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By Kássio Nogueira Cançado

A perda de temperatura das barras de aço no intervalo entre a saída do forno e a entrada do laminador é fator determinante no processo de laminação e na qualidade do tubo produzido. O estudo feito tem como objetivo modelar matematicamente o resfriamento destas barras durante o transporte entre o forno e o laminador, permitindo avaliar a temperatura mínima necessária para desenfornamento e também o máximo tempo de transporte sem comprometer o processo de laminação, possibilitando um melhor setup dos equipamentos reduzindo os custos de produção. Os resultados obtidos com o modelo matemático de resfriamento foram comparados com valores reais de temperatura coletados através de campanhas de medições com termopares instalados em uma barra e com medições de pirômetro. Valores de temperatura foram coletados com termopares em barras de 270, 230 e 180 mm de diâmetro. As medições com pirômetros foram feitas em barras de 180 mm de diâmetro. O modelo de resfriamento apresentou para todos os casos erro relativo às medições inferiores a 3%.

Aug 17, 2017

By Ernst Lindemann

Steel suppliers are required to deliver sheets with particular qualities and with lightweight-potential to the automotive industry. New types of steel call for new production processes. SMS group has developed a new micro-mill-concept, the core of which is the belt caster. This was first built on an industrial scale and has been put into operation and developed together with Salzgitter Flachstahl GmbH. The robustness in industrial-scale operation could be verified. The full use of the belt casting technology, mainly related to energy efficiency and CO2 reduction, is realized with the micro-mill-concept. This is an in-line-process, casting and rolling in one line.

Aug 17, 2017

By Maurizio Massimo

Danieli developed the “3Q” suite of process control technologies to address three critical principles: delivering the highest product Quality, in the required Quantity, with Quickness of response required for today’s casting machines. Ever increasing market demands for productivity and slab quality necessitate the latest advances/improvements in equipment design, process technology, and control software for all types of slab casters, and Danieli boasts a unique experience that extends from ultra high-speed thin slab casters to extra high-thickness conventional slab casters. The “3Q” system is monitored and controlled by a unique, intelligent HMI incorporating. Touch screen technology and Operator Assistant tablets. Operator Assistant is a tablet based system that guides the operator through the plant process, so that in the event of a process change or an alarm the operator is automatically presented with the choice of possible solutions / actions. The comprehensive range of technological packages cover all aspects of caster design and automation control, from feeding of liquid steel into the tundish to the final slab leaving the caster.

Aug 17, 2017

By Paulo César Pontelo

Buscando atender seus clientes com soluções inovadoras no campo do tratamento de metais líquidos, a Sidertec efetuou a atualização tecnológica do sistema de dessulfuração primária de uma grande usina integrada brasileira trazendo o seu sistema antes obsoleto para o estado da arte em dessulfuração e ainda substituindo o dessulfurante a base de CaC2 anteriormente utilizado por PureSteel®; tendo como benefícios a otimização do processo, redução de custo de 61% e melhora na condição de segurança operacional pela retirada de produto perigoso do processo da usina. Esta implementação utilizou o Know How Sidertec e se baseou na metodologia de estudo do problema, aprofundamento de engenharia das possíveis soluções e realização do revamping proposto.

Aug 17, 2017

By Marcos Fernando Campioto Junior

O objetivo deste trabalho é criar um modelo automático de suspensão e liberação de suspensão de placas, com base no sucesso de laminação de padrões de aço e outros critérios. Este modelo visa reduzir a instabilidade operacional no Laminador de Tiras a Quente (LTQ) da ArcelorMittal Tubarão, através da redução do risco potencial de geração de sucata na linha. Além da redução potencial do risco, espera-se gerar um ganho de produtividade das áreas responsáveis pela solicitação e liberação da suspensão de placas. Através da automatização destas liberações e das suspensões, espera-se aumentar a disponibilidade de estoque diária para programação de chances de laminação e evitar intervenções manuais de maneira padronizada. Este modelo será utilizado nas etapas de criação de placa e aproveitamento de placas no pedido. Além disso, o modelo será rodado automaticamente todos os dias visando avaliar todo o estoque.

Aug 17, 2017

By R. F. Selden

The material in this paper is intended simply, to be an inquiry into some of the theoretical aspects of the occurrence of methane and carbon dioxide in coal, with a brief resume of the more recent literature. Several discussions on various phases of the subject have been published, a few of which (4, 20, 25, 88, 90)4/ have more or less extensive bibliographies of tie earlier literature. In large measure the pertinent literature deals with the unusual aspects of the subject, and in consequence it might appear that the normal aspects have not been given due consideration here. The latter information is largely a matter of practical field experience, and since that which is normal to one locality is often abnormal to another no sharp differentiation appears to be necessary or, in fact, possible. No attempt will be made to present a critical discussion of the relations between the presence of gases in coal and pertinent geologic features or mining practice. Although the presence of foreign gases in the ventilating air of many mines is not particularly noticeable, in many others the evolution of methane and perhaps small amounts of carbon dioxide (or sometimes the reverse - large amounts of carbon. dioxide with perhaps sore methane) is quite apparent.

Jan 1, 1934

By R. F. Selder

The material in this paper is intended simply to be an inquiry into some of the theoretical aspects of the occurrence of methane and carbon dioxide in coal, with a brief resume of the more recent literature. Several discussions of various phases of the subject have been published a few of which (4, 20, 25, 88, 90) have more or less extensive bibliographies of the earlier literature. In large measure the pertinent literature deals with the unusual aspects of the subject, and in consequence it might appear that the normal aspects have not been given due consideration here. The latter information is largely a matter of practical field experience, and since that which is normal to one locality is often abnormal to another no sharp differentiation appears to be necessary or, in fact, possible. No attempt will be made to present a critical discussion of the relations between the presence of gases in coal and pertinent geologic features or mining practice. Although the presence of foreign gases in the ventilating air of many mines is not particularly noticeable, in many others the evolution of methane and perhaps small amounts of carbon dioxide (or sometimes the reverse - large amounts of carbon dioxide with perhaps sore methane) is quite apparent. The presence of small quantities of carbon dioxide can be attributed to oxidation of the carbonaceous matter exposed to the air. In the few cases in which this explanation is not sufficient, obviously the carbon dioxide must escape as such from the coal and neighboring strata.

Jan 1, 1934

By A. G. Loomis

Although secondary-recovery methods have not been applied widely in California, it is apparent that increasing attention and effort must be given to this phase of recovery if the State is to maintain its high rank as a petroleum producer. Steadily increasing demands for petroleum products and decreasing rates of discovery of new oil fields, with rapid depletion of existing reserves, emphasize the prospect of an adverse situation of supply and demand in the not-far-distant future. If the trend of discoveries becomes more favorable or if more complete economic recovery of the oil in place can be obtained by secondary recovery, this situation can be averted. Not only are these reserves of economic importance to the petroleum industry for meeting increasing market demands; but economic reclamation of such reserves is an important conservation measure, which will prolong the productive life of many fields. Accordingly, progressive operators in California are alert to the possibilities of secondary recovery and have done much to implement such operations wherever feasible. Most current operations are of the pressure-maintenance type, in which the reservoir pressure is maintained or partly maintained by injecting natural gas to in-crease oil recovery. The possibilities of recovering additional oil from stripper fields by gas drive and water flooding (including water disposal) also are being tested in experimental field projects. Table 1 summarizes current gas-and water-injection projects in California.

Jan 1, 1952

By R. F. Tenney

This report has been prepared because little detailed information has been published on the production and use of anthracite producer gas for industrial-process and brick-kiln heating. To obtain this information, an investigation was conducted by the Federal Bureau of Mines in cooperation with a building-brick manufacturer (firing both periodic and tunnel kilns with anthracite producer gas) and with a manufacturer of anthracite-gas producers. In addition to a study of available plant records, 2 weeks was spent in systematic observation and measurement during regular operation of the Hazleton Brick Co. plant, Hazleton, Pa., in July 1953. This report presents the results of this investigation and a description of producer and periodic-kiln equipment, operating procedures, and labor requirements. A summary of the conditions of producer and kiln operation is given for the 2-week observation and for the 11 preceding months. The two 10-foot standard anthracite-gas producers consumed 301 tons of Rice and Buckwheat No. 1 anthracite, as delivered, averaging over 13,000 B.t.u. per dry pound during the 2-week period, with a producer hot-gas efficiency of 95 percent, at an average gas offtake temperature of 5400 F. The yield of gas5/ of 153 gross B.t.u. per cubic foot amounted to 140,000 cubic feet per ton of fuel as fired, or 73,500 cubic feet per kiln heating hour, which was sufficient for kiln requirements.

Jan 1, 1960

By John Blackshaw

NEW sources of supply of tungsten concentrates became necessary when the flow from the Far East was blocked in 1942. In Canada, one source has been noted in the workings of the Hollinger mine at Timmins, Ontario. For many years, a small amount of scheelite had been removed with the gold ore, and an appreciable tonnage of scheelite still remained in the mine. At the request of the Dominion Government, a plant was built to recover this scheelite in the form of a concentrate that could be used by the alloy-steel industry without further preparation. The plant began operating early in March, 1942, and a small tonnage of ore, carrying scheelite and gold values, has been treated daily since then. The possibility of recovering the scheelite had been considered on several previous occasions. Each time the proposal had been given up because the total profits from the enterprise were estimated to be insufficient to repay the capital cost of building the recovery plant. At the time the plant was built, additional information had been gathered about the tonnage and grade of the scheelite ore in the mine, and several thousand tons of ore grading higher than 0. 25 per cent WO3 (tungstic trioxide) were known to be available.

Jan 1, 1943

By Z. F. Zhou, X. Y. Zhou, V. G. Papangelakis, Z. D. Jankovic, S. M. Ulyanov, S. N. Lvov

Recently developed flow-through electrochemical techniques (1,2) were employed for measuring pH in high concentration aqueous solutions and geothermal brines. The pH values of (1) 5.0 mol kg-1 NaCl + x mol kg-1 HCl, (2) 3.0 mol kg-1 of NaCl + 0.5 mol kg -1 of KCl + 1.0 mol kg-1 of CaCl2 + x mol kg-1 HCl (x < 0.1 mol kg-1), and (3) mixtures of Al2(SO4)3-H2SO4-H2O, MgSO4-H2SO4-H2O, and NiSO4-H2SO4-H2O solutions have been measured at temperatures from 100 to 280°C. The obtained experimental data and their thermodynamic analysis demonstrated that the electrochemical system can be used for on-line pH monitoring of high concentration aqueous solutions with an accuracy of ±0.1-0.3 pH units over a wide range of temperatures. Greater deviation exists in real laterite leach solution measurements due to in situ precipitation of Na-alunite. The system is excellent for research and process development work. Further work is needed to ensure robust operation under pressure leach conditions of laterites.

Jan 1, 2004

By W. M. Mark

This investigation was undertaken to develop methods to improve the quality of titanium sponge produced by the Bureau of Mines modification of the Kroll magnesium reduction process. Research revealed that by systematic elimination of detrimental impurities introduced with the raw materials and by improved handling and processing techniques, high-quality ductile titanium with a hardness of less than 110 B.h.n. (Brinell hardness number) can be produced consistently. This improvement was accomplished by helium (or argon) stripping of residual atmospheric and other dissolved gases from the titanic chloride, preliminary dehydration of crude titanium sponge, and careful regulation of the titanium tetrachloride (TiC14) feed rate to the reactors.

Jan 1, 1960

By D. A. Rice

As part of a cooperative effort between the Bureau of Mines and the Florida Institute of Phosphate Research (FIPR), with input from the phosphate industry, the conversion of phosphogypsum to sulfur is being investigated. The proposed process incorporates the thermal reduction of phosphogypsum to calcium sulfide (CaS) and a hydrometallurgical treatment to convert calcium sulfide to sulfur (S°). The research described herein is focused on the latter half of the process. It was demonstrated that calcium sulfide could be converted to ammonium bisulfide (NH4SH), and that ammonium bisulfide could be oxidized by air in the presence of a catalyst, to elemental sulfur, which was adsorbed on the catalyst. Two methods for recovering sulfur from the catalyst were developed: (1) thermal treatment to volatilize sulfur, and (2) leaching the sulfur from the catalyst with liquid anhydrous ammonia. Over 90 pct of the sulfur adsorbed on activated carbon (the catalyst) was recovered by both methods. Based upon the encouraging laboratory investigations, a hydrometallurgical scheme was proposed for the overall conversion of calcium sulfide to elemental sulfur.

Jan 1, 1990

By Robert H. Bedford

The New Almaden mine was discovered in 1824, and since that date production of quicksilver has exceeded 1,000,000 flasks. Because of this high production record, the New Almaden area was, upon passage. by Congress of the Strategic Minerals Act of 1939, immediately considered by the Bureau of Mines as a promising location for exploration. In 1941, the Federal Geological Survey undertook a survey of the entire district. R. R. Trengove, an engineer of the Bureau of Mines, made a preliminary study for a project in 1942, and in August 1943 the Bureau, in close cooperation with the U. S. Geological Survey, began the development project described herein. The Bureau of Mines drilled 36 holes, totaling 6,807 feet of diamond drilling, along the contact between the serpentine and Franciscan, sandstones and other sedimentary formations. The ore bodies are found along this contact and occur in the carbonate-silica rock. This report briefly describes the location, history, and ore deposits of the property. The recent operations are outlined, and the work performed by the Bureau is explained in detail.

Jan 1, 1950

By Paul W. Billwiller

Introduction In 1937, the Britannia Mining and Smelting Company, Limited, was carrying on an extensive exploratory diamond-drilling programme. Most of this drilling was done on the 4100 level, the lowest working level in the mine. One of the exploratory diamond-drill holes, at approximately 12,500 feet from the portal of the tunnel, encountered heavily mineralized stringers of chalcopyrite and sphalerite in silicified grey schist. The mineralization was encountered just to the hanging-wall of the green mottled schist at a point 350 feet south of the 4100 tunnel. To delimit this new orebody, drifts and cross-cuts were driven on 3500, 3800, and 4100 levels to the hanging-wall in the area of the projected mineralization. On the 3500 level, the top of the mineralized zone was encountered. The zone was thoroughly explored by drifting and diamond drilling. The mineralization, however, was not sufficiently concentrated to be of commercial grade. On the 3800 level, the zone was found to consist of disconnected stringers of chalcopyrite and pyrite. Drifting was continued to the west and a long lens-shaped area of grey schist containing fairly heavy stringers of chalcopyrite was delimited. This lens later proved to be very close to the top of the commercial mineralization of the No. 8 orebody. On the 4100 level, a diagonal cross-cut was driven to the footwall of the downward projection of the mineralized zone. Diamond-drill holes from this cross-cut indicated a zone of heavy mineralization. A drift was driven off the cross-cut parallel to the zone and some distance to the footwall of it. Further diamond drilling disclosed a mineralized zone approximately 300 feet long and 35 feet wide containing sphalerite, chalcopyrite, and pyrite. The foregoing development work indicated a fairly large lens of mineralization of sufficient concentration to be classed as ore between the 4100 and 3800 levels. To explore this mineralization at depth, long diamond drill holes, dipping at minus 57° and minus 80°, were planned from some point to the hanging-wall of the orebody. The 4100 level was not suitable for small development headings, due to wider gauge track and larger cars than on the levels above. Therefore, a raise was driven from the diagonal cross-cut on the 4100 level to a point some 70 feet above and just inside the footwall of the orebody. From the top of the raise, drifts were expanded east and west to delimit the ore zone. In addition, a long cross-cut was driven 350 feet to the hanging-wall, and drifts were opened east and west from the end of the cross-cut to provide diamond-drill stations for the exploration of the orebody at depth.

Jan 1, 1946

By James J. Dowd

The investigation to evaluate the reserves of coking coal is being made by the Bureau of Mines in three parts: (1) To estimate known (measured plus indicated) recoverable reserves of all coking coal, (2) to upgrade marginal coals through effective preparation, and (3) to study the carbonizing properties of coal and coal blends not now widely used for metallurgical coke making. This is the seventh of a series of reports giving the results of studies by counties under part (1) of the investigation. (See appendix.) This report covers Floyd County, KY., which comprises parts of the Paintsville, Prestonsburg, Harold, Hindman, and Pikeville quadrangles. (See fig. 1.) A base map for each bed in each quadrangle was made to the scale of 1 inch equals 1,200 feet. Maps of mines, locations of drill holes, bed and total coal thicknesses, and the outcrop of the bed were plotted on the maps. With all avail-able data plotted, isopach lines were drawn to limit areas of known unmined reserves in beds up to 14 inches thick, 14 to 28 inches thick, 28 to 42 inches thick, and over 42 inches thick. These areas of coal reserves also were divided into "measured" and "indicated" categories. All areas in each thickness range and in each category, mined-out areas, areas excluded from the estimate but which may contain reserves based only on geologic inference, and areas outside of the outcrop were measured by planimeter on the base maps. Estimates of total reserves 14 inches and more thick and maps for individual beds were prepared from these data.

Jan 1, 1951

On December 16, the General Services Administration (GSA) suspended weekly sales of surplus silver from the national defense stockpile because Congress approved the Defense Appropriation Act, which contained an amendment to halt silver sales. The amendment, introduced by Senator James A. McClure (R., Idaho), prohibits sales for 6 months while the impact of the sales and alternative methods of disposal are evaluated. The GSA sold 2 million troy ounces since sales started October 14. 46.5 million troy ounces were authorized to be sold during this fiscal year and an additional 58.6 million troy ounces were authorized to be sold over the following two fiscal years. The stockpile held 139.5 million troy ounces of silver when sales began in October. Brush Wellman, Inc., a vertically integrated producer of beryllium products announced plans to modify its Delta, Utah beryllium concentrate processing facility to utilize beryllium concentrates containing as little as 7% beryllium oxide. The company plans to invest $2.5 million for this modification with completion expected in mid-1983. Implementation of this plan to consume lower grade beryllium minerals will significantly increase world reserves of beryllium concentrates.

Jan 1, 1981

By R. A. Beall

This paper summarizes the development of a furnace for producing titanium castings. The general problem is outlined and chronological details are given on the construction and operation of four different casting furnaces, all utilizing consumable-electrode arc heating and water-cooled copper crucibles. Of the two methods of pouring, the tilt-pour technique has been more satisfactory than bottom tapping. Mold design, electrode fabrication, and deep-pool production are discussed. INTRODUCTION In the early summer of 1953 the Bureau of Mines was contacted by the Department of the Army through Watertown Arsenal to explore the possibility of conducting research on casting titanium metal. The objective of the program was "to develop a technique for producing formed castings of titanium metal not less than 40 pounds in weight and without introduction of deleterious contamination."

Jan 1, 1956

By Thomas M. Nasiatka

This report briefly describes the present state of the art and the technological highlights of tunneling from its inception to the present. The discussion is concerned primarily with tunnels driven through relatively competent rock for mine development and various civil purposes. In addition to pinpointing the major technological breakthroughs in tunneling, this report indicates their general effect on the speed of tunneling. The tunneling speeds are based upon data from approximately 80 tunnels listed in the appendix. These data include length; cross section shape and dimension; type of rock; tunneling method; method of breaking, loading, and transporting the rock; average linear progress rate; and cost in values during the period of construction. Most of the tunnels described have diameters of 15 to 30 feet.

Jan 1, 1968

By R. C. Kellner

Duval Sierrita Corporation, a wholly-owned subsidiary of Duval Corporation, operates an 86,000 STPD copper-molybdenum concentrator near Tucson, Arizona. Shortly after production commenced in February, 1970, it became apparent that the reduction crushing system represented a limitation to reaching the design capacity of 72,000 STPD. The development work performed on the reduction crushers in order to first meet design capacity, and to subsequently increase production to 86,000 STPD is described in this paper. The Sierrita plant is a conventional three stage crushing sys- tem. All crushers were supplied by the Allis-Chalmers Corporation and consist of two 58 x 89 Superior gyratories, four 138b EHD hydrocones, and ten 384 hydrocones. Screening is performed prior to and subsequent to secondary crushing and in closed circuit with the tertiary crushers. Typical throughput rates and equipment sizes are presented in Figure No. 1.

Jan 1, 1975