Submitted Report

8/3/2019 Submitted Report

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A.Company ProfileName of the company : Jaypee Rewa Plant (JRP)

Jaiprakash Associates Limited

Cement Division.

Establishment Year : 1986

Chairman : Mr. Manoj Gaur

No of Employees : 3330

Products

Production Capacity : 3.3 MTPA

Motto : Work for Quality, Safety,Health

& Environment

Product Range (Cement)

Type - Grade Brand Name

OPC-53 SUPER PLUS

OPC-43 TIGER

OPC-33 BUNIYAD

OPC - IRS T-

40/53S

BULAND

PPC BUNIYAD

PPC BULAND

PPC


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B.Brief HistoryYear 1979:

Jaiprakash Associates Private Ltd. (JAPL) formed. Ultra Rasayan Udyog Ltd. was formed for setting up

Malathion Technical plant in Sikandrabad (U.P.),

which was changed to Jaiprakash Enterprises Ltd.

Year1980:

Hotel Siddharth was set up.Year1982:

Hotel Vasant Continental was set up.Year1986:

Commissioning of 1st unit of 1 MTPA Jaypee RewaPlant.

Formation of Jaiprakash Industries Ltd. (JIL) byamalgamating JAPL into Jaypee Rewa Cement Plant.

Year1991:

Commissioning of 2nd unit of 1.5 MTPA Jaypee RewaPlant (JRP) in District Rewa (M.P).

Year1992:

Formation of JaiprakashHydro Power Ltd (JHPL).


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Year1995:

Formation Jaiprakash Power Ventures Ltd (JPVL). Hotel Jaypee Residency Manor set up.

Year1996:

Commissioning of 1.7 MTPA Jaypee Bela Plant (JBP) inDistrict Rewa, M.P.

Year1999:

Jaypee Palace Hotel, Agra set up.Year2000:

Acquisition of land for Jaypee Greens Ltd.Year 2001:

Commissioning of .6 MTPA Jaypee Blending Units atAllahabad district in U.P. The first of its kind in the

country.

Jaypee Institute of Information Technology (DeemedUniversity Since November 1, 2004) at Noida, U.P.

Year2002:

Commissioning of 1.0 MTPA grinding unit in districtAmbedkar Nagar in U.P.

Jaypee University of Information Technology (StateUniversity), Waknaghat was set up.


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Year2003:

Commissioning of 25 MW captive Thermal PowerPlant-1 at JRP.

Formation of Jaiprakash Associates Ltd (JAL) formedby merging JIL with Jaypee cement Ltd.

Year2004:

Commissioning of 25MW captive Thermal PowerPlant-2 at JRP.

Commencement of Work for setting up 3MnTPACement Plant at Baga & Baghri at District Solan in H.P.

and 1.5 MTPA.

Year2005:

Successful completion of up-gradation scheme,enhancing the total capacity of Rewa Operation to

7.0 MTPA.

Shares of JHPL Listed on BSE/NSE. First hydro powercompany to be listed in the country.

Year2006:

Setting up of Madhya Pradesh Jaypee MineralsCorporation Ltd. (MPJMCL).

Commissioning of 38.5MW captive Thermal PowerPlant-3 at Jaypee Rewa plant.

Railway siding operational at Jaypee Bela plant.

Commencement of work for setting up a new greenfield 1.5 MTPA cement plant in district Sidhi, M.P.

Acquisition of cement plants & assets of U.P. StateCement Corporation Limited (in Liquidation) of 2.5

MTPA capacity.


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Acquisition of Gujarat Anjana Cement Limited forsetting up a Green field cement plant of 1.2 MTPA

capacities Bhuj district in Kutch, Gujarat.

Year2007:

Signing of MOU with Gujarat Mineral DevelopmentCorporation (GMDC) for setting up a new Green Field

Cement Plant of 1.2 MTPA capacity, in JV in Kutch

district, Gujarat.

Signing of MOU with Government of H.P, or setting upa new Green Field Cement Plant of 2.0 MTPA capacity

at Chamba district in H.P.


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C.IntroductionJaypee Rewa cement is sub division of

Jaiprakash Associates Ltd. Jaiprakash

Associates is one of the biggest construction

companies in India. Mr. Manoj Gaur is the

Executive chairman of this company with its

head office is in New Delhi.

Jaypee Rewa cement is single largest

production unit. Its annual production is

about 3.3 Million Tons. There are two units installed for the production of

clinker namely Unit-1 &Unit-2.

Unit-1: Supplied by Krupp. Plysious (Germany). 1.5 million ton capacity was

commission in December 1986.

Unit-2: Supplied by F. L. Smidth (Denmark) 1.8 million ton capacity was

commission in April 1991.


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D.Cement ManufacturingProcess

I. MiningThe cement manufacturing process

starts from the mining of limestone,which is the main raw material for

making cement. Limestone is excavated

from the quarries at about 6 m from

ground level after drilling and blasting

and than loaded on to the dumpers

which transport the material and

unload it into the hoppers of limestone crusher.

II. Crushing Stacking & Reclaiming ofLimestone:

The limestone crusher crushes the limestone to

approximately 70 to 80mm size and discharge

the material onto a Belt Conveyer which takes itto the Stacker via the Bulk Material Analyzer.

The material is stacked in longitudinal

stockpiles and than Limestone is extracted

transversely from the stockpiles by the

Reclaimers and conveyed to the Raw Mill


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hoppers for grinding of raw meal.

III. Crushing Stacking & Reclaiming ofCoal:

The process of making cement

clinker requires heat. Coal is used as

the fuel for providing heat. Raw coal

is stored in the coal yard. Raw coal is

dropped on a belt conveyer from a

hopper and is taken to a crusher for

being crushed. Crushed coal

discharged is stored in the longitudinal stockpiles from where it is

reclaimed by the Reclaimer and taken to the coal mill hopper for grinding it

to fine coal.

IV. Raw Meal Drying/Grinding &Homogenization:

Reclaimed limestone along with some laterite

stored in their respective hoppers is fed to the

Raw Mill for fine grinding. The hot gases coming

from the Cooler House are used in Raw Mill fordrying. Grounded Raw Meal is than transported

to the Electrostatic Precipitator (ESP) /Bag

house, where it is collected and then stored and homogenized in the

concrete SILO. Raw meal extracted from the SILO is than fed to the top of

the pre-heater for pyro-processing.


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V. ClinkerizationCement clinker is made by

pyro-processing of Kiln feed

in the pre-heater and the

rotary Kiln. Fine coal and air

is used as fuel to heat the

Kiln and the pre-calciner

located at the bottom of the

5/6 stage pre-heater. Hot clinker discharged from the Kiln drops on the

gate cooler and gets cooled. The clinker discharged by the Cooler House

falls onto the pan conveyor and it is than transported to the clinker

stockpiles/SILO. The clinker is than taken from the stockpiles/SILO to the

Ball Mill Hoppers for cement grinding.

VI. Cement Grinding & StorageClinker and Gypsum (for OPC) and also Pozzolana (for PPC) are extracted

from their respected hoppers and fed to the cement mill. These ball mills

ground the fed materials to a fine powder. The mill discharge is than fed to

the elevator, which takes the material to the separator, which separates

fine product and the coarse material. The latter is sent to the mill inlet

again for regrinding and the fine product is stored in concrete SILO.

VII. PackingCement extracted from SILO is than conveyed to the automatic electronic

packers where it is packed in 50 Kg polythene bags and dispatched in

trucks.


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SHUTDOWN OPERATIONS

INKILN AND COOLER HOUSE

(UNIT-2)

I. Detailed Descriptiona. Rotary Kiln

Kiln is cylindrical rotary equipment rotating on supporting rollers at about

3.5 RPM and discharges on the completion of calcinations reactions. Firingis done from Kiln outlet with the help of burner pipe.

i. Technical specification of Rotary Kiln:Unit-2

Maker FLS

Pre-calciner SLC

Diameter 4.75 M

Length 75 MCapacity 5500 TPH

Rpm 3.8

Burner pipe Duoflex

Slope 8

Fuel Used Coal

Thrust roller Hydraulic


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Thermal Load 14.44

Supporting Roller 6nos

ii. Construction:a. Kiln inlet (consist seal, grease pump, lines, cylinders etc)b. Girth gear (Gear, pinion, spray system)c. Thrust roller (Hydraulic cylinder, oil line)d. Supporting roller & tyre (Consist of bearing, chair plate, bolts etc)e. Kiln outlet seal (S.S shims, crown shell, seal)f. Burner pipe(consist of air pipe, coal pipe, diesel pipe etc)

Kiln inlet

Kiln inlet is sealed by sealing arrangement. Greasing is done by

pneumatic pump seal. It consists of 10 to 14 segments so that it can be

mounted and disassembled from Kiln inside. A conical section forms an

extension of the inlet ring. A brick retaining ring has been mounted at

the end of conical section.

Girth Gear

Kiln is rotating by Gear pinion arrangement.

Girth gear is mounted on Kiln with the help of

spring plates.


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Specifications of Girth Gear are as follows:

KILN GIRTH GEAR

P.C.D. 7149 mm

No. of Teeth 220

Width of Teeth 640 mm

Thrust Roller

The function of thrust roller is to control

axial moment of Kiln in both upward &

downward directions.

Supporting Rollers & Tyre

Supporting rollers are for support of Kiln. They are in contact with tyre

which is fitted in Kiln shell.

Kiln Outlet

There is a sealing arrangement at Kiln outlet.

Burner Pipe

It is for firing of fine coal into the

Kiln. Air is controlled by damper

and fine coal by solid flow meter.

Duoflex type of burner is used inKiln Unit-2


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iii. MaintenanceRefractory Lining

The high temperature inside the Kiln leads to severe

thermal shocks which cause cracks in the brick lining as

well as Castable. Also, during the half yearly maintenance as

the Kiln is stopped, leads to high temperature changes

which causes cracks in the brick lining. This may cause the

molten liquid to reach the Kiln shell causing damage to it.

Hence the Kiln stoppages are usually averted as much as

possible. It may be noted that temperature of shell does not

rise beyond 300 C

The Castable is used wherever brick lining cannot be used

in Kiln generally in sections which are not straight.

Process of Replacing Brick Lining

Check the refractorybrick lining during the

maintenance time.

If the brick lining iscracked than we replace

the lining.

The cost of brick lining isquite high so we use

bricks according to the

temperature they are

supposed to sustain. Usually high alumina percentage bricks

are placed near the Kiln Inlet where the temperature is

highest and material flows in molten form.


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During lining of bricks a ceramic plate is placed in betweenthe two refractory bricks using adhesive. This is provided to

avoid stresses in the brick during thermal expansion.

A Ram is placed inside the Kiln which presses and supportsthe brick lining.

The last brick to be placed is known as Key Brick which isplaced with 2 shims maximum in order to tighten the whole

ring.

When the entire lining is completed, the pneumaticallydriven brick lining machine is used in order to press the

lining for final fit.

The bricks which were used were DALMIA 625 and 425where first letter denotes the diameter and last two the

thickness of insulation.

For e.g.: 625 means the brick is for lining 6 m diameter Kilnand insulation thickness is 250 mm. Since the diameter of

the Kiln is 4.75 m so these bricks are placed in the ratio of

1:1.

Castable is placed over the tip casting plate by weldingsmall sections

over the tip

casting plates and

than filling

Castable in it.

After the Castable

has solidified we

cut the extruding

parts. And remove

the support plates.


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Tip Casting Plate

The Tip Casting plate is placed

at the tip of the Kiln outlet.

These plates are those overwhich a ring of Castable lining

is made. These plates protect

the Kiln shell from the hot

molten material when the

Castable lining has worn off due to the continuous abrasive

action of between molten material and tip.

Process

Tip Casting Plate is imported from outside and is placed just

on the tip of the Kiln and screwed to the tip. Later this forms

a base for the Castable.

Chair Plate, Shims and Guide Blocks

The live ring migration is

equal to the relative motion

between Kiln Shell and Tyre

during a single revolution. It

is an indicator of ovality of

Kiln Shell. Chair plates are

inserted between the Kiln

Shell and Tyre and Shims areinserted in between to

reduce the clearance. This

stops the mitigation. It should be seen that mitigation of

Tyre does not exceed beyond 20 mm as it would reduce

Kiln lining life.


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Guide blocks are also provided to keep the live ring in its

axial position on the Kiln shell. This implies the transfer of

axial thrust on the Kiln shell between live ring and side

guides. The relative moment of the face depends upon the

ovality of Kiln shell. Therefore, there is a chance of high

wear.

The maximum clearance between the guide blocks and the

tyre should not exceed 4 mm.

At the time I was at the Plant a design change of guide block

was taking place. Previously adjustable guide blocks used to

be bolted over the Chair Plates. But over a period of time the

nuts used to get jammed and were no longer adjustable

hence the newer version of guide blocks were directly

bolted over the Chair Plates.

Crown Shell and Sealing Plate

Due to high

temperature andoxidation due to

atmosphere

surrounding it the

crown shell and sealing

plate may wear off and

get damaged. So during

shut down these

damaged plates need to

be checked and should be replaced if damage to them is

more than a limit.

The function of Crown shell is that it acts a nozzle for the air

blowing from side cooling the lip of the Kiln.


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Also Sealing plate does not allow the hot gases from the Kiln

to escape thus trapping energy.

Rollers

Rollers are also

checked because

they sustain heavy

loads hence even a

small particle will

lead to great loss

and wear the

surface. These

rollers are not

replaced rather grinded so as to make them polished and

workable.


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b.Cooler HouseIt is a vital part of Kiln System and a decisive influence on plant performance.

It is for the cooling of clinker (less than 100 degree), as produced in Kiln.

i. Technical Specification of Grate cooler

ii. Main Functions of Cooler HouseClinker cooler has two main functions to perform. These are as follows:

1. To cool the hot clinker quickly (from 1400to normally 100-200 degrees).2. To provide necessary hot air byrecuperating as much heat as possible from

hot clinker by heating up air use for

combustion of coal in pre-calciner and Kiln.

After introduction of red hot clinker into

the cooler, it falls over IKN plates. These

are fixed grate plates and hence to move

the clinker an air blaster is placed at the

start of the Cooler House. After this the

clinker moves to mechanically driven

gates. These grates are such that one row of grates is fixed and one row of

Type Folax

Make FLS(Germany)

Capacity 5500 TPD

Size 37.8m length*5.1m width

No. of gates 4

No. of cooling Air fan 11


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grates is reciprocating with the help of motor. These reciprocating grates

ate installed over a beam which moves over the rollers. The grates are

having holes from which pressurized air flows and cools the clinker

quickly.

Clinker cools down gradually as it moves, due to the air blown by the

centrifugal air pumps which is taken from the atmosphere. Air flowing

from below through the cooling grate plates helps in cooling the clinker

quickly

Clinker escaping out of the cooler is fed to a hammer crusher, since lumpy

material requires crushing. Crushed material is transported to clinker silo

through deep bucket conveyor. Temperature of clinker escaping out of

cooler is about 208oC.

iii. Grate Cooler operationThe grate cooler operates with a cross current principle in which the

clinker moves horizontally while cooling air blow in from below through

the grate and clinker layer.


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As the hot clinker falls from Kiln, it forms clinker bed on the grate plates

and is than transported through the cooler over alternatively fixed and

reciprocating grates. At the inlet of Cooler House, clinker is quenched and

spread evenly across the cooler width by the cooling air. The grate is

fabricated in order to obtain a thick clinker layer and a uniform

distribution of air through the clinker bed in the interest of heat recovery.

During the clinker transportation

from the cooler, a part of dust and

small size clinkers fall off from the

grates and get collected into

hoppers under the grates. These

hoppers have dust bin valves attheir bottom which opens only

when a certain weight has been

reached. The dust is released in the

same DBN conveyors which carry

the clinkers. The drag chain and

rotary air lock system feed these

clinkers and dust to clinker

transport system. A dust collecting ESP is also installed known as cooler

ESP. Exhaust gases from collection is fed to the ESP for dust collection.

iv. ConstructionCooler parts are as follows:

IKN Grate (fixed) - IKN kids, Fans

Cooler I-IV Grate - S.S Grate plates, S.S Bolts

Cooler Fans - Fan, Belts, Pulley, Motors

Hammer Crusher: - Hammers, Pans, Rollers


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IKN Grate

It is a stationary grate plate. Previously, there

used to be similar S. S Plates in place of IKN

plate but a change was made by the productiondepartment. They are not only having a

guaranteed 1 year life but also have increased

the production of Unit-2.

IKN-KIDS

There are 6 to 8 stationary and stepped enclosed air beams. These air

beams are aerated by individual ducts. Refractory side dams are used to

collect and aerate segregated clinker from discharge. Air blasters are

used to avoid snowman formation.

S.S Grate Plates

These plates are of old design. It

has holes over it with air blowing

from below. Due to air blowing

with heavily from below causes

widening of air holes which causes

clinker to pass from it to lower

chamber where rollers

reciprocating the plates are

placed.


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Fans

For Cooling purposes high efficiency fans are placed below over the

ground which suck air and send it for cooling

Cooler Fan

Maker REITZ

Fan Capacity- In/Out 46190m3/hr,

45360 m3/hr

Pressure 4.7 KPa

RPM 1480

Hammer

At discharge end of cooler hammer crusher is provided consisting of a

rotor with shaft. Hammers are mounted on each row. Hammers are

casted out of high chrome or manganese steel. Clinker is crushed to a

size of 15-25mm by Hammer Crusher.

v. MaintenanceShutdown Activities

All Cooler Grate Plates, Side Blocks should be checkedIf we find that the Grate Plates have worn off too much by

abrasion action of clinker or high velocity air gushing from below

than it is replaced. During my visit this operation was going in the

Cooler House. The old Grate Plates had their holes widened due

the high velocity air and also the thickness of those plates was

reduced due to the Clinker abrasive action. The replaceable lip is

also checked. A lip is provided in order to hold the side grate


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plates. These plates in a row are welded to each other and any gap

bigger than 3 to 5 mm is filled between the Grate Plates.

All compartment internals as pull rod, single and twin supporting rollersand grease lines should be checked.

All Grate connecting rod and non-drives must be checked Dust valve hopper leakage should be checked for holes etc which needs to

be patched and under Grate compartment jail needs to repaired/replaced

Just below the Grate plates there is a net type arrangement which

is used to allow the dust to fall into hopper connected to dust

valves. This net sometimes gets clogged by large clinkers which

need to be removed. Also sometimes they may create a hole in the

hopper causing leakage.

The net over the leaking hopper

is cut in this and the hopper is

thoroughly checked for holes and

repaired.

Hammer crusher hammers, impactplates, lining needs to be repaired/

replaced

Hammers get worn off due to

continuously striking the clinker and

breaking it to smaller pieces. The

hammer are either replaced or used

again by reversing them.

The impact plate just below the crusheralso gets worn off by continuously

striking clinker over it. There might be

holes created in them. The size of the

crushed piece can also be set by a screw

provided for changing inclination of


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impact plate.

Also hard basing is done at the end of the Cooler House so as to

protect it from continuous abrasion taking from the moving

clinker. The welding alloy LH 745S is used for this purpose itprovides hard surface at high temperature.

Pan conveyor or damaged track wheels should be checked and changed. Under Grate beams etc. should be checked All Cooler Fan Belts, bearing, Impellers should be checked.


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A.Company ProfileName of the company : Bokaro Steel Plant (SAIL)

Establishment Year : 1972

Chairman : Mr. S.P Verma

No of Employees : 25000

Products

Production Capacity : 4.3 MTPA Steel

Products

CokeAmmonium Sulphate

Naphthalene

Crude Anthracene

Road Tar

Crude Benzol

Nitration Grade Benzene and

Toluene

Solvent Naphtha

Light Pyridine

Ferrous Sulphate

Pig Iron

Steel


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B.IntroductionBokaro Steel Plant, the biggest steel complex in India, was designed with

the collaboration of former USSR. It is one of the main units of Public

Sector Organization, Steel Authority of India (SAIL). Bokaro Steel City is

situated on the bank of river Damodar in the North, river Garga in the

East, Chas-Ramgarh road in the south and Muri -Chandrapura line in the

west. It is about 50 kms from Dhanbad, which is on the main Delhi-

Howrah Railway line. It has been long acknowledged that Bokaro would

be one of the best possible locations for a large sized Iron & Steel Plant.

Its present capacity is 4.3 MT and is rapidly modernizing itself to double

its production. At present it is working with 5 Blast Furnaces and 8 Coke

Oven batteries.

Units of Bokaro Steel Plant

1. Raw Material & Handling Plant (RMHP)2. Coke Ovens3. By Product Plant4. Sintering Plant5. Blast Furnace6. Steel Melting Shop7. Slabbing Mill8. Hot Strip Mill9. Hot Rolled Coil Finishing

10. Cold Rolling Mill11. Roll Grinding and Bearing Shop12. Slag Granulation Plant13. Scrap & Salvage Department14. Refractory15. Research & Control Lab16. Inspection & Quality Control17. Industrial Engineering Department18. Water Supply19. Oxygen Plant20. Acetylene Plant


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21. Protective Gas Plant22. Machine Shop23. Forge Shop24. Structural Shop25.

Steel Foundry26. Pattern Shop

27. Ingot Mould Foundry28. Iron & Copper Foundry29. Thermal Power Plant30. Production Planning & Control


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C.Brief Description of UnitsVisited

I. Raw Material & Handling PlantPurpose:

1. To obtain homogeneity ofchemical and physicalcomposition of different raw

materials received from

different sources by method of

blending.

2. To keep an optimum stock ofmaterials in order to take care

of irregularities of supplyarising due to strike in railways, mines etc.

3. To release the wagons irrespective of consumption of material bycustomers. Thus, it avoids the demurrage charges.

II. Coke OvensMetallurgical and Engineering Industries generally require coke as fuel.For the production of solid, porous, coke ovens of certain characteristic

properties needed.


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In Bokaro Steel Plant, coke is chiefly used as fuel and for reduction of

iron ore. The Coke Oven here is largest in India. It has got 8 batteries at

present. Each battery contains 69 ovens.

The process of making coke consists of the destructive distillation of

coal in the absence of air. The coal is heated in closed chamber thereby

driving out the volatile components present in the coal and leave

behind the residue called coke. This phenomenon is called as the

carbonization of coal. The carbonization of coal can be carried out at

different temperature depending upon the type of coke we need.

Different sections of Coke Oven plant are:

1. Coal Tower2. Coal Handling Plant3. Coke Oven Battery4. Coke Sorting Plant

III. By Product PlantThe high temperature carbonization of coal is basically adopted for production of

metallurgical coke for use in Blast Furnace. The gas so produced is also used as fuel

for making, shaping and treatment of steel after detailed process of cleaning to make

it suitable for plant uses. In the process of cleaning some primary by-products,

namely crude tar, benzol, ammonium sulphate etc are obtained. The primary and

secondary chemicals that can be produced from these are of great importance for

the growth of chemical industry.

IV. Sintering PlantIt has been found that the production rate can be increased if the raw

material is sent into the Blast Furnace in sintered form. Keeping this in

view, BSL has the largest plant in India. There is provision for partially


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cooling the sinter on the machine itself. The ignition furnace is of double

hearth and provision is there for adding extra amount of coke on the

topmost layer of the charge. This plant not only helps in supplying a

suitable charge for the Blast Furnace, but also eliminates other intricate

problem.

V. Blast FurnaceIt is the root plant of any steel producing complex. It is the unit where

reduction of Iron Ore takes place. Hot metal is the final product from

the Blast Furnace. There are five furnaces, each of capacity 2640 Tons/

Day with a useful volume of 2000 cubic meter. The annual capacity of

Blast Furnace is 4.82 MT.

VI. Steel Melting ShopThe raw material for the Steel Melting

Shop is Hot Metal coming from Blast

Furnace. Here pure oxygen is blown

into the hot metal. Impurities are

oxidized and metal is transformed

into steel.

The Steel Melting Shop at Bokaro is

largest in India with an annual

production of almost 4.3 MT. There

are 5 LD Converters in SMS 1 of 100 T each where as in SMS 2 these LD

converters are of annual capacity of 300 T each. The steel produced is

meant for plates and sheets.


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VII. Auxiliary ShopsThe main function of Auxiliary Shops of

Bokaro Steel Plant is to extend help in a

specified manner to the principal

production line by producing spare parts

to exact specifications. The objective of

the set up of various Auxiliary Shops is

the economization of the production

complex and/or easy running of the production process. Some of these

Shops are as follows:

1. Ingot Mould Foundry2. Steel Foundry3. Forge Shop4. Machine Shop5. Structural Shop6. Pattern Shop


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D.Detailed DescriptionI. Raw material and handling plant

This plant deals with the raw materials which are coming from various

sources. It deals with around 10 MT of raw material per annum that

amounts to about 400 to 500 wagons which has to be unloaded per day

with each wagon carrying 60-70 tons per wagon. Mr. R.R. Kumar (AGM

RMHP) described about the plant and gave an introduction about its

operations and functions.

a.Functions of RMHP1. Unloading of Raw Materials within a given time

The material which comes within the plant by the well spread railway

routes within the plant has to be unloaded as quickly as possible. For

this purpose Tipplers are provided in the yard where each wagon is

uncoupled and placed inside the Tippler and tilted to be emptied. The

amount of wagons which have to be emptied is so much sometimes

that they have to remain docked in the yard for days and because of

this reason the company has to pay a heavy leverage of 10 15 Crores

each year.

2. Storage with proper blendingThis function is achieved by two types of machines Stacker and

Reclaimer. To keep the plant running we need continuous supply of

raw materials which is achieved by stacking them in 18 different

beds. Since the quality of material may differ hence blending is

needed. Stacker distributes the material in piles horizontally using

boom conveyors. so when Reclaimer reclaims the material, it takes


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the entire pile at a time hence blending the different composition or

material together.

3. Supply to Internal CustomersThese are the following Internal Customers of RMHP

1. Refractory Material Plant (RMP)2. Blast Furnace3. Sintering Plantb.Types of raw material

c. ProcessThe Raw Material coming from different parts of the world reaches

RMHP via rail routes to the captive yard inside RMHP. At this yard

there are 4 Tipplers located whose function is to unload the raw

materials. There are 3 cradle tipplers and 1 hydraulic tippler. Thecradle type tippler has a cradle located at top and on 1 side on which

the BOX wagon rests while it is being toppled by an angle of 170

where as the hydraulic tippler holds the wagon by hydraulic arms

and topples it. The cradle type unloads a wagon at the rate of 20

wagons/hr where as the hydraulic type unloads it at the rate of 12

RAW MATERIAL SIZE SOURCE

Iron Ore Lump

(Hematite)

10-40 mm Kiriburu,

Meghanathburu

Iron Ore Fines

(Hematite)


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wagons /hr. But the cradle type Tippler may cause damage to the

wagons which may increase railways cost of material handling and is

quite noisy.

There is a R & C sampling lab also known as Yard Lab nearby

consisting of equipments such as jaw crusher, evaporator etc. This

lab takes sample from each rake (59 wagons) of material arriving at

the yard. They do the physical size test and classify the material as

fines and lump. For chemical test the material is converted to a fine

powder and sent to the R & C Lab where a spectrometer test is done

in order to determine the composition of the raw material. This is

done so as to maintain the quality of the raw material.

Below each Tippler there are two hoppers located which empty the

raw material over to oppositely moving conveyor belts which empty

it in a chute moving over a conveyor which carries it to the junction

house. The junction house than decides where the raw material has

to be sent. There are numerous junction houses within the plant

which keeps the track of material movement. Each junction house

has 3 conveyors moving in each direction in which 2 are used and 1

is kept in case of breakdown of one of them.

The junction house sends the material for stacking in 18 beds

(280m*27.5m*9m) with the help of double boom stackers. The raw

material in beds is as follows:

Bed 1 Sinter (It could be either purchased sinter in

case of shortage or it could be for storage

during breakdown)

Bed 2 to 6 Iron Ore Fines

Bed 7 to 10 Iron Ore Lump

Bed 11 to 14 Flux for Sintering Plant


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Bed 15 to 17 Materials for RMP

Bed18 Sinter, L.D, Slag, Corzite

There are 2 stackers for Bed 15 to 18 and rest 4 stackers for Bed 1 to

14. These stackers moves between the bed and could be moved from

one position to other by placing it on a platform. These stackers

could stack at the rate of 1200 Tons/Hr. Similarly there are 6 barrel

type Reclaimers, 1 Bucket Wheel Reclaimer and 1 Shovel and

Travelling Reclaimer which are used for reclaiming the raw material

and sending it to the customers. The Barrel Type Reclaimer reclaims

the material at the rate of 1000 Tons/ hr and Bucket Wheel

Reclaimer reclaims at the rate of 500 Tons/ Hr.

There are screening units for limestone and lump ore within the

RMHP. The raw materials have to travel miles within the plant so

there is possible breakage of materials hence they have to be

screened before sending it to the internal customers since the size of

material is very important during charging. The capacity of both

screens is 500 Tons/Hr.


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II. Blast Furnace and Pig CastingMachine

a.Raw materialMATERIAL SOURCE

Iron Ore RMHP

Coke Coke Oven

Sinter Sintering Plant

Limestone RMHP

b.ProcessThe raw materials (Iron Ore, Coke, Sinter, Limestone etc.) are carried

to the blast furnace by conveyor belts from their respective sources

(RMHP, Coke Oven, Sintering Plant). The notable part during

charging is the size of the charge. Hence the fines and the lumps of

ores are separated in the RMHP itself. Further during material

handling of raw materials there is fine generated at different levels

so there are Vibrating Dust Separators at the start of the Blast

Furnace from where fines are separated and sent to the sinter plant

to be converted into Crude or Spongy Iron.

The raw material is emptied into their respective hoppers until they

reach Skip Pit where the raw material is weighed by weighbridge and

is loaded in the Skip (13.5-14.5 m3). In a Shift maximum 45 charges

are done with each charge having 20 skips. A same schedule is

followed for each charge. There could be a positive or negativedifference of 500 Kg but the total raw material in each charge

remains the same. The Skip moves over the rail in the skip bridge

and empties the contents at the top of the Blast Furnace. The skip is

operated by means of the skip wrench located in the wrench house.


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The hot blast is supplied from the stoves to the bustle pipe and is

blown through the tuyers at the bottom of the Blast Furnace

respectively located in the Cast House. The molten Iron and Slag flow

through the iron runner and the Slag runner. These runners are

made up of refractory powder (CaCO3, Al2O3, and SiO3) which needs

to be rebuilt after every 2 months. A new L&T furnace has a Siphon

Hall which sucks and separates Slag from the Iron thus there is no

need of two different tap holes. Just beneath the Cast house, at the

end of the runner there is a ladle wagon run by a locomotive which

carries the molten Slag to a Slag yard where it is stored in pits and

molten Iron to SMS. About 5% of this Pig Iron is sent to the Pig

Casting Machine (PCM). At the end of each runner there is manually

controlled swivel and rocker type runner which helps in pouring themolten material in ladles.

The waste gases from the blast furnace are taken through uptakes

and gas outlets to the dust catcher and further to the Gas Cleaning

Plant (GCP). This cleaned gas is taken through gas pipes to the stoves

for heating the blast pipes. There are checker plates in it which can

me made of refractory material or graphite which gets heated up and

the heats the cold blast sent by turbo-blasters which is sent to Bustle

pipe. The gaseous products of combustion evolved in the hot blast

stoves are exhausted through the chimney.

c. Blast FurnaceThe foundation has to carry a very heavy load. It constitutes piles

driven to the bed rock over which a huge reinforced concrete

structure is constructed. The steel columns mounted on the concrete

ring support the mantle ring. The Blast Furnace shell and the insidebrickwork is supported by mantle ring. The hearth bottom consisting

of fireclay bricks and carbon blocks is laid out within concrete ring.

The hearth is a cylindrical portion where the iron slag notch and

tuyers are located. The bosh is the section which slopes outwards

just above the hearth. The body is again a cylindrical portion above


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the bosh. The shaft which is in the form of a cone comprises the

portion above the body. The throat cylindrical in form is at the top of

the shaft.

There are box type coolers within the refractory lining of the throatand shaft through which water circulates. The coolers are mounted

to the shell of the Blast Furnace. The bottoms of the hearth and side

walls are having plate type coolers.

In 2000 m3 Blast Furnace, the Iron notch is situated at the height of

1.1 m above hearth bottom. The slag notch is located at a height of

1.8 m above iron notch. The tuyers through which the blast is blown

are located at a height of 3.4m above the iron notch. Hot blast from

the stoves passes through the Bustle pipe and tuyers (28 no.) into

Blast Furnace. The Bustle pipe is located at a height of 5.5m above

the iron notch. Another important feature of the recently

modernized Blast Furnaces is Coal Dust Injection System (CDI).

Previously the company was planning to replace the old coke based

furnaces by gas based furnace due to poor availability of

metallurgical coke and high cost of import of metallurgical coke from

Australia and New-Zealand. But CDI reduced the present

consumption of coke by 50%.

The charging mechanism is Bell Less Type. These systems use

multiple hoppers to contain each raw material, which is then

discharged into the blast furnace through valves. These valves are

more accurate at controlling how much of each constituent is added,

as compared to the skip or conveyor system, thereby increasing the

efficiency of the furnace. Some of these bell-less systems also

implement a chute/bin in order to precisely control where the

charge is placed. This valve system is easy to control and have

replaced the old Bell Systems. In the Furnace, a stirrer is placed for

equally distributing the raw material inside. A Bleeder Valve is

placed at the top of the Blast Furnace to release pressure if it exceeds

10000kg also a wench is provided to open it as and when required.


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In the cast house, the electric mud gun, tap drilling machine and the

slag notch stopper is located. Tap Hole drilling machine is used for

drilling out and opening the Hole (iron notch) for tapping the hot

metal. The closing of the hole at the end of tapping is accomplished

by means of clay gun. The opening and closing of slag notch is carried

out by the slag notch stopper.

Reduction by means of CO begins in the shaft and proceeds in steps

from the highest Iron Oxide (Fe2O3) to the intermediate oxide

(Fe3O4) and further down to the lowest oxide (FeO).The reaction

between FeO and CO is

FeO + CO = Fe + CO2

This is called indirect reduction of the iron and takes place around

600-1000 C. The chemical reaction between FeO and solid C is:

FeO + C =Fe + CO

This is called as the direct reduction of Iron and takes place around

1100 C. Usually 50-60% of iron is reduced in the blast furnace by

indirect reduction and 40-50% by direct reduction. This metallic iron

formed initially is in the solid state since the melting point of pureiron is 1540 C

The carburization of the spongy metallic iron takes place in the

presence of CO and its melting point is lowered to around 1200 C.

This carburized iron with about 2 % C melts and drops through the

incandescent coke on the wall of the wall of the furnace hearth. At

this time the iron absorbs more carbon up to 4% and settles at the

hearth bottom as liquid pig iron.

The reduction of Manganese, Silicon and Phosphorous from the

charge takes place in the furnace simultaneously with the reduction

and carburization of Iron. These elements also go over into the pig

iron.


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The slag forms at the lower part of the shaft due to the oxides of Iron,

Lime, Silica and Alumina. Liquid ferrous slag is formed at 1200 C and

at a certain proportion of the above oxides. As it moves down into

the hearth, it is heated and dissolves coke ash, fluxes and the

remainder of ore gangue

The production of each Blast Furnace is about 2600-3000Tons/Day.

d. Pig Casting MachineAbout 5% of the production of Blast Furnace is sent to PCM because:

1. Poor quality of Hot Metal2. SMS Breakdown3. Excess production by Blast Furnace & SMS not able to process

the entire lot.

Vital Equipments are:

1. Wagon Shunting Wrench2. Ladle Shunting Wrench3. Ladle Tilting Wrench4. Belt5. 4 PCM6. 2 Lime Preparation Plant (LPP)

The molten material comes to the PCM via Locomotive and than a

ladle shunting wrench is used to pick the ladle and place the ladle for

pouring where another wrench tilts the ladle over a conveyor belt

with pig cast coated with lime. The lime sprayed over the Pig Cast

does not allow the Pig Iron to stick to the cast. Water is sprayed over

the Pig Cast to cool it as the conveyor is moving. Just beneath, whereporing takes place over the Pig Cast, there are plates below which

dont allow the splashing to damage the machine elements below.

The splashed metal is again taken for pouring by a skip. This

prevents the loss of material.


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Limestone is used to prepare the Lime by mixing it with water. A

large amount of heat is evolved during this process. This is pumped

to the Lime sprayer which sprays it over the Pig Cast from below.

This process is continuous with the conveying action. The Pig Cast is

kept in the Cold Pig Yard and can be transported using Locomotives.

There are 4 electromagnetic cranes having 10 Ton capacity each

which are used for transferring Pig Iron to the Wagon.

At the time of my visit the PCM was closed for maintenance.


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III. Machine ShopIn order to keep the plants

continuously in working conditioneach plants have their own Area

Repair Workshop which deals

with the specific maintenance

problem of that Plant.

The Machine Shop is the Centre

Repair Workshop where parts are

given final touches. It has got 4

Bays, LE (Light Engineering), ME

(Medium Engineering), HE (Heavy

Engineering) and Assembly Bay. Each Bay has got an overhead Crane

with a capacity varying from 5 tons to 30 tons.

LE Bay houses simple lathes and turret lathes with bed length varying

from about 1m to 3.5m. It also has small size gear hobbing machine and

milling machines.

ME Bay houses medium size gear hobbing machine, Gear shapingmachine etc.

HE Bay houses Asias largest vertical boring machine with stroke length

of 4m. It also houses other large size vertical and horizontal boring

machines.

The Assembly Bay is the place where the parts are assembled and final

product is ready for dispatch.

Near the Machine there is another shop Structural Shop which houses

an Annealing Furnace which is used for annealing large size ladles etc.


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IV. Forge ShopThe Forge Shop is a part of auxiliary shops of Bokaro Plant. It takes its

raw material from Steel Foundry and from outside as per specificationand supplies it to the internal customer Production Planning Shop (PPS)

which gets the further work done by Machine Shop

a.Machines

b. ProcessThe job is first heated in the furnace at about 1200-1250C just below

the melting point of iron. Then it is picked up by crane incase the job

exceeds human holding capacity and the pneumatic ally driven jaws of

manipulator holds it. The manipulator jaws are pneumatically driven

and not hydraulically because we require impulse action in the jaw

arms of manipulator. When the hammer strikes the job, the job applies

impulse force over the jaws which if hydraulically driven remain rigid

hence the job breaks where as the pneumatically driven hammers are

flexible to impulse force and leaves and holds the job immediately as

Steam & Air Forging Hammer NO

5T 1

3T 1

2T 1

Pneumatic Forging Hammers

1T 2

4T 2

25T 2

2 Ton Forging Manipulator 2

1 Ton Forging Manipulator 2

Band Saw 1

Bogie Hearth Furnace 3

Box Type Furnace 2


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hammer strikes. The manipulator moves over the railroad by a

mechanical drive and because we require accurate movements of arms

of jaws we use hydraulically driven mechanism.

During forging due to heavy forces over the job its crystal structuredistorts which is improved by heat treatment. Sometimes a job becomes

soft on cooling in case of copper where as sometimes the job becomes

hard in case of iron. Hence annealing and seasoning is done later for

proper hardness of the job. The hardness is checked by the Inspector

who pierces the job and checks the depth and measures it with the

standard. Sometimes rough sizing of job is also required in that case the

Forge Shop has a band saw which cuts the job in blanks. Sometimes the

job is not required immediately but after a period of time. In that casethe job is sent to open entry where they are seasoned in open to

improve the crystal structure of the part.

There are two types of furnaces present in the shop

1. Bogey TypeThis type of furnace is used for heating the job entirely at a

single time. There is a bogey in which the job is placed and it

goes inside the furnace.

2. Box TypeThis type of furnace is used if the job is not to be heated

entirely i.e. a part of it is kept outside and part of it is heated

in the furnace.

The fuel which is used in the furnace is Coke Oven Gas and Oxygen in

the ratio of 1:4 and small amount of Hydrogen.


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A centre core is also prepared from High Silica Sand and additives. The

mixture is prepared as follows:

1. High Silica Sand : 100 Kg2.

Part A (Binder) : 20 Kg

3. Part B (Hardener) : 1 Kg4. Part C (Accelerator) : 4 Kg

The mixture is thoroughly mixed and it is placed inside the Core Box but

it is not rammed. It sets itself to the size of the pattern and thats why it

is known as self setting sand. It is than sent to 3 ovens where it is heated

with CO gas for 10 hours and than it is cooled for 1 hour inside the oven

and 1 hr outside the oven. The stopper dryer is than used for drying the

core by keeping it at 100-120 C for about 48 hours.

The mold is prepared from the two parts the drake and the copes After

these two things are prepared than the mold is prepared by placing the

prepared core over the drake and keeping the cope over it. A sheet

pattern is placed in between the core and case of cope. The molding

sand is sand now filled in between the core and the case and rammed by

sand slinger.

Now as the mold is prepared, hot metal coming from the Blast Furnaceis poured in the mould through the runner and the gate present in the

mould and it is kept for solidification for about 72 hours. Later the cope

and drake is lifted using a cope lifting machine. A 5 % coal powder is

added in the additives in molding sand which when comes in contact

with the hot metal causes a gaseous layer to be formed between the

casting and the sand. The graphite paint is also applied over the molding

sand which prevents the sand fusion.

To collapse the core, we strike the casting over iron pillars and thus the

core collapses and breaks away.

It must be noted that Silica Sand cannot be used for molding basic

materials (Magnesium etc.) since Silica Sand is slightly acidic. For this

purpose Olivine Sand is used which is generally found in Europe.


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After the Ingot Mould is prepared the milling operation is performed

over the ends of the molds to remove the bulges or extra material

attached.

Finally, the Ingot Mold is placed over bottom plate. This bottom plateacts like a reinforced plate for holding the Ingot Mould and sent to Steel

Melting Shop (SMS).

The Ingot Moulds have a life of about average 25 castings.

The Ingot Molds are of following specification:

1. 17 Ton2. 20 Ton3. 25 Ton4. 28 Ton

The first two are having ribs so that the Ingot formed gets ribs for

holding it in Slabbing Mill.

There are two other foundries namely:

b.Iron and Copper FoundryIt is where non-ferrous alloys such as copper, brass, zinc and aluminum

as well as Cast Iron casting are done.

c. Steel Foundry :The foundry takes scrap steel from the SMS and use it for its casting

purposes.


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VI. Steel Melting Shopsa.Steel Melting Shop (SMS)-1

The Steel Melting Shop-1 consists of 4 L-D Convertors which is used for

converting the Hot Metal from the Blast Furnace into Ingots.

Process

The process of converting hot metal into is a 5 step process. It is as

follows:

1. Hot Metal from the furnace is supplied by rail routes to SMS-1 throughladles to Mixer Bay Mixer which use CO gas as fuel. The furnaces are

preheated to about 1300 C to prevent metal sticking to the furnaces.

This heating is done in order to prevent the hot metal sticking to the

ladle. This is done in order to homogenize the old hot metal and the new

feed.

2. The Hot Metal is sent to the LD Convertor via ladles (5 No each of 130Ton) which reduces the C % to .10 to .15 %. In this Limestone and

Dolomite is added to remove the impurities in the form of slag. Oxygen

blasting is done in order which causes the impurities to burn away by

forming oxides and the proceeding chemical reaction causes the

temperature rise.

3. After conversion is completed, tapping is done. During tapping, Ferro-Mg and Silicon-Mg is added to remove oxygen which can cause blister to

be formed in casting. If the carbon percentage has decreased too much

than re-carburization is done using coke bags which is purged through

Argon Gas.

4. After tapping is done in the ladle, the ladle is lifted using cranes andtapping is done using sliding gate mechanism. The gate is opened which

is fitted below the ladle and the mould is filled. Aluminum shots added


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to the casting if oxygen content is found to be high since it forms Al2O3

which is lighter and floats over the surface.

b.Steel Melting Shop (SMS)-2 & CCSThis is a new shop which is set up in conjunction with continuous

casting shop. The process of conversion from hot metal to steel is same

as in the case of SMS-1. The only difference is that here we have only 2

converters instead of 5 in SMS-1 but of higher capacity of 300 Tons.

In continuous casting shop we have a Steel Refining Unit in which the

refining of steel is done. It is used for heating a ladle of 300 Tons at a

time using an electric arc. The Aluminum bricks are added which are

used for removing oxidized material from the crude steel also the

refining of other elements such as Cr, Mn etc is done. The ladle is than

kept over a car and sent to the continuous casting machine over which it

lifted by crane and kept over high Cr manganese pipe which could

sustain higher temperature. This fluid as flows starts solidifying and

passes through the mold thereby taking the shape of slab. Now it is cut

to the actual size by means of acetylene gas. The Slab is than send to Hot

Strip Mill to produce steel rolls upto thickness of 2 mm which is later

sent to the Cold Roll Mill for reducing its thickness to .15 mm.


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VII. Coke Oven and BPPThe main purpose of the coke oven is to provide blast furnace quality coke to

the blast furnace. During the process of coke preparation a large amount ofvolatile material and dust escapes which is processed in the By-Product Plant

which to give a range of products which are used in various fields like

pharmacy, roads, railways etc.

The coke arrives via rail routes to the tippler (2 No which unloads in the

similar fashion as in the case of RMHP and send via 2 conveyor belts to the

Silo. There are 81 Silo. These Silo's are numbered from 1 to 53 odd numbers, 2

to 54 even numbers and 1A to 53A odd numbers. Capacity of each Silo is 2500

Tons. Each Silo consists of coal coming from a different source namely

Australia, New-Zealand, Karghali, Kathara, Moonidi, and Jharia etc. These coals

have different ash percentage and different volatile material. The captive coal

mines of the SAIL produces coal of various qualities having ash percentage

between 15-25% where as the imported coal have ash percentage between 7-

8%. So accordingly these need to mix in order to obtain coke. The Indian Coal

and imported coal are mixed in the ratio of 1:4 almost. From the Silo the coal

is sent to Hammer Crusher which has a capacity of crushing 350Tons/Hr.

which crushes the coal to about -3.2 mm size. The homogenization and mixingof coal used to occur via mixture but now it is not anymore used. The mixing

occurs automatically when the coal is transferred through several conveyor

belts. From t

The crushed coke is transferred to Coal Tower (4 no's) with each having a

capacity of 3200 Tons. From there the coal i supplied to the 8 Coke Oven

Batteries.

Coke Oven Battery consists of 69 coke ovens and 70 heating walls. In eachCoke Oven there are 3 charging holes on the top and is charged by the

charging car. On the side of the Coke Oven one would see a huge Push car

which is used to ram out the coke prepared in the oven. The leveling ram

levels the top of the coal. On the other Side one would see the Guide car which

supports the rammed column of coke and guides it to the quenching car.


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The Coke Oven walls are made up of refractory material having hole in

between through which the Coke Oven Gas and Blast Furnace Gas as a fuel are

burnt which causes the bricks to become red hot. There is no air inside the

oven so the coal burns without air at about 1200 C. The flue pipes of the

refractory tunnel s connected by the flue tunnel with Twin reverse valve by

help of which flow reverses after some time. The two heating walls are

connected over the top by means of pipes. It carries the burnt gas out through

the chimney. The top of the coke oven is connected by pipes coming out which

is connected to the pipe which carries the burnt particles and volatile particles

to the By Product Plant.

From the coke oven it is sent for quenching in Quenching Tower where water

is dropped from the overhead pipe. The Quenched coke is sent for CokeCrushing Station and than to Coke Screening Station from where the coke of

25 mm size is sent to Blast Furnace and coke of size between 25-80 mm is

sent to crushing station again.

Submitted Report

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