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By K. C. Dean

Discarded automobiles represent the greatest single resource of reusable metals, plastics, and rubber in the United States. This report presents results of Bureau of Mines research, conducted from 1965 to 1983, on separating and recovering useful materials from the scrapped hulks, using old and new metallurgical techniques combined with standard scrapyard methods. The Bureau determined the materials composition of three composite cars designated as circa 1960, mid-1970's, and early 1980's, and used these cars to study smokeless incineration and hand-sorting techniques. In studies on treating rejects from automobile shredders, the Bureau designed a process that included air classification, water elutriation, magnetic separation, handpicking, and heavy-medium separation, and also investigated cryogenics and liquation. Complete recovery of cop-per and other metals was economically made by hand and tool dismantling, leaching, or selective melting of starters and generators. Techniques are also discussed for plastic recovery and waste tire treatment.

Jan 1, 1985

By Robert A. Jankowski

"Following passage of the Coal Mine Health and Safety Act of 1969 (Public Law 911173), the Bureau of Mines initiated a research program aimed at controlling respirable dust exposures of coal mine workers. Respirable dust is the dust that gets into, and interacts with, the lungs of those who inhale it. It has long been recognized as a severe health hazard to mine workers. This program has been implemented by a team effort consisting of the Bureau's in-house capabilities, the Generic Center for Respirable Dust, and contractors, as necessary. Over the years, Bureau research has addressed principally three areas:o Compliance with the Federal 2.0 mg/m3 dust standard (1970-76).o Dust control for longwall mining (1976-1983).o More stringent respirable dust standards due to quartz dust (1983-1987).In addition, fundamental studies have been conducted by the Generic Center for Respirable Dust, with emphasis on penetration of dust into the lung. Accomplishments have been significant, but problems remain, as noted later.The Coal Mine Health and Safety Act of 1969, established a 2.0 mg/m3 dust standard for all coal mining operations, underground as well as surface. At the time of enactment of this legislation, the industry was averaging approximately 4.0 mg/m3. The Bureau of Mines respirable dust research program played a significant role in identifying and developing effective technology to allow better compliance with this new standard, thanks to industry implementation and Federal enforcement."

Nov 1, 1988

By Ballard H. Clemmons

THE future of the steelmaking industry of the Birmingham, Ala., district is closely related to and, in a large measure, dependent on the development of workable, economic processes of ore concentration. Operations thus far in the area have been possible only because of the fortuitous occurrence of iron ore, fluxing stone, and coking coal-all the primary iron-making materials- within a 25-mile radius of the blast furnaces. Commercial ore of the district consists mainly of a 10 to 20-ft hematite-calcite-silica bed locally known as the "Big Seam," a component of the Clinton formation of Silurian Age. At present mining rates, this ore will be available for a number of years. It is largely mined under 1000 to 2000 ft of cover and transported on 15 to 20" slopes that, in some instances, are as much as 10,000 ft long. Under these conditions, particularly with increasing distances from face to portal, mining costs are gradually becoming disproportionately high. Although not a major factor thus far, it should also be noted that the average annual ore output of the district is gradually be- coming more siliceous.

Jan 1, 1950

By Ballard H. Clemmons

THE future of the steelmaking industry of the Birmingham, Ala., district is closely related to and, in a large measure, dependent on the development of workable, economic processes of ore concentration. Operations thus far in the area have been possible only because of the fortuitous occurrence of iron ore, fluxing stone, and coking coal-all the primary iron-making materials within a 25-mile radius of the blast furnaces.

Jan 12, 1950

By Eva B. Kisvarsanyi

An Early Proterozoic orogenic terrane of metasedimentary and metaigneous rocks underlies Nebraska, Kansas, and Missouri. Middle Proterozoic epizonal terranes of anorogenic granite and rhyolite, a known metallogenic province partly exposed in southeastern Missouri, overlap the orogenic terrane on the south. These Proterozoic terranes, covered by less than 1,000 meters of Phanerozoic strata, contain a virtually untapped source of mineral wealth and are one of the last frontiers for geologic exploration in the continen-tal United States. Petrographic study of subsurface samples is a powerful tool in the identification of favorable host rocks for a variety of ore deposits.

Jan 1, 1987

By M. Potesser

Higher prices for natural gas or oil have motivated the copper industry to reexamine the modes of oxygen and oxy-fuel burner usage at operating plants. With rising energy costs and the growing importance of environmental protection, burner usage and burner operations have become the focus of several investigations and optimization efforts. One possible approach to lower energy usage is through combustion using tonnage oxygen. When such oxygen is used, the flame temperature increases and operational efficiency is improved. As well, with the correct technology, due to the presence of lower levels of harmful substances such as NOx in the off gas, there is improved environmental performance. As regards copper production, furnaces are employed for both concentrate smelting or for melting and casting operations. The use of tonnage oxygen in concentrate burners for smelting provides for a higher thermal efficiency. For furnaces employed for melting, air-operated burners may in fact have an initial advantage because a long radiant flame is typically generated, thus providing for a higher degree of heat transmission. This paper describes the new experimental burner chamber of Messer Austria GmbH which provides for testing of the combustion of natural gas with oxygen or oxygen-enriched air and the use of special water cooling ducts that simulates a metal charge during melting, The operational effectiveness of the burner is determined from temperature and off-gas analysis data. The paper also discusses future trends in burner technologies including a new patented burner. Cu2007 - Volume III (Book 2) The Carlos Diaz Symposium ou Pyrometallurgy Edited by A.E.M. Warner, C.J. Newman, A. Vahed, D.B. George, P.J. Mackey, A. Warczok Toronto, Canada,

Jan 1, 2007

By P. Nicholls

Patent records show that the idea that the burning of fuels can be improved by mixing or pretreating them with chemicals 6 dates back to the early years of the last century. By 1845, English and French patents included the specific beneficiations of elimination or reduction of smoke, soot, and clinker; reduction of the ashes, presumably meaning the total weight of refuse from the ashpit; elimination of sulphur fumes; increase in the rate of burning; increase in the time a given charge of fuel would last; and, in most patents, a saving of fuel. The earlier patents specified additions up to 80 pounds or more per ton of fuel, but after 1860 the quantity was rarely more than 4 pounds. There is no record of the extent to which these patents were commercialized, but after 1884 many American patents were assigned to companies specializing in treatment of coal, so it is probable that the products were marketed on a considerable scale at least as early as that date. From 1900 on, many companies marketed proprietary products that were sold under the general name of "fuel savers." Since its establishment in 1910, the Bureau of Mines has continually received inquiries about these products and, at the request of other govern-mental departments, has tested some used in accordance with the instructions of the purveyors; the results were all negative and, within the accuracy of measurements, the products had no effect on the burning.

Jan 1, 1937

By R. M. Hardgrove

PULVERIZED coal was first used for firing cement kilns about 45 years ago, with such success that it has continued in general use. Based on cost, pulverized coal is usually the most economical fuel. In some localities natural gas or oil is cheaper, but 85.5 per cent of all cement kilns at present are fired with pulverized coal. The pulverized-coal flame is well suited to kiln conditions. Its soft, luminous nature gives it a high radiating property and the length of the flame can be readily varied to suit conditions in a kiln of any length. Ash and slag cause most of the difficulties incident to the burning of coal. In a cement kiln, however, the ash, being similar in composition to the raw mix and being deposited uniformly in the mix and clinker, occasions no difficulty as long as it remains constant in quality and quantity. Until 6 years ago almost all cement kilns using pulverized coal employed the bin system. The coal was dried and pulverized in a separate plant and delivered into a bin at the kiln. Thus the bin system requires driers, storage-type pulverizers, conveying systems, individual kiln bins, pulverized-coal feeders and primary air fans. The direct-fired system requires only a pulverizer and a blower. Fig. I shows typical plants. The first installations of direct-fired pulverizers were of the impact type but fineness of pulverization was both inadequate and variable. About 1927 a few direct-fired installations employing tube-type pulverizers were made, which were much more satisfactory. As more efficient pulverizers were developed from 1934 on, equipment for direct firing was installed at a large number of plants, until now 196 of about 900 kilns in use in the United States are direct-fired. Most of these replaced antiquated bin systems. PROCESS OF BURNING CEMENT CLINKERS The process of burning cement clinkers is fundamentally one of heat transfer. In boilers and other heat-exchange apparatus the area of the surface receiving heat from the gases is the best unit for comparing output. This seems to be equally true for kilns. The inside kiln surface is the heat-receiving surface and its area is used as the unit of kiln size in the following comparisons. Heat input is based on British thermal units in the fuel. E. G. Bailey,1 in his work on boiler-furnace heat absorption, has used the unit "B.t.u. available." This is the practical calorific power of the fuel, plus the heat in the air used for combustion. In other words, it is the heat available for useful work in the furnace or kiln. The unit of kiln output is barrels per hour. The composition of the raw mix, the percentage of water in the slurry of wet plants and hardness of burning all affect the output. These conditions, however, are hard to evaluate and probably have less effect on the output than irregularities of raw feed and clinker discharge and inexpert control of combustion. WET VS. DRY PLANTS The study presented here covers 88 plants, of which 41 are wet and 47 dry. Of

Jan 1, 1941

By R. M. Hardgrove

PULVERIZED coal was first used for firing cement kilns about 45 years ago, with such success that it has continued in general use. Based on cost, pulverized coal is usually the most economical fuel. In some localities natural gas or oil is cheaper, but 85.5 per cent of all cement kilns at present are fired with pulverized coal. The pulverized-coal flame is well suited to kiln conditions. Its soft, luminous nature gives it a high radiating property and the length of the flame can be readily varied to suit conditions in a kiln of any length. Ash and slag cause most of the difficulties incident to the burning of coal. In a cement kiln, however, the ash, being similar in composition to the raw mix and being deposited uniformly in the mix and clinker, occasions no difficulty as long as it remains constant in quality and quantity. Until 6 years ago almost all cement kilns using pulverized coal employed the bin system. The coal was dried and pulverized in a separate plant and delivered into a bin at the kiln. Thus the bin system requires driers, storage-type pulverizers, conveying systems, individual kiln bins, pulverized-coal feeders and primary air fans. The direct-fired system requires only a pulverizer and a blower. Fig. I shows typical plants. The first installations of direct-fired pulverizers were of the impact type but fineness of pulverization was both inadequate and variable. About 1927 a few direct-fired installations employing tube-type pulverizers were made, which were much more satisfactory. As more efficient pulverizers were developed from 1934 on, equipment for direct firing was installed at a large number of plants, until now 196 of about 900 kilns in use in the United States are direct-fired. Most of these replaced antiquated bin systems. PROCESS OF BURNING CEMENT CLINKERS The process of burning cement clinkers is fundamentally one of heat transfer. In boilers and other heat-exchange apparatus the area of the surface receiving heat from the gases is the best unit for comparing output. This seems to be equally true for kilns. The inside kiln surface is the heat-receiving surface and its area is used as the unit of kiln size in the following comparisons. Heat input is based on British thermal units in the fuel. E. G. Bailey,1 in his work on boiler-furnace heat absorption, has used the unit "B.t.u. available." This is the practical calorific power of the fuel, plus the heat in the air used for combustion. In other words, it is the heat available for useful work in the furnace or kiln. The unit of kiln output is barrels per hour. The composition of the raw mix, the percentage of water in the slurry of wet plants and hardness of burning all affect the output. These conditions, however, are hard to evaluate and probably have less effect on the output than irregularities of raw feed and clinker discharge and inexpert control of combustion. WET VS. DRY PLANTS The study presented here covers 88 plants, of which 41 are wet and 47 dry. Of

Jan 1, 1941

By D. P. Ziegler

Formulas relating economic optimum busbar cross sectional areas to busbar cost, electric price and financial parameters are reviewed and revised. Application of the formulas is illustrated with discussion of the appropriate choice of parameter values and the sensitivity of the optimum to the parameters. The extension of the single busbar concept to optimization of more complicated arrangements of bus for smelting pots is complicated by the constraint of obtaining a specified current distribution. An example problem illustrates the optimization of a section of a bus network containing a fork, with the imposed limitation of achieving a specified uniformity in the current. In cases where the current in the individual conductors may vary, Kelvin's law does not apply. Further extension of the technique to a full pot set of conductors poses additional problems which are discussed, but whose solution has not yet been accomplished. Aluminium 2006 45th Annual Conference of Metallurgists ofCIM Montreal, Quebec, Canada Edited by

Jan 1, 2006

By Rodrigo Werneck Athouguia

O cerne desse trabalho consiste em demonstrar os resultados obtidos pela implementação de um programa de Lubrificação Confiável na Samarco Ubú com objetivo de reduzir custos através da busca contínua pela lubrificação classe mundial. A Samarco Ubú entende que uma lubrificação de qualidade contribui diretamente para os equipamentos, aumentando a vida útil. A gerência de manutenção lançou no final de 2013 um programa de Lubrificação Confiável com objetivo de buscar continuamente as melhores práticas de lubrificação no mundo.Esse programa abrange desde o recebimento do lubrificante até a manutenção do mesmo no equipamento em condições ótimas de trabalho, capacitação da equipe e as melhores práticas de lubrificação.

Aug 16, 2017

By F. Alsobrook

Industrial minerals are receiving increased attention by metals, coal and other companies seeking to diversify and stabilize earnings. Each industrial mineral has a unique set (and sub-sets) of business dynamics, however, and the diversity can present a bewildering maze to the corporate planner. Shrugging off this complexity and relying on serendipity for entry opportunities often results in unsuitable acquisitions. An effective alternative used in exploration can also be applied to strategic planning. By providing focus and direction, this flexible methodology can prevent wasting corporate resources on random pursuits and result in a quicker, more satisfactory achievement of diversification goals.

Jan 1, 1990

By M. Bunch

"THE SUPER CYCLE IS GONE The utopia of the rising sales volume, for mining companies from 2002-2011, was entirely due to rising production volume and prices. The Australian mining sector experienced an 18 percent annual growth rate in revenues, and 11 percent growth in prices. (1) However, EBIT remained flat during the same time period. In addition, Australian mines saw a 7 percent annual decline in both labor and capital productivity. (2) Mines in the U.S. and Canada produced similar results, whereas the world-wide mining industry has seen a productivity drop of 40% since 2001. (3) The decade “Bull Run” of rising prices was trashed by companies that chased low-quality assets while increasing debt on their balance sheet. It seemed everyone believed the “super cycle” would last forever, while completely ignoring the history of cycle downturns. Worldwide mining operations are as much as 28 percent less productive today than a decade ago, according to new McKinsey research. The results from McKinsey’s new MineLens Productivity Index (MPI), which adjusts for declining ore grades and mine cost inflation, show that the pronounced decline in productivity is evident across different commodities and is seen in most mining players and geographies. (4) McKinsey sees three important areas of focus to address the root causes of productivity decline. 1) Embed effective management operating systems at mines 2) Prioritized operational excellence and capabilities development 3) Focus on innovation Reality has now settled back in and companies are struggling to make ends meet. The basic management staple of controlling costs and improving the production/productivity that was lost in the excitement is now back in play. Traditional cost-cutting approaches, such as across-the-board spending cuts, layoffs, and hiring freezes are only short-term initiatives and will not permanently improve a company’s cost structure or improve long- term competitiveness. This can only be accomplished by engaging front-line employees and empowering them to make necessary improvements in their daily work. It is time for leaders to lead and develop cultures of continuous improvement within their organizations in order to sustain their mining project to the end of mine life. Successful operating managers require two different skill sets of Leadership and Management; knowing how to lead people in their organization and how to manage the work they do."

Jan 1, 2016

By P. J. Petit

"The complex planning required to achieve any planned production yields multiple and dissociated responses over the life of project (LOP). The customary decision-making process negates the possibilities of developing optimized and integral solutions from operating levels up to business and strategic levels. This results in an inefficient project or overall underperformance of the operation.In the project setting, disconnected trade-offs and improved performance studies become inadequate, because they are site-specific and use only a few comparative parameters. They are often based on a small data-set.Decisions taken to achieve overall objectives require the correct determination and dissemination of key performance indicators (KPIs). The KPIs indicate efficiency in operation, whereby the marginal rate of technical substitution corresponds to the rate of production. It is the necessary condition for optimization. Performance realization for sustainability follows optimization modelling, the latter often being presented with financial results such as business net present value (NPV). It considers techno-financial constraints and provides a strategic and aligned outlook of KPI decisions for an enhanced and integrated outcome.This paper explains a mining case study that is rendered efficient, and through business optimization (BO) short-term and sustainable targets are reached. Business optimization increases the NPV by 14.7%. This is achieved by challenging conventional decision-making associated with maximizing business value by including environmental externalities within the LOP."

Jan 1, 2016

By G Campbell-Cowan

Much has been written about the fact that most transformation efforts disappoint. This paper addresses factors that should be taken into consideration in planning and implementing transformation programs to ensure success.In 2009, St Barbara commenced a transformation program to address issues of chronic poor quarterly operational performance; financial pressure caused by the unreliable operational performance; and an inability to develop business plans with integrity and to reliably deliver on the plans. As a result of a number of years of disappointing operational performance, St BarbaraÆs culture was not conducive to business success.This paper uses lessons learnt during St BarbaraÆs transformation program to highlight key characteristics of change programs that can generate significant sustainable benefits. While there were many benefits from the transformation program, the most significant impacts of St BarbaraÆs program have been transformation of the companyÆs culture and capability of people as business leaders; the establishment of a business systems framework to guide the design and development of systems; and developing support functions, for example centralised procurement and supply chain, business improvement and technical services.CITATION:Campbell-Cowan, G, 2012. Business transformation - Lessons learnt for successful change, in Proceedings International Mine Management 2012, pp 135-142 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 20, 2012

By W. H. Gunniss

When the copper smelters were built, in Montana, all of the refractory products which were used in their construction were shipped in from Eastern factories. It was apparent that if a material suitable for the manufacture of these products could be found within the State, a saving of freight could be effected and a new industry built up. Prospecting for such materials was started and experiments were made with samples from numerous deposits. Considerable effort and funds were expended in an attempt to manufacture silica brick from Dillon quartz, a light colored sandstone that is found near Dillon, Mont., on the Oregon Shortline railroad. As a brick material the Dillon quartz was a failure, but it has proved very satisfactory as a silica cement. It is now being used in laying silica brick and for reverberatory furnace bottoms. A bed of quartzite that is particularly suited to the manufacture of high-grade silica brick was finally discovered at Browns Spur, 6 miles west of Anaconda. The material from this deposit is now being used in the manufacture of the Anaconda silica brick, which have gained a wide reputation for heat-resisting and lasting qualities. The analysis of an average sample of this quartz is: SiO2, 96.7; Fe2O3, 0.3; Al208, 2.5; CaO, 0.3 per cent. The very low percentage of fluxing ingredients makes this a most refractory material. All of the Anaconda silica brick are hand molded. Various types of brick machines have been tried, but the hand-mold process proved the best suited to the manufacture of silica brick from this material. The silica is first put through a jaw crusher and is then dumped into wet pans, where 4 per cent. of lime paste is added, to produce a bond. Without the lime the material would not be plastic enough to mold. After a few minutes' grinding in the wet pans the material is conveyed to the molder, who forces it into the molds by hand. The brick are then dumped on pallets and placed in the drier, where they are left. until dry enough to be set in the kilns. Some of the brick are re-pressed before being dried. They are burned about five days, in round down-draft kilns. It is not necessary to have as much heat in the kilns as the brick will be subjected to when in use in the furnaces. Montana refractories are used in smelters throughout the West. Prospecting for fire clays was also carried on. After experimenting with clays from several different deposits, it was found that a mixture of

Jan 1, 1914

By Henry Sturgis Drinker, Rossiter W. Raymond

Jan 1, 1914

By Robert H. Richards

The group of four papers on ore dreseing read at the Butte meeting, all of them dealing with the recent developments at the Great Falls and Washoe plants of the Anaconda Company, form an extremely important contribution to the subject of ore dressing. It proves the efficacy of the new hindered-settling principles first brought out in a paper entitled Close Sizing Before digging' and later elaborated in a paper entitled Development of Hindered-Settling Apparatus: and it is the first large demonstration on this class of mill that has been made. It must be very gratifying to all mill men to have these papers at hand, charged with careful investigations and results pointing to the conclusions reached; the papers cannot fail to be a great help to every designer of mills and to mill men who are working on this class of concentration. The papers have dealt with their subjects so completely and have demonstrated every point from beginning to end in each case so thoroughly it leaves little for the commentator to say in the way of criticism. Therefore it seems best to him to confine himself to adding a few points of history which he believes will be interesting to the readers. Referring to the paper by Mr. Wiggin, and to the fact that the Richards hindered-settling pulsator classifier was turned down, the writer wishes to say that this classifier was the first of its kind that had ever been introduced, and since that time it has undergone great developments which he believes would overcome the difficulties encountered in the test,. In fact, there was one test made at Great Falls which with the Wilfley tables and vanners brought all the tailings down to 0.36 per cent. copper except the fine slime. Since that time, and since the classifier has been further developed, in one Colorado mill it proved a wonderful amalgam catcher, catching in all

Jan 1, 1914

By S. E. Bretherton

This title introduces the subject I wish to describe to my fellow members, very few of whom, I 'hope, have ever had as much trouble with the smelting of ore containing much zinc, either in the lead blast furnace or the matting furnace, as circumstances have forced upon me: First, for several years in Leadville, Colo., after the sulphide ores containing zinc had been developed with greater depth and were sold to the intereats with which I was connected for smelt-ing in the blast furnace for the recovery of the lead, silver, and gold; then, in New Mexico and Arizona, where the principal source of ore supply for our custom smelter was from miners who sent most of their product in the form of concentrates, which we briquetted and smelted in the blast furnace, producing a matte containing copper, silver, and gold, for which we were paid; together with some zinc and lead, which was penalized if in excess of a maximum base set by the refinery to which we sold our copper matte; last, but not least, my experience in Shasta county, Gal., where for the sake of recovering $13 per ton value in copper, silver, and gold, I have smelted ore containing as high as 40 per cent. zinc (the last 18,951 tons smelted averaged 15 3/10 per cent. zinc) which we not only lost, but which it cost us money to lose. After such an experience, and knowing that, instead of being worth only $13 per ton, such 15 per cent. zinc ore should be worth about $30, including zinc at the present market value, the question of recovering the zinc in a profitable manner from such ore became very interesting to me. During several years' time I sent samples, of from 5 to 1,200 lb. each, to be tested by the different best-known zinc-recovery plants, and experimented with several processes proposed by others for the treatment of such ore, with but little encouragement, until I

Jan 1, 1914

By B. H. Dunshee

This paper is not intended to be a technical discussion of square-set framing as used in mines, but merely a short description of the different kinds of framing that have been used in the Butte mines, and what has been decided upon, after years of practical experience, as being the best, taking into consideration the physical condition of the veins and country rock, and also the supply of timber available for mining purposes. Butte is, essentially, a square-set district. Virginia City, Nev., was the first mining camp to use this method of timbering, and to Philip Deidesheimer, who went to the Ophir mine in 1860, is given the credit of solving the problem of square-set framing, where large bodies of ore were stoped and the timbers were supposed to hold the ground from caving without any filling. That he did his work well is shown by the fact that the main features of his framing are in use to-day. In the Butte mines the conditions are such that this method of timbering is generally used. We do not, of course, depend upon the timbers any more than is necessary. The worked-out stopes are filled with waste rock as close behind the miners as possible and not interfere with mining operations. The waste rock is obtained from development work on the different levels or from the surface. In the earlier days of mining in Butte there were numerous independent companies and naturally there were different ideas as to the best way to frame the square sets, although the general features were the same. Timber was abundant for mining purposes and the common practice was to use sawed lumber, generally 10 by 10 in. or 12 by 12 in. square. Some of the mines used for girts 6 by 10 in. or 8 by 12 in. timber, depending upon whether they used 10-in. square or 12-in. square timber for posts and caps. This avoided the necessity of framiug the ends of the girts, and also required less timber for the

Jan 1, 1914