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1. Domestic Production and Use: In 1978, 12 companies operated 31 primary aluminum reduction plants, with 3 firms accounting for 65% of production capacity. Washington, Oregon, and Montana accounted for 31% of the total capacity; Gulf Coast States 23%; Northern States 26%; and other Southern States 20%. Based on published producer prices, output of primary metal in 1978 was valued at $5 billion. Aluminum consumption by 25,000 firms was centered in the East Central United States. Of aluminum consuming industries in 1978, building accounted for about 25%; packaging 22%; transportation 23%; electrical 11%; consumer durables 8%; and other uses 11%.

Jan 1, 1979

By Christopher Mark

This proceedings volume contains papers presented at W U.S. Bureau of Mines (USBM) technology transfer seminars on New Technology for Longwall Ground Control. These seminars were conducted in Washington, PA, on April 12, 1994, and Denver, CO, on May 10, 1994. The papers herein describe several new, highly practical USBM technologies now available for ground control in longwall mines, including lie Coal Mice Roof Rating (CMRR), cable bolts, the MULSIM/NL model, and the Wood Crib Performance Model. Other significant topics addressed include longwall panel layout, coal pillar design, horizontal stress in longwall mines, roof support selection for gate entries, and ground control monitoring.

Jan 1, 1994

By B. A. Filas, H. N. Lammers

Responsible environmental, social, and governance (ESG) practices are not new to mining. It is the ESG acronym that has become the “flavor-of-the-day” with the stock markets, accounting firms, and investment strategists. This increased interest from the financial sector has heightened executive awareness and accountability to where corporate leadership and directors are proactively prioritizing ESG issues from the top down within their companies. This paper aims to convey what the authors believe one needs to know to be able to conduct and prepare effective ESG audits and reports. The emphasis is on how ESG fits within the mining sector, some of the ways that many mining companies have been practicing ESG responsibility for decades, the importance of effective communications with stakeholders, and the roles that regulatory and international lending institutions play in enhancing ESG practice on a global scale as a precursor to the discussion on ESG auditing and reporting. Without this background, the ESG audit may become a purely academic exercise.

Feb 1, 2023

By Charles W. Merrill

The U .S. Treasury stocks of silver have been reduced at such a rapid rate to meet industrial and coinage requirements that they face exhaustion in 3 or 4 years. Alleviation of the silver problem will require increasing supply or reducing demand. This paper examines possible long-range resource development and research programs and improved secondary recovery. The possible reduction or elimination of silver in coinage and development and introduction of substitutes in the arts and industry are also discussed.

Jan 1, 1965

By Charles W. Merrill

The U.S. Treasury stocks of silver have been reduced at such a rapid rate to meet industrial and coinage requirements that they face exhaustion in 3 or 4 years. Alleviation of the silver problem will require increasing supply or reducing demand. This paper examines possible long-range resource development and research programs and improved secondary recovery. The possible reduction or elimination of silver in coinage and development and introduction of substitutes in the arts and industry are also discussed.

Jan 1, 1965

By George C. Stone

WHEN George C. Stone, a Director of the Institute, and so well known to our Members in connection with the Institute's many activities was abroad in 1.919, he secured an interesting collection of these coins, which appeared in Zinc, a publication by the New Jersey Zinc Co. Regarding this collection of coin, Mr. Stone says: "During the war, all gold and most of the silver disappeared, making small change very scarce. As the French Government was fully occupied by the war, it allowed various Chambers of Commerce and other bodies to issue money, both paper and coins. Many of the latter were made of zinc, and I secured several while in Paris. We had all heard of the Belgian and German zinc coins, but I imagine few knew how many different kinds there were. The accompanying plates show both sides of those I got. I took all that the dealer had; but he said that there were a number of others in existence. The coins in the bottom line were issued by the Germans in Belgium during the war and all are still in common use. The first two in the next to the bottom line are German. All of the others were issued by Chambers of Commerce or corporations. A few have been nickel plated; these look and wear much better than the others. "Coins" made of pasteboard were also issued by similar bodies, also notes.

Jan 1, 1920

By Enzo Palumbo, Joël P. T. Kapusta, François Larouche

In light of the rapid deployment of bottom blowing smelting in China over the last ten years, one has to wonder why it has taken the copper industry so long to adopt ultra-high oxygen enrichment via Savard-Lee type injectors. As early as 1976, Kellogg and Henderson suggested, in their landmark paper on energy usage in the copper industry, that ‘maximum use of oxygen enrichment of process air’ was one of seven ‘energy saving features’ for copper matte smelting and converting. Yet today, shrouded injection and high oxygen enrichment has not been implemented in copper bath smelting outside China and Vietnam. In this paper, the authors explore the reasons why bath smelting processes such as the Noranda Reactor and the Teniente Converter still operate around 40% oxygen enrichment, while the bottom blowing SKS/BBS process typically runs at 65 to 75% oxygen, with all three processes producing white metal. Are there fundamental metallurgical explanations for this striking difference beyond the long-standing skepticism towards high oxygen shrouded injection and its perceived high implementation cost?

Jan 1, 2015

By C. J. Sullivan

"The outlook for supplying the world's metal needs in the next twenty-five years is good, although in several cases basic costs are likely to increase with rising demand. Metal prices calculated at a constant dollar from 1900 to the present show that for nickel, copper, silver, lead, zinc and tin, prices -and presumably production costs -fell from 1900 to the early 1930s. Since then, they have generally risen, apparently reflecting some depletion in relation to demand. This tendency has been accentuated since the post-World War II adoption of managed, full-employment, growth economics, which have resulted in a sharp escalation in world demand for metals. (Abandonment of such policies, apparently now under consideration in North America, would, of course, affect the pre-dictions of this paper.) Nevertheless, metal prices generally are still below those prevailing in 1900. Exploration potential exists for disseminated ores of many metals still thought of as characteristic of lode and vein deposits. These include uranium, silver, gold, tin and nickel and, to a lesser extent, lead and zinc. Considering the discovery potential for some principal metals in relation to expected demand and prices, I would tend to rate them as follows: molybdenum, zinc, lead, uranium, silver, gold, tin, nickel and copper."

Jan 1, 1970

By Hal M. Lewers

IN the past few years and especially since the beginning of World War No. 2, gold has attained a new, important. and critical place in the international scene, and in world affairs. In the past, as far back as history records, most wars have been waged for the purpose of acquiring it from someone else by conquest. But now, the most titanic struggle of all time is being waged with the avowed purpose of not only destroying it, but of destroying all that it stands for and represents. A tradition dating back to ancient Rome, affirms that battles are fought by men with weapons, but wars arc eventually won by gold. The validity of that tradition is now being subjected to its major test. Hitler has proclaimed that in his new world order, the work dollar or reichsmark, a beautifully engraved paper currency representing only a theory of value, based on unit of work and production, will become the supreme medium of world exchange, and that gold eventually will he valueless and obsolete.

Jan 1, 1942

The value of processed materials of mineral origin was estimated to have exceeded $297 billion in 1991. U.S. raw non fuel minerals production in 1991 was estimated at $30.8 billion, a 5.8% decline from that in 1990. This estimate was based on data for the first quarter of 1991 (in some cases two quarters) for most of the 21 minerals that for many years have accounted for more than 95% of the industry's production value. The value of minerals production has increased in all but 4 of the last 30 years. The metals component of production value has fluctuated much more than the industrial minerals component, reflecting the greater volatility of metal prices. Employment in metal mining rose slightly in 1991, but this gain was more than offset by a decline in employment in industrial mineral mining, resulting in an overall decline of 3.0% to 164,600 workers in 1991. Prices of several major metals declined during 1991, reflecting weakness in the economy, causing some metal mines to shut down or reduce operations.

Jan 1, 1992

By M. J. H. Ruscoe

"The circulation wear rates of pure nickel, cupronickel and nickel-plated-steel coins were measured and found to be in the ratio 1:3:1 . The relative wear rates of nickel and cupronickel coins were similar to those reported in earlier studies, and the circulation wear data for nickel were used as a reference in laboratory wear tests. A correlation between circulation wear rates and laboratory wear rates formed the basis for a prediction of service life using relief legibility as an 'end of life' criterion. This criterion was determined to be an average surface thickness loss of 12 um. The surf aces of nickel and Nickel-Banded-Steel (N-B-STM) coins were observed to harden both in circulation and in the laboratory tests at a rate of approximately I VHN/year of actual or simulated service life. It was also observed that the laboratory wear rate of N-B -S coins increased as nickel cladding thickness increased and this effect was attributed to differences in surface hardness.Wear test results are also reported for the new Canadian dollar coin material which shows a better wear resistance than pure nickel. IntroductionThe subject of coinage wear has a long history, and a number of studies have been published, concerned both with the measurement of circulation wear rates and with accelerated laboratory tests to simulate the behaviour of coinage materials in service. As early as 1803, wear tests were conducted by Hatchett on gold coinage using various types of vibratory and tumbling machines». These tests were commissioned by King George III of England who was concerned about the wear of gold coins in circulation.Early in this century, Adrian performed laboratory tests that showed that the wear rates of cupronickel 75/25 and nickel coins were in the ratio 3:1 and this ratio was later confirmed in laboratory tests reported by Daeppen and Zurrerw, The latter authors also weighed cupronickel and nickel coins that had been in circulation for various times and observed the same 3: I ratio. There was further support from Tylczak and Blickensderfer who reported significantly higher abrasive wear rates for cupronickel compared to nickel, when rubbed against sand paper."

Jan 1, 1988

By Wendell L. Reich

Percussion drilling dates back to the hand operated star drill and hammer. Eventually steam and compressed air were substituted for muscle power and the mechanical percussion drill was born. From the hand held jack hammers, driving a forged steel bit into the rock, there evolved the jack leg, the rubber tired and crawler mounted drill carrier with automatic feed, increasing power and reducing man?s muscle requirements. Because the reaction of a blow on one end of a piece of steel has to be transmitted to the other end there is a limit to the depth or length of drill steel that can economically be used in out of the hole percussion devices. During the late 1800?s there is evidence that designers were attempting to put the percussion tool at the bottom of the hole, directly on the bit, in order to avoid the long drill steel which absorbed much of the blow, leaving little to be applied to the bit and the rock being drilled.

Jan 1, 1972

Federal Regulations require MESA to regulate the exposure of workers to inhalation hazards in the surface work areas of coal mining and processing operations. (1) The purposes of this study are listed below: 1. Determination of candidate inhalation contaminants for surface work areas of coal mining and processing operations. 2. Selection of appropriate sampling and analytical methods. 3. Performance of qualitative surveys of 56 representative coal mining and processing facilities. 4. Preparation of handbook to provide guidance for inspectors sampling for these contaminants. This report describes the work which was done to accumulate the information which was used in preparing the inspector's handbook. Specifically, this report contains descriptions of the surveys which were performed, analytical results obtained from these surveys, findings and conclusions, and recommendations for additional research.

Jan 1, 1975

By John W. Taber

The Bohemia mining district is a small but intensely mineralized area in western Oregon . For its size , it has made a substantial although somewhat sporadic production of gold throughout a long period of years . The veins also contain lead, zinc , and copper, but in the past these metals have not been recovered in important amounts . In reviewing the progress of mining activity in the district , an effort has been made to gather under one cover all available information on former operations , including methods of mining , production, and geology pertinent to the ore deposits , problems encountered, and other factual data that may affect future mining in the district . A special effort has been made to assemble as many maps of former workings as possible in order that these may be preserved and readily available to assist in future exploration. The data presented herein are based on brief reconnaissance examinations made during several weeks spent in the field in September 1946. These are supplemented by information obtained from various individuals actively or formerly connected with operations in the district . Only the principal properties and several of the more outstanding prospects were actually examined. Many of the older workings were inaccessible.

Aug 1, 1949

By E. D. Gardner

A general survey of the mineral industries of the Black Hills is being made by the Bureau or Mines, but this report is confined to the tin deposits of that region. Because of the strategic importance of tin in a national emergency, special attention was given in the field to deposits of this metal. The present paper outlines the procedure that would be required for determining the potentialities of the most promising deposits as emergency sources of tin and gives estimates of the cost of sampling and rehabilitating some of the old tin mines. Tin mining in the Black Hill was quiescent in 1938. Tin occurs in two areas inn the region. The deposits have received considerable attention, and since 1884 numerous articles have been written about them. It is estimated that between 7 and 15 million dollars has been spent in promotion expenses, acquiring claims, development work, and equipment; production, has totaled about 160 long tons of metallic tin worth about $95,000.3/

Jan 1, 1939

By J. A. Scott, K. Moreau, H. Shang

"Trials of automated technology at underground mine sites around the world have reported increased production and the potential for lower energy consumption. Autonomous mining eliminates a range of delays related to operator downtime and travel to the workface and facilitates continuous operation in conditions that are unsafe for workers. Automation also introduces complexities and safety hazards arising from equipment–personnel interactions; automated processes must be isolated from other stope-cycle–related activities such as production drilling, development, loading, and backfilling, poten¬tially requiring changes to the mine design to maintain an efficient and safe operation. This paper reviews and discusses the implementation of automated equipment in deep underground mining operations and the challenges and advantages associated with the technology. ¦ KEYWORDS Automated equipment, Emissions reduction, Energy, Productivity, Sustainability, Technology, Underground mines RÉSUMÉ Des essais de technologies automatisées dans des sites miniers souterrains aux quatre coins du monde ont indiqué une production accrue et la possibilité de réduire la consommation d’énergie. L’exploitation minière autonome élimine tout un éventail de retards liés aux temps d’immobilisation des opérateurs et aux déplacements vers le front de taille, et facilite l’exploitation continue dans des conditions qui s’avèrent peu sécurisées pour les travailleurs. L’automatisation introduit également des complexités et des risques pour la sécurité, qui surviennent en raison des interactions entre l’équipement et le personnel. On recommande d’isoler les procédés automatisés des autres activités liées au cycle des chantiers telles que le forage de production, le développement, le chargement et le remblai, ce qui pourrait entraîner des changements au niveau de la conception de la mine afin de préserver rendement et sécurité dans l’exploitation. Cet article examine et aborde la mise en oeuvre de l’équipement automatisé dans des exploitations minières souterraines profondes, ainsi que les enjeux et les avantages associés à cette technologie. ¦ MOTS CLÉS durabilité, énergie, équipement automatisé, mines souterraines, productivité, réduction des émissions, technologieINTRODUCTION As the mining industry continues to exhaust easily accessible orebodies, the need for efficient, deep (typically below 2,500 m) mine operations increases (Atlas Copco, 2013a); however, the mining process can become economically infeasible at great depths because operation costs drastically increase. This has resulted in investigations into automating mining operations as the industry strives for improved productivity (Schunnesson, Gustafson, & Kumar, 2009) and ways to remove personnel from hazardous work areas."

Jan 1, 2019

By A. J. Weinig

IN the accompanying figure consider the classified AB in closed circuit with a ball mill, wherein T = Tonnage of new feed C = Ratio of circulating load Now consider that the circulating load is made up of two portions of ore. One portion is due entirely to the characteristics of the ball mill and the tonnage of new feed impressed on the ball mill. This portion of the circulating load in no way is to be blamed on the characteristics of the classifier and is all composed of oversize. Consider, for illustration, that this portion of the circulating load is handled in the A division of the classifier, assuming that the classifier is divided longitudinally into two divisions by an imaginary line. Because the classifier does not usually make a perfect separation of the undersize, a certain portion of the total circulating load is to be directly blamed on the efficiency of the classifier. Let this portion of the circulating load be considered as being handled in the B division of the classifier. Now if the classifier is operating perfectly (100 per cent efficient), the width due to the B division becomes zero and correspondingly the efficiency of the classifier diminishes as B becomes wider in proportion to A. If E is the mechanical efficiency, then

Jan 1, 1934

The Black Hills Mineral Atlas briefly summarizes all important data available on the mines and mineral deposits in the Black Hills that have been explored, developed, mined, or located. The purpose of the atlas is threefold; First, from available data the general potentialities of the Black Hills region can be determined, although it is not possible to calculate actual ore reserves; second, it will provide the necessary basic information regarding a given property or commodity for further detailed study; and third, the compilation is a comprehensive directory of Black Hills deposits.

Jan 1, 1955

By Oliver Bowles

In 1940 the Bureau of Mines issued a report describing all the cement plants of Latin America, their design, capacity, and output, and the cement imports, exports, and requirements of the several countries. Since that time there has been such great activity in cement plant construction that a revision of the paper is highly desirable. The present compilation comprises the essential data in the previous report together with descriptions of all cement plants completed, under construction, or planned since that date and an overall picture of the supply and requirement situation of each country. Before World War I, Latin America was one of the world's largest export markets for cement. Its dependence on outside sources created no special problems of supply until the shortage of shipping and abnormally high prices of the First World War stimulated a movement toward greater self-sufficiency. Under this incentive many cement plants were constructed, and several countries were able by 1939 to manufacture enough cement for their modest needs. Substantial imports were still required for many important areas, and as the volume of demand was rapidly increasing the Latin American countries as a whole were far from self-sufficient in cement when tine Second. World War began. South and Central America depended to a large extent on European countries, chiefly Germany arid Belgium and to a smaller degree Scandinavia, United Kingdom, France, and Italy, to Supply their cement shortages. The cost of manufacture in these European countries was much lower than in the United States, and transportation expense had been kept at a particularly low level because of the two-way trade that had been developed. Ships destined for Latin American ports for coffee, tropical woods; fruits, and other native products could carry cargoes of cement on their westward voyages at very low cost In some instanced cement was taken in exchange for South American -products because cash was not available. Great Britain had withdrawn from this market to quite an extent because of low prices and because trade with its own Empire had been increasingly fostered. United States trade in cement with Latin America had been confined principally to white and other special varieties. In few places could ordinary portland cement made in the United States compete in price with the European products; although in general it was of better quality and cool d be delivered more promptly.

Jan 1, 1946

By Cornelius F. Kelley

DURING the war, events moved with unprecedented rapidity. Situations, industrial, economic and financial, arose over night that stressed to the uttermost the ingenuity and ability of those who dealt with them. It was essentially a time demanding action rapid and concentrated, and not one for discussion, either academic or polemic. As a result, matters of importance were necessarily transacted without the desirable opportunity being afforded of enabling a general understanding to be gained as to the relative merit or demerit involved, and in some instances, legislation essential to enable the consummation of an important matter was passed without attracting the public attention then deeply engrossed in the larger aspects of the situation. The result was that so long as the public mind was occupied, little or no concern was given to questions that ordinarily would have invited immediate attention; and in some instances, only when as an aftermath of war a particular subject has become a matter of discussion, criticism not altogether fair is made without first obtaining accurate knowledge as to the conditions that prevailed, the purpose sought to be accomplished, or the results obtained by the action taken.

Jan 1, 1921