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By Allen G. Gray

It's not news to you that the United States is highly vulnerable to potential problems in supply of critical and strategic metals, and that these metals - chromium, for example - are employed in important bearing alloys. It's also not news to you that there is a significant challenge to improve durability and life of bearing systems which contribute to conservation as well as productivity. The objectives of this workshop are to identify available technologies and opportunities for new technologies in conservation, substitution, and displacement of critical and strategic metals in bearing systems. These considerations are among the most viable options for reducing vulnerability to a cutoff of chromium and other critical metals and action should be taken to identify and develop those technologies now rather than after a crisis is upon us.

Jan 1, 1984

By E. D. Gardner

Ore and concentrate are transported on, the surface at western mining districts by (1) railroads, (2) surface trams, (3) aerial trams, (4) trucks, and (5) wagons, and (6) on the backs of animals. The daily and ultimate tonnage to be moved is the principal factor governing the selection of the method of transportation. Railroads are preferred when large tonnages are to be hauled over relatively long distances. The mine-haulage system may be extended or surface trams built to the mill or shipping point if a practical track grade is possible and if the distance is relatively short. Aerial trams have a special field of usefulness for transportation over steep or excessively rough terrain.

Jan 1, 1936

By Jan Zwarcendyk

This study is primarily directed toward providing an understanding of the economic complexities associated with subsidence damage on the surface resulting from underground mining. Some of the pertinent theories on the physical stresses involved are reviewed, and both remedial measures and relevant laws in various countries are discussed. Part I (Chapters 1-3) is an historical overview of various aspects of subsidence problems (theoretical, remedial, and legal) during pre-World War I, between World Wars, and post-World War II, respectively. Part II (Chapters 4-9) presents a comprehensive analysis of the economic aspects of subsidence in relation to the following mining alternatives: (a) carrying out the lowest cost mining method without regard for any surface subsidence, (b) special mining techniques, (c) partial mining, (d) full recovery with stowing, and (e) sterilization or leaving the mineral unmined beneath selected areas. These alternatives are evaluated in terms of their measurable expenses.

Jan 1, 1971

By Scott Turner

The monetary metals , gold and silver , have recently been the object of such general interest that the United States Bureau of Mines has received many inquiries regarding them . Though requests for technologic information have been numerous , they have been exceeded in number by those concerned with economic aspects of these metals . The nature of the latter communications indicates that the public is not generally aware that various Bureau publications are available which deal with the economic situation of gold and silver . For this reason , it is deemed advisable to present a brief résumé of the papers which are obtainable from the Bureau or the Superintendent of Documents , together with the text of three articles recently prepared by the Director , reprints of which are not otherwise available . The Bureau of Mines compiles figures showing mine production of gold and silver , by districts and States , and cooperates with the Bureau of the Mint in determining the total annual output in the United States as a whole . 3 It recently established an annual canvass to determine the consumption of silver in the arts and industries of the United States , and published an economic paper covering such use in 1928 and 1929 , followed by an information circular on silver consumption by industry during the 2 years subsequent . A 4-year record is thus provided for those interested in utilization of silver . The Bureau has also published summarizations of all available data upon world production since 1493 of gold and of silver . It has , furthermore , rendered available a compilation of production- data of silver mines of the world , and an analysis of it , showing the proportions of silver and other metals contained in all the ores from which silver is derived . " All of these papers are concerned solely with putting into readily usable form statistical data and other factual material ; they do not offer theories or express opinions upon controversial questions related to these metals . Three other recent papers concerned with gold and silver are presented below in order to put them in shape for distribution by the United States Bureau of Mines . All three of them are by the Director of the Bureau . It should be noted that these papers do not commit

Jul 1, 1933

By LUDWIG VOGELSTEIN

WE are indebted to Mr. Barbour for his valuable contribution to the literature on copper statistics; it is to my knowledge the only intelligent attempt to throw light on a much misunderstood subject. If I should appear to criticize some of his findings and arguments, I do not want to leave the impression that I do not appreciate the article; I think Mr. Barbour has been painstaking, and even where one might not agree with his conclusions, he has opened our eyes and stimulated us in our search for the truth.' It might be well to define the term "secondary copper" and to make a few remarks about the origin and the reasons for the variation of the supply. Mr. Barbour has touched on these points, but not sufficiently to make them clear to those not in the business.

Jan 1, 1931

Wildcat strikes in the Appalachian coal fields, primarily in West Virginia, have resulted in an estimated 4.5 million ton loss in coal production during July and through the first week in August. Since then, the strike intensified further, and on August 9, nearly all of West Virginia's 60,000 miners were off the job with another 10,000 miners on strike in eastern Kentucky. The Bureau of Mines estimates that West Virginia's coal output is currently (8/9) eight million tons below last year when the state produced 108 million tons. West Virginia, the Nation's second largest coal producer of coal behind Kentucky, has not failed to mine over 100 million tons a year since 1938. At the end of the second week in August, nearly all coal miners in West Virginia remained out. The strike is a protest against a cutback in union health and retirement benefits. An announcement June 23 about the United Mine Worker's health and retirement fund precipitated the strike, Fund directors said that because of inflation and production losses caused by earlier wildcat strikes and the severe winter, miners would have to pay the first $250 of hospital costs and 40 percent of doctor bills, up to $500 a year. Previously, the funds paid all hospital and doctor bills. According to the West Virginia Coal Association each day of the strike in West Virginia results in a loss of coal production of 500,000 tons, a loss of $3.8 million in miners wages and $1 million in contributions to the UMWA's health and retirement fund.

Jan 1, 1977

By C. H. Bertoni, A. Vachon

The Corner bay copper deposit is the first significan discovery on the south limb of the Dore Lake Complex, located at the eastern end of the Detour Lake-Chibougamau greenstone belt, Quebec. The deposit was discovered in March, 1981, after 26 years of intermittent work in the area. Mineralization is found in a shear zone cut ting rocks ranging in composition, from gabbroic anorthosites to anorthositic gabbros which have been intensely altered and deformed by at least two tectonometamorphic events. Both the copper-bearing shear zone and its host rocks are cut by a large NE-striking gabbro dyke. Most of the known mineralization is found east of the dyke, but two deep exploration holes have shown that the down dip extension is present to the west of the dyke. The mineralized shear varies from one to 15 metres in width, strikes around 010° and dips from 70° to 80° to the west, and has been tested for a length of 700 metres. The wall rocks are usually chloritized and silicified. Mineralization is characterized by chalcopyrite, pyrite, molybdenite, magnetite, and sphalerite occurring mainly as the matrix to quartz-carbonate breccias in the "main" shear zone. The predominant sulphides are pyrite and chalcopyri te as crystals or fragments. The brecciated mineralized shear shows evidence that there was at least one remobilization of the shear and it is suggested that copper-bearing fluids invaded the shear during its remobilization. The exact timing and source of mineralization are not known. Up to February 1984, 38 holes had been drilled to outline indicated reserves to a depth of 450 m of 1,5 million tonnes grading approximately 4% copper, 0.34 gm, gold and 13.71 gm silver per tonne. It is believed that there is considerable reserve potential in the block west of the gab bro dyke, the down dip extension of the main zone.

Jan 1, 1984

By César Bernal M

El presente trabajo busca establecer el mejor plan de explotación de la mina Cobriza a través del nuevo proyecto de expansión. El plan de explotación señala que los ciclos de explotación, el número de tajeos requeridos por el método de corte y relleno, la selección del equipo de mina, así como los servicios auxiliares para suministrar el tonelaje necesario de mineral a la nueva planta de Coris.

Nov 8, 1982

By Iara Patricia Vieira de Oliveira

O coque desempenha três principais funções no Alto-Forno sendo elas: física, térmica e química, em se tratando do papel físico, a função estrutural é de primordial importância, pois não pode ser assumida por outro combustível, com isto as indústrias avaliam a resistência mecânica a frio para garantir uma marcha estável no reator, porém os ensaios padronizados não são suficientes para avaliar a resistência do coque. Neste contexto este trabalho desenvolveu uma metodologia para avaliar de forma individual a resistência mecânica a compressão do coque nas granulometrias típicas do coque metalúrgico e como os principais defeitos, poros e trincas governam a resistência do material. Foram realizados testes de compressão, análise de microestrutura, microtextura, inspeção visual de trincas, MEV. Os resultados das análises realizadas no coque mostraram que a tensão média de ruptura aumenta com o aumento da granulometria.

Oct 30, 2017

By H. W. Gillett

This bulletin is issued by the Bureau of Mines as a contribution to the increase of safety and efficiency in the preparation and utilization of the mineral resources in the United States. Notable among the drains on these resources are the demands made by the nonferrousmetal industries, and in these the losses occasioned in melting brass and bronze are worthy of particular attention. This statement will be better appreciated by a consideration of the size of the brass industry. MAGNITUDE OF THE BRASS INDUSTRY. According to the Thirteenth Census, in 1909 there were in the United States 1,021 fu-ms that dealt mainly in brass and bronze. This total included jobbing foundries, manufacturing plants that both cast and machine a brass or bronze product, and rolling mills, but did not include iron foundries having nonferrous departments nor the numerous large brass-foundry departments of manufacturing plants that produce the castings used in the manufacture of electrical apparatus, cash registers, pumps, and the thousands of machines that require brass castings for their construction. Penton's Foundry List for 1910 gives about 1,150 exclusively nonferrous foundries and about 2,300 iron or steel foundries that also melt brass. If the rolling mills and. jobbing foundries in manufacturing plants be included, and if due credit be given to the rapid growth of the industry in the last few years, largely through the stimulation of the automobile busi¬ness, it is probable that not less than 3,600 plants are to-day melting brass or bronze.

Jan 1, 1916

By Irving D. Cohen

In order to overcome our reliance upon foreign energy sources for both crude supply and finished products, we must realize the goals proposed by Project Independence. In general this involves expanding production of existing and new oil, gas, and coal resources, utilizing and improving nuclear technology and the developing of new energy sources such as solar, geothermal, oil shale, tidal, wind and stimulation techniques. There is a continuing debate, both in the scientific community and the consuming public as to the potentiality of nuclear power generation being cost effective and environmentally and safety conscious. The development of new sources of energy does not occur overnight; it is rather a continuing effort in time and money to achieve the goal of providing energy to an ever increasing demand. The public has been accustomed to the availability of energy whenever and wherever it was needed. The era of "energy gluttony" has begun to fade into the realm of "energy awareness". Unfortunately, it required the action of another country to bring the picture that has been discussed many times in the past by energy suppliers into correct focus. Nevertheless, the public responded by conservation efforts to reduce energy wastefulness. Still, the demand for foreign importation of energy supplies is on the rise. What is our recourse? The largest known unexploited energy resource available in the United States is our coal resources. Moreover, the Department of the Interior has noted that 63 counties in Montana, Wyoming, and the Dakotas hold 60% of the nation's least expensive strip minable coal. This western coal is the most abundant and least costly Fossil Fuel in the United States. It is acknowledged that western coal is an important input in meeting the energy needs of our nation.

Jan 1, 1976

By William P. Stroud

Chemical alteration of the compressive strength of sandstone has been investigated by the U.S. Bureau of Mines (USBM). Successful development of this technology would offer an attractive alternative to the methods now used for stress control in mines. Sandstone cores were stressed to failure under uniaxial compression at two different strain rates. Specimens saturated with either distilled or tap water showed an average 14% reduction in stress at failure compared with those dried in vacuum. Samples saturated with dilute solutions of aluminum chloride, hydrochloric acid, and polyethylene oxide showed no statistically significant difference in failure stress compared with those saturated with water. By contrast, compressive strength of the cores was increased some 7% by saturation with the nonpolar solvent carbon tetrachloride. No correlation was found between zeta potential and compressive strength.

Jan 1, 2010

By Douglas A. Anderson

Much progress has been made in understanding the forward process for blast vibration simulation: that is, how to create a resultant seismogram from an empirically determined seed waveform. What has not been successfully investigated to date is the reverse process: Determining the contribution of each borehole to the resultant seismogram. It might seem that these should be two sides of the same coin, but the reverse process is much more complicated. That is because the source, geological path, and receiver contributions must be unraveled and then dissected. If that can be done, a relationship can be developed between the seismic source properties and the explosive interaction with the surrounding rock. This paper presents a first step in the unraveling process, through analysis of blast seismograms using wavelet transforms.

Jan 1, 2013

By Markus Reuter, Antoinette van Schaik

In this paper the link between process metallurgy, classical minerals processing, product centric recycling and urban/landfill mining is discussed. The depth that has to be achieved in urban mining and recycling must glean from the wealth of theoretical knowledge and insight that have been developed in the past in minerals and metallurgical processing. This background learns that recycling demands a product centric approach, which considers simultaneously the multi-material interactions in man-made complex ‘minerals’. Fast innovation in recycling and urban mining can be achieved by further evolving from this well developed basis, evolving the techniques and tools that have been developed over the years. This basis has already been used for many years to design, operate and control industrial plants for metal production. This has been the basis for Design for Recycling rules for End-of-Life products. Using, among others, the UNEP Metal Recycling report as a basis (authors are respectively Lead and Main authors of report), it is demonstrated that a common theoretical basis as developed in metallurgy and minerals processing can help much to level the playing field between primary processing, secondary processing, recycling, and urban/landfill mining and product design hence enhancing resource efficiency. Thus various scales of detail link product design with metallurgical process design and its fundamentals.

Jan 1, 2014

New Copper Deposit in Chile. - The recent copper discovery in Chile, made jointly by U.S.-owned Empresa Minera Utah de Chile, Inc., and Getty Mining Chile), Inc., awaits the passage of Chilean legislation which is expected to govern the terms of new foreign investment in the country's mining sector. Named La Escondida, the discovery is reported to have the potential for producing 100,000 tons of refined copper per year. This compares with Chile's total refined primary copper production in 1980 of 811,000 metric tons, and to U.S. refined primary production in 1980 of 1,122,000 metric tons derived from domestic material, and 89,000 metric tons from foreign material. U.S. Firms Buy Chilean Properties. - A bid of $18.1 million, made jointly by Chevron and St. Joe Minerals Corp., won over competing bids for the purchase of the Libra and Mena gold-silver-copper deposits in northern Chile. Chevron is the lead partner and owns 70% of the venture. The two properties purchased have not been developed to any significant extent. They are located near St. Joe's El Indio gold-silver-copper mine. The venture is also looking at the possible purchase of two other mines in the area.

Jan 1, 1981

By G. O. Allard, A. Gobeil

The Chibougamau area is the eastern segment of the MatagamiChibougamau greenstone belt. The Archean rocks of the area consist of two mafic-to-felsic volcanic cycles ( Roy Group) overlain by a sedimentary-volcanic sequence (Opemisca Group). The Roy Group volcanics are intruded by many coeval and comagmatic differentiated gab bro sills. The Supracrustal rocks of the Roy Group and Opemisca Group have been folded about north-south axes, refolded isoclinally about east-trending axes and metamorphosed to the greenschist facies. The same lithologies have been identified east of the Grenville Front at amphibolite grade. The first volcanic cycle consists of 3000 metres of porphyritic pillowed basalts and comagmatic gabbro sills (0batogamau Formation) overlain by a thin sequence of felsic pyroclastics, porphyritic dacites, and iron formation (Waconichi Formation). The Dore Lake Complex is a sill-like layered complex intruded in the upper part of the Waconichi Formation. The second cycle consists of 3600 metres of pillowed basalts and gabbro sills (Gilman Formation) overlain by a volcanosedimentary assemblage less than 1000 metres thick (Blondeau Formation). The Cummings Complex consists of the Roberge sill (dunite and peridotite) at the base, the Ventures sill (gabbro) and the Bourbeau sill (leucogabbro and quartz ferrodiorite) at the top. It is emplaced within the Blondeau Formation. The Opemisca Group sediments and minor porphyritic K-rich andesites (Stella, Hauy, and Chebistuan Formations) form narrow belts preserved in the synclines of the area. The Proterozoic rocks of the Chibougamau area consist of conglomerates, arkoses, and argillites with dropstones of the Chibougamau Formation. North of Chibougamau, the Mistassini Basin forms an elongate northeast-trending basin filled with sediments of the Mistassini Group. Conglomerates, sandstones, argillites, dolomites, stromatolitic dolomites, and iron formation are the principal sediments within the basin.

Jan 1, 1984

By Jos. R. Guiteras

This paper describes the operations of the St. Joe Mining & Milling Co. in Boulder County, Colo., as of June 1936. Later a brief visit was made to the mine in September 1936; information obtained at that time has also been recorded. The company operates a gold mine, the Grand Republic, in the Sugar Loaf mining district; a 100-ton flotation mill in Lefthand Canyon near Gold Hill; and a custom sampling punt, the Boulder Ore Sampling Works, at Boulder, Colo.

Jan 1, 1937

By Bill Mariucci, Gary Almeraris

All Rights Reserved. Printed in the United States of America. Information contained in this work has been obtained by SME, Inc. from sources believed to be reliable. However, neither SME nor its authors guarantee the accuracy or completeness of any information published herein, and neither SME nor its authors shall be responsible for any errors, omissions, or damages arising out of use of this information. This work is published with the understanding that SME and its authors are supplying information but are not attempting to render engineering or other professional services. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Any statement or views presented here are those of individual authors and are not necessarily those of the SME. The mention of trade names for commercial products does not imply the approval or endorsement of SME.

Dec 1, 2009

By Zay Jeffries

AN acute current shortage of copper, with the prospect that conditions may become worse, indicated by Office of Production Management information. Present estimates of copper requirement for defense indicate that nearly all the available metal will be required in the future for this purpose. Severe dislocations are, expected, but the objective is to distribute the copper available for civilian use in such a manner as to minimize these dislocations. The advisory committee on metals and minerals has been asked for a suggestions which may be helpful in meeting this situation.\

Jan 1, 1941

The Aluminum Company of America (Alcoa) announced that the second unit at its experimental facility at Palestine, Tex. would begin production -in 1979, increasing the capacity of the facility to 30,000 tons per year. The plant uses an experimental process based on the electrolysis of aluminum chloride and reportedly uses 4 to 5 kilowatt hours per pound of aluminum produced, compared to an industry average of about 7 to 8 kilowatt hours per pound. Alcoa has reportedly signed a letter of intent with the Chinese government under which Alcoa will conduct feasibility studies on two new integrated aluminum projects and modernization of an existing aluminum plant. If the study results are favorable, Alcoa Engineers Inc. and the Import and Export Company of the Chinese Ministry of Metallurgical Industry could negotiate agreements to provide Alcoa technology and services for the projects.

Jan 1, 1979