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By Rafael Lopes

O rendimento metálico é um dos principais indicadores de processo de laminação de longos, uma vez que tem influência direta na redução do custo de produção, sendo fundamental no atual cenário econômico da siderurgia brasileira. Em função disso faz-se necessário identificar as principais causas de perdas metálicas para aumentar o índice desse indicador, utilizando a metodologia DMAIC. Como resultado houve o aumento de 1,22% alcançado pela otimização dos parâmetros de processo do tratamento térmico, redução do comprimento do descarte da cabeça e cauda da barra na tesoura e melhoria na automação das válvulas do sistema de têmpera e autorevenido.

Aug 17, 2017

By Carlos Alberto Perim

Devido à obstrução no distribuidor, os aços ultra baixo carbono estabilizados ao titânio apresentavam baixo sequencial de lingotamento na ArcelorMittal Tubarão (AMT). Foram identificadas práticas utilizadas na redução de obstrução nestes aços, que foram adotadas para a produção na AMT. Uma das práticas foi estabelecer uma relação entre alumínio e titânio com menor propensão à formação de compostos de alumina e óxido de titânio que se aglomeram na região da válvula superior do distribuidor. Também foram introduzidas melhorias no processo visando a melhorar a condição de fluxo na região próxima da saída do aço no distribuidor. Neste projeto, um aço UBC de maior volume de produção foi escolhido e novas práticas foram adotadas para sua produção. Amostras de aço foram retiradas de corridas produzidas nesta condição e foram enviadas para análise na ArcelorMittal Research USA. Os resultados mostraram melhorias nos índices de qualidade tanto em laminados a quente como em laminados a frio. Neste trabalho será apresentado um resumo das ações adotadas na AMT, que resultaram em um aumento do sequencial médio de distribuidor, permitindo atingir um máximo de 18 corridas. Os níveis de esfoliação com esta nova prática atingiram também nível mínimo histórico.

Aug 16, 2017

By B. S. W. Buffam

"The property of Aunor Gold Mines, Limited, is in Deloro township, Ontario, about 3 miles southeast of Timmins. It consists of a group of eleven claims between the Buffalo Ankerite and Delnite mines.In the autumn of 1909, two brothers, John A. and W. S. Mitchell, joined the 'gold rush' to Porcupine. By the time they arrived the township of Tisdale, in which the Hollinger and Dome discoveries had been made, was staked solid but they managed to locate four claims in the northern part of Deloro township. Sufficient surface work was performed to bring the claims to patent in 1915. Following the Porcupine fire the Mitchells left the north to follow the oil developments in southwestern United States. In 1935 because of the rise in the price of gold and the successful development of the l3uffalo Ankerite and Delnite mines, they returned to Timmins and organized Augite Porcupine Mines, Limited, which combined the original four claims in Deloro and two adjoining claims controlled by Montreal River International Silver Mines, Limited. There were few rock exposures on the property, and as the overburden was generally deep surface exploration was impracticable. A programme of diamond drilling was, there; fore, undertaken in an endeavour to locate the western extension of the orebearing formation of the Buffalo Ankerite mine. This drilling was started in August 1936, and 5 months later ore was intersected at a depth of 500 feet on the south boundary of the property."

Jan 1, 1954

By Michel Rodrigue, Sylvain Duchesne, Louis Racine

"LocationThe Louvicourt mine is located 20 km east of Val d'Or in Abitibi, in the northwest part of the province of Quebec. The mine is located on Highway 117 connecting Val d'Or to Montreal and very close to the main railway networkHistoryFive successive exploration attempts by Aur Resources resulted in the discovery of the large Louvicourt orebody in June 1989. Construction of the surface and underground infrastructures commenced in the spring of 1991. Milling operations commenced in July 1994. The entire project cost CDN$290 million, almost CDN$20 million less than initially estimated. The concentrator infrastructure cost CDN$64 million.Louvicourt mine is owned in partnership by Novicourt Inc. (45%), Teck Corporation (25%), and Aur Resources Inc., the administrator (30%).Brief DescriptionLouvicourt mine is the largest producer of base metals (Cu and Zn) in Abitibi-Temiscamingue. Its average daily production is nearly 4300 t of ore, for an annual production of 200 000 t of copper concentrate (28% Cu) and 33 000 t of zinc concentrate (57% Zn). After only a few weeks of operation, it had attained its objectives for the most part, and operations continue to be improved."

Jan 1, 2000

Aur Resources is Canada's leading copper mining company with producing mines and development projects in North, Central and South America. Copper production from Louvicourt Mine in Quebec, Quebrada Blanca and Andacollo Mines in Chile was a record 245 million pounds in 2001. Located 600 km North of Montreal, Louvicourt Mine is a joint venture between Aur Resources (30%), Novicourt Inc (45%) and Teck-Cominco (25%). Aur Resources is the mine operator with 280 employees working to produce a copper and zinc concentrate. In operation since 1994, the mine has produced a total of 12,606,000 metric tonnes of ore grading 3.6% Cu, 1.5% Zn, 26 gr./m.t. Ag and 0.9 gr./m.t. Au. This highly mechanized mine reached full production in August 1995 at 4,000 tpd. From 1996 to 2001, the average mine production rate was more than 4,300 tpd. The Louvicourt Mine continued its record of solid performance in 2002 and is expected to continue to do so for the balance of its 2.5 years mine life.

May 1, 2003

By Robert Hamilton

Aur Resources is Canada's leading copper mining company with producing mines and development projects in North, Central, and South America. Copper production from Louvicourt Mine in Quebec, Quebrada Blanca, and Andacollo Mines in Chile had a record of 245 million pounds in 2001. Located 600 km North of Montreal, Louvicourt Mine is a joint venture between Aur Resources (30%), Teck Cominco (45%), and Novicourt (45%). Aur Resources is the mine operator with 280 employees working to produce a copper and zinc concentrate. In operation since 1994, the mine has produced a total of 12,606,000 metric tonnes of ore grading 3.6 % Cu, 1.5 % Zn, 26gr./m.t Ag, 0.9gr.m.t Au. This highly mechanized mine reached full production in August 1995 at 4,000 tpd. From 1996 to 2001, the average mine production rate was more than 4,300 tpd. The Louvicourt Mine continued its record of solid performance in 2002 and is expected to continue to do so for the balance of its 2.5 years mine life.

May 1, 2003

By A C. Edwards

The Mongol-Okhotsk belt consists of detached fragments of the Circum Pacific fold belt which have been trapped within the Mongol-Okhotsk fold belt. In its western part, the structures of the belt form an east-facing loop that is not connected with the other orogenic structures of Central Asia. In the eastern part of the belt (the Mongol-Okhotsk suture zone) the terranes form a zone between the Siberian craton to the north and the Bureya composite terrane to the south, that is linked with the Circum Pacific belt. The accretionary terranes, together with their Precambrian backstops, form a series of consistently-stacked, paired units that are bounded by northwest and north trending sinistral strike-slip faults. The ages of the rocks forming these accretionary complexes vary from Late Precambrian - Carboniferous in the west to Cambrian - Jurassic in the east. The terranes developed due to a progressive westward stacking of the accretionary complexes during the process of accretionary growth. The magmatic rocks young eastward indicating that migration of the magmatic front of the arc followed the eastward growth of the accretionary complexes. The accretionary terranes may be differentiated by their Paleozoic lithological assemblages. Only the Selemdzha, Niman, and Kerbi terranes located in the eastern part of the Mongol-Okhotsk suture zone contain significant amounts of black shale, and it is these terranes that host the bulk of the hardrock and placer gold mineralisation that is present within the suture zone. Gold mineralisation is present both as vein style and disseminated mineralisation within structural duplexes.

Jan 1, 1999

By K. Howard Poulsen

Shear zones are tabular tructures which tend to occur either discordantly within, or concordantly along the margins of, competent rock masse uch as plutons, sill or flows. They contain deformed equivalents of their host rock and are common sites for gold mineralization localized in tructure oriented y tematically relative to the shear zones and internal linear fabric. Apan from genetic implications, hear zone analysis proves useful in exploration for this type of deposit because the zones are generally wider and more continuous than associated mineralization and because there is an element of predictability to mineralization geometry (i.e. vein orientation. plunge).

Jan 1, 1986

By P. H. Mell

CAN the auriferous slate deposits of the Southern mining region ever be successfully worked? is a question that has been often asked me by persons seeking investments in Southern mines. As the subject is one that has given me much thought during the past few years, I have decided to present my conclusions to the members of the Institute for their consideration. Those who have had the opportunity of exploring the region mentioned above, will readily recall to mind numerous localities, to which their attention was directed by would-be miners, as "rich and desirable properties," in which there were but few quartz seams running in every direction through fine-grained talcose slate. Most of the gold in sued formations was always found disseminated through the slate, and but a small percentage contained in the quartz. Such are the deposits I propose to discuss in this paper. Of course there are many excellent quartz mines in the South that are paying the owners good profits, and many more to my knowledge, that are not being worked for obvious reasons. But it is out of the question to suppose that these slate deposits can be practically

Jan 1, 1881

Probably no other country or coutinent has so many rich deposits of various different minerals as Australia. Long ago in the days of my boyhood in the old land the marvellous discoveries of high percentage copper at Burra Burra, Peak Downs, Yudanamutana, and other mines, was one of the principal themes of conversation in mining circles whilst the specimens of malachite, azurite, etc, brought home by returning miners were the admiration of my boyish eyes.Later on the WalIaroo and Moonta mines still further helped to heighten the reputation of Australia as a copper-producing country. During the 21 years that the writer has been resident in the Australian colonies, other mineral deposits have sprung into prominence, and with a Mount Bischoff for tin, a Broken Hill for silver and lead, and a Mount Morgan for gold, Australia can now boast that it has had within its borders the leading mines of the world, in four different minerals, and still at least maintains that pre-eminence in gold, silver and tin. To the miner from the old land, Australian mining is at first a revelation and a wonder. In very many instances he looks in vain for the regular strike and dip of the veins he has been accustomed to'Smooth hanging and foot alls are often wanting. 'Huge irregular deposits, like those mentioned above, viz., Burra Burra, Mount Bischoff, Broken Hill, and Mount Morgan, are mysteries that will take time to fathom-if, indeed, they are ever thoroughly understood and in many a smaller deposit there is much to interest alike the professor in the college and the miner in the mine.

By D Preedy, J K. Claflin, S R. J La Brooy

This paper summarises the lessons learned during a recent carbon reactivation kiln upgrade project at the Sukari Gold Mine in Egypt. The kiln is being replaced to ensure that the plant achieves full value from the current throughput expansion from 5 to 10 Mt/a.The suitability of the original engineering design criteria for kiln selection and the adequacy of the original kiln are reviewed in the light of the carbon chemistry, operating experience and a site inspection of the kiln. Particular aspects of the reactivation facility are discussed including: predrying, preheating, feeding, gas seals, kiln heat transfer, steam injection, counter-current sweep gas flow, carbon cooling, fines minimisation and removal.Design criteria for a carbon predryer, reactivation kiln and cooler combination for carbon heavily fouled by high molecular weight frothers and collectors are discussed and the abridged Ausenco datasheet for the combination is presented.Responses to a request for a budget price sent to most of the worldÆs suppliers of carbon regeneration kilns are summarised.CITATION:Claflin, J K, La Brooy, S R J and Preedy, D, 2013. Ausenco carbon reactivation design criteria, in Proceedings World Gold 2013 , pp 401-410 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By Markus A. Reuter, Jacob Wood, Robert Matusewicz

Over the last 20 years, significant improvements in copper smelter productivity have been realized through the advent of continuous smelting processes. This progress has until recently however, not been carried through to copper converting. Peirce-Smith converting has been widely used by the copper industry for 100 years but is limited by its batch nature in achieving large scale of production. A logical next step is therefore copper converting on a continuous basis with its inherent environmental benefits. A number of continuous converting technologies are currently in use or being developed within the copper industry, the majority of these operating with calcium-ferrite slags. A notable exception however is the Ausmelt Continuous Copper Converting (C3) technology which has focused on operation with ferrous-calciumsilicate or loosely called olivine type slags. This paper discusses the merits of the Ausmelt C3 process and the advantages offered in terms of operational flexibility and process control arising from the use of lime modified iron silicate slags. It also examines the effects of key process variables pertinent to continuous copper converting from both a theoretical and experimental/operational perspective.

Jan 1, 2009

By Stephen Hughes

Ausmelt Top Submerged Lancing (TSL) Technology has gained widespread commercial acceptance in the lead and zinc industries, as an efficient and highly flexible pyrometallurgical reactor with accompanying excellent environmental performance. For the processing of lead and zinc bearing feed materials twenty one (21) Ausmelt furnaces are now in operation, under design or under construction. With recent increases in the value of both lead and zinc and an ever increasing focus on the sustainable use of resources, interest in the processing of secondary feed material sources as well as metal containing residues has substantially increased. Ausmelt Technology has proven to be well suited to the economic recovery of values from such sources. This has for example culminated in Ausmelt?s commitment to the Whyalla Zinc project as the owner/operator of a facility for the treatment of zinc bearing secondary feeds. This paper describes Ausmelt?s recent developments in the fields of lead and zinc processing, as well as further investigations into new processing areas, including the direct smelting of zinc concentrates. Ausmelt?s TSL Technology can now be regarded as Best Available Technology (BAT) for metal production.

Jan 1, 2008

By Joseph Sofra

It has become increasingly evident that sustainable metals production in the 21st century requires producers to balance the needs of cost effective, high value production with that of responsible plant operation. This is becoming more difficult as lower grade and more complex feed materials, including recycled scrap and residues, are being processed to reduce production costs and decrease exposure to primary metal market fluctuations. One particular facet of the metals industry facing these challenges in the 21st century are copper producers, The recent steady decline in the copper price has seen the industry cut expenditure, tighten control on income streams and focus on high returns on capital investment. For these reasons copper producers are looking towards flexible technologies that can deliver high value products, with minimal environmental impact at low capital and low sustainable operating costs. Ausmelt's Top Submerged Lancing (TSL) technology for copper production is a low cost, proven technology for the processing of both primary and secondary copper materials. Both the smelting and converting operations introduce significant advantages in environmental performance, improved process efficiencies and high rates of metal recovery, Ausmelt has made significant gains in the past 4 years in establishing a strong market position for its copper technology, New installations in China, South Africa and India as well as existing operations in Zimbabwe and China have demonstrated its effectiveness. This paper reviews the application of Ausmelt Technology for both smelting and converting of primary and secondary sources, It discusses Ausmelt's design and implementation philosophy, and how this philosophy meshes with the needs of the end user.

Jan 1, 2003

By R. Matusewicz, A. Kaye

Ausmelt Top Submerged Lancing (TSL) Technology has gained widespread commercial acceptance in non-ferrous applications, including the processing of lead and zinc primary concentrates and secondary (post-consumer) materials. TSL is highly flexible and efficient, and is one of the few technologies which can process primary and secondary feeds, and use varying fuels, to deliver high recoveries and excellent environmental performance. With the recent high value of both lead and zinc, and an escalating awareness of the sustainable use of resources, focus on the processing of secondary feed material sources has surged. Ausmelt Technology has proven to be well suited to the economic recovery of values, with twenty-two (22) Ausmelt furnaces processing lead and zinc bearing feed sources now in operation, under design or construction. This paper describes Ausmelt's progress in the fields of lead and zinc processing, and developments in new processing areas such as EAF dust processing and linking to innovative hydrometallurgical technology. Ausmelt has recently committed to the Whyalla Zinc project as the owner/operator of a facility for the treatment of zinc bearing secondary feeds. This project is due for start up in the first quarter of 2008.

Jan 1, 2008

By Joseph Sofra

It has become increasingly evident that sustainable metals production in the 21" century requires producers to balance the needs of cost effective, high value production with that of responsible plant operation. This is becoming more difficult as lower grade and more complex feed materials, including recycled scrap and residues, arc being processed to reduce production costs and decrease exposure to primary metal market fluctuations. One particular facet of the metals industry facing these challenges in the 21 st century arc copper producers. The recent steady decline in the copper price has seen the industry cut expenditure, tighten control on income streams and focus on high returns on capital investment. For these reasons copper producers arc looking towards flexible technologies that can deliver high value products, with minimal environmental impact at low capital and low sustainable operating costs. Ausmelt's Top Submerged Lancing (TSL) technology for copper production is a low cost, proven technology for the processing of both primary and secondary copper materials. Both the smelting and converting operations introduce significant advantages in environmental performance, improved process efficiencies and high rates of metal recovery. Ausmelt has made significant gains in the past 4 years in establishing a strong market position for its copper technology. New installations in China, South Africa and India as well as existing operations in Zimbabwe and China have demonstrated its effectiveness. This paper reviews the application of Ausmelt Technology for both smelting and converting of primary and secondary sources. It discusses Ausmelt's design and implementation philosophy, and how this philosophy meshes with the needs of the end user.

Jan 1, 2003

On August 22, 1966, just 20 months after writing sales agreements with Japanese steel mills, Hamersley Iron Pty Ltd made its first contractual shipment of 52,000 tons to Yawata Iron and Steel Co Ltd. As world news, the event was not spectacular. But to mining men it represented an astonishing achievement. Twenty months of feverish effort and the expenditure of more than $100 million had created a large open-pit iron ore mine, a crushing plant, storage and load-out facilities for sized ore, and a supporting township at Mt Tom Price; a 182-mile standard gauge railway; and port and loading facilities for a nominal loading capacity of 6000 tph as well as a port town, Dampier, on King Bay. The project was executed in the sparsely inhabited, arid, dissected-plateau country of the Hamersley Range in the northwest sector of Western Australia. Hamersley, 60% owned by Conzinc RioTinto of Australia Pty Ltd and 40% by Kaiser Steel Corp, holds sale contracts for ore and pellets valued at $770 million. The main contracts are with the Japanese, who are to be supplied with 65.5 million tons of ore during the 16 years from August 1966 to August 1982 and 18 million tons of pellets over a 10-yr period beginning in early 1968. Of lesser importance at this time, but presaging trends, are contracts for a total of nearly 1.5 million tons to be shipped to England and Western Europe during the years 1966-68. A pellet plant with a capacity of 2 million tpy is now under construction at Dampier and is to be on stream early next year. Another interesting project for which the plans are set, is a desalination plant for sea water to supply industrial requirements and potable water for the town of Dampier.

Jan 5, 1967

By John Mathews

IT is a great honor to be asked by. the Board of Directors of this Institute to deliver the Henry Marion Howe lecture. The invitation carries with it a great responsibility, which I accept with considerable hesitation and with a feeling of unworthiness to perform the duties expected of me in this hour devoted to the memory of the life, character, and work of the late Professor Howe. Many of you recall the scholarly address delivered here a year ago by Prof. Albert Sauveur, and the beautiful tribute he paid-to his friend and colleague of many years in the great work of changing the art of iron making into the science of iron. My association with Professor Howe, was of brief duration-only one year-and the relation was that of pupil to teacher. My feeling toward him in later years was always that of a humble disciple at the feet of a master. He attained his third academic degree in the year that I was born. I recall the pride I felt when, after entering the, steel industry, I received from him, from time to time, letters asking for information or, perchance, asking my opinion, and he was always most punctilious in acknowledging the source of such bits of information in his writings. It was also my good fortune to sit at the feet of another great teacher-Sir William Roberts-Austen, at the Royal School of Mines. I mention him because his name was used by Osmond in coining the word "austenite," which is the subject of this address, and Osmond's suggestion was heartily approved by Howe. These three international metallurgists were the best of friends and delighted to honor the achievements of one another. There are other reasons for mentioning Roberts-Austen at this time. It was an introduction from Howe that opened to me the door of his -laboratory as well as of his heart. It was while at Roberts-Austen's laboratory that I .worked side by side with William Campbell

Jan 4, 1925

By Malcolm F. Hawkes

AUSTENITE grain size has long been recognized by metallurgists as an important property of steels because of its influence on toughness, hardenability, machinability and creep strength. Much research has been carried out on wrought steels to develop methods for disclosing austenite grain size, and to provide knowledge of the grain-size -characteristics of steels produced and heat-treated in various ways. Much less work in these fields has been done on steel castings; partly because, owing to the variable and complex microstructures of cast steels, it is frequently very difficult to obtain results that are not questionable. The object of this investigation, therefore, was to establish, for a wide variety of carbon and alloy cast steels, suitable methods for disclosing austenite grain size and some knowledge of the grain-size variations to be expected. The steel foundryman is interested in austenite grain size at two different stages in the manufacture of his products; one is just after the steel is cast, and the other is after any reheating operation carried out above the critical temperature range. In both, it must always be kept in mind that the grain size being sought is actually a previous austenite grain size, and that the austenite no longer exists once the steel has cooled to room temperature. The problem of the investigator is always to use evidence obtained from the structure at room temperature to deduce this previous austenite grain size, which was established the last time the steel existed at a temperature above the critical range. Since most steel castings today are at least annealed or normalized, the measurement of austenite grain size established by heat-treatment will be considered first. More than So commercially produced cast steels representing a wide variety of compositions and melting practices were used in the study. For each steel, grain-size determinations were made after each of three widely varying heat-treating schedules; namely, one hour at 1550°F, one hour at 1700°F, and six hours at 1700°F. The list of steels and results obtained on them will be found in the appendix. (See page 21.) A discussion of the knowledge gained on the applicability of various test methods and on grain-size characteristics of cast steels in general follows. MEASUREMENT OF AUSTENITE GRAIN SIZE ESTABLISHED BY HEAT TREATMENT METHODS SUITABLE FOR DETERMINING AUSTENITE GRAIN SIZE AFTER HEAT- TREATMENT AT ORDINARY TEMPERATURES AND TIMES It was desired, as one of the results of this investigation, to be able to recommend to steel foundries a method, or methods, of disclosing grain size best suited to accurate

Jan 1, 1947

By Antonio Augusto Gorni, Kenji Camey, José Herbert Dolabela da Silveira

Recently several studies have been developed on the use of microalloyed steels with low Mn content (below 1%) in the controlled rolling of heavy plates for the manufacture of pipes. However, this novel concept of alloy has peculiarities in its thermomechanical processing. Lower Mn contents should lead to the acceleration of NbCN precipitation kinetics during rolling, leading to a reduction in the soluble Nb content in austenite that delays its recrystallization by drag effect. This fact, plus the heavy and fast passes applied under virtually isothermal conditions in a heavy plate rolling mill with high power, increases the risk of partial recrystallization during the finishing stage of the controlled rolling, since strain hardening of austenite becomes significant and the interaction between precipitation and recrystallization is increasingly delayed. The objective of this study was to analyze the evolution of mean flow stress during the finishing stage of controlled rolling in these low Mn, high Nb microalloyed steels, in order to better understand the metallurgical mechanisms acting during this process and identify conditions that allow full compliance with the requirements of this product class.

Oct 1, 2019