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Global slag news Japan slag report Slag grinding Application of GGBS in China GS 2006 reviewed

FEBRUARY 2007

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4 Global Slag News

11 Japan slag report – JFE Steel Corporation profi le

18 Slag grinding with the Polysius Roller

Mill in China

23 Application for GGBS in China

28 Global Slag Conference 2006 reviewed

31 Loesche America’s 9th Discussions of the Round

Table Seminar in Miami

33 Global Slag Magazine Subscription form

CONTENTS FEBRUARY2007

This month’s front cover...

Delegates at the 2nd Global Slag Conference, in Bangkok in November 2006, were able to witness EAF slag being poured in one of the few indoor slag tipping facilities in the world, at the Siam Construction Steel Company at Mab Ta Phut, Rayong.

The next globalslag Conference will take place 19-20 November 2007 in Istanbul (see page 31).

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NEWS

4 globalslag MAGAZINE February 2007

Belgian and Swedish inventors develop battery recycling method

Belgium/Sweden: Daniel Cheret of Stabroek, Belgium, and Sven Santen of Hofors, Sweden, have developed a process for the recovery of cobalt (Co) and nickel( Ni). According to the US.Patent & Trademark Offi ce, the invention relates to a ‘process for the recovery of Co or Ni, comprising the steps of preparing a metallurgical charge comprising Fe, slag formers, and a useful load containing either one or both of Co and Ni; feeding the charge to a shaft furnace; and smelting the charge so as to form a Co or Ni-bearing alloy, an Fe-bearing slag and a gas-eous phase, characterised in that the useful load comprises at least 30% electrochemical batteries or their scrap, and in that the redox potential in the furnace is chosen so as to slag at least 20% of the Fe, and at most 20% of the Co or 20% of the Ni present in the charge.’

The inventors were issued US.Patent No. 7,169,206 on 30 January 2007. The patent has been assigned to Umicore, Belgium. The original application was fi led on 18 April 2005.

Imidro tenders fi rst two units for Kahnuj pigment works Iran: Iran Mines & Mineral Industries Development & Renovation Organisation (Imidro) has issued a tender for the fi rst two units of its Kahnuj pigment complex. A second tender, for the pigment processing plant, will be issued in the new Iranian year after 21 March 2007. The current tender covers a benefi ciation plant with capacity of 130,000t/year and a slag processing unit with capac-ity of 70,000t/year, which will feed a 50,000t/y pigment plant. Bids are due by 3 March 2007, but the deadline could be extended. The technology for the pigment plant is more complex, and there is a concern that the diffi cult international situation could deter foreign companies from bidding. Imidro has pushed back the date for issuing a tender. Kar Azin Consulting Engineering Com-pany is the project consultant.

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Dissolution of steelmaking slags in acetic acid for precipitated calcium carbonate production

Finland: A promising option for long-term storage of CO2 is to fi xate carbon dioxide as magnesium- and calcium carbonates. Slags from iron and steel works are potential raw materials for carbonation due to their high contents of calcium silicates. Precipitated calcium carbon-ate (PCC) is used as fi ller and coating materials in paper. If slag could be used instead of limestone for producing PCC, considerable energy savings and carbon dioxide emissions reductions could be achieved.

In a paper of the University of Helsinki, the leaching of calcium from iron and steel slags using acetic acid was investigated. Thermody-namic equilibrium calculations at atmospheric gas pressures showed that extraction of calcium is exothermic and feasible at temperatures lower than 156°C, while the precipitation of calcium carbonate is en-dothermic and feasible at temperatures above 45°C. The formation of calcium- and magnesium acetate in the solution was found to be ther-modynamically possible. Laboratory-scale batch experiments showed that iron and steel slags rapidly dissolve in acetic acid in a few minutes and the exothermic nature of the reaction was verifi ed. While silicon was successfully removed by fi ltration using solution temperatures of 70-80° C, further separation methods are required for removing iron, aluminium and magnesium from the solution.

Zinifex Port Pirie BF shut down after explosion Australia: Australia’s Zinifex has shut down a blast furnace at its Port Pirie smelter following a steam explosion in January 2007 caused by molten slag coming into contact with water.

Repair work is expected to last for 7-10 days and as a result lead and silver production in 2007 will be reduced by approximately 6000t and 7600kg respectively. Op-erations other than the blast furnace will continue largely unaff ected and so the impact on production of other met-als at Port Pirie will be minor, the company announced. “The damage was not to the blast furnace itself but to the slag granulation system nearby. However in order to ef-fect repairs to this equipment safely we have taken the precautionary step of shutting down the blast furnace,” Zinifex said. The fi nancial impact from the shutdown is estimated at less than US$4m. An employee was injured as a result of the incident but according to the company he is recovering well.

Total Zinifex production of zinc and lead in the fi rst half to 31 December 2006 fell 10% from 2005 primarily due to planned maintenance shutdowns at its Rosebery, Port Pirie and Clarksville mines, and an unplanned shutdown at its Century mine.

Cobalt production losses at Chambishi as smelter to be shut down Zambia: Zambia’s Mine Safety Department (MSD) has rec-ommended that the smelter at Chambishi Metals Plc on the Copperbelt be shut to facilitate refurbishment of its slag furnace. The slag furnace at Zambia’s largest cobalt producer exploded in January 2007 but there were no fatalities. Mines minister Kalombo Mwansa said that the shutdown could last between 45 days and 60 days. He added that the com-pany’s management was doing all they could to shorten the shutdown period. Mwansa explained that the shutdown was necessary to enable Chambishi to do a good job that would prevent a recurrence of the problem.

The shutdown would result in a loss of at least 7t a day in cobalt production, with daily losses estimated at US$300,000 (Euro230,975). Mwansa, however, noted that the plant was going to shutdown for two months for maintenance. The Chambishi Metals Plc copper/cobalt smelter had steadily in-creased output from about 500t per year in 2001 to 3500t by 2005. The design capacity is 3700t per year.

“The Chambishi smelter of strategic importance to Zambia as it is the largest producer of cobalt...The plant is also a signifi -cant player in the mining world because cobalt prices increased by US$3 (Euro2.31) per ton following reports of closure of the furnace. The current price of cobalt is US$40,000 (Euro30,799) per ton,” Mwansa said. He added that though MSD investiga-tions were ongoing, it appeared that the explosion was caused by the sudden collapse of the refi nery’s refractory brick lining. “To prevent a recurrence, we have instructed management at [Chambishi] to completely shutdown the smelter to allow for total refurbishment of the slag furnace whereby the entire refractory brick lining should be replaced,” Mwansa explained.

NEWS

globalslag MAGAZINE February 2007 5

Harsco Corp. completes Excell Materials acquisition US: Harsco Corp. has completed its acquisition of Excell Materials, Inc., a multinational company that extracts high-value metals content on behalf of leading steelmakers and also spe-cialises in the development of minerals technologies for commercial applica-tions. The acquisition is expected to be immediately accretive to Harsco’s earnings. Excell posted 2006 sales in excess of US$100m (Euro76.95m) and maintains operations at nine locations in the United States, Canada, Brazil, and South Africa. The company has also established a presence in Europe for future expansion. Excell joins Harsco’s Mill Services Segment and will also share technologies and resources with the company’s Reed Minerals division, a market leader in the production of mineral abrasives and roofi ng granules from slag materials.

All-time record loading of blast furnace slag

India: The Visakhapatnam Port established an all-time record in loading of granulated blast furnace slag in bags in a day. A quan-tity of 5225t of granulated blast furnace slag in bags with a gang shift output of 435t was loaded in a day in January 2007 from the vessel M.V. Alyia at EQ-4 berth. This sur-passes the previous best record quantity of 4031t with a gang shift output of 336t in a day on 26 October 2006 from the vessel M.V. Leonis. Toshali Cements Pvt. Ltd., imported the cargo. Srivalli Shipping and Transport were the stevedores and Seaport Shipping Pvt. Ltd. is the steamer agent for M.V. Alyia.

Southern Copper completes Ilo modernisation Chile: Southern Copper Corp. has completed a modernisation programme at its Ilo copper smelter in southern Peru that brings the plant into compliance with prevailing environmental regulations. Following an expenditure of US$600m (Euro461.86m), the smelter will now capture more than 92% of its sulphur-dioxide emissions, up from 33% previously. Production will be maintained at current levels, with the smelter processing 1.2Mt of copper concentrates per year.

For the fusion process the furnace utilises an Isasmelt technology furnace, a stationary vertical furnace, 17m high with a treatment capacity of 165t of copper concentrates per hour. It also uses two rotary furnaces to separate the matte with 62% copper content from the slag. The conversion process uses four Peirce Smith converter furnaces to pro-duce 99.3%-pure copper. That metal is subsequently sent to the new anode plant, which has two 400t-capacity rotary furnaces and two casting wheels that produce 99.7%-pure copper anode. Anodes are sent to the refi nery to produce 99.9%t-pure copper cathode.

Mallard lashes Exide on slagUS: A Senior Government minister has lashed out at Exide Technologies for stock-piling ‘toxic’ battery waste near people’s homes, demanding the company cease operations - or move. Hutt South Labour MP Trevor Mallard has also criticised Hutt City Council, accusing it of failing ‘basic health responsibilities’ to its residents by al-lowing the mass storage to continue unchecked. Mallard has written to Lower Hutt Mayor David Ogden seeking an assurance that no further slag is stored or transported within the Hutt Valley’ till all outstanding resource consent issues are resolved.

The slag, a hazardous waste containing lead and arsenic, is a byproduct of Exide’s Waione St battery-recycling smelter in Moera. Exide has amassed about 5000t of chemical waste in warehouses around Seaview – some near homes and a school – without enforceable inspection or storage regulations. Though Exide had fi nally lodged a consent application amid growing local concern, the problem had dragged on for more than a year and was beyond a joke, Mr Mallard said. “I’m very concerned. There just doesn’t seem to be a proper process in place for storage or disposal. There are health issues that fl ow from that. No one is absolutely aware of what the health eff ects of the waste are. Proper consent arrangements are not being enforced and that’s not good enough.”

Exide was forced to apply for consent when it was revealed that it had amassed the slag in drums at four sites, after the council stopped accepting it at Wainuiomata landfi ll. The hazardous waste contains a known carcinogen but Exide says that it is inert and poses no health risk the way it is stored. The company, which had lead emis-sion limits imposed on it in 2005 amid health concerns, hopes to resume sending the slag to the landfi ll once new processing equipment is installed. It is yet to provide a sample to the council for testing. Mallard said that Exide should not be allowed to produce or store the material in residential areas without adequate controls. “If they can’t get their systems consented then it needs to be shifted. Not knowing what’s in it – I wouldn’t like it close to my place.”

Moera resident Angus Gibb’s property backs on to a Randwick Road warehouse where the slag has been handled by workers in breathing apparatus and protective clothing. He welcomed the government’s involvement and hoped it would hasten a resolution. “The council’s taking a long time to sort this out. I think Mallard’s realised he’s got to move them along. Everyone’s fed up that it’s got this out of hand.”

Hutt City Council spokesman Don Carson said that Exide was responsible for ap-plying for consent but only did so once large volumes of slag were accumulated. There were no immediate plans to force Exide to stop producing the material, but the council estimated it would hit the 7500t threshold it had applied for by Septem-ber 2007. The council would take action if consent arrangements were not fi nalised before then. “We will be telling Exide we need time for testing and considering the resource consent, and that they can not expect to go beyond the 7500t. If that means they get to the 7500t and stop processing, then so be it.”

Exide logistics general manager Brian Smith said that details requested by the council had been prepared and all the slag at Randwick Rd moved to Hutt Park Road. Processing equipment was to be trialled and samples would be sent for testing.

Russian Satka Cast Iron Smelt-er ferromanganese output at 74,800t in 2006 Russia: Russian Satka Cast Iron Smelter in Chelyabinsk region, southern Ural, in-creased its output of ferromanganese by 62% year-on-year to 74,800t in the period January to November 2006, reported on 15 January 2006.

In comparison, the plant, located in the city of Satka, produced 46,152t of ferroman-ganese in the period January to November 2005.

NEWS


News in Brief

Russia: Russian Satka Cast Iron Smelter in the Chelyabinsk region, southern Urals, increased production of ferromanga-nese by 52% year-on-year to 82,026t in 2006, 4% over plans, it was reported on 5 February 2007. The plant also produced 60,715t of broken slag. The electricity output of Satka Cast Iron Smelter rose by 5.9% in 2006, 3.4% more than planned. In December 2006 alone, the plant’s output of ferromanga-nese stood at 7226t and production of broken slag totalled 6774t.

Turkey: Adana Çimento, a cement producer owned by Oyak Group, will invest Euro48m (US$62.38m) for two new projects. The company will invest Euro16m (US$20.79m) to convert one of its furnaces for white cement production. The new furnace will become operational in January 2008 and will increase the company’ s annual white cement pro-duction capacity. Adana cimento will also spend Euro36m (US$46.79m) to set up a grinding facility, which will utilise the slag, received from Isdemir, an iron producing company. The new grinding facility, which is expected to become op-erational in 2009, will increase the company’s grey cement production capacity by 20% to 41Mt.

Russia/India: The Russian government signed the agree-ment with Indian Saraf Agencies Private Ltd about launching a joint venture producing titanium products. The plant will be constructed in the Indian state of Orissa where the il-menite deposit is located and will produce titanium dioxide and titanium metal. Under the agreement, 75% of products will be supplied to Russia: 30,000t of titanium dioxide, up to 45,000t of titanium slag and, if necessary, titanium sponge. Russia will own 55% of the joint venture. 10% of Indian debt to Russia will be written off in the course of cooperation.

Ministry of Environment claims that Azeraluminium is polluting the environment

Azerbaijan: The ‘Azeraluminium’ alumina factory in Gyanja is pol-luting the environment with alunite and bauxite waste, an offi cial of the Ministry of Environment and Natural Resources of Azerbaijan announced.

“Alunite and bauxite are both used as a raw material; the mineral materials that the factory needs account for 48-50% of the composi-tion; the rest is debris. That debris is accumulated in slag basin and pollutes the natural environment,” the ministry announced.

It was added that the factory had more than 11Mt of alunite slag and 5.7Mt of bauxite debris piled up on the premises at the mo-ment. “The waste handling standards are ignored and this results in the pollution of not only the site but also the areas adjacent to it.“ The ministry has fi ned the factory and plans to liquidate the envi-ronmental pollution. Azeraluminium actually incorporates and runs an alumina factory in Gyanja, an aluminium works in Sumgait and an alunite mining department in Zaglik.

Further cuts in duties possible

India: The Indian government may further cut duties on industrial raw materials to tame infl ation, according to a local resource. The government is considering cutting the excise duty on slag and the import duty on petcoke to check cement prices, an unnamed Ministry of Finance offi cial said. The government is worried about a more-than-50% rise in cement prices in 2006, which has pushed infl ation to a two-year high. The Indian government completely re-moved the 12.5% import duty on portland cement. It also reduced the import duty on primary and semifi nished aluminum, zinc, copper, tin and other base metals to 5% from 7.5% as part of the government’s steps to check infl ation.

India’s infl ation rate measured by the wholesale price index, stood at a two-year high at 6.12% in the week ended 6 January 2007.

US: Carpenter Technology plans to invest US$115m (Euro88.32m) in expanding melt capacity and related infrastructure at its Reading, Pennsylvania, facilities, according to the US specialty alloys producer. The premium melt expansion will allow the company to meet the demand expected over the next several years from its key end use markets, including aerospace, energy, medical, and specialty applications in automotive and truck, the company announced. “Carpenter believes that more than US$500m (Euro384.2m) of organic growth opportunities in its highest margin business exist in these markets over the next several years. These markets require high-performance products made to exacting specifi cations for critical applications that can-not be easily substituted,” it added. At the core of the premium melt capacity expansion programme will be an approximate 40% increase in vacuum induction melting (VIM) capacity, the company said. VIM furnaces are typically used in the fi rst melting step to produce materials for demanding applications such as high temperature and highly corrosive environments, high pu-rity alloys for medical procedures, and specialty applications in automotive and truck. The expansion programme also includes

four vacuum arc remelting furnaces (VA) and two electro-slag remelting furnaces (ER), used in the production of higher-mar-gin products for critical end applications such as rotating aircraft engine parts, high performance automotive and truck engine parts and medical devices. These furnaces will augment the company’s existing 27 VA and ER furnaces, two of which were added in December2006, Carpenter added.

The expansion programme will also include related anneal-ing, homogenisation and other process machinery, associated testing equipment, raw materials management systems, and information technology infrastructure. Construction is expected to begin in late fi scal year 2007 and be completed by mid-fi scal year 2009. “This expansion of our premium melt capacity refl ects the increasing demand for premium alloy materials that is at the heart of Carpenter’s growth plan,” said Anne Stevens, chairman, president and CEO, in a statement. “The investment is a con-tinuation of our strategy to focus on higher-value materials that have applications in niche markets.” Carpenter produces and distributes specialty alloys, including stainless steels, titanium alloys, superalloys and various engineered products.

Carpenter Technology plans US$115m (Euro88.32m) premium melt expansion

NEWS


‘Snow-like dust’ drops on port

UK: A rogue rag is being blamed for a pollution scare that coated part of the centre of Teignmouth, Devon, with ‘snow-like dust.’ The cloud escaped from a slag silo on the docks, and blew towards the town and harbour area. Several residents complained about their homes and cars being covered with the material, and Teignbridge Council has launched an inquiry into what went wrong. Port manager Dave Atkin explained that the silo belonged to Civil and Marine Slag Cement Ltd, and contained granular blast furnace slag used in the building industry. On this occasion a tanker driver was loading his own vehicle, when one of the valves jammed and some mate-rial escaped. It was discovered that the jamming was caused by a rag, which was already in the material. Unfortunately there was unusual warm, wet weather that evening, which exacerbated the situation, and some material blew into the nearby Teign Street and town area. An inquiry was carried out by Associated British Ports, the slag company and the Teignbridge Council environmental health department to fi nd out what went wrong, and remedial measures will be taken to try and prevent it happening again.

“It was an unfortunate accident, and we all apologise to those who suff ered from the pollution. I believe the slag company has personally approached all those who complained to make amends.” A spokeswoman for Teignbridge Council said that they were gathering all the evidence about the incident to discover exactly what happened, and would then make a decision what action, if any, to take.

One resident said that the wet weather turned the material into ‘a creamy slag’ and next morning it had been turned into ‘whitish, sticky puddles.’ The resident was concerned that the dust could cause health problems, but Teignbridge Council said they did not believe there was any cause for concern.

Five shipyard fi ned for break-ing environment law

Vietnam: The central province of Khanh Hoa, Vietnam, has decided to fi ne the Hy-undai-Vinashin Shipyard for its violation of the Law on Environment. Hyundai-Vinashin will have to pay US$5317 (Euro4085) for its discharge of used NIX particle into the sur-rounding environment during the process of ship repair. The act has caused pollution, particularly to My Giang and Ninh Yen hamlets, Ninh Phuoc commune, Ninh Hoa district. NIX is the trademark of copper slag and it is largely used in the world for sur-face preparation by blasting. However, the process has impacted on the environment. The threat of pollution is raised during the blasting process and persists until the NIX becomes waste, according to a website of the Ha Noi-based National Centre for Scien-tifi c and Technological Information.

Hyundai-Vinashin is also required to take further drastic measures to tackle the envi-ronmental issues and compensate aff ected people, as well as assist them in moving to new places. The shipyard is a joint venture between the Hyundai Group of the Repub-lic of Korea and the Vietnam Shipbuilding Industry Corporation of Vietnam.

It had previously taken measures to tackle pollution. The measures included building a storage unit to keep used NIX and reduce the environmental impacts of used NIX by putting it into road construc-tion. However, the measures have failed to pay off , as the volume of used NIX has mounted up day-by-day and the proper treatment now goes beyond the joint ven-ture’s capacity.

Steel by-product can benefi t arable and grassland farming

US: Green fertiliser, or AgSlag, now has proven benefi ts for arable and grassland farming, according to Tarmac and Newcastle University. Made from steel slag dust, a by-product of the steel manufacturing industry, spreading Agslag on agricultural land reduces the amount sent to landfi ll. The new research also shows it is capable of boosting grass growth, restoring the natural pH balance and mineral content of the land, increasing crop yield and improving the well-being of livestock. The product also has a lasting eff ect and, in most cases, land only requires treatment every three to fi ve years. Dr Howard Robinson, head of product development at Tarmac, said: “Our fi eld trials in Scotland have proven that AgSlag rejuvenates grassland and benefi ts grazing stock by producing thicker, lush pastures. It can also help to prevent disease in the vegetation and encourage the growth of a more diverse range of grass and plant species.” Dave Merrilees, senior soil and water management specialist at the Scottish Agricultural Association, said: “The fi eld trials showed a similar grass yield can be achieved by a single application of AgSlag, compared with separate applications of ground or magnesium limestone and triple-super-phos-phate. Application of AgSlag to an acid soil with low phosphorus status resulted in a pH increase from 4.9-5.6 within seven weeks of application. It also increased plant uptake of magnesium, reducing the risk of hypomagnasaemia in livestock.”

Searchlight Minerals Corp exercises option to acquire 100% ownership of Clarkdale Slag Project

US: Searchlight Minerals Corp, a mineral exploration company, said that it has exercised its option to acquire all the outstanding shares of Transylvania International Inc, a sub-sidiary of Verde River Iron Company LLC to acquire 100% of Clarkdale Slag Project and consequently the title to the property. Searchlight Minerals Corp expects the acquisition to close on or before 15 February 2007 subject to the terms and conditions of a previ-ous option agreement with Verde River Iron Company LLC. The acquisition will provide Searchlight with a 100% ownership in the Clarkdale Slag Project on closing. The company presently has a joint venture with Verde River Iron Company LLC following which it can earn up to a 50% interest in the Clarkdale Slag Project. Searchlight is seeking to recover precious and base metals through the reprocessing of slag material from a slag pile lo-cated in Clarkdale, Arizona, the ‘Clarkdale Slag Project.’

Cement exports through Zhangjiagang Port

China: Statistics released by Zhangjiagang Entry-Exit Inspection and Quarantine Bu-reau in Jiangsu Province on 11 January 2007 show that the volume of cement exported through Zhangjiagang Port reached 150 batches, with total export volume reach-ing 2.807Mt, and the export value stood at US$110.49m (Euro84.75m). Cement export-ing companies through Zhangjiagang Port are Zhangjiagang Hailuo Cement Company, Suzhou Huaxin Cement Company and Jiangsu Shanggang Group. The exported cement products include cement, cement clinker and slag cement, which are mainly exported to the US, Australia, Nigeria, Qatar, South Korea and Taiwan.

NEWS


AK Steel to hold fi rst meeting about Dick’s Creek cleanup

US: AK Steel Corp. held the fi rst of three community information sessions in January 2007 about the cleanup of Dicks Creek. The Middletown-based steelmaker is required to update the com-munity using various tools as part of an agreement reached in 2006 with the federal and state environmental protection agen-cies. The meeting included updates about the cleanup and a question-and-answer session.

“The specifi c scope of the work has already been determined and agreed to by the parties,” said Alan McCoy, AK Steel’s vice president of government and public relations. “This session is simply intended to inform the public.” The nearly US$13m (Euro9.98m) eff ort to clean up two streams – Dicks Creek and the Monroe Ditch – contaminated with ‘signifi cant’ toxins is part of an agreement reached with federal and state EPAs to settle a six-year-old lawsuit. That settlement addresses claims that AK Steel violated the federal Clean Water, Clean Air and Resource Conservation and Recovery acts, as well as, Ohio environmental regulations in and surrounding its 2700-acre Middletown Works. The results of the initial investigation show that a major source of the contamination came from former oil/water separator ponds on the south side of AK Steel’s slag processing area behind Tube City IMS, which were used between 1966 and 1983. The contami-nants most likely were released into nearby waters during heavy rains, the company explained.

Contamination of the creek has long been a focus of commu-nity concern because of children’s access to the area, according to the Sierra Club’s Ohio chapter. AK Steel said that it expects to conduct additional sampling in 2007 of the Dick’s Creek fl ood-plain and the slag processing area, and then prepare additional information sessions.

SMS Demag gets contracts from German and Indian plants Germany: SMS Demag AG, Düsseldorf, Germany, has received two major orders. The company received an order from Salzgit-ter Flachstahl GmbH, Salzgitter, Germany, for the modernisation of converter ‘B’ at its Salzgitter LD melt shop. SMS Demag pre-viously modernised converters ‘A’ and ‘C’ for Salzgitter in 2000 and 2001.

The scope of supply for the new order includes the con-verter vessel with trunnion ring and slag skirt. The revamp, SMS Demag said, would raise the converter volume by 35m3, which is expected to extend the service life of the wear lining. Com-missioning is scheduled to take place in April 2007.

SMS Demag also received an order from India’s Jindal South West Steel Ltd. for the supply of a melt shop de-dusting plant, including a gas scrubber and basic oxygen furnace gas recov-ery unit, for its Toranagallu Works.

The scope of supply for the Toranagallu project includes the engineering and fabrication of special components plus engineering of the secondary de-dusting unit. The project will employ the Baumco CO system for scrubbing and recovery of process gas. Commissioning is scheduled to take place in March 2008.

South Africa’s Exxaro to buy Namakwa Sands

South Africa: South Africa’s Exxaro Resources, the country’s biggest black-owned mining group, will pay US$281.7m (Euro216.36m) to buy the Namakwa Sands project from Anglo Operations Ltd. Exx-aro also said that it would pay US$25.06m (Euro19.24m) for a 26% stake in Anglo Operations’ Black Mountain Mining Ltd zinc and lead mine as well as the Gamsberg zinc project. Anglo Operations Ltd is a wholly owned, indirect subsidiary of mining group Anglo American Plc , which is also a major shareholder of Exxaro.

The deal will position Exxaro as one of the world’s largest suppli-ers of titanium dioxide feedstock and zircon, it said. The purchase consideration for Namakwa Sands will be subject to various adjust-ments, but the total purchase price will not exceed US$467.9m (Euro359.3m). Black Mountain’s purchase price will also be adjusted for various factors such as movements in working capital balances and exploration expenditure incurred by Anglo Operations, but the maximum purchase price will not exceed US$62.84m (Euro48.16m). The mining operations of Namakwa Sands is a mineral sands mine at Brand-se-Baai in the Western Cape Province, while it has a smelter near Saldanha Bay at which ilmenite is smelted to produce titanium dioxide slag and pig iron. The Black Mountain base metal mine in the Northern Cape Province of South Africa exploits lead, zinc, cop-per and silver from the mining of ore from various deposits. Lead and copper concentrates, from which silver is also extracted, are ex-ported to various smelters world-wide through the port of Saldanha Bay. The Gamsberg zinc project provides for a possible life-of-mine of approximately 30 years, which at 300,000t yearly of zinc, would be the largest single mine and concentrator in the world. Exxaro, a coal, base metals and heavy minerals producer emerged from the split of diversifi ed miner Kumba Resources, and merger with unlisted black-owned Eyesizwe Coal, which heads a consortium of black groups with a 55% of Exxaro.

Azovmash produces slag car for Russian Cheliabinsk-based metallurgical plant

Ukraine: Mariupol-based Azovmash company (Donetsk region) has produced a SHS-100-3600 slag car for Russian Cheliabinsk-based metallurgical plant. According to a local resource, currently, transportation of the machine is being provided. The slag car will be used in oxygen-converter shop of the plant.

Besides, soon, it is expected to produce a furnace-charg-ing gear with the diameter of 4.8m3 and a gas-tight seal for blast-furnace hearth for the same customer. Cheliab-insk metallurgical plant produces constructive carbonic and alloyed, heatproof, rust-preventive, ball-and-roller, transformer, instrumental steels and also diff erent metal constructions. In summer of 2006, Azovmash won tender for supply of the slag car.

Azovmash opened joint-stock company was created in 2000. It runs Ukrainian largest producers and designers of railway cars and heavy machine building products: Mariupol-based heavy machine building plant, Azovobschemash, Mariupol-based thermal plant, and Main specialised design and technological institute.

NEWSNEWS


US: In its ongoing commitment to preserve and protect the environment, Tube City IMS Corporation, a provider of products and services to steel mills and foundries throughout the United States, Canada and Europe, said that the removal of mer-cury-containing devices from scrapped vehicles entering its Tube City Division, West Miffl in, Pennsylvania, processing plant is progressing well. Removing the mercury-containing components before scrapped vehicles are processed and sent to steel mills for melting helps prevent toxic mercury emissions from adversely impacting Pennsylvania’s air and water quality. Once removed, the mercury-containing devices are then sent to approved, certifi ed processors for further

recycling. Although the Tube City Division began formal participation in Pennsylva-nia’s new voluntary Mercury-Containing Automobile Switch Removal Programme in the summer of 2006, the Company initiated a ‘Zero Mercury’ programme to train, notify suppliers and reject mercury-containing scrap years earlier. “We are pleased with our progress at the West Mif-fl in operation, but we really plan to ramp up our eff orts in 2007,” said Joseph Curtin, President and Chief Operating Offi cer of Tube City IMS, Tube City Division. “We are proud to participate in this important ef-fort by the state to remove mercury from the steel scrap supply. It’s a great feeling to know that we are playing a vital role to ensure that all of us have a safe environ-

ment in which to live. Commitment to an important programme such as this will reap dividends in the form of a cleaner environment tomorrow.”

Tube City IMS Corporation, through its Tube City and IMS Divisions, is a lead-ing provider of outsourced steel services, including raw materials purchasing and sales worldwide, scrap management, scrap optimisation, and slag processing and metal recovery services to integrated steel mills, mini-mills and foundries. Tube City IMS has operations at 67 plants throughout the US, Canada and Europe. The company’s Tube City Division is head-quartered in Glassport, Pennsylvania, and its IMS Division is headquartered in Hor-sham, Pennsylvania.

Tube City IMS Corporation pleased with progress of mercury-containing devices removal programme at West Miffl in

US: Frustrated that the new owner of contaminated beachfront property in Oxnard, California, is moving too slowly with cleanup plans, the US Environmental Protection Agency (EPA) has begun its own emergency stabilisation of a massive waste pile next to sen-sitive wetlands. The Ormond Beach property, once controlled by metal recycler Halaco Engineering Co., was purchased and leased in September 2006 by Chickadee Remediation Co. The fi rm intends to restore the property for residential development. But Robert Wise, an offi cial with the EPA’s emergency response section, said that the company was slow in submitting its plan for stabilising the giant waste pile. The slag heap covers about two-thirds of the property and is more than 45ft high in some spots. “They couldn’t meet the deadlines,” Wise said. “Finally, we got tired of them drag-ging their feet and decided to do it ourselves.”

Although Chickadee turned in a preliminary work plan, Wise said that the company did not follow up with a specifi c safety plan, detailing how regulators could monitor air quality during the stabilisation process and how it would comply with federal hazard-ous waste standards. “If they can’t put together a plan in a timely manner, how can we trust them to actually do the cleanup?” Wise asked. The agency’s US$2.5m (Euro1.92m) emergency stabilisation plan will take about two months to complete and involve bulldoz-ers and other equipment to reshape the slag piles to make them less susceptible to erosion from wind and rain, Wise explained. The sides of the new piles will be covered in mesh made of coconut fi bre to further protect them from the elements. Additionally, EPA contractors will install fencing and public warning signs. Chicka-dee would be responsible for the cost of the stabilisation, offi cials said. Dick Sloan, president of Chickadee Remediation, said that his company paid US$2.6m (Euro2m) for 28.5 acres of the Halaco property that includes the slag heaps. He said that it spent an ad-ditional US$270,000 (Euro207,814) for a 24-year lease on the 15 acres where the old smelting plant is located. He disputed the EPA’s cost estimate for stabilising the site until the cleanup can begin. “We had estimated we could do that part for a couple of hundred thousand dollars.... You can certainly do that for way under a half-million,” he said. “If they’re planning to spend more

than US$2m, that’s ridiculous. That number is totally out of line.” Sloan believes that contaminates at the site -- including aluminum, arsenic, cadmium, copper, chromium, lead, magnesium, nickel, zinc and radioactive metals -- can be treated on site and the waste piles then re-contoured for future use. “Looking at the data, there’s no justifi cation to dig up that material, haul it off somewhere and bury it,” said Sloan, adding that Chickadee could complete its long-term cleanup within two years. “Even though it looks like heck, the levels of contaminants and toxicity is not that high,” Sloan said.

Environmentalists and regulators say that they are pleased that something is being done to arrest the ongoing degradation to sur-face and groundwater near the site. “This is a huge threat to water quality when you know what constitutes this wall of waste,“ said Francine Diamond, chairwoman of the Los Angeles Regional Water Quality Control Board, which revoked Halaco’s water discharge permit in 2003, forcing it to cease operation. “We were well aware that the [surrounding] wetlands were totally impacted and con-taminated. It was also leaching into groundwater, so we needed to be aggressive.” In January 2006, the water board asked the EPA to consider adding the Halaco site to its national priorities list of Su-perfund sites. A formal recommendation to include Halaco on the list is expected in spring 2007. Sandi Matsumoto, project manager for the Nature Conservancy’s offi ce in Ventura County, said that since 2002 her organisation and the California Coastal Conserv-ancy have purchased more than 540 acres of wetlands adjacent to the Halaco site with a goal to ultimately acquire similar property nearby to revitalise habitat for wildlife and to restore the ecosys-tem. Together, the Ormond Beach wetland, an adjoining 900 acres of freshwater wetlands and the 1500 acre Mugu Lagoon make up Southern California’s largest coastal wetland.

An environmental watchdog group that once sued Halaco to curb its polluting operation said that Chickadee’s plans to treat contaminants on site is insuffi cient to protect public health. “What we’d like to see is the whole property properly remediated,” said Kira Schmidt, executive director of Santa Barbara Channelkeeper. “Long-term, the entire pile and the soil underneath needs to be removed.”

Oxnard’s Ormond Beach wetlands: EPA steps in to stabilise pile of waste

NEWSEUROPENEWS

10 globalslagMAGAZINE February 2007

UDOT to retest slag for Legacy project

US: The Utah Department of Transportation (UDOT) said that it will retest slag from the former Geneva Steel site that is being planned for use on the Legacy Parkway to ensure that the material is environmentally safe. The slag will be tested by an independent, outside contractor, UDOT spokesman Nile Easton said. The test will occur before the material is used on Legacy, but no time frame for the testing has been set, he added.

“All indications are that it will meet our specifi cations and will be a safe product for the Legacy Parkway,” Easton said. The slag contains trace amounts of aluminum, silica and lead, according to state offi cials. There is a very small potential for those constitu-ents to leach into groundwater, according to the state Department of Environmental Quality (DEQ).

Legacy is a 14-mile highway being built near the Great Salt Lake wetlands in Davis County. In 2001, work on the road was stopped by a judge after a lawsuit by the Si-erra Club and Utahns for Better Transportation. The lawsuit raised concerns about the environmental sensitivity of the area where Legacy was being built, and asked that UDOT further study the environmental impacts of the road to animals in the area. A settlement last year has allowed work to resume on the road. Alan Moore, programme manager with the Hazardous Waste Management section of the DEQ, said that tests done by outside companies on the Geneva slag have shown that it is safe for use as a road base. The tests found that any constituents that might leach from the slag would be below ‘background levels,’ or what is already within the soil, he said. DEQ does not plan to retest the slag, he added. The agency has not done any previous tests on the slag but has reviewed tests done by outside consultants for Multiserv, the company that has processed and sold the slag for about 40 years. UDOT has previously used the slag on an intersection project in Utah County. Because of the material’s light weight, slag is used to help stabilise and prevent settling in road structures, according to UDOT. The contractors using the slag on Legacy are Ames Contractors and Ames & Wadsworth Contractors. They were given approval to use the slag by UDOT.

News in Brief

US: An explosion at the U.S. Steel mill did not injure anyone or cause any damage. The explosion was caused when hot slag, a byproduct in the steel making process, was loaded onto wet ground, said U.S. Steel spokesman John Arm-strong. “It can make quite a lot of noise,” Armstrong said. He said the slag, which can be 2700 to 2800 degrees, was appar-ently hotter than expected when put on the wet ground.

China: Panzhihua Iron & Steel (Group) Co. produced 172,000t of vanadium slag in 2006, which makes it the second largest vanadium producer in the world. 2006 has been a good year for the va-nadium market. Panzhihua Iron & Steel Co. has made great eff orts to ensure the production and quality of vanadium. The company organised a series of strategic measures to analyse, monitor and adjust the production process. Standard man-agement was also applied to command and guarantee the production. Besides, new techniques were introduced to improve the output. The annual eff orts made by the company were rewarded. Both the output and profi t have a seen huge increase. Its leading role in the in-ternational market remains as well.

US: A worker killed 27 December at Mittal Steel USA Inc.’s steel plant in Coat-esville, Pennsylvania, died of massive head injuries, according to the Chester Country, Pennsylvania, Coroner’s Of-fi ce. The Coroner’s Offi ce identifi ed the victim as 24-year-old Brian Pluck of Coatesville. Pluck, an employee of the MultiServ division of Harsco Corp., reportedly was struck by a train at the plant, where part of his job was hooking and unhooking rail cars. Investigations into the incident are under way by Harsco, the United Steelworkers union and the US.Occupational Safety and Health Administration (OSHA). The Mul-tiServ division of Harsco provides mill services to numerous metals producers around the country. Its contract at Mittal Steel Coatesville was for cleanup of slag and other waste materials.

Dniprospetsstal tobuild complex to recycle slag In Serednia Gorge, Zaporizhia region by 2008

Ukraine: The Zaporizhia-based Dniprospetsstal electrical and metallurgical plant is going to build a complex to recycle slag in the area of Serednia gorge (Zaporizhia region) before 2008, according to the general director of the plant Serhii Shybystyi. Now the complex design is being developed, he added. The estimated cost of the project will be about US$7m (Euro5.36m). The facility will allow extracting up to 10,000t of metal annually, and full recycling of raw material on the ground is to be completed by 2013.

Equipment will be purchased from a Finnish company, whose name has not been reported yet. It is known that the company supplied the equipment for simi-lar projects in Ukraine. The complex is to be put in operation in August 2007.

Dniprospetsstal is going to independently explore slag dumps belonging to the plant in Serednia gorge, according to local news resources. The company intends to create its separate subdivision for economic activity without rights of a legal entity.

On 11 May 2006 the Court of Appeal rejected the claim of Rehionpromservis company (Kyiv) to prolong the agreement on leasing slag dumps near Serednia gorge that belong to Dniprospetsstal. The Serednia gorge landfi ll of slag dumps in Zaporizhia is the place where Zaporizhstal metallurgical plant, Dniprospetsstal metallurgical plant, Zaporizhia ferroalloy plant, and Zaporizhkoks coke plant dump their industrial waste.

Dniprospetsstal produces sectional iron and forged products from special steel grades: stainless, tool, rapid, bearing, and construction steels, as well as nickel-based heat-resistant alloys.

globalslag MAGAZINEGlobal Slag Magazine staff PRo Publications International Ltd

Japan slag report - JFE Steel Corporation profi leA growing Japanese steel production and a corresponding increase in slag output has forced Japan to develop new alternative ways of using slag. globalslag MAGAZINE gives an overview of several environmentally friendly slag applications.

The growth of steel production in Japan over the last half century has been accompanied by a corre-

sponding increase in slag output from the nation’s blast furnaces and electric arc furnaces. Disposing of the growing volume of slag has become a major task for the steel industry which has been forced to develop inven-tive uses for slag to try and solve the problem.

New uses for Japanese slagLeading Japanese steel makers continue to invest sig-nifi cant resources in developing new uses for slag that are both benefi cial as well as environmentally friendly. Th e steel industry’s diffi culties disposing of slag are recognised by the government which requires regional governments to buy processed slag and other recycled waste products to support Japan’s grow-ing recycling programme.

In 2004 Japan produced 34.7Mt of slag as a bi-product of steel production. Blast furnace slag accounted for 91% of the total tonnage while the remain-ing 9% was electric arc furnace slag. Five Japanese steel makers operate blast furnaces. Nippon Steel produced 12.6Mt of blast furnace slag, accounting for 36% of total domestic slag pro-duction, followed by JFE Steel which produced 11.9Mt of blast furnace slag, accounting for 34% of Japan’s total slag output. Th ree other steel producers operating blast furnaces – Sumitomo Metal Industry, Kobe Steel and Nisshin Steel produced a further 26% of slag output combined, while

more than 20 steel companies operating electric arc furnaces account for the other 9% share of Japan’s slag production.

JFE Steel CorporationJFE Steel Corporation is one steel manufacturer at the forefront of developing new uses for blast furnace slag. A leading member of Nippon Slag Association, JFE Steel is part of JFE Holdings Inc, a joint holding com-pany established on 1 April 2003, by Kawasaki Steel Corporation and NKK Corporation following the two steel companies‚ decision to merge their steel making operations. JFE Holdings is the world’s third largest steel company aft er Arcelor and Nippon Steel, and consists of


Below: Tokyo by night.


TECHNOLOGYglobalslag MAGAZINE

fi ve companies including JFE Steel and JFE Engineering. Following the merger of Kawasaki Steel and NKK, JFE Steel operates facilities that include nine blast furnaces at various sites across Japan.

“Some 99% of our slag is a bi-product of the steel we make. We are not dumping it. Th is is important. All 99% will be processed into slag products,” explained Dr Tatsuhito Takahashi, general manager of JFE Steel Corporation’s Technology Planning Department. “We have got JIS (Japan Industrial Standard) standard rat-ing for our slag products. In Japan selling 99% is a good market. Under the law we can sell our slag products to a lot of diff erent customers but we cannot sell slag for dumping.”

A short history of slagTh e main use of blast furnace slag in Japan during the early years of the 20th century as the fl edgling steel industry began to develop was for landfi ll on steel companies‚ its own premises being used as a founda-

tion on which to expand their steel plants. From the late 1960s a sizeable share of slag began to be used in road construction to form road base. Th e next major development was the growing use of slag to make slag cement, which remains an important use of slag today.

“An estimated 85% to 95% of steel industry slag is used on construction projects for central and pre-fectural governments, while an estimated 70% to 80% of blast furnace slag from iron making is used to blend with cement,” Dr Tatsuhito said, “Some companies make blast furnace powder for cement production and export the powder, for example, to Southeast Asian countries. Th eir economies are growing so they need a lot of cement.”

JIS standards for Portland blast furnace slag ce-ment (PBFSC) Type A permit the slag content of Type A cement to vary from over 5% to a maximum of 30%. PBFSC Type B cement has a slag content of 30% to 60%, while PBFSC Type C cement has a slag content ranging from 60% to 70% slag. Of the

various types, PBFSC Type B cement is the most popu-lar slag cement currently used in Japan.

According to industry fi gures, about 14Mt of PBFSC cement was used in Japan in 2003, while CO2 emissions were estimated to be reduced by about 4Mt. As part of eff orts to support development in the use of proc-essed slag, the government has gradually introduced a system of certifi cation for PBFSC cement along with other construction materials containing processed slag. Certifi cation attests to the quality of the material and its environmentally friendly contents.

“In 2001 we got certifi cation for our blast furnace slag cement, then in 2002 certifi cation for blast furnace slag cement fi ne aggregate,” Dr Tatsuhito said, “Th e same year sub-road material were certifi ed – asphalt and rock materials. In 2003 grinding slag for civil works especially harbour works was certifi ed. In 2004 certifi cation was awarded to steel making slag used for ground improvement in harbour fl oors with sand piling for compaction. In 2005, slag aggregate for slag cement

(electric furnace oxidising slag) was added to the list of certifi ed prod-ucts. So now there are eight certifi ed items; in other words 74% of our products are certifi ed as ecologically friendly. Th e government also buys slag products, but not at a fi xed price. A market price is paid.”

Slag and the Kyoto ProtocolSlag cement use recently has received a boost as a result of the Japanese government’s declared commitment to achieve environmental pollution emission targets agreed during the 1997 Kyoto protocol negotiations, including a reduction in CO2 emis-sion. Th e manufacturing process for slag cement produces 38% less CO2 emission than the process used for


Scenes from Tokyo.

TECHNOLOGY

Portland cement production due to less limestone being burned for slag cement production than that required for Portland cement. Under a revised plan to reduce CO2 emission introduced by the government in 2005, the use of blended cement including slag cement is rec-ommended as one course of action that Japan needs to take to reduce the present level of CO2 emission.

Support for the production and consumption of slag cement and other certifi ed slag-based materials has been provided by the government’s longwinded titled law concerning the Promotion of Procurement of Eco-Friendly Goods and Services by the State and other Entities (Law on Promoting Green Purchasing). Introduced in 2000, the law is intended to encourage the use of a wide range of environmentally friendly ma-terials and products of which processed slag products are just one group. Regional governments throughout Japan have been instructed to buy environmentally friendly materials as part of their offi cial procurement programme and report on their purchases each year.

“Green is a good image for Japanese people. Some 74% of slag products in Japan are green products,” Dr Tatsuhito noted, “We tried to get green product certifi -cation. It was tough work but we got it. Th e government will buy green products. Th at’s the new rule. Prefectural governments should use these products. Every year the government reports on how many green products were used during the year.”

Slag applicationsIn 2004, some 25.3Mt of slag was used in Japan, some to make products that eventually were exported. Cement production used 15.5Mt, equivalent to 61% of total slag use. Some 5.5Mt, almost 22% of total slag use was for cement production intended for export. Highway con-struction used a further 4.2Mt equivalent to 16.5% of total slag use while 2.7Mt or almost 11% was used as aggregate. Th e remaining tonnage was employed for various uses including civil engineering purposes which used 1.8Mt of the total and soil improvement which consumed 493,000mt or 2% of the combined total.

As a member of Nippon Slag Association, JFE Steel also cooperates with other steel companies in research-ing, developing and commercialising new uses for processed slag products. Aft er attending the Euroslag 2005 conference in Norway and presenting a position paper on Japan’s slag product development programme Germany, JFE Steel and other Japanese steel maker members of Nippon Slag Association decided to pre-pare a more detailed slag industry position paper to present to central and prefecture government authori-ties in Japan.

Completed in April 2006, the Japanese version of the position paper is intended to inform government offi cials about all aspects of slag and the steel indus-try’s eff orts to fi nd benefi cial uses for its disposal. Th e

position paper describes the production of slag as a bi-product of iron and steel making along with the history of slag use in Japan and rising slag output levels. Details also are provided of slag transport arrangements as a hazardous cargo due to its alkaline content. According to Dr Tatsuhito, the paper highlights the usefulness of

slag in certain applications such as marine and coastal struc-tures, car parks and airport runways. Various sections of the paper emphasise the related environmental benefi ts that can be obtained at the same time as supporting Japan’s steel industry by using a natural bi-product.

Eff orts by the Ministry for Economic Trade and Industry

(METI) to promote slag use are covered in detail. Chap-ters are devoted to explaining the big project use of slag for car parking areas at Chubu International Airport in the third city of Nagoya and the runway of the New Kansai International Airport in Osaka. Information also is given on the usefulness of slag in marine protec-tion including government guidelines for using slag in harbour construction and improvement projects, also the use of slag for coastal rehabilitation schemes.

JFE Steel has been involved in the development of various new uses for slag with some of the develop-ments having been started by R&D departments and technology centres under Kawasaki Steel Corporation and NKK Corporation before the two steel makers merged in 2003.

Heat island phenomenonOne recent development is the use of slag to construct car park surfaces and pedestrian pavements in major cities as part of eff orts to tackle the ‘heat island phe-nomenon’ found around the world whereby ambient air temperatures in the centre of large cities are higher than in smaller towns and cities.

Historical records show that the temperature in Tokyo has risen by 3 degrees Centigrade since 1900 while the temperature increase in small and medium

globalslag MAGAZINE


The entrance of JFE Steel Corporation.

size cities across Japan has been 1°C over the past 100 years. Th e reasons for the higher increase in tempera-ture in Tokyo are thought to include heat exhaust from airconditioning units, rising vehicle exhaust, other energy consumption and the growing area of artifi cial pavement and buildings that prevent cooling moisture being released from the earth’s surface.

To help reduce the heat island phenomenon in Tokyo and other large cities, JFE Steel has developed a water re-taining pavement made of slag that traps rainfall which then cools the atmosphere as it evaporates. Th e water retaining pavement consists of open-graded asphalt concrete pavement with water retaining material fi lled into voids in the pavement. JFE Steel has developed water retaining material containing ground granulated

blast furnace slag which has been used for many roads in Japan. Dr Tatsuhito explained that the water retaining material is mixed with water to form a slurry which is then used to fi ll purpose made voids in the open-graded asphalt concrete pavement. Aft er being left to age for about three hours, the water retaining material solidifi es in the pavement voids and the water retaining pavement is complete. According to Dr Tatsuhito the porosity of the water retaining pavement is about 70% with the average diameter of the pores being 1.9μm. Water is absorbed into the pores by capillary action and then released as vapour once the rainfall has ended.

JFE Steel has experimented with various densities of water retaining pavement to develop the optimum cooling pavement design. Research has shown that fi ll-ing pavement voids with 40% to 75% of water retaining material is to be recommended for reasons of economic effi ciency and hydraulic permeability. Hydraulic per-meability is reduced with increased fi lling of water retaining material. Once fi lling with water retaining material reaches 80% density, the fi nal pavement lacks water permeability.

Th e performance of various water retaining pave-

ments has been measured at various sites around Japan. JFE Steel research teams sprayed water on the pave-ment at the rate of fi ve litres per square metre and then measured the pavement temperature and that of the soil 20mm below ground surface. Using adjacent test sites of conventional dense graded asphalt concrete and water retaining pavement, the research team discovered that the highest temperature the conventional dense graded asphalt concrete pavement reached was 52°C while the high temperature for the water retaining pavement was 40°C, almost the same as the underlying soil.

Th e cooling eff ect of water retaining pavement can last for up to one week aft er rainfall if water is fully absorbed into the pavement. Aft er one week the temperature diff erence between conventional dense graded asphalt concrete pavement and water retaining pavement is about 6°C to 8°C. Th e heat transferred to a person walking over the diff erent types of pavement is calculated to be 30% less when walking on water retain-ing compared to conventional pavement.

“Th ere is a lot of rainfall in Japan. Tokyo and neigh-bouring Kanagawa prefecture have been using this water retaining pavement for about two years,” Dr Tatsuhito explained, “Th e volume of water retaining material used in pavement construction is increasing. Th e material must be used to build new roads as the surface of old roads is contaminated. Water retaining pavement can be used for roads, pedestrian pavements and parking lots. Th e diff erence for the road surface temperature is 6°C to 8°C compared with conventional pavement. Th is idea would be very good for hot countries. In Japan, traditionally we throw water on the ground around our homes when it is hot and the ground cools as the water evaporates. Th is method of pavement construction uses the same mechanism.”

Artifi cial coral reefsAnother use for blast furnace slag that JFE Steel has de-veloped is to make carbonated marine blocks to restore damaged coastal environments by creating artifi cial coral reefs and improving the sea bed in inshore waters. Th e company decided to develop the marine blocks following discussions with marine biologists includ-ing Professor Mineo Okamoto at Tokyo University of Marine Science and Technology, and staff at Kyushu University in southern Japan who are involved in a project to rehabilitate coral reefs near Okinawa Island and elsewhere in Japan’s southern seas.

Japanese coral reefs suff ered severe bleaching in the summer of 1998 and again in the summer of 2001. In 1998 some 90% of the corals around Okinawa Island died due to the eff ects of the bleaching with the remain-ing coral being damaged again in 2001. Sekisei lagoon, Japan’s largest coral reef, which lies 450km southeast of Okinawa Island, also was damaged by the 1998 and 2001 summer bleachings though not as severely as the corals off Okinawa. Th e task facing marine biologists was to replace the damaged coral to avoid the serious threat of eventual coral extinction on the aff ected reefs and nearby smaller reefs which rely on the large reefs for coral larvae. Aft er the idea of transplanting coral frag-

globalslag MAGAZINE


Dr Tatsuhito shows slag, ceramic and neutral material discs on the slag blocks for corals to hide underneath. “We are testing these cogs from northern Japan to Okinawa in the south,” he explained.

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ments was rejected as too diffi cult to apply to Japanese coral reefs, the team of marine biologists decided to ex-periment obtaining coral larvae through mass spawning and raise them in situ for future transplantation to coral reefs decimated by bleaching.

In experimenting with diff erent materials used for stone settlement sticks to which coral larvae could at-tach themselves and grow, the marine biologists asked JFE Steel to supply marine blocks made of slag which were tested along with blocks made of pottery stone and limestone.

Th e company decided to use slag particles less than 3mm diameter, Dr Tatsuhito explained, compacting them in a mould to which 20% CO2 exhaust gas satu-rated with water vapour was introduced. Th e reaction time was 48 hours during which the mould pressure was kept slightly higher than atmospheric pressure. Th e marine blocks were then left in the open air for one year aft er production to cure, aft er which no cracks or surface destruction was discovered on inspection. Th e main carbonation product was calcite while a small amount of aragonite also was detected in all marine block samples.

“ Aft er seven months the slag blocks were covered in algae”Th e fi rst fi eld test of industrial size marine blocks

took place at Setoda-cho near Hiroshima. JFE Steel placed 15 industrial size marine blocks measuring 1m by 1m by 50cm in a 2.5m high, 7m wide pyramid wall with the blocks being spaced 50cm apart to allow the sea water to fl ow through and around the pyramid wall. Less than a year aft er the blocks were put in place, a diving inspection a large variety of plants living on the blocks and many species of fi sh

living around them, in comparison to adjacent Portland cement blocks to which no plant had become attached.

“Aft er seven months the slag blocks were covered in algae while the cement blocks used in the same tests re-mained bare, probably because of their alkaline content. Th e reaction between the slag block and the CO2 makes calcium carbonate which is the same material that sea shells and sea coral are made from,” Dr Tatsuhito said, noting that the slag block’s porosity is another factor encouraging coral and other marine plants to attach themselves and grow.

Aft er having shown the suitability of slag blocks to form artifi cal coral reefs, the research project has moved on to test the suitability of diff erent materials for coral larvae to attach themselves to which can later be moved to other locations that require coral restoration. Slag is one of several materials being used to make discs that are placed in small piles on the slag blocks near to where existing coral will spawn. Once coral is attached to the small discs, these can be transferred to other sites for coral to regenerate. “We are trying to recover the coral seas. JFC Steel co-works with Professor Mineo Okamoto who uses slag, ceramic and neutral material discs on the slag blocks for corals to hide underneath. We are testing these cogs from northern Japan to Okinawa in the south,” Dr Tatsuhito explained. “Th e slag blocks are very stable every time I have checked them. Coral eggs hatch once a year in May. At that time I go scuba diving with Professor Mineo Okamoto to put the slag discs on the blocks for coral larvae to settle on.”

Pictures below: Coral bleach-ing. When corals bleach they commonly lose 60-90% of their zooxanthellae (symbiontic algae incorporated in the coral) and each zooxanthella may lose 50-80% of its photosynthetic pigments.

Bottom right: Japanese newspapers report on slag use in coral reefs.

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Ingo Engeln Polysius AG

Slag grinding with the Polysius Roller Mill in ChinaGranulated blast furnace slag has been used as an component of blast furnace cement for many years. The replacement of a certain clinker portion by blast furnace slag saves raw materials and thermal energy for pyroprocessing. Ingo Engeln from Polysius AG gives an overview of the Asian slag market and the use of Polysius’ vertical roller mills in China and South Korea.

Granulated blast furnace slag, a by-product of pig iron production, has been used as an important

component of blast furnace cement for many years, due to its latent hydraulic properties.

Th e replacement of a certain clinker portion by blast furnace slag does not only mean to save raw ma-terials and thermal energy for pyroprocessing, but also provides for advantageous characteristics of the blast furnace cements:• low heat of hydration helps to prevent cracks in the concrete due to temperature stresses, • high resistance against sulphate attack,• high resistance against alkali-aggregate reaction,• high binding capacity of chlorides in blast furnace slag cement pastes,• the low electrical conductivity of concrete made with blast furnace cement resulting in a positive eff ect on the corrosion protection of the concrete reinforcement.1,2

Intergrinding - separate grindingFor a long time, the applicable standards allowed ce-ment clinker and granulated blast furnace slag to be ground together in tube mills, but especially by utilisa-tion of tube mills the clinker mainly accumulates in the fi nes fraction, while the granulated slag accumulates in the coarse range (Figure 1).

Because the proportion of pulverised blast furnace slag predominates in the blast furnace cement, the slag can only inadequately participate in the hydration as a result. Th e consequence is loss of quality. Intergrinding in roller mills provides very similar particle size distri-butions for clinker and slag and thus provides a better quality of the blast furnace cement.3

Th e results based on studies by Schwiete and Döl-bor in 1963 already show the positive infl uence on the strength development of cements when grinding granu-lated blast furnace slags to high fi nenesses (Figure 2).4

Th erefore, it is an indisputable fact that it is neces-sary to grind the granulated blast furnace slags to high fi nenesses in order to generate good strength proper-ties. Th e intergrinding of clinker and granulated blast furnace slag inevitably necessitates the energetically un-favourable grinding of the clinker to higher fi nenesses as necessary. Th e only way to avoid this is to grind clinker and slag separately.

For the design of a slag grinding plant the special properties of granulated blast furnace slag have to be considered. Granulated blast furnace slag is moist, abra-sive, fi ne grained and diffi cult to grind. It also needs to be ground very fi nely. Th ere are several grinding sys-tems on the market meeting the requirements for slag grinding, but no other grinding system has gained so much importance during the last decade as the vertical roller mill.

Polysius roller millFig. 3 shows the Polysius roller mill. Th e essential com-ponents of the Polysius roller mill are the grinding table, the two pairs of rollers, which can move vertically as well as rotationally around the guide axles, the housing, the adjustable nozzle ring, the drive unit with motor, and the separator.

Features of Polysius roller mill Th e double-grooved grinding track uses a defi ned gap between the rollers and the grinding track to prevent

Figure 1: Infl uence of grinding methods on the grain size distribution.


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the material from fl owing out at the sides. Th is reduces the specifi c power consumption. Th e grinding rollers can move in the vertical direc-tion and follow the wear profi le, ensuring an even wear profi le and a constant material bed thickness. Each grinding roller can also be twisted through 180°, i.e. the inner roller can become the outer roller, so the wear profi le, and hence the throughput, remain virtually constant over the entire running period. Th is minimises internal recirculation in the mill and stabilises the material bed. It reduces the gas velocities in the nozzle ring and thus saves energy. It is best if used in conjunction with the external material circuit.

Th e Polysius roller grinding mill has used a bucket elevator from the outset for returning the recircula-tion material. Th is reduces the amount of air-borne recirculation within the mill, which lowers the pressure loss and improves the smooth running of the mill. Th e bucket elevator is also a great help dur-ing maintenance work.

Typical fl owsheet of Polysius slag grinding plant with roller millTh e fl owsheet in Figure 4 shows the typical arrange-ment of a Polysius slag grinding plant with a roller mill. Fresh slag and sometimes gypsum are transported from the storage to the mill feed hoppers by conveyor belts. Aft er being discharged from the hoppers, the mill feed material is proportioned by weighbelts and then carried by conveyor belts to the mill. Protection against tramp metal is provided here by a suspended magnetic separa-tor. A metal detector is installed in the conveying route to take away metallic objects. A heated coarse feed valve is used as an airlock device in the material feed equip-

ment. Th e feed chute is very steeply inclined and is in principle integrated into the tailings cone of the high-effi ciency separator. Th e external material circuit is a closed system, consisting of a bucket elevator, vibrating through, magnetic drum and feed chute to the tailings cone. In order to prevent material from caking onto the recirculation bucket elevator, adequate hot air is supplied by a specially installed fan. Th is also heats the vibrating trough and the magnetic drum. Dust removal is ensured via the mill. Th e hot air used for drying is generated by a hot gas generator. Th e fi nished mate-rial is transported by the circulating mill air directly to a bag fi lter, where it is collected and then conveyed to the pulverised slag silo. A portion of the circulating mill air is returned to the mill, which helps to save thermal energy.

Insulation and heatingAnother point to consider is that the exit gas from the grinding plant has a high water vapour content. Its tem-perature must therefore be prevented from dropping below the dew point and plant components such as cir-culating bucket elevators, chutes and pneumatic trough conveyors must be carefully insulated or even heated to prevent clogging.

Slag grinding plant with roller mill in Kwangyang, KoreaTh e fi rst roller mill for this application was put into


Figure 2, above: Compressive strength depending on grinding fi neness of clinker and slag.

Figure 3, left: Polysius roller mill.

Figure 4, below: Flowsheet of a slag griding plant with a roller mill.

operation in Korea in 1995. Polysius designed and sup-plied a type RMS-51/26 roller mill with an integrated high-effi ciency SEPOL RMS-435 separator.

Th e output of the mill was 76t/h at a fi neness of 4840cm2/g according to Blaine. Th e residue on the 44mm screen was below 2%. Th e specifi c power con-sumption for the mill was 33.2kWh/t, for the mill fan 8.7kWh/t and that for the separator was 1.4kWh/t, measured at the counters of their drive motors. Also remarkable is the low pressure drop of only 34mbar in the mill.

During the next years further slag roller mills of various sizes followed in France, Spain and the US. But nowhere in the world have so many roller mills for granulated blast furnace slag grinding been sold as in China dur-ing the last 6 years.

First Polysius slag roller mill in ChinaTh e fi rst Polysius roller mill for slag grinding in China is in operation since 2002 in Anshan in the province of Liaoning. Th e grinding plant of the Angang Group Slag Development Company is exactly the same size as the one which has been in operation since 1995 just a few hundred kilo-metres away in Korea.

Th e grinding plant for Anshan was designed for a grinding capacity of 90tph at a ground blast furnace slag product fi neness of 4000cm2/g according to Blaine. However, following the market trend, the plant now produces 83tph of ground blast furnace slag

with a fi neness of 4300cm2/g (acc. to Blaine). Th e specifi c power requirement for roller mill, separa-tor, recirculating bucket elevator and system fan is 38.4kWh/t measured at the counters of the mo-ors and referred to the product fi neness of 4300cm2/g (acc. to Blaine).

Th e hot gas needed to dry the granulated blast furnace slag, which usually has a moisture content of 8-12%, is delivered by a hot gas generator. Th e residual moisture content of the ground blast fur-nace slag is less than 0.3%.

Th e photo in Figure 5 shows the mill just erected complete with separator, the mill outlet duct connected to the fi lter and the whole mill nicely painted.

Wear protectionTh e grinding plant, which is carefully maintained by the owner, provided high availability and trou-blefree operation. None of the wear protection plates in the mill housing and in the grit cone of the separator have yet needed replacing. Only the ceramic castable in the upper housing section of the separator was replaced by wear-resistant

steel plates soon aft er the commissioning. Once a year, aft er approx. 3500 operating hours and production of 300,000t of ground blast furnace slag, the surfaces of the grinding elements are refurbished by build-up welding during a planned maintenance stoppage. Th e specifi c wear of grinding track and roller tyres, taken together, is 7.3g/t.

For long service life of the grinding tools not only the appropriate wear lining is important. Th e iron ex-traction system in the external material circuit is an extremely important feature of the Polysius roller mill for slag grinding.

Iron extraction systemIt is a well-known fact that iron particles in the granu-lated blast furnace slag are the main cause of wear in the mill. Th erefore it is extremely important to remove the maximum possible amount of this iron. Th e exter-nal material circuit is very well suited for this purpose, because it handles a large quantity of material, some of

20 globalgypsum MAGAZINE January 2007

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Figure 5, above: Slag grinding plant in Anshan at fi nal phase of erection.

Figure 6, below: Iron extraction system.

which is already partly ground.Th e material passing through the nozzle ring falls

onto a discharge ring rotating with the grinding table. Th is material then passes via a discharge chute into the bucket elevator.

Th e material discharged by the bucket elevator is fed to a vibrating trough, to ensure a uniform feed rate to a magnetic drum separator. Th e aeration of this magnetic drum separator is so designed that practi-cally pure iron with no granulated slag is removed from the stream of material. Aft er the magnetic drum, the recirculated material fi nally returns to the grind-ing table. Th e picture in Figure 6 shows typical iron contents found in a slag grinding plant with vertical roller mill. Th e incoming granulated blast furnace slag has an iron content of 0.28%, corresponding to an iron quantity of 210kg/h.

Th e recirculating material in the bucket eleva-tor has an iron content of 0.7%. Th e magnetic drum separator removes around 170kg of iron per hour in permanent operation. Th e iron contents found in the roller mill and in the fi nish product impressively illus-trate the effi ciency of the external material circuit for concentrating the iron and facilitating its removal. Such effi cient extraction of iron in the grinding process has a very positive eff ect on wear in the mill.

Wear measurement on grinding toolsSpecial gauges for rollers and grinding table enable the operator of the grinding plant to measure the wear on the grinding tools at regular intervalls (Fig. 7).Transferred to a wear sheet (Fig. 8) the measured values provide an accurate picture of the wear profi les for rollers and grinding track. In black colour the worn of material is indicated. Th is wear sheet shows typical wear profi les for slag grinding and it can be clearly seen that the wear on the inner rollers is lower than on the outer rollers. In this case the roller units can be turned by means of the roller pair dismantling device. Th e former inner roller now becomes the outer roller. Th us all four rollers get equal wear profi les and maximum utilisation of the roller liners is achieved. For once rewelded, hardfaced liners the turning of the roller units usually happens aft er 3000-4000 operating hours. A further important aspect when using a roller mill are the conditions and possible ways of carrying out maintenance work. Simple

access and rapid exchangeability of the grinding ele-ments are the prime requirements here.

Polysius roller mills therefore off er the option of replacing complete roller pair units. Special installation equipment, which facilitates rapid replacement through the large maintenance doors in the housing, is provided for this purpose.

Rewelding of grinding tool linersIn China most customers decide for refurbishment of the grinding tool liners by build-up weldings, a work which is usually carried out by local compa-nies. Th e photo in Figure 9 shows the arrangement for build-up welding of the grinding track in a Polysius slag roller mill in China.

Th e welding material used is usually much harder than the material of the original liners and thus pro-vides the advantage of longer service lives. Reportedly the intervalls between the reweldings of the grinding tool liners can be 6000-7000 operating hours.

Design optimisationDuring the last few years the design of the Polysius roller mill has even been improved (Fig. 10). On the existing mill of the size RMS 60/29 in Camden, New Jersey, several modifi cations have been carried out to improve

the performance. Th e mill housing now is smaller and has a round cross sec-tion to avoid dead zones, the separator housing is smaller, the recirculating material is passed into the grit cone and the wear protection for guide pins and brackets has been improved.

Aft er optimisation the capacity jumped from 86.3t/h to 99.0t/h based on the same compressive


globalslag MAGAZINE

Figure 7, above: Wear measure-ments on grinding tools.

Figure 8, left: Evaluation of wear measurements.

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strength values to achieve the grade 120 quality of the fi nish product. Th e desired product quality was now achieved with 5700cm2/g according to Blaine and thus approx. 300cm2/g less than before. Th e modifi cations also led to a smoother mill operation and to reduced fuel consumption.

Th e optimised mill housing design leads to con-tinously increasing gas velocity over the height of the roller mill, the conveying capacity of the gas stream is increased and in consequence undesired internal circu-lations which cost energy are avoided. Th us it is ensured that particles of fi nish product fi neness are exposed to the separator and can leave the grinding circuit as early as possible. Th is again leads to coarser material on the grinding table, more stable mill operation and better

grinding effi ciency.Th e fi rst 2 Polysius roller mills for slag grinding with

optimised housing in China belong to ACC Ya-Dong Cement Corporation. Th e slag grinding plant in Nan-chang is in operation since November 2005. Th e roller mill is a type RMS-51/26 with an SEPOL RMS-435 separator.

For a feed material consisting of 95% slag, 4% gyp-sum and 1% limestone a capacity of 80t/h fi nish product with a fi neness of 4400cm2/g according to Blaine was warranted. Th e residue on the 45mm screen must not exceed 5%. Th e specifi c power consumption warranty for mill, separator and fan was 35.5kWh/t, measured at the counters of the drive motors.

During commissioning in November 2005 for a mix-ture of 97% slag and 3% gypsum a capacity of 94t/h at a fi neness of 4580cm2/g according to Blaine was achieved. Th e residue on the 45mm screen was 2.4%. Th e specifi c power consumption for mill, separator and fan was 35.48 kWh/t referring to the fi neness of 4580cm2/g ac-cording to Blaine, measured at the counters of the drive motors. For the mill drive only a bonus compared to a tube mill of 2.95 was determined. Th is means that a tube mill would require almost 3 times as much energy for the mill drive as the Polysius roller mill.

In the last few years further slag meal producers de-cided for the Polysius roller mill and made it one of the most popular slag grinding mills in the world and espe-cially in China. Eight Polysius roller mills for granulated blast furnace slag are meanwhile in operation in China and 5 further units have been sold in recent months.

In China and South Korea, many granulated blast furnace slag grinding plants are already in operation, but the number of granulated blast furnace slag grind-

ing plants in South-East Asia is still low. Customers from South-East Asia who are now interested in slag grinding are invited to send their inquiries to the Polysius subsidi-ary in Singapore

References1. Geiseler, J., Kollo, H., and Lang, E.: “Infl uence of Blast Furnace Ce-ments on Durability of Concrete Structures” ACI Materials Journal, 92 ( 1995 ) 3, ( May-June ), S. 252/2572. Lang, E.: “Blast Furnace Cements” in “Struc-ture and Performance of Cements, 2nd Edition” by J. Bensted and P. Barnes3. Lohnherr, L., Menzel, K.: “Operating experi-ence with the production of slag cements in a roller mill” in “Polysius teilt mit – 209”4. Schwiete, H.-E., Dölbor, E.: “Einfl uss der Abkühlungsbedingungen und der chemischen Zusammensetzung auf die hydraulischen Eigen-schaft en von Hämatitschlacken” Westdeutscher Verlag, Köln und Opladen 1963.

Figure 9, above: Rewelding of a grinding track.

Figure 10, below: Optimisation of the Polysius roller mill.

globalslag MAGAZINEDr En Yi Chen EnGro Corporation Ltd

Application of GGBS in ChinaIn China, quality Ground Granulated Blastfurnace Slag (GGBS) (S95, blaine 4200-4500cm2/g) produced with vertical roller mills are being used to substitute clinker in conventional cement manufacturing as well as to partially replace OPC for ready-mixed concrete production, for which the percentage of GGBS usage is typically at 10-15% and 20-25% respectively. Such low percentage of GGBS in the mixing ratio, however, whilst achieving the purpose of saving some costs, is insuffi cient in enhancing concrete structural durability. A long journey remains ahead for the newly established slag grinding industry to reach the day when all the inherent qualities of GGBS and its superior characteristics over fl y ash or other pozzolanic materials are fully appreciated.

This article touches on GGBS with blaine ranging 4200-4500cm2/g, complying with GB/T 18046 S95

and produced ideally with the state of the art equip-ment -vertical roller mills (VRM). Compared with GGBS produced by ball mills (BM), which is at typi-cal blaine of 3800-4000cm2/g, VRM-produced GGBS is very much superior in terms of fi neness, production effi ciency, cost-eff ectiveness, product reactivity and its applications. Regardless of the chemical composition, signifi cant diff erences between VRM GGBS and BM GGBS are with blaine fi neness and particle size distribu-tion (see Table 1 and Figure 1).

Development of GGBS Production in ChinaChina has witnessed a rapid growing rate in slag grind-ing and the production of quality GGBS has been seen literally across the country since the mid-1990s, credit being given to the eco-friendly economic development policy adopted by the central government for the steel industry and the increased awareness and recognition of the benefi ts on the use of quality GGBS not only by cement manufacturers and ready-mixed concrete play-ers, but also by real estate developers, architects and designers and the public. With the establishment of the national standard GB/T 18046 announced in year 2000, market demand for quality GGBS has been given a big boost.

First operating VRM in Shanghai in 1997: 1997 marked the fi rst milestone in the rather short history of quality GGBS production in China when commercial op-erations of its fi rst modern slag grinding plant (with design capacity 500,000t/year) began in Baosteel of Shanghai. Since the birth of this fi rst VRM for slag grinding in China, quality GGBS has been commercial-

ised successfully and most rapidly in China.Development of GGBS production: Figure 2 shows

the number of slag grinding plants set up in China over the last decade. Between 1997 when the fi rst VRM GGBS plant was set up at Baosteel, Shanghai and the end of 2007, the number of operating slag grinding plants has increased from one to a projected 49. Out of the 49 GGBS plants, about 45 plants were set up over the 5-year period. from 2002 to 2007. Th is rapid growth trend has resulted in China being the largest market for relevant grinding mills technology for the next 3 to 5 years.

A correspondingly rapid uptrend in GGBS produc-tion since 2002 is shown in Figure 3. Within a mere 10 years from the time when the fi rst VRM came into being in China, the total GGBS production has gone from a zero position to an amazing projected 31.2Mt per year by end of 2007, a fi gure likely to be the highest in the world for GGBS produced by VRMs.2

Slag grinding: An industrial sector independent of the cement industry: Compared with other countries, a unique phenomenon has emerged in that slag grind-ing industry has become a sector to be reckoned with, independent from the cement industry. Table 2 shows the projection that about 65% or 20Mt of GGBS is to be produced by non-cement related manufacturers in China by 2007.

Continuous expansion of slag grinding plants:

Table 1: Particle size distribution of GGBS samples produced by VRM and BM

GGBS samples GGBS-VRM 4800

GGBS-VRM 4500

GGBS-VRM 4400

GGBS-BM 4000

GGBS-BM 3800

GGBS-BM 3500

Blaine (cm2/g) 4800 4500 4400 4000 3800 3500D50 (μm) 10 11 11 17 19 20D75 (μm) 20 21 22 34 44 27D90 (μm) 29 30 34 52 67 57D100 (μm) 88 74 105 148 176 209




As reported3, China’s top 62 steel mills produced a total of 277.63Mt of pig iron in 2005, accounting for 86% of the total pig iron production of the whole country. Th is fi gure is projected to be 299.84Mt for 2006 (accounting for 84% of the total amount produced by the country). Th erefore, based on a very conservative estimate, total raw slag generated by these 62 steel mills in 2005 is ap-proximately 83.29Mt, and this fi gure is projected to be around 89.96Mt for 2006. Due to the rather high invest-ment capital required for each VRM slag grinding plant, (average costs for a plant with 600,000t/year designed capacity is approximately US$11.57m or Euro8.88m), in order that a reasonable return on investment may be

realised, it is almost a prerequisite that the plant is sup-ported by a steel mill generating at least 300,000t/year of slag.

As shown in Figure 4, there will be a total of 45 slag grinding plants in operation among the top 62 steel mills in China by year-end of 2007. By then, about 73% of the top 62 steel mills will have either their wholly owned or associated companies engaged in slag grinding and together producing up to 29.9Mt/year GGBS (i.e. utilis-

ing about 36% of the raw slag generated by this group in 2005). Th erefore, expansion of slag grinding capacity in China is expected to continue at least for the next 5 years if the huge slag resources are to be fully utilised to churn out high quality and value-added GGBS.

Application of GGBS in ChinaTwo main usages of GGBS with cement producers being top consumers: Taking the path experienced in

other countries, China has used its increased amount of GGBS mainly as (a) clinker sub-stitution in blended slag and normal cement production, and (b) supplementary cementi-tious material in ready-mixed and site-batched concrete production. At present, benefi ts derived from costs reduction is the direct and key driving force for the adoption of GGBS.

Further investigations show that cement manufactures in China are projected to produce a total of about 10Mt/year of GGBS in 2007, which amount is nearly fully used consumed by the cement plants in the production of slag cement, incorporating properly designed and effi cient cement mixing equipments. Typical blended slag cements produced are P.S 42.5 and P.S 32.5 (com-plying with GB 1344) with GGBS contents of 25-35% and 50-60% respectively. It is estimated the costs of GGBS (S95) to cement producers is

around US$10.28 (Euro7.89) to US$12.85 (Euro9.86) per ton (depending on the raw slag price), versus about US$16.7 (Euro12.82) to US$18.0 (Euro13.81) per ton being the costs of producing clinker. Th erefore, for incorporating every one ton of GGBS, cement pro-ducers stand to make an additional profi t of US$3.85 (Euro2.95) to US$5.14 (Euro3.94) which translates into 10-15% increase to the bottom line.

Where does the balance quantity of GGBS end up?

Table 2: Slag grinding plants run by non-cement manufacturers in China (projected by year 2007)

Slag grinding plant Number % Output (Mt/year) %

Plant run by cement manufacturers 16 33 10.80 35Plant run by non-cement manufacturers 33 67 20.40 65

Total (projected by 2007) 49 100 31.20 100

Table 3: Increased profi t made by use of GGBS in cement production

Case 1 - A cement plant with throughput of 1.2Mt/year P.O 42.5 with rotary kiln clinker

Cement product

Cement selling price

(US$/t)

Th roughput (Mt/year)

GGBS price at delivery

(US$/t)

Substitution of cement

(%)

GGBS usage (Mt/year)

Total throughput (Mt/year)

Increase in profi t (million

US$/year)P.O 42.5 29.57 1.20 20.57 10 0.12 1.32 1.08Case 2 - A cement plant with throughput of 0.4Mt/year of P.O 32.5 with vertical shaft kiln clinker

Cement product

Cement selling Price

(US$/t)

Th roughput (Mt/year)

GGBS price at delivery

(US$/t)

Substitution of cement

(%)

GGBS usage (Mt/year)

Total throughput (Mt/year)

Increase in profi t (million

US$/year)P.O 32.5 25.71 0.40 20.57 20 0.08 0.48 0.411Note: Cement plants quoted are operating in Tangshan City, Hebei Province of China (March 2006).

Figure 1: Particle size distribution of GGBS samples produced by VRM and BM.


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Th ey are sold to cement manufacturers or concrete pro-ducers, key considerations being again savings in costs of production. Examples are given in Table 3 and Table 4 on how the cement and concrete producers generate additional profi ts through the use of GGBS (separate product).

In accordance with the geographical location of each slag grinding plant and its market coverage (within 150-200km radius), GGBS markets can be categorised into three, i.e. 1st-tier city, 2nd-tier city and 3rd-tier city. Table 5 shows the projection of GGBS quantity to be shared by the above three market categories in China by year 2007.

According to market information collected, it is found that due to the huge diff erence in macro eco-nomic development among the above 3 diff erent tiers of city, the use of GGBS is also entirely diff erent. Table 6 gives the projection of GGBS to be used in cement and concrete production in each market.

Th erefore, by 2007, there will be about 42% (or 8.52Mt) of GGBS available to concrete players, with the balance 58% (or 11.88Mt) going into cement produc-

tion. Our further investigation suggests that due to the constraint of effi cient mixing facilities, cement plants which are buying GGBS from local markets are using it for producing P.O 42.5 and or P.O 32.5 at an average mixing ratio of 15% (see Table 3). Th is fi gure is about half of what is being used for slag cement production at cement mixing plants which are using their own-pro-duced GGBS.

Th e total amount of GGBS used for cement produc-tion in China in 2007 is projected to account for 73% of total production, equivalent to 22.68Mt (i.e. the sum total of 11.88Mt produced by non-cement producers and 10.8Mt produced by cement producers). Th e bal-ance 27% or 8.52Mt of GGBS will be used for concrete production at a typical ratio of 25%-30% (replacing 80-90kg cement per cubic meter in design mix) by the whole country.

Durable concrete requires high percentage mix-ture of GGBS: Th ere is no doubt that GGBS is now

recognised worldwide as a green construction material capable of producing durable concrete structures. Apart from cost reduction the most important technical ben-efi ts, which GGBS imparts to concrete, include:(a) Lower temperature rise in concrete, reducing the risk of thermal cracking in massive concrete structures.(b) Elimination of the risk of damage caused by alkali-

silica reaction (ASR).(c) High resistance to chloride ingress, reducing the risk of rein-forcement corrosion.(d) High resistance to attacks by sulphate and other chemicals.

Extensive applied studies over the many projects conducted glo-bally prove that in order to produce high performance concrete (HPC) structures with desired durability and satisfactory strength, ‘adequate’ GGBS percentage is essential.4 For the applications where durability is required, a 55%-65% GGBS content (in combination of OPC) is gener-ally recommended5 or, a higher dosage of 70%-85% has been speci-fi ed for structures subject to severe environment.6 Same observations

were found in our studies on GGBS sample from Tang-shan Tanglong Materials Comp. Ltd, China (see Figure 5 and Figure 6).

Delay in specifi cation of unifi ed national standard and misconception slowed down the shift of empha-sis in use of GGBS from cost-savings to durability in China: Th e fi rst job reference reported using GGBS (ball mill product with blaine about 4000cm2/g) for concrete durability was successfully done in 1996 at Beijing airport extension project, in which about 60% GGBS was used to prevent the raft foundation from thermal-cracking.8 Th is represented a breakthrough of GGBS application in China because prior to this there was no specifi cation allowing the use of GGBS in concrete. Th ree years later (i.e. in 1999) the fi rst local practice code for application of concrete with GGBS (DG/TJ08-501-1999) was set up in Shanghai, China. Since then GGBS has been widely used in concrete production, particularly for the bene-fi ts of both cost reduction and durability within the city.

globalslag MAGAZINE

Figure 2, above: Development of slag grinding plants equipped with VRMs in China (1997-2007).

Figure 3, left: Development of GGBS production by VRM plants in China (1997-2007).


Following Shanghai, Beijing established its own local specifi cation namely Applied Technical Specifi cation of Mineral Admixtures in Concrete (DBJ/T01-64-2002) in 2002, in which GGBS as one type mineral admixture is offi cially allowed to be used for concrete production. As a result, the usage of GGBS in concrete production maintains at very high percentage in both capital cities exclusively in China.

However, in most of the other cities in China, the fact is that the use of GGBS in concrete production has not been offi cially announced to be permissible even as of the time of writing. Most of the concrete suppliers in these cities would not put GGBS even in the mix design proposal, though in actual fact it is widely known that they frequently do eventually adopt 20%-30% GGBS as cement replacement, which is - however - not disclosed when they submit to the owner or consultant of the project for approval. Th ey are fully aware that, if they

disclose the truth, the owner or consultant will not give their approval due to the lack of relevant national technical guidelines to support the same. Th erefore, this situation will continue until a national specifi cation for making durable concrete structures is available. For this reason, no accurate or offi cial data of GGBS used for making durable concrete structures (or high perform-ance concrete) are available in China. It is, however, generally estimated that this sector accounts for about 5%-8% of the total GGBS output.

As compared to the fast growth of GGBS production, the transition of emphasis on the GGBS applications from one of cost-saving to concrete durability has proven to be a much slower process. Constraints en-countered by the industry are:(a) (from national level) delay in establishing unifi ed national standards and technical guidelines for use of GGBS in durable concrete structures, and (b) (from the public) misconception on GGBS as a low grade replacement material (this could well be true in the case of traditional BM GGBS which is of very low fi neness, but not if GGBS is produced by VRM).

In fact, changing the public’s misconception on GGBS being a by-product from steel and iron produc-tion and, hence, a replacement material of low quality which is therefore not conducive to high quality mineral admixture for producing high performance concrete, will take even longer time than the setting up of a na-tional standard. Th is poses a real challenge ahead for the construction industry in China.

Concluding remarks• Development of quality GGBS production with VRMs has been experiencing an accelerated growing rate since 1997 in China. It is projected to have 49 modern slag grinding plants in operation, which will produce

globalslag MAGAZINE

Table 4: Cost-saving made by use of GGBS in ready-mix concrete production (C30 Pump, typical mix design)

Markets in China

Cementitious material

Unit price (US$/t)

Control mix (kg/m3)

GGBS 20% (kg/m3)

GGBS 25% (kg/m3)

GGBS 30% (kg/m3)

GGBS 35% (kg/m3)

Beijing

Cement P.O 42.5 39.22 300 240 225 210 195GGBS (S95) 24.43 0 60 75 90 105Fly ash (glade I) 18.00 88 88 88 88 88

Cost saving (US$/m3) 0.00 0.88 1.11 1.33 1.55

Tianjin

Cement P.O 42.5 38.57 310 248 233 217 202GGBS (S95) 23.14 0 62 78 93 109Fly ash (glade II) 9.64 80 80 80 80 81

Cost saving (US$/m3) 0.00 0.95 1.19 1.43 1.67

Shanghai


Cost saving (US$/m3) 0.00 0.91 1.11 1.33 1.55

Chongqing


Cost saving (US$/m3) 0.00 0.59 0.76 0.86 1.01Note: Delivery prices in the local markets in August 2006.

Figure 4: Slag grinding plants set up by the top 62 steel and iron manufactures in China.



31.2Mt/year in total by end of 2007. China slag grinding industry is now becoming a stand alone industry sector independent from cement industry.• Continuous expansion of existing slag grinding plants is foreseen in China in the next at least 5 years in order to maximise the utilisation of its huge raw slag resource for producing high quality and value-added product of GGBS.• China has used its increased availability of GGBS mainly as clinker substitution in cement production and supplementary ce-mentitious material in concrete production (accounting for 73% and 27% of the total GGBS output respectively). At the present time, benefi ts from cost reduction is the direct and key driving force for the use of GGBS.• Due to the lack of unifi ed national stand-ards and technical guidelines for use of GGBS in durable concrete structures a very low amount or 5%-8% of the total GGBS output is estimated to be used for concrete production especially due to requirement of durability in 2006 and 2007.• Misconception of GGBS being a low grade replacement material used for cost-saving by cement or concrete sup-pliers is a major barrier in GGBS being acknowledged and used for durability purpose in China. It slows down the change in perception of its key value from cost-sav-ing to durability in China. Education to all concerned is the only answer to this unfortunate situation.

Reference 1. Global Slag Staff , Slag Grinding in China, Global Slag, June 2005, pp.26-30.2. Joe Harder, Development of Slag Use in Th e cement Industry, Global Slag, September 2006 , pp. 32-33.3. Ranking of China Steel Manufactures by the Output of Pig Ion in 2005 (in Chinese), published on January 22nd 2005 by SteelMy.com, www.SteelMY.com.4. S F Han, et al, Studies on Green High Performance Concrete (GHPC), Proceedings of National Sympo-sium on High Performance Concrete and Mineral Admixtures (in Chinese), Zhuhai, China, March

2006, pp. 1-19.5. Slag Cement Association, Suggested Specifi cations for Slag Cement in Concrete (Slag cement in Concrete, No. 13), www.slagcement.org.

6. British Standard Institute, BS 5328: Part 1: 1997.7. D S Guo, E Y Chen, et al, Experimental Modeling of Tem-perature Rise of Mass Concrete by FDM Method, Th e 26th International Conference on Our World in Concrete & Struc-tures: 27-28 August 2001, Singapore, pp261-268.8. G L Zhu and S S Shun, Applications of Steel & Iron Slag in Building Materials Industry, China Cement, July 2006 (in Chinese), pp. 33-35.

Table 5: Categorisation of markets for GGBS (separate product) in China (projected by year 2007)

Market category by cities1st-tier cities 2nd-tier cities 3rd-tier cities Total

(Mt/year) % (Mt/year) % (Mt/year) % (Mt/year)

GGBS output (by 2007) 5.50 27 8.90 44 6.00 29 20.40Note: 1st-tier cities are the four capital cities of China, i.e. Beijing, Shanghai, Tianjin and Chongqing. 2nd-tier cities are the provincial capital cities and those medium cities located in coastal developed economic zones. 3rd-tier cities are medium cities located further inland.

Table 6: GGBS ued in cement and concrete production in diff erent markets in China (projected by year 2007)

Market Category1st-tier cities 2nd-tier cities 3rd-tier cities Total

Cement Concrete Cement Concrete Cement Concrete Cement ConcreteGGBS output

(by 2007)(%) 10 90 70 30 85 15 58 42

(Mt/year) 0.55 4.95 6.23 2.67 5.10 0.90 11.88 8.52

Figure 5, above: Eff ect of GGBS on chloride ion penetration of concrete (C35, W/B=0.43, ASTM C1202, water-cured at 27°C).

Figure 6, below: Eff ect of GGBS on temperature rise in concrete under adiabatic conditions (prediction using SSY concrete - a simulation software developed by EnGro Central Laboratory7).


globalslag MAGAZINE


Dr Robert McCaff rey Conference convenor

Global Slag Conference 2006 reviewedThe 2nd Global Slag Conference and Exhibition took place 20-21 November in Bangkok, Thailand, and attracted 110 delegates from 22 countries. Over two days, 17 presentations were given, on slag markets, on slag optimisation, on grinding options and on slag utilisation.

The 2nd Global Slag Conference started off with a fi eld trip to the east of Th ailand. Nearly 40 del-

egates traveled to see the operation of the Electric Arc Furnace at the Siam Construction Steel Company at Mab Ta Phut, Rayong. Slag is tapped using the eccentric bottom tapping method, leading to low slag volumes. Slag services at the plant are provided by Siam Steel Mill Services (SSMS), a joint venture with the Edw. C. Levy Group and Th ai partners. Aft er tapping, the slag pot is carried using a Kress slag pot transporter to a fully-en-closed slag tipping facility – one of the few in the world. Molten slag is tipped into the pit, and then the skull (the iron-rich plug at the bottom of the pot) is knocked from the pot once every two or three trips. Slag is allowed to cool for at least 8 hours (and more generally 24 hours) before being excavated. Front-end loaders equipped with tyre chains are used to load the slag into trucks

for transport to the SSMS slag processing facility.

Aft er a pleasant lunch at the Laemchabang Golf Club, delegates ar-rived at SSMS’s neat Bowin plant to view the facility. At the plant, slag from the various local steel mills is kept sepa-rately, so that each company’s recovered

metal can be returned to it aft er processing. Skulls are shattered by drop-ping a giant steel ball on them from a height of 20m using a magnet-equipped crane, while some have to be cut using welding gear. Primary crushing of the slag is

with a locally-manufactured jaw crusher, and second-ary crushing to produce a cubical aggregate is with a cone crusher, again locally-manufactured (‘Nordberg might be good,’ says Sitthisak Wittayangkoon, SSMS chief operating offi cer, ‘but it is too expensive.’) Metal is recovered from the crushed slag by using overband and drum magnetic separators. Delegates were able to see a demonstration of volume stability testing at the facility, before departing to see the use of slag aggregates in the wearing course of a local highway. Th e fi eld trip, organ-ized with the kind cooperation of Mr Wittayangkoon, was a great success.

A convivial welcome reception took place on Sunday evening in the Global Slag exhibition area (including stands from Aumund, Kalenborn Kalprotect, Gebr. Pfeiff er, Prathyusha Shipping, Rexnord and RSG Inc). Th rough the conference, delegates used the exhibition area to meet contacts and to network, and the event was rated very highly for its potential for making new contacts in the global slag industry.

Conference commencesTh e conference itself commenced on the Monday morning. Craig Heidrich of the Australasian (iron and steel) Slag As-sociation detailed Australia’s approach to lowering greenhouse gas emissions. Craig pointed out that Australia has a very carbon-intensive economy, and that its per capita emissions are actu-

Global Slag Conference fi eld trip: Above: tyre chains are required on slag-excavating front-end loader; above right: slag-tipping in the enclosed facility; right: trip participants.


globalslag MAGAZINE

ally twice those of even the famously carbon-profl igate Americans. Australia has not ratifi ed the Kyoto protocol, believing that it is not in Aus-tralia’s national interest, and has recently become a found-ing member of the AP6 group of Asian nations and America, which is moving towards a ‘Kyoto-lite’ approach to cli-mate change. Even given these constraints, Australia will only be around 10% over its Kyoto commitments in the 2008-2012 period, so, as Craig says, ‘the target is within sight, but more needs to be done.’ Th e slag sector in Australia has made massive progress, with utilisation rates increasing from 21% in 1985 to 78% in 2005. Craig also stated that production of one tonne of GGBFS created 143kg of CO2, from drying, milling and transport (delivered up to 100km from the processing site), very signifi cantly lower than cement clinker, and off ering great potential for increased use as supplemen-tary cementitious materials.

Th e second paper at the conference was given by Dr E. Y. Chen of EnGro Corporation, Singapore, on the subject of the growth of the application of GGBS in China. Starting only in 1997, with the commissioning of a 0.5Mt/year VRM at Baosteel in Shanghai, there are projected to be 49 VRMs in China grinding slag by the end of 2007, grinding a total of around 31Mt of GGBS, out of a total of around 100Mt of slag being produced in China. A signifi cant proportion of the GGFS plants are operated by non-cement companies. Continuous expansion in the sector is foreseen in the future.

D. Venkateswaran of Indorama Cement, New Bombay, and his co-authors, then detailed a possible treatment method for the benefi ciation of electric arc furnace (EAF) slag, for use as cementitious products. Th e laboratory-scale project heated EAF slag to 1500°C and then quenched it rapidly in water, to try to create a glass phase with improved cementitious properties. However, the authors frankly admitted that their treat-ment actually decreased the amount of glass in the samples, compared to untreated slag, although it did decrease the amount of iron oxides in the slag. Th e authors found that the treated slag was of comparable strength to normal GGBS slag in a Portland Slag Ce-ment formulation.

Sang-tae Cha of Ecomaister, Korea, proceeded to give an impressive presentation on the industrial-scale benefi ciation of EAF slag. In short, his patented process is a high-speed air blowing system using a catalyst and water, operating on the stream of molten EAF slag being poured out of the tundish. Th e slag stream is converted into spherical balls with a glassy fi nish, the size of which can be controlled by varying the operational param-eters. As was later pointed out by one of the conference participants, the process also has the eff ect of separat-ing out the metal-rich fraction of the slag, since heavier

spherules will fall closer to the air-blowing apparatus than non-metal-rich spherules. Th e presentation cre-ated a huge amount of interest.

William Tan of Bulk Materials International then gave an excellent overview on the use of GGBS in the cement industry, and force-fully made the point that the increased use of slag as a clinker substitute will be a strong factor in decreas-ing the cement industry’s overall contribution to global warming through a reduction in the industry’s greenhouse gas production.

Barry Woodbine of Aumund outlined his com-pany’s varied solutions to ‘effi cient and reliable handling of GBFS and GGBFS at grinding plants and cement works.’ Included among the Aumund Group’s equipment are the Samson surface feeder, chain bucket elevator, Centrex silo extraction system, and Schade stacking and reclaim systems for slag and GGBFS.

Whereas Barry gave a general overview, Sikhil Su-pekar of Sterlite Industries (India) gave a very specifi c presentation, detailing the possible use of granulated copper slag in the manufacture of slag cement. Th e au-thor found that the slag could be used as a source of iron in the cement raw mix, and that the amount of copper contained in the slag was not detrimental to clinker for-mation. Copper slag can also be used in the preparation of Portland Slag Cement, at up to 35% substitution, with no appreciable detrimental eff ects.

In the eighth paper presented to the conference, Kent Ege Jensen of Bangkok-based LV Technology detailed some of the parameters that must be taken into account when using converter slag as an alternative raw material for cement clinker. Kent concluded that it really is pos-sible to substitute up to 20% of raw meal with converter slag, with the MgO content of the slag being the limiting factor in the case presented. With the addition of the slag, (paying attention to the capacity of the cooler to


Above: Delegates from Korea and Italy at the welcome reception.

Below: Slag Atomisation Technol-ogy in practice.

cope with extra through-put), cement production was increased by 23% at the plant in question.

Gala DinnerDelegates were able to enjoy cocktails on the hotel terrace before embarking on a dining yacht for a nocturnal cruise down the Chao Phrya river, through the heart of Bangkok, accompanied by a Th ai band - oddly-enough

belting out country and western standards. Still, a good time was had by all.

Second dayTh e conference was honoured by the chairmanship, on its second morning, of industry stalwart Paul Ratcliff e, of Holcim Group Support, Switzerland, who brought his decades of experience to bear on the proceedings.

Th e second day of the conference commenced with Stefan Seeman, a PhD candidate student, presenting his research into the impact of grinding technologies and conditions into the performance of slag cement. His compact paper condensed three or more years of research into just 25 minutes, but his conclusions were still fascinating: No signifi cant diff erences were meas-ured in strength developments of a BFS III cement ground to 3000 Blaine, created in a high-pressure grind-ing roll system, in a VRM or in a ball mill. However, grinding atmosphere had a marked eff ect on ground slag properties, with slag ground in humid air having lower strength development, and slag ground in high-CO2 conditions having lower compressive strength, possibly due to incipient carbonation reactions.

Ingo Engeln of Polysius AG then gave an eloquent presentation on the use of the Polysius roller mill for the grinding of slag, particularly with regard to the manage-ment of wear. Th e machines are already in use in China and Korea for the comminution of slag. York Reichardt of Gebr. Pfeiff er then outlined the features of the MPS vertical roller mill for slag and slag cement.

In a quietly controversial paper, author Hans Jorgen Nielsen of LV Technology concluded, amongst other

things, that - aft er the study of more than 300 vertical roller mills - the use of secondary rollers in a vertical mill has a negative infl uence on the effi ciency of mill operation, and that pressure should be applied to all rollers.

Next was Caroline Hacklaender-Woywadt of Loe-sche GmbH, who outlined the operation of the largest Loesche mill, the LM 56.3+3, at Rajganpur, India. She also mentioned the management of wear rates in the mill, but then proceeded to shock the delegates with an ‘exposé’ of the critical diff erences in the calculation of Blaine, according to EN and ASTM standards. As she pointed out, it can make around a 12% diff erence in Blaine value when using the diff erent calculation methods, which could be a costly discrepancy when it comes to guarantee values: manufacturers and cement producers please take note.

Ho-Young Lee, CEO of VCEM Materials Co. Ltd., Korea, then gave a gracious presentation of his positive experiences with KHD’s roller grinding system.

Th e fi nal two presentations at the conference di-verged in topic somewhat. K. Sairaman of GE Energy, Pune, India, spoke about fi ltration challenges for the op-erators of air pollutions control equipment for venting slag grinding mills. Mr Sairaman gave details of a VRM in Zhangjiagang, China, which copes with a maximum temperature of 100°C and diff erential pressure of 800Pa, and which is at 105% of its design capacity.

Th e fi nal presentation was given by Sitthisak Wit-tayangkoon, of Siam Steel Mill Services Limited. He gave an overview of Th ailand’s economic growth over the years since the Asian Crisis of 1997, pointing out that GDP growth has been above 5% for the last few years, and pointing out that respectable amounts of capital are being spent on infrastructure projects, such as Bangkok’s fantastic new Suvarnabhumi airport. Siam Steel Mill Services provides slag pot, slag handling and slag processing services to a group of steel mills in the east of Th ailand at Rayong, as well as in the Saraburi region, north of Bangkok.

Awards and prizesFollowing the completion of the conference programme, delegates voted for their favourite presentations. Dr Chen’s presentation on slag grinding in China came a strong fourth, while Caroline Hacklaender-Woywadt’s paper on slag grinding with the LM56.3+3 mill (and Blaine calculation variations) came third. Th e Slag At-omisation Technology (SAT) detailed by Sang-Tae Cha garnered him the second prize, but the paper by Stefan Seeman, co-authored with Dr Martin Schneider and Dr Michael Müller-Pfeiff er, both of the VDZ in Germany, was the worthy and popular winner of the Best Presen-tation Award at the second Global Slag Conference.

3rd Global Slag Conference Following a show of hands at the farewell party, the 3rd Global Slag Conference, with the theme ‘Adding value to slag,’ will be held 19-20 November 2007, in Istanbul, Turkey. See you there!

30 globalgypsum MAGAZINE January 2007

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Above: The conference room was full throughout the event.

Right: Stefan Seemann collects his award for the best presenta-tion.

Slag producers,Sellers and Buyers,

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gl bal slag CONFERENCE &EXHIBITION2007

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Loesche America’s 9th Discussions of the Round Table Seminar in MiamiFrom 29 November to 1 December 2006, guests, clients experts and their spouses from all over the world were invited to join the 9th Discussions of the Round Table, organised by Loesche America, Inc., a subsidiary of Loesche GmbH of Düsseldorf, Germany.

2006 was a year of celebration for Loesche. At the end of August 2006,

the company celebrated its 100th an-niversary (see Global Cement Magazine October 2006) in a spectacular three-day event in Düsseldorf and Bilbao. Loesche has been in the business of designing and manufacturing grinding mills since

1906, employing over 400 peo-ple in more than 20 countries. Additionally, Loesche America, Inc. was celebrating its 10th an-niversary in Florida.

From 29 November to 1 December 2006, Loesche America hosted international participants at its 9th annual seminar called ‘Discussions of the Round Table,’ at the Trump International Sonesta Beach Resort in Miami Beach,

Florida. Th e seminar was hosted by Loesche America, Inc. of Pembroke Pines, Florida, a subsidiary of Loesche GmbH, Germany. Th e company is an international market leader in vertical roller mills used for dry grind-ing in the coal, cement, lime, minerals and utilities industries.

Other sponsors of this event were Bedeschi America, Inc., Florida, a subsidiary of Bedeschi S.P.A. from Italy; Beumer Corporation, located in Branchburg, New Jersey; Kreisel GmbH & Co. KG from Krauschwitz, Germany; and Vautid-Verschleiss-Technik from Ger-many.

Following a welcome evening fi lled with live Jazz music at the pool bar, guests attended a two-day sym-posium, which covered many aspects of the industry and included advice to improve operations in grinding plants. Th e aim of this event was to learn more about the latest uses for Loesche technology, to interact with other Loesche customers with similar needs and questions, and to discuss specifi c needs directly with Loesche’s specialists from the headquarters in Germany and its offi ce in Florida.

First dayAft er the welcome speech by Blaz Jurko, general man-ager at Loesche America, and Dr Th omas Loesche, managing director at Loesche GmbH and grandson of the company’s founder, the fi rst presentation was given by Arnaldo Bertola. In his role as manager of engineering projects at Fru-Con, St. Louis, Missouri, he presented the upgrading of Buzzi Unicem’s River Cement Selma Plant in Missouri with a LM60.6 roller mill. Th e second presentation was given by Wolfgang


Above: Linda Jurko and Carlos Es-cobar did a great job in organising this event. Below left: Discussion at one of the round tables. Below right: Beumer’s information booth in exhibition and coff ee break area.


globalslag MAGAZINE

K. Salchov, regional export manager at Vautid-Versch-leiss-Technik, Germany. He addressed the issue of how to reduce abrasion in the cement industry and, in par-ticular, in vertical mills.

Aft er a coff ee break fi lled with discussions, chats and networking, Putt Wetherbee of the Mineral Products Division at Florida Rock Industries, Inc. talked about fi ne classifi cation improvements within its ‘Calcium Carbonate Project’ with Loesche Mills. Aft erwards, Dr Caroline Hackländer-Woywadt, manager for clinker/slag grinding at Loesche’s headquarters in Düsseldorf, Germany, showed slag grinding applications with Loe-sche mills and results from aging tests with slag. Aft er the lunch break, Elko Hoettges of Beumer Corporation in Branchburg, New Jersey, presented Beumer’s world of high quality material handling systems. At this point, Global Slag Magazine wants to congratulate Beumer Corporation for 30 successful years in America. Sub-sequently, Bernhard Schröder of Loesche GmbH, gave an overview of Loesche grinding mill operations for petcoke and explained the company’s grindability test method as a basic procedure for sizing a mill. Aft er a coff eebreak, Kerry Kaminski and Steve Hudolin of DTE Energy Services presented a paper on petcoke grinding in the US on the basis of the LM28.2D grinding plant at Vicksburg, Mississippi.

In the evening of the fi rst day, Loesche America wel-comed its guests on board a luxury yacht. In spite of a quite turbulent sea, everybody enjoyed the delicious dinner, a relaxed atmosphere, good live music and a great time on the dancefl oor.

Second dayTh e second day of the seminar was opened with a co-au-

thored paper presented by Chester Adams, project manager of Caribbean Cement Company Ltd, Jamaica, and Victor Turnell, consultant at Loesche America. Th ey showed the progress in their clinker grinding upgrading project with a LM46.2+2 mill in Kingston. Aft erwards, Th omas Turano, general manager at Bedeschi America, Inc. explained ad-vantages, characteristics and crushing fl exibility of double roller crushers. Th is was followed by Matt Allers of Giant Cement Company, who introduced a new Bedeschi limestone roller crusher which re-

places a hammer mill from the 1940s. Aft er a coff ee-break, Daniel E. Bush of Grand Board of Light & Power, and Robert Somer-lad of Loesche America presented a paper on NOx emission control and boiler performance improvement at Grand Haven’s J. B. Sims Plant, Michigan.

Finally, Chris Oesch, director of projects at Loesche America, hosted a very informative breakout discussion with several groups. Each group focused on a special subject area:

• clinker/slag grinding• raw materials grinding and • coal/petcoke grinding.In each group, specialists from Loesche discussed

specifi c needs, requirements and experiences of customers and clients. Aft er a short sum-mary by the several group chairmen (and -woman), Blaz Jurko closed the offi cial part of the 9th ‘Discussion of the Round Table’ semi-nar in Miami.

Th e aft ernoon of the second day was spent in diff erent ways. Sunbathing, jet skiing and shopping were the most common acitivi-ties. Finally, the day was fi nished with beach volleyball by night, dinner and impressive Reggae live music (including Limbo dancing and Karaoke) at the Hotel beach area. Global

Slag can only presume that some delegates continued on into South Beach aft er the offi cial beach party was over. Most of the delegates stayed in Miami until Saturday to join some of the sporty activities off ered by Loesche America. Some went to play Golf, and some ‘early birds’ even went on a deep sea fi shing cruise. Congratulations to Steve Hudolin of DTE Petcoke, LLC for catching a 7’ sailfi sh. It was a successful day for the deep sea fi shermen (and women, see picture).

Global Slag Magazine wants to thank Loesche America for the invitation to this seminar and wishes to meet all delegates again at the 10th “Discussion of the Round Table” in 2007.

Above: Chris Oesch, director of projects at Loesche America, Inc. in discussion with delegates during a coff ee break.

Below: Thomas Turano of Bedeschi America, Inc. presenting his paper.

Beach volleyball at night

Proud fi shermen and their catch of the day.

Foto by Carlos Escobar

Foto by Carlos Escobar


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to the advertiser’s name, complete the coupon below and fax a photocopy of this entire page to us on+44 1372 743838 or post to us at the following address: GS: Global Slag Magazine,

PRo Publications International Ltd, Adelphi Court, 1 East Street, Epsom, Surrey KT17 1BB, UK.Editorial enquiries should also be directed to PRo Publications International Ltd, quoting the name of the

company in question and the page number upon which the item appeared.Prior to faxing or posting please ensure that you have marked

the companies you are interested in.Name.................................................................................................................................................................................................................Position.............................................................................................................................................................................................................Company..........................................................................................................................................................................................................Nature of business........................................................................................................................................................................................Address ............................................................................................................................................................................................................Telephone ................................................................................................ Fax...............................................................................................e-mail ........................................................................................................ Internet .....................................................................................Please send details of: ........................................................................................................................Pages............................................


Contents Subscribe

. Filter Bags

. Filter Pockets

. Filter Press Cloths

. Filter Accessories

BLF Bad Lauchstädter Filtermedien GmbH & Co. KGAhornstraße 3aD-06246 Bad Lauchstädt Fon + 49 (0) 3 46 35 - 2 15 80 Fax + 49 (0) 3 46 35 - 2 15 62E-Mail: blf-fi [email protected]: www.blf-fi lter.de

WOKU Baltica Bendra Lietuvos-Vokietijos UABNeries kr. 16bLT-3026 Kaunas Fon + 370 - 37 - 36 35 22Fax + 370 - 37 - 36 28 50E-Mail: [email protected]: www.woku.de

Please visit our website www.woku.de

for detailed information or call us!

Leading in industrial fi ltration

Reliable products for environmental protection

WOKU Filtermedien GmbH & Co. KGKaiser-Wilhelm-Straße 90D-59269 Beckum-NeubeckumFon + 49 (0) 25 25 - 20 57Fax + 49 (0) 25 25 - 44 38E-Mail: [email protected]: www.woku.de

31.12.2

003

0

1.01.1979

25

years

www.woku.de

eGC 2007-11 November

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Transcript of eGC 2007-11 November