaybemuchhigherthanwhatstraighttheoreticalcalculationsindicate.Experienceisthebestguide.

Recommendations:BailingVelocityBailingVelocityisdependentonthreethings:ACFM(freeair),holediameter,anddrillpipeoutsidediameter.Thevaluenormallycalculatedisageometricandtheoreticalvaluethatassumesaperfectlydrilledstraightholewithnoairlossesoutthesideoftheholesthroughcracksandfractures.Wemustassumethisbecausenooneevermeasuresablastholespecificallyforitsdiameter.

Undernormalconditionsofdryrock,verylightwaterinjection,littleornogroundwater,andfewifanyjointsorfractures,minimumbailingvelocitiesof5,000to7,000feetperminute(FPM)canbeused.Insituationswheretherockisadenser,heaviermaterial,velocitiesupto9,000FPMcouldbeusedwithlittleproblem.

Insituationswheretherockiswet,ordense,orthereisahighpenetrationrate(above180feetperhour),bailingvelocitiesof9,000FPMormoremaybeneeded.Again,itwilldependonindividualsituations.

Theoverridingrecommendationforbailingairistohaveaminimumof1,000feetperminuteChipExitVelocitywithdrillpipeworntoreplacementdiameter.Ifthiscon-ditionismet,bailingperformancewillbegoodunderallotherconditions.

Annularpressurecalculationswillnotbediscussedhere.Oncethereaderunderstandsthe‘basics’ofcompressedairuseinblastholedrilling,theyshouldpursueanad-vancedknowledgeofrotaryblastholeannularpressuresbyobtainingthosematerialsfromSecorocinGrandPrairie,Texas,USA.

ThefollowingdiscussionofParticleSettlingVelocityisintendedtoillustratetheproblemsofvaryingrockdensi-tiesandchipsizes,andhowtheyaffecttherateofchipremovalfromthedrillhole.


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ParticleSlip(orSettling)VelocityCuttingsparticlesfallthroughairatvelocitiesdependentonparticledensity,particlediameterandshape,andairdensity.Large,heavyparticlesfallfasterthansmall,lightones.“Slipvelocity”isthespeedatwhichaparticlefallsthroughstillair.Itisalsocalledsettlingvelocity.Slipvelocitiesinairmaybemuchhigherthanonewouldexpect.

Ifthebailingvelocityinaholeisnotgreaterthantheslipvelocityofagivensizeparticle,thatparticlewillnotbecarriedfromthehole.Itwillberegrounduntilitisofasmallenoughsizetobecarriedoutbytheairstream.Remember:biggerchipsindicatemoreefficientdrilling,andyieldfasterpenetrationrates.ThefollowingparticleslipvelocityequationisfromWalkerandMays,JournalofPetroleumTechnology,July1975.

ParticleSlipVelocityVt={(2Gxdpx(DenP-DenF))/(1.12xDenF)}.5

Where:Vt=TerminalSlipVelocityofparticle,ft/secG=Gravity,32ft/sec2

dp=DiameterofParticle,feetDenP=DensityofParticle,lb/cubicfootDenF=DensityofFluid,lb/cubicfoot

given: Chipdiameter=.125”,.25”,.50”

DenP= 145lb/ft3forSandstone 168lb/ft3forGranite 181lb/ft3forDolomite

DenF= .07651lb/ft3forairatsealeveland59oF

TerminalSettlingVelocity,feet/minute:

Alsotakeintoconsiderationthatasaltitudeincreases,airdensitydecreases;thus,particleslipvelocitywillincrease.Movingfromsealevelto5,000feet,airdensitydropsto.0637lb/cuft.Thesettlingvelocityofa1/2inchchipofgraniteincreasesfrom4330ftto4755ft.Itcannowbeseenthatchipsdonotleavetheholeatthecalcu-latedbailingvelocity,andthatlossofairfromanypartoftheholecanreducetheactualbailingvelocitytobelowthesettlingvelocityofthechipsthebitactuallygener-ates.Recommendedbailingvelocitiesof5,000FPMareaminimumrecommendation!

BitPressureDropSufficientairpressureatthebitmustbepresenttoinsurethatplentyofairisgoingthroughthebitbearings.Bearingairisnecessaryto:1)keepthebearingscool,and2)keepthebearingsclean.Hotand/ordirtybearingswillcauseearlybitfailure.

Withairpressuresystemswhoseminimumoperatingpressureisgreaterthan35psig,AtlasCopcoSecorocgenerallyrecommendsbitpressuresof40psigto45psigminimum.Thisrangehasbeenfoundtoprovideenoughpressureinthebearingstokeepthemcleanandcool,andstilldirectplentyofairthroughthenozzlesforgoodbottomholecleaning.

TheAtlasCopcoDrillingSolutionsblastholedrillaircom-pressorisnormallycapableofgenerating110psigatthereceivertank.Becauseofthehigherlevelofairpressureavailableonthesedrillsfortriconedrilling,Secorocsug-geststhattriconebitpressurescanbeinthe60-65psirangewithoutcausinganyproblems.Fullvolumewillbedeliveredaslongastheaircompressorsareproperlyadjusted,andoperatingtotheirspecifiedparameters.

nozzleSelection

BearinglifeBearinglifecanbeincreasedbyusingsmallernozzlesinthebit.Withsmallernozzles,proportionallymoreairisforcedthroughthebearingsystem,providingmorecleaningandcooling.Dullingcharacteristicsofbitsshouldbedetermined.Ifshirttailerosionandexpo-sureorlossofouterbearingsiscommon,increasedairthroughthebearingswillprobablyhelpbearinglifebykeepingtheconebackfaceandshirttaillipcleaner.

Ifbitfailureisnotduetoanerosivebearingfailure(suchasdescribedabove),andthecuttingstructureisnothighlydamagedoreroded,smallernozzlescouldagainhelpbyforcingmoreairthroughthebearings.Inthisinstance,however,itisthecoolingofthebearingsthatisbeingenhanced.Asthebearingsrotateunderload,heatisgenerated.Toomuchheatbuildupcausesthermaldegradationofthebearingmetal.Theairinthebearingsstillretainssomeoftheheatgainedduringcompres-sion,andmaynotprovideenoughcoolingcapacityatlowpressures(andflowrates)forthebearings.Athigherpressures,thecoolingcapacityoftheairisincreasedduetotheincreasedvolumepassingthroughthebearings,sothebearingsstaycooler,prolongingtheirlife.

BottomholeCleaningBottomholecleaningisafunctionofthe“force”or“power”theairblastexertsonthebottomofthehole.Twothingsmusthappen.First,theremustbeenoughpowerexertedonthecuttingstodislodgethemfromtheirpositionontheholebottom.Cuttingsmaybe

airpractices Particle settling velocity

Chip Diameter

Sandstone Granite Dolomite

1/8” 2013 2166 2249

1/4” 2847 3064 3181

1/2” 4031 4339 4503


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layinglooseonthebottom,ortheymightbepartiallyorcompletelytrappedunderalayerofcrushedmaterial.Second,thecuttingsmustbetransportedoutfromunderthebit.Thefirstsituation,freeingthecuttings,requiresmore“power”thantransportingthecuttings.Oncecut-tingsareloose,theyarerelativelyeasilytransported.

Inthe“ForceExertedByAirCalculation”totheright,theforceofairleavingabitnozzleiscalculated.Pressuresandtemperaturesareactualparametersfoundonadrillequippedwithatwo-stagecompressor.

Airvolumeisconvertedtoweight.Airvelocityatnozzleexitiscalculated.Multiplyingtheairdischargein“poundspersecond”bytheairvelocityin“feetpersec-ond”givesthequantity“poundfeet/sec2”Thisconvertstoameasureofforce,kgmeter/sec2,the“Newton”.Thecalculationsareallat“StandardConditions”.

Inthe“ForceExertedbyAirCalculation”,itcanbeseenthatsmallernozzleswillapplymoreforcetotheholebottomforcleaning.Theaddedbenefitisincreasedairthroughthebearings,keepingthemcleanerandcooler.

ForceexertedbyairCalculation

Somethingisseeninthiscalculationthatrunscontrarytopopularwisdom.Asnozzlesizeincreased,thevolumeandweightofairdelivereddecreased.Thiscanbeattrib-utedtoinaccuraciesinairtemperature,airpressure,and

thevariationsofthecoefficientofflowfortheorifices.Theaboveflowswerecalculatedwitha.80coefficientofflow.Ifthecoefficientwas.78for1/2”and.82for5/8”,theflowswouldbevirtuallyidentical.Theactualairtestwasdonewith7/8”,1”,and11/8”orifices.Withacoefficientof.78,calculateddSCFM’sfortheorificeswere796.9,796.5,and797.2SCFMrespectively.Norealchangefromsmalltolarge.

Cautionisadvised.Althoughthevolumeschangedverylittle,theamountofforceincreaseswithvelocity.Theincreasedscouringaction,ifcarriedtoanextreme,couldresultinincreasederosionofthebit.Theincreasedblastwillcarrycuttingsatahighervelocity,possiblytothedetrimentofthebit.Thiscanbeespeciallytrueifpen-etrationratesarehighandcuttingsareabrasive.

Keepinmindthat30%to50%oftheairinabitgoesthroughthebearings,andisnotusedtocleanthebot-tomofthehole.Onlywithadequatepressureinthebitcanyoumovecuttingsoutbeforetheycanbereground.

Increasedforceonthebottomoftheholewillgivebettercleaning.BettercleaningequalshigherROP.HigherROPequalsalowerTotalDrillingCost.

given

1/2” 9/16” 5/8” Nozzle Diameter

79 psig 57 psig 42 psig Tool Air Pressure

117º F 117º F 117º F Tool Air Temperature

260 CFM 252 CFM 246 CFM dSCFM

Calculate

1/2” 9/16” 5/8” Nozzle Diameter

.3250 lb/sec .3157 lb/sec .3072 lb/sec Air Weight Delivered

3089.5 ft 2470.5 ft 1952.6 ft Air Velocity

138 N 107 N 82 N Newton’s Force/ Nozzle

1 lb ft / sec2 = .1382 kg meter / sec2

1 kg meter / sec2 = 1 Newton

Calc./nozzle

(CFM) / 60) x .07494 = lb per second

CFM / 60 / Nozzle area (sq. ft.) = Air velocity, ft/sec

lb/sec x ft/sec = lbft/sec2

airpractices Force exerted by air


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Air Compressor Intake Rating - CFM

Bit Diameter 750 900 1050 1200 1400 1900 2600 3800

inches mm’s inches mm’s inches mm’s inches mm’s inches mm’s inches mm’s inches mm’s inches mm’s inches mm’s

55/8 143 1/2 12 1/2 13 9/16 14 5/8 16 11/16 17 3/4 20 15/16 23 11/8 28

57/8 149 7/16 12 1/2 13 9/16 14 5/8 15 11/16 17 3/4 20 15/16 23 11/8 28

6 152 7/16 12 1/2 13 9/16 14 5/8 15 5/8 17 3/4 20 15/16 23 11/8 28

61/4 159 7/16 12 1/2 13 9/16 14 5/8 15 5/8 17 3/4 20 15/16 23 11/8 28

63/4 171 7/16 11 1/2 13 9/16 14 9/16 15 5/8 16 3/4 19 15/16 23 11/8 28

73/8 187 7/16 11 1/2 13 9/16 14 9/16 15 5/8 16 3/4 19 7/8 23 11/8 28

77/8 200 7/16 11 1/2 12 1/2 13 9/16 14 5/8 16 3/4 19 7/8 23 11/16 28

81/2 216 3/8 9 7/16 10 1/2 12 1/2 13 9/16 15 11/16 18 7/8 22 11/16 27

9 229 3/8 9 7/16 10 1/2 12 1/2 13 9/16 15 11/16 18 7/8 22 11/16 27

97/8 251 1/4 6 5/16 9 3/8 10 7/16 12 1/2 13 11/16 17 13/16 21 11/16 26

105/8 270 1/8 4 1/4 7 3/8 9 7/16 10 1/2 12 5/8 16 13/16 20 1 26

290mm 290 X X 1/4 6 5/16 8 3/8 10 7/16 12 5/8 16 13/16 20 1 26

11 279 X X 1/4 6 5/16 8 3/8 10 7/16 12 5/8 16 13/16 20 1 26

121/4 311 X X 1/4 6 5/16 8 3/8 10 7/16 12 5/8 16 13/16 20 1 26

133/4 349 X X X X 3/16 6 5/16 8 3/8 10 9/16 15 3/4 19 1 25

15 381 X X X X 3/16 4 1/4 7 3/8 10 9/16 14 3/4 19 1 25

16 406 X X X X X X 3/16 5 5/16 8 1/2 13 11/16 18 15/16 24

171/2 445 X X X X X X X X 3/16 5 7/16 12 11/16 17 15/16 23

airpractices Suggested nozzle sizes

SuggestednozzleiDSizesforSecorocTriconeRotaryBlastholeBits

Nozzle ID Calculations use the following as constants:• SuggestedBitPressureof65psiforAtlasCopcoDrillsonly(pressureatCabGaugewillbehigher).• 110°Fdeliveredbitairtemperature• 70°Faircompressorintaketemperature

EnterAltitudeofDrillSiteinFeet:1000Metersx3.28=Feet A/TFactor:1.057

ATLAS COPCO

Drills Only


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ATLAS COPCO

Drills Only

SuggestednozzleiDSizesforSecorocTriconeRotaryBlastholeBits

Nozzle ID Calculations use the following as constants:• SuggestedBitPressureof45psiforotherbranddrillsonly(pressureatCabGaugewillbehigher).• 110°Fdeliveredbitairtemperature• 70°Faircompressorintaketemperature

EnterAltitudeofDrillSiteinFeet:1000Metersx3.28=Feet A/TFactor:1.019

Air Compressor Intake Rating - CFM

Bit Diameter 900 1200 1600 2000 2500 3000 3600 3800

inches mm’s inches mm’s inches mm’s inches mm’s inches mm’s inches mm’s inches mm’s inches mm’s inches mm’s

55/8 143 X X X X X X X X X X X X X X X X

57/8 149 5/8 16 3/4 18 13/16 21 X X X X X X X X X X

6 152 5/8 16 3/4 18 13/16 21 X X X X X X X X X X

61/4 159 5/8 16 11/16 18 13/16 21 X X X X X X X X X X

63/4 171 5/8 15 11/16 18 13/16 21 X X X X X X X X X X

73/8 187 5/8 15 11/16 18 13/16 21 X X X X X X X X X X

77/8 200 9/16 15 11/16 18 13/16 21 X X X X X X X X X X

81/2 216 9/16 14 5/8 17 3/4 20 X X X X X X X X X X

9 229 9/16 14 5/8 17 3/4 20 7/8 23 1 26 X X X X X X

97/8 251 1/2 12 5/8 15 3/4 19 7/8 22 1 25 X X X X X X

105/8 270 7/16 11 9/16 14 11/16 18 13/16 21 15/16 24 X X X X X X

290mm 290 7/16 10 9/16 14 11/16 18 13/16 21 15/16 24 X X X X X X

11 279 7/16 10 9/16 14 11/16 18 13/16 21 15/16 24 X X X X X X

121/4 311 7/16 10 9/16 14 11/16 18 13/16 21 15/16 24 11/16 27 13/16 30 1 31

133/4 349 5/16 9 1/2 13 11/16 17 13/16 20 15/16 23 11/16 26 13/16 30 1 31

15 381 5/16 8 1/2 12 5/8 16 3/4 20 15/16 23 1 26 11/4 29 1 30

16 406 1/4 6 7/16 11 5/8 16 3/4 19 7/8 23 1 26 11/4 29 15/16 30

171/2 445 1/4 6 3/8 9 9/16 14 11/16 18 7/8 22 1 25 1 28 15/16 29

Other brand

Drills Only

airpractices(otherbranddrills) Suggested nozzle sizes


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airrequirementsandnozzleselection Tricone bits

Inrotaryblastholedrilling,thereisalwaysaconcernwithdeliveryofairinsufficientvolumeandattheproperpressuretoassureoptimumbitperformancewhendrill-ingwithrecommendedbitweightandRPM.

Sufficientairvolumeshouldbeprovidedtoproduceanannularreturnvelocityof5,000-7,000ft./min.forlight,drymaterials;and7,000-9,000ft./min.formaterialsthatarewetand/orheavy,andwhendrillingatpenetrationratesof35mperhourorhigher.

Todeterminevolumetricrequirements,thesimpleFlowequationQ=AVmaybeused.Sincefrictionlossesintheannulusofrelativelyshallowholesofblastholedrillingarenegligible,thisbecomes:

(D2-d2)Q= V183.35

Thetableonthispageshowsvolumetricrequirementsincubicfeetoffreeairperminutenecessarytoprovideboth5,000and7,000ft.permin.annularvelocityforvari-ouspossiblecombinationsofholesizeanddrillpipesize.

Theequationusedisthesimpleflowequation:Q=AV.

Withallconstantscombinedandareaexpressedasdifferencebetweenholeandpipeareas,thisequationbecomes:Q=27.27(D2-d2).

• Q=cubicfeetperminutefreeairnecessarytoobtain 5,000feetperminutesannularvelocity

• d=drillpipeoutsidediameter,inches

• D=holediameter,inches

ShouldQbedesiredforsomeannularreturnvelocity“V”otherthan5,000feetperminute,theresultobtainedaboveorfromthetableshouldbemultipliedbythefac-tor:V/5000.

Example:A97/8”holebeingdrilledwith73/4”drillpipeatadesiredannularvelocityof5,000ft.perminute.

Solution:Q=27.27[(97/8)2-(73/4)2]=27.27[97.52-60.06]=1022cu.ft.permin.(shownintable)

Had7,000ft.permin.velocitybeendesired:

Theaboveequationmayalsoberewrittentosolveforannularvelocity“V”whenavailablecompressorcapac-ity,holesizeandpipesizeareknown.

Q=(1022) V70005000

=1431cu.ft.permin.

V(ft./min.)= 183.35Q(D2-d2)

AirVolumerequirementsforvariousholediameteranddrillpipecombinations-for5,000ft.and7,000ft.permin.annularvelocity

D.holediameter(in)

D.pipeO.D.(in) Q.-5,000CuFt/minfreeair

Q.-7,000CuFt/minfreeair

41/2

27/8 327 458

31/2 218 305

4 116 162

43/4

27/8 390 546

31/2 282 395

4 178 249

51/8

27/8 491 687

31/2 382 5354 280 392

55/8

27/8 637 892

3/12 530 742

4 426 596

61/4

31/2 732 1,025

41/2 513 718

5 382 535

63/4

31/2 908 1,271

4 805 1,127

41/2 690 966

5 560 784

73/8

31/2 1358 1,900

41/2 932 1,305

51/2 658 921

77/8

31/2 1358 1,900

41/2 1138 1,503

51/2 867 1,214

61/2 625 875

65/8 493 690

7 355 497

9

41/2 1665 2,331

51/2 1383 1,936

65/8 1063 1,488

7 873 1,222

73/4 570 798

97/8

7 1323 1,852

73/4 1022 1,431

85/8 627 878

9 450 630

11

7 1964 2,749

73/4 1662 2,323

85/8 1272 1,7799 1090 1,526

121/4

85/8 2063 2,888

9 1882 2,635

10 1365 1,911

103/4 941 1,317

133/410 2429 3,400

103/4 2004 2,806

15

10 3409 4,772

103/4 2985 4,179

12 2209 3,093

13 1527 2,138

171/2

10 3743 5,240

14 3007 4,21016 1370 1,918


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airrequirementsandnozzleselection Tricone bits

nozzlesizeselectionNozzlesshouldbeselectedsothatthepressureinsidethebitis40-45psi.Thecaboperatingpressurewillbesomewhathigher,dependingonthetypeofdrillandCFMofaircirculated.Typically,oncompressorsratedat65psi,pressureinsidethebitwillbe8-15psilowerthanwhatthecabgaugeshows.Ondrillswith80-100psiratedcompressors,bitpressurescanbe25-50psilowerthanthecabgaugereading.

Theproperprocedurefordeterminingthecorrectnozzlesizeisasfollows:

1. Removethebitandperformanairtest.Recordall pressurereadings.Besuretouseatleastoneorifice plateintheairtestthatwillgive40-45psiatthetool.2. Determinewhatthecabpressureiswhenthetool pressureis40-45psi. 3. Re-installthebitwiththeoriginalnozzles.Runtheair compressorandrecordthecabairpressure. 4. Ifyoudonotgetthecabairpressurethatyousaw with40-45psitoolairpressureduringtheairtest, continuetoinstallandcheckdifferentsetsofnozzles inthebituntilyoudogetthecabpressurethatcor- respondsto40-45psiinthetool. 5. Onceyougetthesamecabairpressurewithnozzles thatyougotduringtheairtestwith40-45psitool pressure,youhavefoundthecorrectsizenozzlesto useinthebit.

ThetableonthepreviouspageshowsapproximatebitairpressurethatcanbeexpectedwiththelistednozzlesandCFM.Thiscanbeusedasastartingpointfordeter-miningcorrectnozzlesize.

howtoremoveandinstallairblastnozzles

nozzleremoval

1. Useascrewdrivertopryuptheheadofthenail lockingthenozzleintoplace.

2. Whenthenailheadispriedup,grabthenailwith pliersandpullthenailcompletelyoutofthebit.3. Removethenozzle

nozzleinstallation

4. Putthenozzleintothenozzleboss,withthe bevelededgetotheinside,theflatendtotheoutside. Placeanozzlenailintothenozzlehole.

5. Withahammer,poundthisnozzlenaildownuntilthe nailheadcontactsthebit.

6. DONOTflattentheheadofthenozzlenailagainst thebit.


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airrequirementsandnozzleselection

Procedureforusingpressuredroptables

1. Establishmaximumoperatingpressureandair volumedeliveredfortheaircompressorbeingused. considerationshouldbegiventoaltitude,volumetric efficiency,ambienttemperatureandmechanicalcon- ditionofthecompressorwhenestablishingtheseval- uesifactualvolumeinnotknown.NOTE:Anairtest isthebestwaytodetermineactualdeliveryofair volumeandpressure.

2. Fromthetable,choosethe“airvolumedelivered” columnnearesttheactualvolumeestablished underitem1. 3. Proceeddowntheproper“airvolumedelivered” columntothe“bitsizerange”forthebitbeingused.

4. Readtheairpressurerequiredforforcingairthrough thebit.Thepressurerequireddependsonthesizeof theairblastnozzles. 5. Selectthesmallestnozzlediameteravailablewithin thegivenbitsizerangethatcanbeusedwithout exceedingthemaximumoperatingpressureofthe compressor.Notethat10-50psishouldbereserved forasafetybufferandotherpressurelossesinthe systemdependingondrilltypeandmanufacturer.

Example 1a.Bitsize:77/8”b.Airvolumedelivered:900cfmc.Maximumoperatingpressurerig:65psiFromthetable,select7/16”nozzle(49psi),thisallows16psiforsafetybufferandsystemlosses.

Example 2a.Bitsize:9”b.Airvolumedelivered:1200cfmc.Maximumoperatingpressurerig:50psiFromthetable,select11/16”nozzle(39psi)

Actualairvolumesdeliveredtothebitisakeyfactorinpreventingearlybearingfailureandprovidingpropercleaningofthetool.Pressuredropslistedaboveareap-proximateforuseasguidelinesonly.Actualpressureswilldependonbitcondition,bearingtype,andairpipingconditions.

PleasecontactyourAtlasCopcoSecorocrepresentativeforassistanceindeterminingthebestnozzlesizeforindividualbitsandminesitecondition.

Bit size rangeAPI Pin

size

Air course size 3 each

Nozzle selection Air pressure drop across Atlas Copco Secoroc blasthole bits with various nozzle size. Air volume delivered - cubic feet per minute

200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300 2400 2600 2800 3000

5”to6”27/8”31/2”

5/16”3/8”1/2”9/16”

10 22 47 62 77

16 35 47 59 71

10 25 35 45 55 65 75

18 26 34 42 50 58 66 74

11 18 24 31 38 44 58 58 64 71

61/4”to73/8”

31/2”

5/16” 42 52 62 72 81

3/8” 33 43 51 61 69 78

7/16” 27 34 41 48 57 65 73 79

1/2” 23 29 33 41 48 54 61 67 73 79

9/16” 18 23 29 34 41 47 51 56 62 67 73 79

77/8”to9” 41/2”

3/8” 27 36 45 55 66 75 83

7/16” 21 28 35 42 49 55 63 69 75 81

1/2” 21 27 33 39 45 51 59 67 76 84

9/16” 20 26 32 37 43 49 55 61 67 73 80

5/8” 21 26 31 36 41 47 52 57 62 69 73 79

11/16” 20 25 29 34 39 44 50 55 60 65 71 77

3/4” 21 25 29 34 37 41 47 51 55 60 65 70 75 79

97/8”to11” 65/8”

3/8” 26 36 46 54 62 70 77

7/16” 19 27 35 42 50 58 65 72 79

1/2” 21 27 33 39 45 53 60 66 71 77

9/16” 20 26 32 38 43 49 54 59 64 68 73 78

5/8” 19 25 32 36 41 46 49 53 58 62 66 70 74 78

11/16” 20 24 29 34 39 43 47 51 54 58 62 66 70 74 78

3/4” 19 22 26 31 36 40 43 47 50 54 57 61 64 68 71 75 79

7/8” 20 24 26 30 32 35 38 41 44 46 49 52 55 59 63 69 75

1” 19 21 23 25 28 30 33 35 38 40 42 47 52 57

121/4”to15”65/8”to75/8”

7/16” 19 25 30 35 41 46 53 58 63 69 75

1/2” 18 23 27 33 38 43 47 52 56 60 65 70 75

9/16” 19 23 27 31 34 38 42 46 50 55 59 63 67 72

5/8” 19 22 25 27 31 34 38 42 46 49 53 57 61 64 68 72

11/16” 20 23 26 29 32 35 39 42 45 48 52 55 58 62 66 70

3/4” 19 22 25 28 31 34 37 40 42 45 48 51 53 57 61 65

7/8” 17 19 21 23 25 27 28 30 33 35 37 40 42 44 47

1” 17 19 21 23 25 27 29 33 37 41

11/8” 17 19 21 25 27 29 31

11/4” 17 19 23 25


ROTaRyDRillingTOOlS

Bit size rangeAPI Pin

size

Air course size 3 each

Nozzle selection Air pressure drop across Atlas Copco Secoroc blasthole bits with various nozzle size. Air volume delivered - cubic feet per minute

200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300 2400 2600 2800 3000

5”to6”27/8”31/2”

5/16”3/8”1/2”9/16”

10 22 47 62 77

16 35 47 59 71

10 25 35 45 55 65 75

18 26 34 42 50 58 66 74

11 18 24 31 38 44 58 58 64 71

61/4”to73/8”

31/2”

5/16” 42 52 62 72 81

3/8” 33 43 51 61 69 78

7/16” 27 34 41 48 57 65 73 79

1/2” 23 29 33 41 48 54 61 67 73 79

9/16” 18 23 29 34 41 47 51 56 62 67 73 79

77/8”to9” 41/2”

3/8” 27 36 45 55 66 75 83

7/16” 21 28 35 42 49 55 63 69 75 81

1/2” 21 27 33 39 45 51 59 67 76 84

9/16” 20 26 32 37 43 49 55 61 67 73 80

5/8” 21 26 31 36 41 47 52 57 62 69 73 79

11/16” 20 25 29 34 39 44 50 55 60 65 71 77

3/4” 21 25 29 34 37 41 47 51 55 60 65 70 75 79

97/8”to11” 65/8”

3/8” 26 36 46 54 62 70 77

7/16” 19 27 35 42 50 58 65 72 79

1/2” 21 27 33 39 45 53 60 66 71 77

9/16” 20 26 32 38 43 49 54 59 64 68 73 78

5/8” 19 25 32 36 41 46 49 53 58 62 66 70 74 78

11/16” 20 24 29 34 39 43 47 51 54 58 62 66 70 74 78

3/4” 19 22 26 31 36 40 43 47 50 54 57 61 64 68 71 75 79

7/8” 20 24 26 30 32 35 38 41 44 46 49 52 55 59 63 69 75

1” 19 21 23 25 28 30 33 35 38 40 42 47 52 57

121/4”to15”65/8”to75/8”

7/16” 19 25 30 35 41 46 53 58 63 69 75

1/2” 18 23 27 33 38 43 47 52 56 60 65 70 75

9/16” 19 23 27 31 34 38 42 46 50 55 59 63 67 72

5/8” 19 22 25 27 31 34 38 42 46 49 53 57 61 64 68 72

11/16” 20 23 26 29 32 35 39 42 45 48 52 55 58 62 66 70

3/4” 19 22 25 28 31 34 37 40 42 45 48 51 53 57 61 65

7/8” 17 19 21 23 25 27 28 30 33 35 37 40 42 44 47

1” 17 19 21 23 25 27 29 33 37 41

11/8” 17 19 21 25 27 29 31

11/4” 17 19 23 25

Abovepressuredropsareforbitswithoutanti-backflowvalves.Forbitswithanti-backflowvalves,add3psi.

Tricone bits


ROTaRyDRillingTOOlS

Rockformation&drillability Tricone bits

generalrockcharacteristicsFromthestoneageuntilthepresenttime,manhasworkedtoimprovehisabilitytodrillholesin“rock”.Theterm“rock”generallyreferstoallthematerialthatformstheessentialpartoftheearth’ssolidcrust,andincludesloose,incoherentmassesaswellastheveryfirm,hardandsolidmasses.Mostrocksareaggregatesofoneormoremineralsandaremostreadilyclassedaccordingtotheirmethodoforigin,asigneous,sedimentaryormetamorphic.

Igneous rocks

Extrusiveigneoustypes:rhyolite,andesite,basalt,dacite,latite,tuff,agglomerate

Intrusiveigneoustypes:granite,monzonite,granodior-ite,diorite,gabbro,peridotite,syenite

Igneousrocksformbysolidificationfromaveryhot,moltenmasscalledmagma,eitherontheearth’ssurfaceorbelowit.Igneousrocks(wheretheyhavenotbeenalteredaftertheirformationbyweatheringorotherchemicalaction)canbeveryhardandtoughandpos-sesslowporosity.

Therearetwomainclassesofigneousrocks:“extrusive”and“intrusive”.“Extrusive”igneousrocksarethoserocksthatareexpelledontothesurfaceoftheearthbyvolcanicactivity.Commonrocksofthistypearebasalt,andesite,rhyolite,andlatite.“Ashflows”fromtherocktypecalled“tuff”.“Agglomerate”isavolcanicrockmadeupoffragmentsofotherrocksthathavebeenpickedupandtransportedbymoltenlavaasitflowsoverthelandsurface.“Extrusive”igneousrockswillgenerallyhaveaveryfinecrystallinestructureduetothefactthattheycooledrapidlyfromtheoriginalmoltenrock.

“Intrusive”igneousrocksarethoserocksthatsolidifybelowthesurfaceoftheground.Theywillgenerallyhaveacoarsecrystallinestructure.Intrusiverocksthatcooledveryslowlywillhavethelargestcrystalstructure,whilethosethatcooledmorequicklywillhaveasmallercrystalstructure.

igneousrocksandtheirdrillabilitiesIgneousrocksareusuallydifficulttodrillespeciallywheretheyarefreshandunalteredbyweatheringoralteration.Lowdrillbitlifeandlowpenetrationratesarethegeneralrule(ascomparedtomostcommonsedi-mentaryrocks).Ingeneral,igneousrockshighinquartzcontents,i.e.,thegranite-dioritegroup,areveryhard,brittleandabrasive.Thosethatcontainlessquartzandmoreferr-magnesiumminerals,i.e.,gabbro,basaltor

periodotitie,arelessabrasive,butbecauseoftheinter-lockingnatureoftheferro-magnesiumminerals,tendtobetougherrockstodrillinspiteofthefacttheyare“softer”andlessabrasive.

Ifsilicified,(silicahasbeenintroducedintotherockthroughalterationprocesses)igneousrocksofbothex-trusiveandinstrusivetypescanbeverydifficulttodrill.Itisverycommonforextrusiveigneousrocks(volcanicstobesilicified.

Sedimentary rocks

Types:conglomerate,sandstone,siltsone,claystone,mudstone,shale,graywacke,limestone,dolomite,coal,phosphaterock,ironformation

Sedimentaryrocksareformedbyanaccumulationofsedimentsinwaterorair.Thesesedimentsmayconsistofrockfragmentsorparticlesofvarioussize,shapeandchemicalcompositiontoformconglomerate,graywacke,sandstone,siltstone,shale,claystoneandmudstoneinorderofdecreasinggrainsizeandroughlyinorderofdecreasingrockhardness.

Coalandligniteareformedbythecompactionanddecompositionofplantswhichaccumulatedintropicalswamps.Certainlimestonesanddolomitesareformedfromtheunderwateraccumulationofanimalremainssuchascoralandshellfish.

Sedimentaryrocksalsoformastheproductofchemi-calactionorevaporation.Rocksofthisoriginincludelimestone,dolomite,phosphaterockandavarietyofsalts.Chemicallydepositedlimestoneanddolomitecanbevery“tough”rockstodrill.

Ironformationisa“catch-all”termforhard,layered,tough,brittle,veryfinegrainedironbearingrocksthatincludetaconite,bandedironformationandchertyironformation.Itisofsedimentaryorigin,occurringthrough-outtheworld,andisthesourcerockformostoftheword’sironore.Ironformationsandtheiralteredoren-richedequivalentsconstitutesomeofthemostdifficultofallrockstodrill.


ROTaRyDRillingTOOlS

Rockformation&drillability Tricone bits

MetamorphicrocksTypes:slate,quartzite,marble,hornfels,schist,gneiss

Metamorphicrocksareformedbytheactionofheat,pressure,andchemicalactiononpre-existingrocksofanytype.Generally,somechangeinchemicalcomposi-tionhastakenplacefromtheoriginalasaresultoftheheat,pressure,andintroducedchemicalconstituents.Metamorphicrockscanrangefromverycoarsegrainedtoextremelyfinegrained,dependingonthedegreeofmetamorphism.

Argilliteresultsfromverymildmetamorphismofshale,mudstoneorclaystone.Slateresultsfromanincreasedlevelofmetamorphismonthosesamerocks.Quartzitecanbeformedfromsandstone,graywackeorarkose.Quartziteisformedwhensilicaisintroducedintosandstoneand/orsiltstones,andcementstheindividualgrainstogether.Marbleisderivedfromlimestoneordolomite,andisarecrystallizationoftheoriginalstruc-ture.Hornfelsisatermappliedtofine-grainedrocksformedbyintensecontactmetamorphosis(heat,pres-sure,introducedchemicals)atthebordersofigneousrockmasses.Hornfelsaremassiverocksunlikeschistorgneissdescribedbelow.

Schistisalowgrade“regional”metamorphicrockwhichhasfoliatedstructureandcanbesplitintothinplates.Someoftheoriginalstructureoftherockmaystillbepresent.Therecanbemineralsegregation,wheresomemineralsmayoccurinbands,wheretheydidnotoccurinbandsandintheoriginalrock.

Gneissisahighgradetoveryhighgrade“regional”metamorphicrockthatisgenerallycoarse-grainedandbanded,inwhichthebandsalternatebetween“mafic”(ironrich)mineralsand“felsic”(noniron)minerals.

Similartovariousigneousrocksinthattheyarecrystal-lineandhavesomeofthesamemineralconstituents,metamorphicrocksareusuallydifficulttodrill.Thisiscausednotonlybythehardnessandcharacterofthevariousmetamorphicminerals,butbythegeneralinter-lockingcharacterofmineralcrystalswhichproducesatoughrock,difficulttospall.

Rockdrillingcharacteristics-generalEachofthemanytypesofigneous,sedimentaryandmetamorphicrockshasitsownparticulardrillingcharac-teristicsproducedbyitsmineralcompositionandgrainsize.Otherfactorsgreatlyaffectingrockdrillabilityare:rockjointsorfractures,beddingorothertypesoffolia-tionandalteration,whichmaybesimplesurfaceweath-eringorverycomplicatedchemicalalterationprocesses

suchasthosewhichusuallyareassociatedwithporphy-rycopperorebodies.

Rockjointsoccurinvirtuallyeveryknownrocktype.Essentially,itisaplaneofweaknessalongwhichrocktendstobreak.Itcanbeseeninmostquarriesandmines.Rockcanalsobefracturedinlocationsadjacenttoblastedareasinminesandquarries.

Whatevertheagencythatcausesthem,fracturesinrockaredetrimentaltoblastholedrilling.Theycan“rob”re-turnairfromthedrillhole,therebyreducingabilityofthereturnairsupplytoremovecuttingsfromthedrillhole;secondly,fracturedrockmayneedtobedrilledwithlessthanoptimumdownpressureand/orrotationspeedinordertopreventtoothorinsertbreakage.

Rockdrillabilitycanbeconsiderablyaffectedbytheangleatwhichadrillbitintersectsbeddingorschistosityplanes.Drillingindirectionsparalleltobedding/schistos-ityplaneswillusuallyproduceahigherdrillingrateandlessbitwearthandrillingatanangletobedding/schisto-sity.

Alterationofrockbysurfaceweatheringcanbeseeninmostminesandquarries.Thisprocesscanchangeaveryhardrocksuchasagraniteintoacrumblysandstone.Itiscausedlargelybytheactionofoxygen,carriedbysur-facewaterorgroundwater,onthecomponentmineralsofrocksandcanextendtodepthsof100mplus.

Alterationassociatedwithmetallicorebodiescanalsoaffectrockdrillabilitiesbychangingthemineralcomposi-tionoftherock.Ingeneral,chemicalalterationproducesarockwhichissofterthantheoriginalrock.


ROTaRyDRillingTOOlS

Rockmechanicsdata Tricone bits

Rock Specificgravity

Coompressivestrength,UCS

Poisson’sration

stressvs.strain

Modulusofrigidity young’smodulusofelasticity engineeringclassificationofintactrock

Psi Mpa Psi Mpa Psi gPa BasedonUCSstrength

Basedyoung’scompressibility

amphibolite 3.07 61,335 423 6,641,000 45,800 15,080,000 104.0 A,veryhigh 1-low

andesite 2.81 26,535 183 3.944.000 27,200 9,367,000 64.6 B,high 2-medium

argillite 2.81 19,720 136 - - 12,194,500 84.1 B,high 1-low

Basalt 2.94 44,950 310 4,596,500 31,700 11,295,500 77.9 A,veryhigh 2-medium

Chert,dolomitic 2.67 29,290 202 0.14 3,436,500 23,700 8,149,000 56.2 B,high 2-medium

Conglomerate 2.67 23,925 165 4,698,000 32,400 11,295,500 77.9 B,high 2-medium

Diabase 2.94 46,545 321 5,408,500 37,300 13,891,000 95.8 A,veryhigh 1-low

Diorite 3.01 39,730 274 0.29 6,119,000 42,200 15,515,000 107.0 A,veryhigh 1-low

Dirorite,augite 2.74 48,285 333 0.25 4,886,500 33,700 12,194,500 84.1 A,veryhigh 1-low

Dolotmite 2.60 18,995 131 0.18 2,900,000 20,000 6,902,000 47.6 B,high 2-medium

gabbro 3.00 44,805 309 0.33 6,394,500 44,100 17,255,000 119.0 A,veryhigh 1-low

granite 2.66 37,700 260 0.2 3,422,000 23,600 8,584,000 59.2 A,veryhigh 2-medium

granite,aplitic 2.65 51,185 353 0.26 4,756,000 32,800 11,687,000 80.6 A,veryhigh 2-medium

granite,gneissic 2.66 30,305 209 0.02 1,299,200 8,960 2,697,000 18.6 B,high 3-high

granite,pre-Cambrian 2.80 - - 0.27 7,583,500 52,300 11,904,500 82.1 - 2-medium

granodiorite 2.74 36,540 252 0.24 4,060,000 28,000 9,947,000 68.6 A,veryhigh 2-medium

greenstone 3.02 39,005 269 6,104,500 42,100 15,225,000 105.0 A,veryhigh 1-low

hematiteore 5.07 88,015 607 - - 29,000,000 200.0 A,veryhigh 1-low

hornfels 3.19 77,285 533 5,930,500 40,900 13,891,000 95.8 A,veryhigh 1-low

limestone 2.68 22,330 154 0.28 3,842,500 26,500 9,874,500 68.1 B,high 2-medium

limestone,chalky 1.89 4,205 29 0.02 780,100 5,380 1,609,500 11.1 D,low 3-high

limestone,dolomitic 2.78 28,710 198 0.29 5,452,000 37,600 14,094,000 97.2 B,high 1-low

Marble 2.72 23,925 165 0.3 4,393,500 30,300 11,397,000 78.6 B,high 2-medium

Marble,taconite 2.71 9,005 62 - - 6,945,500 47.9 C,medium 2-medium

Marlstone 2.31 21,895 151 0.11 1,609,500 11,100 3,610,500 24.9 B,high 3-high

Meta-rhyolite 2.84 18,125 125 4,582,000 31,600 11,397,000 78.6 B,high 2-medium

Monzonite,Quartz 2.68 22,475 155 0.22 - - 10,498,000 72.4 B,high 2-medium

Phyllite,green 3.24 18,270 126 4,756,000 32,800 11,092,500 76.5 B,high 2-medium

Quartzite 2.65 54,230 374 0.13 4,466,000 30,800 10,150,000 70.0 A,veryhigh 2-medium

Quartzite,hematitic 4.07 42,485 293 0.2 5,887,000 40,600 14,195,500 97.9 A,veryhigh 1-low

Sandstone 2.34 477 3 0.1 - - 57,855 0.4 E,verylow 3-high

Sandstone,argillaceous 2.80 15,225 105 0.05 2,146,000 14,800 4,509,500 31.1 C,medium 3-high

Sandstone,calcareous 2.60 22,910 158 0.16 3,465,5000 23,900 8,018,500 55.3 B,high 2-medium

Sandstone,ferriginous 2.60 19,140 132 0.22 2,189,500 15,100 5,553,500 38.3 B,high 3-high

Sandstone,navaho,cemented 2.15 12,601 87 -0.09 890,300 6,140 1,508,000 10.4 C,medium 3-high

Sandstone,navaho,cemented 2.31 13,094 90 -0.03 1,624,000 11,200 3,146,500 21.7 C,medium 3-high

Schist,sericite 2.70 23,490 162 3,799,000 26,200 8,700,000 60.0 B,high 2-medium

Shale 2.81 31,320 216 0.09 3,857,000 26,600 8,439,000 58.2 B,high 2-medium

Shale,carbonaceous 2.30 16,240 112 0 949,750 6,550 2,015,500 13.9 B,high 3-high

Shale,siliceous 2.80 33,495 231 0.12 4,422,500 30,500 9,874,500 68.1 A,veryhigh 2-medium

Siltstone 2.76 37,120 256 3,668,500 25,300 7,714,000 53.2 A,veryhigh 2-medium

Skarn,garnet-pyroxene 3.28 18,850 130 5,046,000 34,800 12,499,000 86.2 B,high 1-low

Syenite 2.82 49,935 303 4,103,500 28,300 10,701,000 73.8 A,veryhigh 2-medium

Syenite,porphytric 2.70 62,930 434 4,393,500 30,300 10,295,000 71.0 A,veryhigh 2-medium

Tactite,epidote 2.87 38,570 266 0.11 4,016,500 27,700 8,903,000 61.4 A,veryhigh 2-medium


ROTaRyDRillingTOOlS

Rock Specificgravity

Coompressivestrength,UCS

Poisson’sration

stressvs.strain

Modulusofrigidity young’smodulusofelasticity engineeringclassificationofintactrock

Psi Mpa Psi Mpa Psi gPa BasedonUCSstrength

Basedyoung’scompressibility

amphibolite 3.07 61,335 423 6,641,000 45,800 15,080,000 104.0 A,veryhigh 1-low

andesite 2.81 26,535 183 3.944.000 27,200 9,367,000 64.6 B,high 2-medium

argillite 2.81 19,720 136 - - 12,194,500 84.1 B,high 1-low

Basalt 2.94 44,950 310 4,596,500 31,700 11,295,500 77.9 A,veryhigh 2-medium

Chert,dolomitic 2.67 29,290 202 0.14 3,436,500 23,700 8,149,000 56.2 B,high 2-medium

Conglomerate 2.67 23,925 165 4,698,000 32,400 11,295,500 77.9 B,high 2-medium

Diabase 2.94 46,545 321 5,408,500 37,300 13,891,000 95.8 A,veryhigh 1-low

Diorite 3.01 39,730 274 0.29 6,119,000 42,200 15,515,000 107.0 A,veryhigh 1-low

Dirorite,augite 2.74 48,285 333 0.25 4,886,500 33,700 12,194,500 84.1 A,veryhigh 1-low

Dolotmite 2.60 18,995 131 0.18 2,900,000 20,000 6,902,000 47.6 B,high 2-medium

gabbro 3.00 44,805 309 0.33 6,394,500 44,100 17,255,000 119.0 A,veryhigh 1-low

granite 2.66 37,700 260 0.2 3,422,000 23,600 8,584,000 59.2 A,veryhigh 2-medium

granite,aplitic 2.65 51,185 353 0.26 4,756,000 32,800 11,687,000 80.6 A,veryhigh 2-medium

granite,gneissic 2.66 30,305 209 0.02 1,299,200 8,960 2,697,000 18.6 B,high 3-high

granite,pre-Cambrian 2.80 - - 0.27 7,583,500 52,300 11,904,500 82.1 - 2-medium

granodiorite 2.74 36,540 252 0.24 4,060,000 28,000 9,947,000 68.6 A,veryhigh 2-medium

greenstone 3.02 39,005 269 6,104,500 42,100 15,225,000 105.0 A,veryhigh 1-low

hematiteore 5.07 88,015 607 - - 29,000,000 200.0 A,veryhigh 1-low

hornfels 3.19 77,285 533 5,930,500 40,900 13,891,000 95.8 A,veryhigh 1-low

limestone 2.68 22,330 154 0.28 3,842,500 26,500 9,874,500 68.1 B,high 2-medium

limestone,chalky 1.89 4,205 29 0.02 780,100 5,380 1,609,500 11.1 D,low 3-high

limestone,dolomitic 2.78 28,710 198 0.29 5,452,000 37,600 14,094,000 97.2 B,high 1-low

Marble 2.72 23,925 165 0.3 4,393,500 30,300 11,397,000 78.6 B,high 2-medium

Marble,taconite 2.71 9,005 62 - - 6,945,500 47.9 C,medium 2-medium

Marlstone 2.31 21,895 151 0.11 1,609,500 11,100 3,610,500 24.9 B,high 3-high

Meta-rhyolite 2.84 18,125 125 4,582,000 31,600 11,397,000 78.6 B,high 2-medium

Monzonite,Quartz 2.68 22,475 155 0.22 - - 10,498,000 72.4 B,high 2-medium

Phyllite,green 3.24 18,270 126 4,756,000 32,800 11,092,500 76.5 B,high 2-medium

Quartzite 2.65 54,230 374 0.13 4,466,000 30,800 10,150,000 70.0 A,veryhigh 2-medium

Quartzite,hematitic 4.07 42,485 293 0.2 5,887,000 40,600 14,195,500 97.9 A,veryhigh 1-low

Sandstone 2.34 477 3 0.1 - - 57,855 0.4 E,verylow 3-high

Sandstone,argillaceous 2.80 15,225 105 0.05 2,146,000 14,800 4,509,500 31.1 C,medium 3-high

Sandstone,calcareous 2.60 22,910 158 0.16 3,465,5000 23,900 8,018,500 55.3 B,high 2-medium

Sandstone,ferriginous 2.60 19,140 132 0.22 2,189,500 15,100 5,553,500 38.3 B,high 3-high

Sandstone,navaho,cemented 2.15 12,601 87 -0.09 890,300 6,140 1,508,000 10.4 C,medium 3-high

Sandstone,navaho,cemented 2.31 13,094 90 -0.03 1,624,000 11,200 3,146,500 21.7 C,medium 3-high

Schist,sericite 2.70 23,490 162 3,799,000 26,200 8,700,000 60.0 B,high 2-medium

Shale 2.81 31,320 216 0.09 3,857,000 26,600 8,439,000 58.2 B,high 2-medium

Shale,carbonaceous 2.30 16,240 112 0 949,750 6,550 2,015,500 13.9 B,high 3-high

Shale,siliceous 2.80 33,495 231 0.12 4,422,500 30,500 9,874,500 68.1 A,veryhigh 2-medium

Siltstone 2.76 37,120 256 3,668,500 25,300 7,714,000 53.2 A,veryhigh 2-medium

Skarn,garnet-pyroxene 3.28 18,850 130 5,046,000 34,800 12,499,000 86.2 B,high 1-low

Syenite 2.82 49,935 303 4,103,500 28,300 10,701,000 73.8 A,veryhigh 2-medium

Syenite,porphytric 2.70 62,930 434 4,393,500 30,300 10,295,000 71.0 A,veryhigh 2-medium

Tactite,epidote 2.87 38,570 266 0.11 4,016,500 27,700 8,903,000 61.4 A,veryhigh 2-medium

guidesforbestbitperformance Tricone bits

I. Exercisecareinmaking-upandbreaking-outthe drillbittoavoiddamagingthebitthreadsanddrill steel. A.Aftertheconnectionisbroken,avoiddown pressureonthebitbreakerwhenunscrewing. Hoistthedrillsteelhighenoughforthebit todropfromtheboxconnectionintothebit breaker. B.Makesurethedeckiscleanandthebitbreaker isproperlymountedinitsholder. C.Cleanthethreadsonthenewbitandonthe drillsteel,makesurethematingshouldersare cleanandaquality“anti-galling”lubricanthas beenapplied. D.Stabcarefully-avoidexcessivepressureon highanglethreadflank.Re-levelthemachine ifthedrillstemboxdoesn’talignwithbitpin.

E.AlwaysuselowtorqueandslowRPMwhen makingupconnection.Matingshoulders shouldsmoothlymakeupto1/8”withlow torque.

II. Whenanewbitisinstalled,drillatreducedweight forashortbreak-inperiod.Usethe1/3-2/3rules: • 1/3ofnormalweightandRPMfor1/3 ofthefirsthole • 2/3normalweightandRPMforthenext1/3rd ofthehole.

• Normaldrillingparameterstofinishthehole.

A.Afterthebreak-inperiod,bitconesshould becheckedtobesurethatallareaboutthe sametemperature.Onehotconegenerally indicatesthattheairpassagetothatparticular bearinghasbecomeobstruction.Ifonecone ishotthebitshouldbeinspectedbeforeany damageoccurs.

B.Makesurethatallassemblygreaseisblown outofallthreecutters.Whentheairisturned on,airshouldblowoutofthebackofeach cone.

III. Provideadequateairtothebittoinsuretrouble freebearingperformanceandreducedabrasion wearonconesandshirttails.

A.Thecompressedairservestwofunctions: • Airtothebearings,tocoolandcleanthe assembly.

• Holecleaningtoremovecuttingsfromthe blasthole.

• Toinsuremaximumbearinglife,a40psimini- mumpressuredropacrossthebitisdesirable.

B.Holecleaningisbasedonfeet/minuteofup holeannularvelocity.

• Airvolumeshouldproduceaminimum of5,000linearfeetperminuteannular returnvelocityforremovaloflightcuttings and7,000feetperminuteforheavymaterial.

• Lowup-holevelocitycausescuttingstofall backtobottomuntiltheyareregroundsmall enoughtobecarriedoutofthehole.

• Anincreaseintorque,torquefluctuations, eitherhydraulicpressureoramp’s,oran increaseinairpressure,areallindications thattheholeisnotbeingcleaned.

C.Someindicationsthattheholeisnotbeing properlycleanedare: • Increaseintorqueindicationthroughhigher hydraulicpressureorhigherampmeter reading. • Increaseinairpressure.

• Excessofcuttingsinthebottomofthehole (morethanonefoot-aftercompletionof holeandaftermakingacleaningpass).

•Heavywearand/ordamageindicationson shirttails.

D.Somereasonsforanincreaseinairpressure whiledrilling:

• Fastpenetration,notcleaningtheholes.

• Foreignmaterialinthebit,comingfrom insidetheairsystem,orcuttingscomingin throughtheairnozzlesorshirttails.

• Airpassagestothebearingsbecoming pluggedwithcuttings.

IV. Turntheaironbeforeloweringthebittocollarthe hole.Keeptheaironuntilthebitisfinished drillingandisoutofthehole.Alwaysrotatethe bitwhenmovinginoroutofthehole. A.Makesurethecabgagepressureisatitsnormal readingandairiscirculatingthroughthe bitbeforestartingtodrill.Inadequateairto thebearingsisaprincipalcauseofoverheating andearlybearingfailure.


ROTaRyDRillingTOOlS


B. Alwaysrotatewhencomingoutoftheholeto: • Helpcleancuttingsfromthehole.

• Keepcuttingsfromenteringthebearings aroundthebackfaceofthecone. • Eliminatethepossibilityofcloggingand jammingoftherollerstabilizerrollers. (Ifused.)

C.Alwaysrotatewhengoingintheholeto:

• Decreasethepossibilityofdamagingthebit orstabilizeronaledgeorotherprotrusionin thehole.

D.Neverusethehydraulicdownpressureonthe bittoaidinlevellingthemachine.

V. Maintainashighapressuredropacrossthebit aspossiblewheninwetholes,orwhenwater injectionisused.

A.Theextrapressuredrophelpstokeepwater andcuttingsfromenteringthebearings.

B.Whenaddingextradrillsteelinwetholes, alwaysmakethreeorfourcleaningpassesto getthebottomoftheholeascleanaspossible.

C.Neverremoveanydevicethatthe manufacturerhasinstalledfrominsidethebit.

VI. Regularlyinspectthebitandfeelthecones tobesurethatallareaboutthesame temperature.Onehotconegenerallyindicates thatthepassagestothatparticularbearinghave becomeobstructed.

A.Whenmakingthisinspectionrotatethecones andmakesurethebearingsarecleanandnot lockedwithcuttings.

B.Iftheconesdonotrotatefreely,startthe aircompressorandblowthecuttingsfromthe bearings,thenrepeattheinspection.

C.Anytimetheconescannotbefreed,thebit shouldbetakenoffforinspectionandcleaned.

VII. Neverallowthebittodropwhileontheend ofthedrillsteel,evenfordistanceofafew inches-droppingthebitcancausecrackingof thewelds,and/orindentationsinthebearing races.Resultswillbeprematurebearingfailure.

VIII.Whenapartiallydullbitsitsidleforashiftor longer,rotatetheconesbyhandtoinsurethat theyturnfreelybeforedrilling.

A.Ifthebitsitsidleforanylengthoftime,in freezingconditions,andwherewater injectionisused,watercanfreezeinsidethe bearingsandairpassages.Theairtemperature fromcompressorwillnormallymelttheiceif enoughtimeisallowedbeforestartingtodrill.

B.Thedrillsteelandbitshouldbewarmbefore thewaterinjectionisused.Thiswillprevent thewaterfromfreezingtothecoldsurfaces.

C.Apartiallydullbitshouldneverbeleftdown theholewhenrepairsrequireloweringthe headassemblytothedeck.Thisbitshouldbe substitutedbyadullbittoprotectthedrill steelthreads.

D.Proceduresforcleaningabitthathasbeen takenoffthedrillandwillbereused:

• Flushthebearingswithwatermakingsure thewaterisgoingthougheachbearing.

• Forceairthrougheachbearing.

•Oilbearingsandsubmergeinnon-detergent oil.

IX. Occasionallychecktheairpressurewiththe bitofftoinsurethattherearenoobstructions intheholeswivelorsteel.

A.Apressurereadingwiththebitoffcanbe takenateachbitchangeandrecordedon thedrillreport.Achangefromtheprior readingwillhelpdetermineifanew obstructionornewleakhasdeveloped.

B.Ateachbitchangeanyforeignmaterialinthe dullbutshouldbenotedorinvestigated.

X. Properlymaintainthedrillsteelanditsthreaded connections.Abentsteelwilloftencauseearly failure.

A.Abentdrillsteelwillcauseexcessloadingon oneoftwoconeswithresultingbearing failureonthosecones.

B.Wearpatternsononesideofthedrillsteeland stabilizerarealsoindicationsoftheproblem.


ROTaRyDRillingTOOlS


XI. Blastholebitsdrillmosteconomicallywhen sufficientweightisappliedtocausespallingof theformation.

A.Whenspallingoccursthecuttingsarelarge andthepenetrationrateisimproved.

B.Ifasufficientamountofweightisnotapplied, thecuttingstructurewilltendtoskidalong thebottomcausingearlywear,thusreducing penetrationrateandshorteningbitlife.

C.Iftoomuchweightisusedfortheformation, thecuttingstructurecanbeburiedtofull depth,trappingcuttingsbeneaththebit.This willcauseerosionoftheconemetal,prevent theformationfromchipping,andreducethe

penetrationrate.Ifcuttingsareforcedintothe cone,bearingscanlockup.Heavyweightswill alsoreducehoursofbearinglife.

XII. Selectingcorrectrotaryspeedisusuallyamatter oftrialanderror,dependingupontheformation beingdrilled.

A.SlowerRPM’swillreducethepenetrationrates andgenerallyincreasebitlife.

B.FasterRPM’sincreasethepenetrationrates andifexcessiveRPM’sareused,ittendsto shortenbitlife. C.Increasedpenetrationrateisusuallytheresult ofbetterspallingoflargecuttings.


DThhaMMeRSPeCiFiCaTiOnS

industryoverview

Technicalspecifications

Model Ql50 Ql55QM Ql60 Ql65QM Ql70 Ql80

Product code 9705-05-50-00 9705-05-51-08 9706-05-50-00 9706-05-51-08 9708-08-50-00

Product No. 51983120 51997591 52324258 52324266 52315231 52083623

generalspecifications english Metric english Metric english Metric english Metric english Metric english Metric

Connection 3 1/2 API Reg Pin 3 1/2 API Reg Pin 3 1/2 API Reg Pin 3 1/2 API Reg Pin 4 1/2 API Reg Pin 4 1/2 API Reg Pin

Outside diameter (in/mm) 4.60 116.8 4.88 124.0 5.44 138.2 5.75 146.1 6.00 152.4 7.13 181.1

Length w/o bit shoulder to shoulder (in/mm) 42.0 1,066.8 42.0 1,066.8 44.6 1,131.8 44.6 1,131.8 44.6 1,131.8 57.5 1,460.5

Length with bit extended (in/mm) 46.3 1,176.3 46.3 1,176.3 49.5 1,256.3 49.5 1,256.3 49.5 1,256.3 63.5 1,611.6

Length with bit retracted (in/mm) 45.3 1,149.4 45.3 1,149.4 48.1 1,220.7 48.1 1,220.7 48.1 1,220.7 61.7 1,567.2

Weight w/o bit (lb/kg) 132.0 60.0 162.0 73.6 200.0 90.9 244 110.9 272.0 123.6 446.0 202.7

Backhead across flats (in) 2 X 3 1/2 AF 2 X 3 1/2 AF 2 X 4 AF 2 X 4 AF 2 X 4 AF 2 X 5 7/8 AF

Minimum bit size (in/mm) 5.13 130.3 5.50 139.7 6.00 152.4 6.50 165.1 6.50 165.1 7.88 200.2

Maximum bit size (in/mm) 6.00 152.4 6.00 152.4 8.50 215.9 8.50 215.9 8.50 215.9 12.00 304.8

Bore (in/mm) 3.742 95.05 3.742 95.05 4.500 114.30 4.500 114.30 4.500 114.30 5.873 149.17

Piston weight (lb/kg) 31.0 14.1 31.0 14.1 42.6 19.4 42.6 19.4 42.6 19.4 112.0 50.9

Stroke (in/mm) 3.75 95.3 3.75 95.3 3.75 95.3 3.75 95.3 3.75 95.3 3.75 95.3

Maximum pressure differential (psig/bar) 350.0 24,1 350.0 24.1 350.0 24.1 350.0 24.1 350.0 24.1 350.0 24.1

Maximum choke diameter (in/mm) 0.38 9.65 0.38 9.65 0.38 9.65 0.38 9.65 0.38 9.65 0.50 12.70

Make-up torque (ft-lb/N-m) 5,000.0 6,770.0 5,000.0 6,770.0 6,000.0 8,124.0 6,000.0 8124.0 6,000.0 8,124.0 8,000.0 1,0832.0

airconsumption

100 psi/ 6,9 bar (scfm/m3/min) 202.0 5.7 202.0 5.7 305.0 8.6 305.0 8.6 305.0 8.6 166.0 4.7

100 psi (bpm) 1,116 1,116 1,116 1,116 1,270 1,270 1,270 1,270 1,270 1,270 968 968

150 psi/ 10,5 bar (scfm/m3/min) 310.0 8.8 310.0 8.8 431.0 12.2 431.0 12.2 431.0 12.2 437.0 12.3

150 psi (bpm) 1,266 1,266 1,266 1,266 1,370 1,370 1,370 1,370 1,370 1,370 1,050 1,050

200 psi/ 13,8 bar (scfm/m3/min) 422.0 11.9 422.0 11.9 561.0 15.8 561.0 15.8 561.0 15.8 707.0 20.0

200 psi (bpm) 1,401 1,401 1,401 1,401 1,470 1,470 1,470 1,470 1,470 1,470 1,132 1,132

250 psi/ 17,2 bar (scfm/m3/min) 538.0 15.2 538.0 15.2 695.0 19.6 695.0 19.6 695.0 19.6 977.0 27.6

250 psi (bpm) 1,521 1,521 1,521 1,521 1,570 1,570 1,570 1,570 1,570 1,570 1,215 1,215

300 psi/ 20,7 bar (scfm/m3/min) 658.0 18.6 658.0 18.6 832.0 23.5 832.0 23.5 832.0 23.5 1,248.0 35.3

300 psi (bpm) 1,626 1,626 1,626 1,626 1,670 1,670 1,670 1,670 1,670 1,670 1,297 1,297

350 psi/ 24,1 bar (scfm/m3/min) 783.0 22.1 783.0 22.1 973.0 27.5 973.0 27.5 973.0 27.5 1,518.0 42.9

350 psi (bpm) 1,716 1,716 1,716 1,716 1,770 1,770 1,770 1,770 1,770 1,770 1,379 1,379

Operationalspecifications

Feed force (lbs) 1,500-2,500 1,500-2,500 2,000-3,000 2,000-3,000 2,000-3,000 3,000-4,000

Rotation speed (rpm) 40-60 40-60 30-50 30-50 30-50 20-40

The quarry and mining operations typically have high equipment utilization, drilling 60%, or even up to 80%, of the working day. Companies drilling small to medium blast holes between 85 mm (3 3⁄8") - 152 mm (6") find thatperformance and service life are critical.Forthoseoperationsdrillinglargeblastholes(greaterthan152mm6"),performance,reliability,fuelefficiency,service-lifeandsupportarecritical.ThisisoftentheidealapplicationforconsideringpremiumDTH(Down-The-Hole)hammerswithfasterdrillratesresultinginlesstimeinthehole.Thisnotonlyreduceslabourcosts,butlowerswearandtearonexpensivedrills.Forsurfacemining,presplittingisoftencar-riedouttoimproveslopestability.Thepre-splittingholesareoften115-140mm(4½"-5½")andcanbemadebeforethedrillingoftheproductionholes.

Undergroundminingapplicationshavehighcost-per-houroperationaloverheads,andcangenerallybenefitfromservicecontractsofferingonsiteserviceandsupport.

Health/Safety/Educationissuesarealsoveryimportant.TheseoperationsgenerallychoosepremiumDTHhammerswithresultingfasterdrillratesandhigherreliability.

TheSecorocsolutionAllminingoperationshouldconsiderproductivityham-mersthatoffergoodperformanceandhighreliability.TheSecorocCOPGoldDTHhammersincorporatethelatesttechnologyandarethemostfuelefficient,reliableandhigh-estperformanceDTHhammersinthemarkettoday.Ifyoutypicallyrunhammersuntiltheywearout,butstillwantthepossibilitytorebuildthehammerforlongerservicelife,thenchooseSecorocCOPGold.

Forholeslargerthan203mm(8"),thehammerofchoiceisSecorocTD.TheTDhammersprovide,astheCOPGold,highestpossibleperformanceincombinationwithrelia-bility.TheTDhammersarealsopossibletorebuiltwithaneconomykit.


DThhaMMeRSPeCiFiCaTiOnS

Some nice picture of Quantum leap ham-mers to put here

Technicalspecifications

Model COP44gold COP54gold COP54goldQM COP64gold COP64goldQM TD35

Product code 9704-03-34 9705-05-34 9705-05-36 97056-05-34 9706-05-36 9703-03-60-00

Product No. 89001469 89001243 89001255 89000959 89000960 52312923

generalspecifications english Metric english Metric english Metric english Metric english Metric english Metric

Connection 2 3/8 API Reg Pin 3 1/2 API Reg Pin 3 1/2 API Reg Pin 3 1/2 API Reg Pin 3 1/2 API Reg Pin 2 3/8 API Reg Pin

Outside diameter (in/mm) 3.90 100.0 4.72 120.0 4.90 126.0 5.59 142.0 5.80 146.0 3.13 79.4

Length w/o bit shoulder to shoulder (in/mm) 40.8 1,037.5 44.1 1,119.0 51.5 1,194.0 45.6 1,158.0 49.5 1,258.0 31.4 798.6

Length with bit extended (in/mm) 45.9 1,166 47.9 1,217 47.9 1,217 49.5 1,258 49.5 1,258 35.2 894.1

Length with bit retracted (in/mm) 44.4 1,128.5 49.1 1,247 49.1 1,247 50.8 1,290 50.8 1,290 33.9 862.1

Weight w/o bit (lb/kg) 89.3 40.5 145.2 66.0 166.7 75.6 209.0 95.0 240.3 109.0 65.0 29.5

Backhead across flats (in) 1 3/4 X 2 1/2 AF

Minimum bit size (in/mm) 4.33 110.0 5.28 134.0 5.5 140.0 6.14 156.0 6.5 165.0 3.54 89.9

Maximum bit size (in/mm) 5.12 130.0 5.98 152.0 6.00 152.0 7.01 178.0 7.00 178.0 3.93 99.8

Bore (in/mm) 3.23 82.0 3.940 100.00 4.720 120.00 2.521 64.03

Piston weight (lb/kg) 17.4 7.9 33.0 15.0 33.0 15.0 45.1 20.5 45.1 20.5 12.0 5.5

Stroke (in/mm) 4.53 115.0 4.53 115.0 4.53 115.0 4.53 115.0 4.53 115.0 4.00 101.6

Maximum pressure differential (psi/bar) 507.0 35.0 435.0 30.0 435.0 30.0 435.0 30.0 435.0 30.0 350.0 24.1

Maximum choke diameter (in/mm) NA NA NA NA NA NA NA NA NA NA 0.35 8.89

Make-up torque (ft-lb/N-m) NA NA NA NA NA NA NA NA NA NA 3000 4062

airconsumption

100 psi/ 6,9 bar (scfm/m3/min) NA NA 186.0 5.3 186.0 5.3 220.0 6.2 220.0 6.2 142.0 4.0

100 psi (bpm) NA NA 1,247 1,247 1,247 1,247 1,350 1,350 1,350 1,350 1,289 1,289

150 psi/ 10,5 bar (scfm/m3/min) 222.0 6.3 285.0 8.1 285.0 8.1 347.0 9.8 347.0 9.8 219.0 6.2

150 psi (bpm) 1,500 1,500 1,364 1,364 1,364 1,364 1,456 1,456 1,456 1,456 1,509 1,509

200 psi/ 13,8 bar (scfm/m3/min) 325.0 9.2 389.0 11.0 389.0 11.0 485.0 13.7 485.0 13.7 288.0 8.1

200 psi (bpm) 1,660 1,660 1,482 1,482 1,482 1,482 1,561 1,561 1,561 1,561 1,699 1,699

250 psi/ 17,2 bar (scfm/m3/min) 428.0 12.1 496.0 14.0 496.0 14.0 635.0 18.0 635.0 18.0 348.0 9.8

250 psi (bpm) 1,820 1,820 1,599 1,599 1,599 1,599 1,667 1,667 1,667 1,667 1,858 1,858

300 psi/ 20,7 bar (scfm/m3/min) 531.0 15.0 607.0 17.1 607.0 17.1 797.0 22.5 797.0 22.5 400.0 11.3

300 psi (bpm) 1,980 1,980 1,716 1,716 1,716 1,716 1,773 1,773 1,773 1,773 1,987 1,987

350 psi/ 24,1 bar (scfm/m3/min) 634.0 18.0 721.0 20.4 721.0 20.4 970.0 27.4 970.0 27.4 444.0 12.5

350 psi (bpm) 2,140 2,140 1,834 1,834 1,834 1,834 1,878 1,878 1,878 1,878 2,086 2,086

Operationalspecifications

Feed force (lbs) 1,100-3,300 1,300-4,120 1,300-4,120 1,600-4,400 1,600-4,400 1,500-2,000

Rotation speed (rpm) 25-80 20-70 20-70 15-60 15-60 70-100


SeCOROCgRinDing

Grinding machineButton

bitsDTH/COPROD

bitsReaming

bitsCross-type

bitsIntegrals

Grind Matic BQ2 ■ ■

Grind Matic Jazz ■ ■ ■

Grind Matic Manual B ■ ■

Grind Matic HG ■ ■ ■

Grind Matic BQ2-DTH ■

Grind Matic Manual B-DTH* ■

Grind Matic Swing ■

Grind Matic Senior ■

amachineforeveryoccasion

A useful tip: use a Secoroc grinding template, and you’ll see when it’s time for a regrind.

*CanbeusedforODEXpilotbitsandreamingbits.■ Recommended Canbeused

Every regrinding operation requires its own special tool. The wrong one can easily damage your bits. With Secoroc Grind Matic grinding equipment – complemented by a global service organization– you needn’t worry. Your bits will soon be as good as new.

Therighttoolstogetyoubackonthecuttingedge


SeCOROCgRinDing

grindMaticBQ2-DTh

Semi-automaticgrindingmachineforDTh-andCOPRODbits

grindingcapacityMaximum height of drill bit 650 mm (2'1 5⁄8")Maximum diameter of drill bit 178 mm (7")Minimum distance between buttons 3.5 mm (9⁄64")

TechnicaldataAir pressure, max. 7 bar (101.5 psi)Air pressure, min. 8 bar (58 psi)Air consumption 40 l/minCapacity of cooling-fluid tank 22 lOutput, spindle motor 3.00 kWOutput, table drive motor 0.15 kWOutput, coolant pump motor 0.10 kWSpeed, spindle 14 900 r/minSpeed, table (50 Hz) 22 r/minSpeed, table (60 Hz) 26 r/minVoltage working lighting 12 VWeight, excluding packaging 345 kg (760 lb)Transport dimension L 1 200 x W 1 200x H 1 700 mm (47.24" x 47.24" x 66.93")

accessoriesincludedindeliveryCoolant concentrate, 0.5 lGrinding templates, spherical and ballisticPullerProtective gogglesOperator’s instructions and spare parts list

electricalspecifications Prod.no. Prod.code220 V 3-phase 50 Hz 87003901 3900-49220 V 3-phase 60 Hz 87003904 3900-60380 V 3-phase 50 Hz 87003900 3900-52415 V 3-phase 50 Hz 87003902 3900-54415 V 3-phase 60 Hz 87003905 3900-62440 V 3-phase 60 Hz 87003906 3900-63

nOTe:Grind Matic BQ2-DTH must be completed with grinding wheels, centring cups and bitholders (indicate button size, bit diameter and type ofhammer).

Optionalaccessories Prod.no. Prod.code- Auxiliary set for grinding threaded bits (excl. bitholder and templates) 87003939 9500-3939

grindMaticBQ2

Semi-automaticgrindingmachineforbuttonbits

grindingcapacityMaximum height of drill bit 200 mm (7 7⁄8")Maximum diameter of drill bit 127 mm (5")Maximum bit skirt diameter 120 mm (4.75")Minimum distancebetween buttons 3.5 mm (9⁄64")

TechnicaldataAir pressure, max. 7 bar (101.5 psi)Air pressure, min. 8 bar (58 psi)Air consumption 40 l/minCapacity of cooling-fluid tank 22 lOutput, spindle motor 1.00 kWOutput, driving plate motor 0.15 kWOutput, coolant pump motor 0.10 kWSpeed, spindle 14 900 r/minSpeed, table (50 Hz) 46 r/minSpeed, table (60 Hz) 55 r/minVoltage working lighting 12 VWeight, excluding packaging 222 kg (490 Ib)Transport dimension L 1 730 x W 1 030 x H 1 160 mm (68.11" x 40.55" x 43.94")

accessoriesincludedindelivery

Allen key, 4 mm (1 piece)Centring cupCentring device (1 piece)Coolant concentrate, 0.5 lGrinding templates, spherical and ballisticGrinding wheel, uncoated for centeringProtective gogglesOperator’s instructions and spare parts list

electricalspecifications Prod.no. Prod.code220 V 3-phase 50 Hz 87003801 3800-49220 V 3-phase 60 Hz 87003805 3800-60380 V 3-phase 50 Hz 87003800 3800-52415 V 3-phase 50 Hz 87003802 3800-54415 V 3-phase 60 Hz 87003804 3800-62440 V 3-phase 60 Hz 87003806 3800-63

nOTe:Grind Matic BQ2 must be completed with grindingwheels, centring cups, bitholders (indicate buttonsize and thread dimension) and indexing templates.

grinding

Rig-mounted,semi-automaticgrindingmachinefortapered,threaded,DTh-andCOPRODbits

grindingcapacityMaximum distance between bit holderand grinding wheel 250 mm (9 7⁄8")Maximum diameter of drill bit 254 mm (10")Minimum diameter of drill bit 35 mm (1 3⁄8")Minimum distance between buttons 3.5 mm (9⁄64")

TechnicaldataAir pressure, max. 7 bar (101.5 psi)Air pressure, min. 6 bar (87 psi)Air consumption 25 l/sCoolant container 3 lOutput, spindle motor 1.00 kWSpeed, spindle 15 000 r/minVoltage 24 VWeight, excluding packaging 90 kg (198 lb)Transport dimension L 800 x W 500 x H 700 mm (2'7 ½" x 1'7 5⁄8" x 2'3 ½")

accessoriesincludedindelivery

Box wrench, 11 mmBox wrench, 16 mmGrinding gaugeProtective gogglesOperator's instructions and spare parts list

nOTe:

Grind Matic Jazz must be completed with grindingwheels, centring cups, bitholders and indexingtemplates.

Optionalaccessories Prod.no. Prod.code- Anti-freeze kit 87004315 9500-4315- Main bit holder for DTH/ COPROD bits 87004268 9500-4268- Main bit holder for threaded bits 87004214 9500-4214- Mounting bracket for Atlas Copco drill rig - with cabin 87004628 9500-4628 - without cabin 87004456 9500-4456- 3-leg stand 87004450 9500-4450- Centring tool 87004465 9500-4465

grindMaticJazz,std Prod.no. Prod.code 87004100 9500-4100incl. main bit holder for threaded bits

grindMaticJazz,DTh Prod.no. Prod.code 87004300 9500-4300incl. main bit holder for DTH/COPROD bits

grindMaticJazz


SeCOROCgRinDing

grinding

grindMatichggrindMaticManualB-DTh

hand-heldgrindingmachineforbuttonbits

grindingcapacityButton size 7–20 mm

(9⁄32"–25⁄32")

TechnicaldataAir pressure, max. 7 bar (101.5 psi)Air consumption, unloaded 50 l/sAir consumption, loaded (at 6 bar, 86 psi) 42 l/sHose dimension, air 12.5 mm (½")Hose dimension, water 6.3 mm (¼")Idling speed 17 000 r/minWater flushing pressure, max. 4.5 bar (65.3 psi)Weight, excluding hoses 2.8 kg (6.2 Ib)

accessoriesincludedindeliveryAdjustable angle connectorAllen key, 2 mmAllen key, 3 mmAllen key, 5 mmClaw coupling (6.3 mm)Grease gunGrinding templates, spherical and ballisticHose (PVC 03)Hose (PVC 6; L = 0.1 m)Hose clamp (7–8.5 mm)Hose clamp (11–13 mm)Hose clamp (26–38 mm)NipplePipe (L = 0.3 m)Seal kitSeatSupport ringOperator’s instructions and spare parts list

Optionalaccessories Prod.no. Prod.code- Lubricator 87002750 9500-2750- Reconditioning tool for grinding cups 87002810 9500-2810

grindMatichg Prod.no. Prod.code 87002435 9542

hand-heldportablegrindingmachineforDThbits

grindingcapacityMaximum height of drill bit 506 mm (1'7 7⁄8")Maximum diameter of drill bit 203 mm (8")Maximum diameter of bit shank 170 mm (6 ¾")

TechnicaldataAir pressure, max. 7 bar (101.5 psi)Air consumption (incl. gauge grinding) 25 l/sAir consumption (excl. gauge grinding) 23 l/sCoolant container 10 lIdling speed of hand-held grinder 30 000 r/minSpeed of bit rotation 0–45 r/minWeight, excluding packaging 110 kg (253 lb)Weight, including packaging 148 kg (326 lb)Transport dimension L 1 200 x W 800 x H 940 mm

(3'11 2⁄10"x 2'7 5⁄10" x 3'1 0⁄10")

accessoriesincludedindeliveryAllen key, 5 mmAllen key, 6 mmCentring fingers (4 pcs)Grinding belt (4 pcs)*Grinding templates, spherical and ballisticHand-held grinder (spherical, 30 000 r/min)Open end spanner, 14 mm (2 pcs)Protective gogglesOperator’s instructions and spare parts list

*) When ordering gauge grinding unit, Product No. 87002302 / Product code 9500-2302.

NOTE: Grind Matic Manual B-DTH must be completed with grinding wheels and bitholders.

Optionalaccessories Prod.no. Prod.code- Gauge grinding unit complete 87002302 9500-2302- Grinding belt for gauge grinding (set of 10 pcs) 87002399 9500-2399- Centring fingers (set of 5 pcs), 30 000 r/min 87001935 9500-1935- Clamping device for threaded bits 87002401 9500-2401

grindMatic Prod.no. Prod.codeManualB-DTh 87002300 9425

grindMaticManualB

hand-heldportablegrindingmachineforbuttonbits

grindingcapacityMaximum diameter of bit skirt 90 mm (3 9⁄16")Threaded bits, maximum diameter 127 mm (5")Retrac, maximum diameter 127 mm (5")*Tube drilling, maximum diameter 152 mm (6")*

TechnicaldataAir pressure, max. 7 bar (101.5 psi)Air consumption 15 l/sCoolant container 10 lIdling speed of hand-held grinder 30 000 r/minSpeed of bit rotation 0–45 r/minWeight, excluding packaging 55 kg (121.3 Ib)Weight, including packaging 90 kg (198.4 Ib)Transport dimension L 1 200 x W 800 x H 850 mm (3'11 2⁄10" x 2'7 5⁄10" x 2'9 5⁄10")* Large clamping device necessary

accessoriesincludedindeliveryAllen key, 4 mmCentring fingers (4 pcs)Grinding templates, spherical and ballisticHand-held grinder, 30 000 r/minOpen end spanner, 14 mm (2 pcs)Protective gogglesOperator’s instructions and spare parts list

nOTe:Grind Matic Manual B must be completed withgrinding wheels and bitholders.

Optionalaccessories Prod.no. Prod.code- Vibration absorbing sleeve to fit the hand-held grinder 87001931 9500-1931- Set of 5 centring fingers 87001935 9500-1935

grindMaticManualB Prod.no. Prod.code 87001890 9424


SeCOROCgRinDing

grinding

grindMaticSeniorgrindMaticSwing

grindingmachineforintegrals

TechnicaldataAir pressure, max. 7 bar (101.5 psi)Cutting-edge angle, adjustable 90–130°Grinding wheel - D x T x H 200 x 102 x 32 mm (7 7⁄8" x 4" x 1 ¼) - DI x TI 150 x 80 mm (5 7⁄8" x 3 5⁄32") - Cutting-edge radius, adjustable 80-130 mm (3 5⁄32"–5 1⁄8")Idling speed, electric 50 Hz 2 840 r/minIdling speed, electric 60 Hz 1 690 r/minOutput 3-phase 1.50 kWRod hex. max. 25 mm (1")Weight excluding packaging 105 kg (232 lb)Weight including packaging 120 kg (265 lb)Transport dimension L 800 x W 600 x H 650 mm (2'7 ½" x 1'11 5⁄8" x 2'1 5⁄8")

accessoriesincludedindeliveryGrease gunGrinding templateGrinding wheel, Grind Master HardProtective gogglesSocket wrenchWrenchOperator’s instructions and spare parts list

electricalspecifications Prod.no. Prod.code220 V 3-phase 50 Hz 87002485 9511-49220 V 3-phase 60 Hz 87002493 9427380 V 3-phase 50 Hz 87135402 9511-52380 V 3-phase 60 Hz 87002494 9428415 V 3-phase 50 HZ 87002488 9519415 V 3-phase 60 Hz 87002495 9511-62440 V 3-phase 60 Hz 87002496 0799-8151-63

Optionalaccessories Prod.no. Prod.code- Grinding wheels Grind Master Hard 87002591 9552 Grind Master Soft 87002813 9500-2813- Spacer plate for H19 integral 87000519 9500-0519- Chuck bushing wear guage H19 (0.75") 90002667 9131 H22 (0.85") 90002668 9132 H25 (1") 90002669 9133

grindingmachineforintegrals

TechnicaldataAir pressure, max. 7 bar (101.5 psi)Air consumption (at 6 bar, 86 psi) 25 l/sCutting-edge angle 110°Cutting-edge radius 80 mm (3 5⁄32")Gauge grinding arrangement includedHose connections: - Air 12.5 mm (½") - Water 6.3 mm (¼")Idling speed 4 080 r/minPower output 1,10 kWSize of grinding wheel - D x T x H 125 x 63 x 32 mm (47/8" x 215/32" x 1¼") - DI x TI 80 x 50 mm (3 5/32" x 2")Spindle diameter 16 mm (5/8")Weight incl. grinding wheel and 1.5 m water hose 27.5 kg (61 lb)

accessoriesincludedindeliveryGrinding templateGrinding wheel Grind Master SoftPin wrenchProtective gogglesOperator’s instructions and spare parts list

Optionalaccessories Prod.no. Prod.code- Grinding wheel Grind Master Hard 87002589 9550- Grinding wheel Grind Master Soft 87002811 9500-2811- Chuck bushing wear gauge H19 (0,75") 90002667 9131 H22 (0,85") 90002668 9132 H25 (1") 90002669 9133

grindMaticSwing Prod.no. Prod.code 87002482 9544


SeCOROCgRinDing

Dimension, mm Product No. Product code

7,0 87002566 9500-2566

8,0 87002567 9500-2567

9,0 87002568 9500-2568

10,0 87002569 9500-2569

11,0 87002570 9500-2570

12,0 87002571 9500-2571

13,0 87002572 9500-2572

14,0 87002573 9500-2573

15,0 87002574 9500-2574

16,0 87002575 9500-2575

18,0 87002576 9500-2576

20,0 87002577 9500-2577

7,0 87002579 9500-2579

8,0 87002580 9500-2580

9,0 87002581 9500-2581

10,0 87002582 9500-2582

11,0 87002583 9500-2583

12,0 87002584 9500-2584

13,0 87002585 9500-2585

14,0 87002586 9500-2586

15,0 87002587 9500-2587

16,0 87002588 9500-2588

7–8 87002700 9500-2700

9–10 87002701 9500-2701

11–12 87002702 9500-2702

13–14 87002703 9500-2703

15–16 87002704 9500-2704

17–18 87002840 9500-2840

19–20 87002841 9500-2841

DiamondgrindingcupsforgrindMatichg

For spherical button bits

For ballistic button bits

For button bit steel removal

grindingwheelsforsteelgrindingBoronnitride–buttonbitsgrindMaticBQ2Dimension Product No. Product code

10–14mm 87001530 9500-1530

Spacerfor10mmbutton 87001631 9500-1631





CentringcupsforgrindMaticBQ2/BQ2-DThFor button size Product No. Product code

7,0mm 87001040 9500-1040

8,0mm 87000842 9500-0842

9,0mm 87001047 9500-1047

10,0mm 87001041 9500-1041

11,0mm 87000840 9500-0840

12,0mm 87001042 9500-1042

12,7mm 87000839 9500-0839

13,0mm 87001385 9500-1385

14,0mm 87001043 9500-1043

14,5mm 87001443 9500-1443

15,0mm 87001386 9500-1386

16,0mm 87001387 9500-1387

18,0mm 87003943 9500-3943

19,0mm 87003944 9500-3944


SeCOROCgRinDing

8

9

10

10,95

12,7

14,57

Min.

0,5

Regrind when flatis 173 of button dia.

D

D/3

Dimension, mm Product No. Product code

Spherical

7 87001028 9500-1028

8 87001026 9500-1026

9 87001389 9500-1389

10 87001023 9500-1023

11 87003406 9500-3406

12 87001024 9500-1024

13 87001339 9500-1339

14 87001025 9500-1025

15 87001384 9500-1384

16 87001027 9500-1027

18 87003964 9500-3964

19 87003966 9500-3966

Ballistic

7 87003407 9500-3407

8 87003408 9500-3408

9 87003409 9500-3409

10 87003410 9500-3410

11 87003411 9500-3411

12 87003412 9500-3412

13 87003413 9500-3413

14 87003414 9500-3414

15 87003415 9500-3415

16 87003416 9500-3416

18 87003965 9500-3965

19 87003967 9500-3967

Full ballistic

9 87004359 9500-4359

14.5 87004612 9500-4612

Standarddiamond-grainwheels

grindingtemplatesforbuttonbits

largediamond-grainwheelsDimension, mm Product No. Product code

Spherical

9 87003969 9500-3969

10 87003970 9500-3970

11 87003971 9500-3971

12 87003972 9500-3972

13 87003973 9500-3973

Ballistic

9 87003974 9500-3974

10 87003975 9500-3975

11 87003976 9500-3976

12 87003977 9500-3977

DiamondgrindingwheelsforbuttonbitsgrindMaticBQ2grindMaticBQ2-DThgrindMaticJazzgrindMaticManualB

Product No. Product code

Buttonbits,spherical 90002944 9104

Buttonbits,ballistic 90503414 9105

ButtonbitsDTH,spherical 90510753 9129

ButtonbitsDTH,ballistic 90510758 9130


SeCOROCgRinDing

BitholdersforbuttonbitsgrindMaticBQ2/Jazz/BQ

Product No.Product

code

Threaded bits

HolderR25 87003475 9500-3475

HolderR28 87003476 9500-3476

HolderSR28 87003960 9500-3960

HolderR32 87003477 9500-3477

HolderSR32 87003962 9500-3962

HolderSR35 87003956 9500-3956

HolderR38,T38 87003478 9500-3478

HolderSR38 87003978 9500-3978

HolderSR38retrac,guide 87004081 9500-4081

HolderT45 87003479 9500-3479

HolderTC45 87004569 9500-4569

HolderT51andretrac 87003521 9500-3521

HolderT60 87004562 9500-4562

Tube bits

HolderST58 87003522 9500-3522

HolderST68 87003523 9500-3523

Tapered bits

Holder7°taper 87003524 9500-3524

Holder12°taper 87003525 9500-3525

Reaming bits

Holder64,76and89mmreamer 87003526 9500-3526

Holder89,102and127mmreamer 87003527 9500-3527

Guide bits

HolderSR35guidebit 87004056 9500-4056

HolderR32guidebit 87003992 9500-3992

Byusingtheauxillarysetpart87003939(ProductNo.)/9500-3939(Productcode),GrindMaticBQ2-DTHcanalsousetheabovebitholdersforthreadedbits.

Product No. Product

code

Threaded bit

R25 87000792 9500-0792

R28 87000793 9500-0793

SR28 87003961 9500-3961

R32 87000794 9500-0794

SR32 87003963 9500-3963

R35 87003360 9500-3360

SR35 87003957 9500-3957

R38/T38 87000795 9500-0795

SR38 87003979 9500-3979

T45 87000796 9500-0796

T51 87000802 9500-0802

Tapered bit

with7°taper 87001044 9500-1044

with12°taper 87001045 9500-1045

Tube bit

ST58 87001726 9500-1726

ST68 87001573 9500-1573

Reaming bit

64,76,89mm1) 87000798 9500-0798

89,102,127mm1) 87000799 9500-07991)Centeringpinforbitholders9500-0798and9500-0799. 87001070 9500-1070

Clampingdeviceforregrindingretracbits64–127mmandTDSbits89–152mm(ST58,ST68)withoutbitholder(tocomplete87000772/9500-0772).

87001930 9500-1930

grindMaticManualB(forclampingdevicecompl.87000772/9500-0772GrindMaticB)

grindMaticBQ2-DTh/ManualB-DTh/Jazz-DTh

Down-the-hole bits and COPROD bits


COP32 87002420 9500-2420

COP34 87003691 9500-3691

DHD3.5 87004514 9500-4514

DHD340 87002391 9500-2391

DHD350 87002390 9500-2390

DHD360 87002389 9500-2389

DHD380 87004523 9500-4523

TD40 87004604 9500-4604

RC50 87004605 9500-4605

QL40 87004515 9500-4515

QL50 87004033 9500-4033

QL60 87004002 9500-4002

QL80 87004516 9500-4516

COPROD76 87004414 9500-4414

COPROD89 87003155 9500-3155

COPROD102 87004415 9500-4415

COPROD127 87002396 9500-2396

Down-the-hole bits and COPROD bits


Grind Matic Manual B-DTH only

Threadedbits*T38 87002148 9500-2148

Threadedbits*T45 87002149 9500-2149

Threadedbits*T51 87002147 9500-2147

Threadedbits*ST58 87002158 9500-2158

Threadedbits*ST68 87002154 9500-2154

*Clampingdeviceforthreadedbits

87002401 9500-2401


SeCOROCgRinDing

Bit dimension Dimension (D x T x H), mm Product No.Product

code

29mm 300x19x32 87002619 9500-2619

35mm 300x23x32 87002594 9555

38–41mm 300x26x32 87002595 9556

43mm 300x28x32 87002618 9579

45mm 300x29x32 87002597 9558

48–51mm 300x32x32 87002616 9577

57mm 300x38x32 87002600 9561

76mm 300x52x32 87002603 9564

Gauge grinding wheels

200x13x32 87002613 9574

200x32x32 87002615 9576

10

5

15

110°

2,4

mm

3/32

"

SkivvinkelWheel

1/4"

1/2"

3/4"

1/2" 1/4"3/4"1" 1 1/2"

Ceramicgrindingwheelsforcross-typebits

grindingtemplateforcross-typebits

Product No.Product

code

Cross-typebits 90002611 9102

X-bits 90002612 9103

40 30 1020 0

10

5

15

110°3

mm

1/8"

r= 80 mm 3,5/32"

1/4"

1/2"

3/4"

Grinding machineDimension, mm

Product No.Product

codeD x T x H (mm) DI x TI (mm)

GrindMaticSwing 125x63x32 80x50,hard 87002589 9550

” 125x63x32 80x50,soft 87002811 9500-2811

GrindMaticSenior 200x102x32 150x80,hard 87002591 9552

” 200x102x32 150x80,soft 87002813 9500-2813

Ceramicgrindingwheelsforchiselbit

grindingtemplateforintegralrodsProduct No. Product code

Integralrods 90002610 9101


DRillCare

DRillCare™

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Features Benefits• Guaranteedperformance • Warrantedbetweenscheduledservices• Qualityinspectedandtested • Ensuredreliabilityandhighestavailability• Availablethroughourstate-of-the-artdistributionsystem • Quick,accurateorderfulfillment

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DRillCare

innovativesolutionsAtlasCopcoiscontinuouslydevelopingproductsandservicestomaximizethereliabilityandavailabilityofyourdrillrig.

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hydraulichosefirstaidkitEachkitprovidesanimmediatereplacementforeveryhydraulichoseonyourdrillrig.

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DieselfuelfiltercartAportablefuelcleaningsystemdesignedtoprotectyourinvestment.

Features Benefits• Controlsparticulateingression • Maximizeusablelifeofenginecomponents• Preventswatercontamination • Minimizedowntime• Easyspin-onreplacementelements • Lowermaintenancecost

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glOSSaRy


glOSSaRy

glossaryoftermsAactuator– A motor or cylinder that is being put into motion by the flow of a hydraulic pump.

adapter-adaptor– (both spellings are accepted) A device used to connect two different sizes or types of threads. It is used to connect rotary head spindles to drill pipe, drill pipe to stabilizers and stabilizers to drill bits.

anFO – Ammonium Nitrate Fuel Oil mixture: explosive most commonly used in blast-holes.

angleDrill – Drilling a hole at a 0 to 30 degree angle from vertical (in five degree increments).

annulus – The space between the drill pipe and the outer diameter of the hole made by the bit.

annunciator – An electrical signaling device on a switchboard.

aPi– American Petroleum Institute.

aSMe – American Society of Mechanical Engineers.

aSTM – American Society of Testing Materials.

autolubeSystem – A pump that provides grease to various components of the drill through hoses. It can be manual or com-puter controlled.

BBank – Vertical surface of an elevation; also called the face.

BecoThread – A coarse type of thread used on drill pipe.

Bench – Work area on the top edge of an elevation. The work area for blasthole drills.

Bit,auger – A type of bit used to drill soft formations. It usually has a series of flutes on the outside.

Bit,Claw – A wing-type bit that has multiple flukes. Sometimes called a drag bit.

BitBreaker– A device installed in the centralizer table to hold a bit stationary while the drill pipe is being removed from the bit by reversing the rotation. Also called bit basket.

Bit,DhD – A solid, one piece bit with shaped tungsten carbide inserts in the face. Used in percussion drilling.

Bit,Roller – Also called a tricone bit. It usuallyhas three conical rollers fitted with steel or tungsten carbide teeth that rip the rock loose using down pressure.

Bits – Tools that pulverize formations so thatmaterial can be removed from the hole, gene-rally three-blade, three-cone or percussion.

Blasthole – A drilled hole used for purposes of excavation rather than exploration, geo-logical information or water wells. Holes are used to load explosives for open pit mining, and are usually limited to 200 feet.

Blasting – The act of igniting explosives ina borehole to produce broken rock.

Blowdown– Term used when releasing compressed air from the receiver tank on a compressor when the drill is stopped.

BlowdownValve – The valve that opens when the drill is stopped and releases all the air pressure in the receiver tank.

Bore – To make a hole in the ground with a drill.

Borehole – The hole made by a bit.

Boxend – Fitting on the female end of a drill pipe. See Pin End.

Breakout – Refers to the act of loosening threaded pipe joints, and of unscrewing one section of pipe from another, while coming out of the hole.

BreakoutWrench – A wrench, connectedto a hydraulic cylinder, used to turn the upper piece of pipe while the lower pipe is being held by the fork chuck or sliding wrench.

Bridge – An obstruction in the hole. Usually caused by a caving formation or something falling in the hole.

Burden – Distance from the blasthole to the nearest face. Distance measured from the face to a row of holes. The material to be displaced.

Buttons – Short, rounded teeth of sintered tungsten carbide inserts which serve as teeth in drill bits used for drilling very hard rock.

ButterflyValve– The adjustable inlet valve of the air compressor.

CCable – A strong, heavy steel, wire rope. Also known as wire rope. Used for pulldown

and pullback in the tower. Also used in hoisting. May be rotating or rotation resistant.

CableReel – A device that holds the electri-cal power cable on electric driven blasthole drills.

Carousel – A rotating device that holds extra drill pipe. It can be moved under the rotary head to add and remove drill pipe from the string, or the rotary head moves over it.

Carbide,Tungsten – W2C. A very hardcompound used in inserts in rock bits. It has a very high melting point. It is very strong in one direction but very brittle in another.

Catwalks – Walkways around a working area of a drill.

Cavitation – The pitting of a solid surface by the formation of low pressure bubbles formed in the fluid. Air being allowed into the inlet of pumps.

CentralizerBushing – A circular ring installed around the drill pipe in the drill table to keep the pipe aligned properly with the rotary head. It usually has a replaceable insert in the center.

ChainWrench – A special wrench, consistingof a chain section and a metal vee section, with jaws, that grips the drill pipe and/or the DHD to tighten or loosen the connections.

Collarthehole – Opening at the top of the blasthole; the mouth where rock has been broken by blasting. Usually the first few feet of the blasthole that are cracked and broken.

Compressor – An asymmetrical rotary screw driven device for compressing air. May be single- or two-stage, depending on the discharge pressure.

Console– The panel that contains most of thedrill’s controls. Also called the operator’s panel.

Conveyor – Equipment used to carry mate-rial to crushers and screens for reduction and separation.

Cooler(hydraulicoilCooler(hOC),CompressorOilCooler(COC)) – All drills have a cooler or coolers for the hydraulic fluid and the compressor oil. The engine radiator is also sometimes referred to as an engine cooler.

Coring – The act of procuring a sample of the formation being drilled for geological information purposes.


glOSSaRy

Coupling – A connector for drill rods, pipe or casing with identical threads, male or female, at each end.

Cribbing– A set of wooden ties or metal plates used to add surface area to the jack pads to prevent the pad from sinking into the ground. Also called blocking.

CrownSheaves – The upper sheaves in a tower that supports the cable that connects to the rotary head.

Crosshead – The outer metal can sur-rounding the leveling jack cylinders. The crosshead slide is the lower portion that connects to the bottom of the cylinders and the crosshead cap is the flanged piece on top of the crosshead.

Crusher – Device used to reduce broken rock to a smaller fragment size.

Cut(verb) – Process of excavating material to lower the level of part of an elevation.

Cut(noun)Part of an excavation of a specified depth and width.

Cuttings – Particles of formation obtained from the hole during drilling operations.

DDecking – Process of alternating explosives with inert material in a blasthole to properly distribute explosives or reduce vibrations. Also refers to the metal catwalks around the outside of the drill.

Delayinterval – Elapsed time between deto-nation of individual blastholes in a multiple hole blast.

Derrick– A tall framework over a drilled hole used to support drilling equipment. The part of the drill that contains the feed system and the rotary head. See Tower and Mast.

DhD – Down Hole Drill. An air driven, piston powered device for drilling hard rock. It is alsocalled a hammer.

DhDBushings – The split bushings used to maintain alignment of the DHD while passing through the drill table. See Split Bushings.

DifferentialPressure – The difference in pressure between the inlet and outlet of a component, i.e., a cooler.

Dip – The angle between a horizontal plane and the plane of the ore vein, measured at right angles to the strike.

DiverterValve – A two position, three-way, valve that allows one hydraulic pump to perform two separate functions.

DressingaBit – Sharpening DHD drill bits with a grinder to shape the carbides.

Drifter – An out-of-the-hole drill that rotates the drill rod and provides a percussive force, by means of a striking bar, through the rod to the bit.

Drill – A machine for drilling rock orunconsolidated formations. Also calleda rotary drill. The act of boring a holein the ground.

DrillCollar – A heavy, thick-walled section of pipe used to add drilling weight to the bit and stabilize the drill string.

DrillRod – See Drill Pipe. Hollow, flush-joint-ed, coupled rods used on small percussion type rock drills.

DrillPipe – Hollow tubing, specially welded to tool joints.

Drill/PropelValve– A switch that shiftsthe diverter valves to allow pump flowto go from drill functions to propelmotors.

DrillString– The string of pipe, including subs, stabilizers, collars and bit, extending from the bit to the rotary head, that carries the air or mud down to the bit and provides rotation to the bit.

Driller(Operator)– The employee directly in charge of a drill. Operation of the drill is their main duty.

DrillTable – The area at the bottom of the tower that contains the centralizer bushing or master bushing that the drill pipe travels through.

DustCollector – A vacuum device with a hose attached to the dust hood that pulls cuttings away from the hole and deposits them to the side of the drill.

FFace – Vertical surface on an elevation. Also called bank.

FeedCable – Cables, anchored on the top and the bottom of the tower, that pass through the traveling sheave block and connect to the top and bottom of the rotary head. They are adjusted by tightening the threaded rods on each end.

FeedChain– Heavy duty chain links con-nected to the rotary head through upperand lower sprockets and the traveling sheave block. They are adjusted similar to a cable.

Fill – Process of moving material into a depression to raise its level; often follows the cut process.

Fish– An object accidentally lost in the hole.

Fishing – Operations on the drill for thepurpose of retrieving the fish from the hole.

FishingMagnet – Magnet run in the hole on non-metallic line, to pick up any small pieces of metal.

FishingTools – Tools of various kinds run in the hole to assist in retrieving a fish from the hole. Overshots fit over the pipe while taps fit inside the pipe.

Flats – Machined areas on the side of drill pipe or other components where wrenches can be installed to hold or break the joints. Some pipe have two flats, others have four flats.

Floor – Level area at the base of a bank or face.

ForkChuck – The handheld or “flop-down” wrench used to hold the top of the pipe on the drill table while adding or removing other pipe.

Hhammer – A different name for a DownHole Drill.

hammerBushing – Split bushings installed in the drill table to allow the DHD to start the hole in a straight line. It is removed once the DHD is below the table. Also called DHD bushings.

haulDistance – Distance material has to be moved, such as from a cut to a fill.

haulingequipment – Trucks and other con-veyances for moving material. Also called haul trucks.

hazard – Any condition of the drilling equip-ment or the environment that might tend to cause accidents or fire.

hoist – Device used to pick up drillpipe and other heavy objects. See Winch.

hoistPlug – A lifting device installed inthe box end of a tool. Opposite of lifting bail.

hole – A bore made by rotating a bit intothe ground.

hose,Drilling – Connects rotary head to top of hard piping to allow movement of rotary head. Also called standpipe hose.

hydraulicCylinders – Double actingcylinders that are extended and retractedto perform various functions on a drill. They are powered by hydraulic fluid from a pump.


glOSSaRy

hydraulicMotors – Piston or vane type mo-tors, driven by hydraulic pumps, that rotate various devices on a drill.

hydraulicPumps – Piston, vane and gear type hydraulic pumps that provide flow for the various actuators on the drill.

hydrostatichead – The pressure exerted by a column of fluid, usually expressed in pounds per square inch.

Iinclinometer – An instrument for measuring the angle to the horizontal or vertical of a drill hole or vein.

i.W.R.C. – Abbreviation for Independent Wire Rope Center. This refers to the type of construction of wire rope. This wire rope center is in effect a separate wire rope in itself that provides a core for the line and prevents it from crushing or breaking.

interstagePressure – The air pressure present between stages of a two-stage compressor while the compressor is making air.

JJWrench – Specially shaped wrench to fit the backhead of a DHD. Used to hold a DHD on the table or to remove the backhead from the wear sleeve.

KkellyBar – A fluted or square drill pipe that is turned by a rotary table using a set of pins.

LlevelingJacks– Hydraulic cylinders mounted in a crosshead that raise and lower the drill. Also referred to as outriggers or stabilizers.

liftingBail – A threaded cap for picking up pipe, bits, DHDs and stabilizers. It screws on the pin end. Some bails have a swivel hook while others have solid tops. Opposite of hoist plug.

loaders – Large, front end bucket equip-ment used to pick up material for loading in various types of hauling equipment.

MMainFrame – The welded component of a track mounted drill. The truck frame on a wheeled drill.

MainShaft(axle)– The tube connecting the tracks of a blasthole drill to the main frame.

Makeup – The act of tightening threaded joints. Making a connection.

Makinghole – The act of drilling.

MakingUpaJoint– The act of screwing a joint of pipe into another joint or section of pipe.

Manifold – A pipe or chamber that has several openings for hose connections.

Mast– A vertical structure. See Derrick.

Micron-:-Mu – A unit of length equal to one millionth of a meter, or one thousandth of a millimeter. About 4/100,000 of an inch.

Mid-inletSwivel – Device for removing cuttings from the hole while drilling with reverse circulation equipment.

MinePlan – Plan for making cuts andcreating elevations, benches for efficient removal of material. The mine plan con-siders a variety of factors, including the type and location of material, the size and number of shovels, loaders, and hauling equipment, haul distances, blasthole patterns, etc.

OOscillationyoke – The beam connecting each track of a blasthole track drill with the main frame that allows the tracks to move independently up and down.

Openhole – Any uncased portion of a hole.

Operator – The person who performs the drilling operation with the drill. See Driller.

Overburden – Any unconsolidated material lying on top of the bedrock or the coal seam.

PParasiticload – The load imposed on the engine by the direct connection of the compressor and main pump drive during starting.

Pattern – Layout and distances between blastholes, specifically including burden and spacing.

PenetrationRate – Speed at which a bit advances while drilling, usually measured in feet per hour. Instantaneous or drilling penetration rate is the rate only while drill-ing. Overall penetration rate is the same as the production rate (see production rate).

PercussionDrill – Drill that chips and pen-etrates rock with repeated blows.

Pinend – Fitting on male end of drill pipe. See Box End.

PioneerWork – Drilling in rough, broken or inclined areas. Removing the original layers of dirt and rock.

PipeDope– Special lubricant used to protect the threads on pipe joints. See Thread Lube.

PipeSupport – A device that holds the lower section of pipe in place while connecting to the next joint with the rotary head when angle drilling. Also called rod support.

Pit – An excavation in the ground for the removal of mineral deposits.

PlC – Programmable Logic Controller. A de-vice that monitors many aspects of a drill’soperation.

PotableWater – Water that is safe to drink.

PowderFactor/SpecificCharge– Relation-ship between the weight of explosives in a blasthole and the volume of materials to be displaced. It is measured in pounds per cubic yard or kilograms per cubic meter.

PowerPackBase – The welded channel frame that contains the prime mover, the compressor and the hydraulic pumps and gearbox.

PowerPack – The complete sub-assembly of base, engine, compressor, and hydraulic drive.

Presplitting – Process of drilling a line of small diameter holes spaced relatively close together, generally before drilling a produc-tion blast, and loaded with light explosive charges to create a clean, unbroken rock face.

ProductionRate– Penetration during a given reporting period. This rate includes all lost time including maintenance, breakdowns, long moves, inclement weather, etc.

Propel – To cause to move forward or onward. To drive or tram.

Protectors,Thread – Steel or plastic covers to cover the box and pin ends of drill pipe when they are not being used.

Pump,Waterinjection– Pump used topump water into the drill air stream to keep the dust settled and to assist in flushing the hole.

Pullback– The force available to remove the drill string from the hole.

Pulldown – Force exerted on the drill bit by the thrust of the drill rig and from the weight of the drill string.

QQuickFill– A centralized service station that connects to various systems on the drill to allow remote filling of engine oil, compressor oil and hydraulic oil.


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RRaise – A mine opening, like a shaft, driven upward from the back of a level to a level above, or to the surface.

Reamer – Bit-like tool, generally run directly above the bit to enlarge and maintain a straight hole.

Reservoir –The tank used for storing the hydraulic oil used in the hydraulic system.

ReverseCirculationDrilling – Using a double wall pipe to force air/water down the hole and removing the cuttings between the two pipes. See Mid-Inlet Swivel.

RodChanger – A device that holds extra drill rod (pipe). See Carousel.

RotaryDrilling – The method of drillingthat depends on the rotation of a column of pipe to the bottom of which is attached a bit. Air or fluid is circulated to remove the cuttings.

Rotaryhead – A movable gearbox used toprovide rotation to the drill string. It is connected to the feed chains or cables on each end and to the drill string through the spindle.

SSafetyhook – Attached to the end of a hoist line to secure the hoist plug or lifting bail. Has a safety latch to prevent the load from slipping off the hook.

Scales – Equipment used to determine the weight and value of material being trans-ported from a quarry.

Screens – Devices used to separate broken material into groups of similar size.

ShockSub – A device used to isolate the shock of drilling from the rotary head. It is made of hard rubber layers mounted inside of steel outer rings.

SinglePassDrill – Drill rig with a long tower that permits drilling a blasthole without stop-ping to add drill pipe (rod). Uses a Kelly in place of regular pipe. Uses a rotary table to turn the Kelly instead of a rotary head.

Stemming – Material of a specified depth added on top of a powder column to confine the blasthole and make the explosion more efficient.

StripMine– A large section of land used to remove coal deposits.

Shot – A charge of high explosives depos-ited in a series of holes to shatter the rock.

Shutdown – A term that can mean the end of the shift or workday or an unplanned stopping of the drill due to a system failure.

SlidingFork – A wrench that slides around the flats of the drill pipe to hold the section lower. Controlled by hydraulic cylinder(s). Used in place of a fork chuck.

Slips – Used in the rotary table to hold and break out drill pipe. Also used to hold casing in the table.

Spacing – Distance between blastholes measured parallel with the face.

Spear – Tools of various design that are screwed or wedged inside of bits, pipe, etc.,that are lodged in the hole. See Fishing Tools.

Spindle – The short section of pipe thatrotates within the rotary head, and protrudes out.

SpeedSwitch – An electronic device that changes states when the engine reaches a certain speed. Used to control dual oil pressure switches.

SplitBushings – The removable bushings that allow the DHD or Stabilizer to pass through the drill table while drilling a straight hole. See DHD Bushings.

Stabilizer,DrillPipe – Heavy -walled pipe having special spiral or fluted ribs extend-ing around the diameter, within 1/8 “to 1/4” of hole size. Most stabilizers are fitted just above the bit, while in-line stabilizers keep the hole straight.

Standpipe – Part of the circulating system. The hard and flexible piping from the main valve to the flexible hosing leading to the rotary head. Water injection, DHD oil and foam are injected into this line.

StaticWaterlevel – The distance from the top of ground down to the standing water level.

Strike –The bearing of the outcrop of an inclined bed or structure on a level surface. See Dip.

StuckinThehole– Refers to drill pipe inad-vertently becoming fastened in the hole.

Subdrilling – Bottom portion of a blasthole drilled below the floor level to permit upward displacement of material and thereby prevent a toe at the bottom of a face.

Sub – A coupling with different type or diam-eter of threads at either end. The term pin denotes a male thread, and box, a female thread. To connect two components with different threads. See Adapter.

SuperchargePressure – Inlet oil pressure to the main pump(s) that has been pressurized to prevent cavitation.

Swivel – A coupling on top of the rotary head to allow the spindle to rotate while the main hose remains stationary.

TTableDrive– Drill design that locates the drill pipe rotation mechanism on the drill deck in a stationary position instead of using the rotary head.

ThreadedandCoupledCasing(T&C)– Steel casing using a coupling between each section of pipe. Thread style is right hand, fine thread.

Threadlube – A special compound used to lubricate the threads of drill pipe. See Pipe Dope.

Tongs – A type of wrench used to makeup and break out drill pipe using external forces, such as hydraulic cylinders or cables.

ToolJoint – A drill pipe coupler consistingof a pin and box of various designs and sizes. Deephole drills normally use API style threads, while blasthole drills normally use Beco style threads.

TopheadDrill–Drill design that locatesthe drill pipe rotation head in the drill tower. It moves up and down with the drill string. See Rotary Head.

Torque– A turning or twisting force.A moment caused by force acting on an arm. A one pound force acting on a one-foot arm would produce one lb-ft of torque.

Tower – A tall, slender structure used for observation, signaling or pumping. Term used to indicate the derrick on a blasthole drill. See Derrick and Mast.

TurningToTheRight – Slang term formaking a hole.

Tram – A cable car or a four-wheeled open box in a coal mine. See Propel.

Trammed – To move in a tram.

Tramming – Process of moving a drill.See Propelling.

TravelingSheaveBlock– A series of sheaves, connected to the feed chains or cables, that are moved up and down the derrick by the feed cylinders.

TwistOff – To twist a joint of pipe in two by excessive torque applied by the rotary head or rotary table.

UUl88 – The pneumatic valve that controls pressure and volume on a high-pressure compressor system.


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Undercarriage– The means of moving a track type vehicle. It contains the track frame, rollers, grousers, rock guards, drive sprocket, propel motors and planetary drive.

UpholeVelocity – The speed (in feet per minute) that the cuttings travel out of the hole. This is dependent on the bit size, the compressor size and the pipe size.

WWashpipe – Hard surfaced steel tubes inserted in swivels to allow rotation of drill string and prolong life of packing. They are replaceable in most swivels.

Waterinjection – A method of rotary drilling where water is dispersed in the air while drilling.

WeightOnBit– In rotary drilling, a specified weight is required on the bit for maximum performance. A gauge on the console is calibrated to correspond to the drill string weight.

Winch – A stationary hoisting machinehaving a drum around which a rope is wound.

Wiper,Pipe – An annular rubber disk for wiping drill pipe clean of cuttings when it is being withdrawn from the hole.

WireRope – Rope made of twisted strands of steel wire. Also called cable.


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WheReTOFinDUSFor more information, please contact your local Atlas Copco Customer Center.

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Copyright © 2008 Atlas Copco Drilling Solutions Inc.

Introducing the new and expanded line of the Pit Viper Series drills from Atlas Copco. The venerated PV-351, PV-275, and PV-271 are being joined by the all new PV-235 series. And throughout the line, we’re crafting a better user experience by improving your comfort, control and visibility. Plus, our new power systems add to your bottom line with increased fuel efficiency. So, whether you’re mining precious metal or mineral, follow the line and mine with us.

We’re redrawing the line between productivity and innovation.

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Atlas Copco has worked with the drilling business throughthe peaks and the troughs, both literally and figuratively.Not only have we been producing air pressure and powerfor the drilling industry for many years, we’ve been at the forefront of drill production too.

We know that drilling takes time and that time is money.

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