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By R. Horn

The financial performance of the mining industry, measured by return on equity and capital employed, has been inadequate for many years. Consequently, mining companies are not valued highly by stock markets. Among the more important causes for the decline in the sector are the conservative working practices and reluctance to adapt to change or to develop new technology, although some relatively recent developments such as SX-EW copper and heap leach gold have made a significant impact on the cost base of these metals. The subsidiary business of metals exploration suffers from the same problems as the rest of the industry. The rate of discovery of ore deposits has been falling over many years and since the late 1990s, there has been a sharp reduction in global exploration activity that, if it continues, will further reduce the global supply of new ore reserves. New technological developments, particularly in geophysics and different operational practices may help reverse this trend. Statistical methods for evaluating the risk of ore reserve estimates will also improve the economic return on new mining ventures. The science of ore geology has potential to reduce exploration risk, but modern ore genetic theory has not contributed greatly to recent discoveries. The junior exploration market has almost ceased, but a new style of technically specialized efficient small exploration company has emerged which, in alliances with major companies, may be the vehicle for future global exploration. Exploration in virgin terrains has a higher risk discounted potential for the discovery of very large orebodies than that in known mining districts but mining companies have little financial incentive for this high risk exploration because of the very long lead time to production. Alliances of two or more companies reduce the risk in both the exploration for and development of major new mining projects. If new orebodies are not found, then metal prices will inevitably rise in the long term. Governments of industrial countries, particularly those with a significant mining industry such as Canada, should therefore provide assistance to exploration in order to maintain their existing industry and prevent a metals shortage from developing in the future with its consequent impact on the world economy and increased environmental damage as large lowgrade orebodies are developed to supply an expanding market.

Jan 1, 2002

By H. M. Stewart, N. F. Dawson, J. P. Beukes, P. G. van Zyl, Q. P. Campbell, A. Jordaan, R. I. Glastonbury, L. N. Sadiki

"SynopsisThe physical properties of oxidative sintered pellets produced from typical South African UG2 ore are compared with the physical properties of pellets produced with conventional South African metallurgical-grade chromite ore (from the Lower Group 6 or the Middle Group 1 and 2 seams). A statistical evaluation of the cured (sintered) compressive strengths proved that pellets prepared from UG2 ore are likely to have the same, or better, compressive strength than pellets prepared from metallurgical-grade chromite ore. The cured abrasion strength of the UG2 pellets was also superior to that of the metallurgical-grade pellets. Scanning electron microscopy (SEM) backscatter, secondary electron, and elemental X-ray mapping were used to determine the reasons for the general superior strength of the UG2 pellets. The case study UG2 ore also required 13 kWh/t less energy for milling to attain the required particle size distribution prior to pelletization, which can lead to substantial cost savings. Results presented in this paper can be utilized by ferrochromium (FeCr) producers to better quantify the advantages and disadvantages associated with the use of UG2 ore for FeCr production.IntroductionChromite, a mineral of the spinel group, is the only commercially viable source of virgin chromium units. Geologically, commercial chromite deposits in the world are found in three forms, i.e. alluvial-, podiform-, and stratiform-type deposits (Murthy et al., 2011; Cramer et al., 2004). Alluvial deposits were formed by weathering of chromite-bearing rock with the subsequent release of chromite and gravity concentration by flowing water. However, these deposits are relatively small and of comparatively minor commercial interest. Podiform-type chromite deposits usually occur as irregularly shaped pods or lenses, and their distribution within a mineralized zone is usually relatively erratic and unpredictable, making the exploration of these deposits difficult and costly (Cramer et al., 2004). Stratiform-type chromite deposits occur as parallel seams in large, layered igneous rock complexes with more regular layering and lateral continuity (Cramer et al., 2004). The largest example of a stratiformtype chromite deposit is the Bushveld Complex (BC) in South Africa, which holds an estimated three-quarters of the world’s viable chromite ore resources (Cramer et al., 2004).Several chromite seams exist in the BC. The seams of economic interest are the Lower Group 6 (LG6), the Middle Group 1 and 2 (MG1 and 2), and the Upper Group 2 (UG2) seams (Cramer et al., 2004). The LG and MG seams are specifically exploited for their chromium content, while the UG2 seam is mined primarily as a source of platinum group minerals (PGMs) (Xiao and Laplante 2004). Extraction of the PGMs from the UG2 ore usually involves the liberation of the sulphide by milling and subsequent recovery of the PGM concentrate through flotation (Xiao and Laplante, 2004). Chromite in the PGM concentrate is undesirable; therefore, PGM recovery circuits are specifically designed to ensure maximum rejection of the chromite to the tailings stream. However, the chromite in the PGM tailings can potentially serve as feedstock for ferrochrome (FeCr) production, after beneficiation to increase the chromium content."

Jan 1, 2015

By Robert L. Frantz

This report is a part of the project "Study of the Human Factors Aspects of an Automated Continuous Mining Section". The report covers three phases: Phase I Assessment of the Impact of the Automation Technology on Mining Health and Safety. Phase II Estimation of the Cost-Effectiveness and Productivity of Automation. Phase III Prediction of the Psychological and Organizational Impacts of Automated Mining, The investigation determines that the automation of a continuous mining section will improve the health and safety of the miner, increase productivity and decrease mining costs, result in a more attractive and desirable working environment, and result in a greater rate of return on capital investment.

Jan 1, 1977

By C. M. McCulloch

A geologic study of Mines 32 and 33 in Cambria County, Pa., was conducted as part of a methane control research program. Areas of high methane emission and roof instability are encountered which are related to the structural and stratigraphic features that characterize the geologic setting of these mines. Locally the folds trend N 20° E ±2°, the direction of the butt cleat in the Lower Kittanning coal. The face cleat strikes at N 69° W ±2° and the systematic rock joint in the surface bedrock strikes N 67° W ±2°. This suggests that a directional stress oriented N 70° W produced the folds and influenced the directions of coal cleat and systematic joint sets. Analysis of SLAR indicates three directions of prominent regional lineation: N 39° E, N 31° W, and N 70° W. Little gas was encountered during development mining; large volumes of gas are encountered when roof falls. Most of the gas comes from strata above the mined coal; therefore, to control methane, roof instability must be controlled. Roof falls and high rates of methane emission are most likely where less than 30 feet of many thin layers of limestone, shale, and sandstone occurs between the Lower Kittanning coal and the next coal and in zones along the margins of a sandstone channel.

Jan 1, 1973

By Merwin H. Howes

Gnome shaft, situated about 24 miles southeast of Carlsbad, N. Mex., was designed and sunk by the U.S. Atomic Energy Commission for conducting a peace- time experimental nuclear explosion in the thick salt beds of the Permian Salado formation. Excavation was started July 1, 1960, and completed July 26, 1961. The 10-foot diameter shaft, lined with concrete through the rock section, was sunk 1,216 feet. A drift was driven approximately 1,140 feet on the 1,200- foot level terminating in a shot chamber. On completion of 100 feet of shaft, by means of a truck-mounted crane, facilities were installed for conventional sinking. About 709 feet of rock and 506 feet of salt were encountered in the shaft. Salt beds at this place are reported to be over 1,200 feet thick. The overlying rock section varies greatly in composition and thickness of beds and contains a 28-foot bed of water-bearing dolomite. The aquifer was sealed to facilitate shaft sinking and to prevent water-seepage damage in the salt section of the shaft. Sealing was accomplished by grout injection through holes drilled into the aquifer and by grouting behind the concrete liner.

Jan 1, 1963

By Merwin H. Howes

Gnome shaft, situated about 24 miles southeast of Carlsbad, N. Mex., was designed and sunk by the U.S. Atomic Energy Commission for conducting a peace-time experimental nuclear explosion in the thick salt beds of the Permian Salado formation. Excavation was started July 1, 1960, and completed July 26, 1961. The 10-foot diameter shaft, lined with concrete through the rock section, was sunk 1,216 feet. A drift was driven approximately 1,140 feet on the 1,200-foot level terminating in a shot chamber. On completion of 100 feet of shaft, by means of a truck-mounted crane, facilities were installed for conventional sinking. About 709 feet of rock and 506 feet of salt were encountered in the shaft. Salt beds at this place are reported to be over 1,200 feet thick. The overlying rock section varies greatly in composition and thickness of beds and contains a 28-foot bed of water-bearing dolomite. The aquifer was sealed to facilitate shaft sinking and to prevent water-seepage damage in the salt section of the shaft. Sealing was accomplished by grout injection through holes drilled into the aquifer and by grouting behind the concrete liner.

Jan 1, 1963

By FELIPE SÁNCHEZ, PHILIPP HARTLIEB

Innovation plays a critical role in the mining industry not only as a tool to improve the efficiency of its processes and to reduce costs but also to meet the increasing social and environmental concerns among communities and authorities. Technological progress has also been crucial to allow the exploitation of new deposits in more complex scenarios, such as lower ore grades, extreme weather conditions, deeper deposits, harder rock mass and high-stress environments.  

By H. P. Greenwald

[In many coal-mining countries, during he pest decade, there have seen made extended studies and accurate measurement of movement of roof strata, tests of the physical properties of specimens cut therefrom, and tests of the strength of end load on artificial supports. Naturally, such studies have been more extensive in European countries, where mining conditions are less favorable than in the United States. As a part of its work in the conservation of coal resource and prevention of accidants in mines, the Bureau of brines began systematic measurements of the movement of roof strata to in coal mines in the fall of 1935. It was decided- that, in the beginning, work on a rapidly retreating rib line in a mechanized mine would give the greatest amount of information in a reasonable time. To this end w cooperative tine agreement was made with the Pittsburgh Coal Co., through Dr. L. E. Young, vice: president in charge of operations, for conduct of work in that company's Montour 10 mine operating in the Pittsburgh coal bed. This paper gives an account of the methods used in the investigation, excerpts from the data obtained, and such generalizations as appear to be justified.]

Jan 1, 1937

By H. P. Greenwald

[In many coal-mining countries, during he pest decade, there have been made extended studies and accurate measurement of movement of roof strata, tests of the physical properties of specimens cut therefrom, and tests of the strength of end load on artificial supports. Naturally, such studies have been more extensive in European countries, where mining conditions are less favorable than in the United States. As a part of its work in the conservation of coal resource and prevention of accidents in mints, the Bureau of Mines began systematic measurement of the movement of roof strata to in coal mines in the fall of 1935. It was decided that, in the beginning, work on a rapidly retreating rib line in a mechanized mine would give the greatest amount of information in a reasonable time. To this end a cooperative agreement was made with the Pittsburgh Coal Co., Dr. L. E. Young, vice president in charge of operations, for conduct of work in that company's Montour 10 mine operating in the Pittsburgh coal bed, This paper gives an account of the methods used in the investigation, excerpts from the date obtained, and such generalizations as appear to be justified.]

Jan 1, 1937

By J. R. Kastler

It becomes my pleasant duty to call the meeting to order. This is our fiftieth regular meeting. And the session we are opening today, I am sure: will be as interesting and informative as those in the past. These gatherings present a fruitful opportunity for an exchange of experiences and ideas that will aid all of us in our work in the various segments within the coal industry. Walter Johnson and his Program Committee have arranged a wonderful program for us; Walter, due to his standing in the industry and his large acquaintanceship with the leaders of the industry, has really gone to town in bringing outstanding speakers and personalities to deliberate with us in our proceedings. A lot of things have happened since we last met; in the operating end, and in safety we have made marvellous headway, but we have slipped badly in the marketing end. However, I am sure the messages and discussion you will hear will point out ways and means of overcoming at least some of our difficulties. Before we get on with the program, I want to thank our hard working Secretary, Fred Whiteside, who, by the way, is a charter member of the Institute and has attended every one of the fifty meetings we have held; and the various committees who have been meeting for the past several months and who have arranged this fine program you are to hear. I hope all of you enjoy the convention; the business as well as the social sessions.

Jan 1, 1954

By E. B. Kester

A study of the composition of the corresponding fractions of a primary and a high- temperature tar was undertaken to throw light on the net results of the pyrolysis of the primary products of coal decomposition in high-temperature coking practice, with reference both to total quantities of the chemically similar constituents and to their distribution throughout the boiling range. No exactly parallel investigations are on record. The distribution of substances in high-temperature tars, however, is fairly well understood. Such tars are more or less similar, for they consist of the more stable phenols, aromatic and olefinic compounds resulting from the pyrolytic decomposition of a wide variety of primary tar constituents. For example, from a typical distillation curve for high-temperature tar phenols4 it may be seen that the greatest portion of the phenols distills between 180° and 220° C., a fairly narrow range.

Jan 1, 1932

By Edward W. Parker

(Toronto Meeting, July, 1907.) NOTE.-The material from which this paper has been prepared was collected for the U. S. Geological Survey Bulletin, Contributions to Economic Geology, 1906, and appears also, though in somewhat more extended form without illustrations, in that publication. ALTHOUGH the briquetting of coals and lignites has been carried on for many years in Europe, and has reached a particularly high state of development in France, Belgium, and Germany, it has made comparatively little progress in the United States. The causes for the backwardness of the United States in this regard are several, and first among them has been the abundant supply of cheap raw fuel with which the manufactured article has to compete. With our millions of acres of coal-productive territory, from which the product can in most cases be cheaply extracted, it has appeared in many districts more economical to waste the slack or culm, which con¬stitutes a considerable percentage -of the product, than to attempt to save it at the additional expense required for briquetting. It is for this reason that the view in all sections of the anthracite-region of Pennsylvania is marred by the unsightly culm-banks which encumber the ground, and that in some of the bituminous-districts one sees huge piles of unmarketable- slack allowed to burn up in order to get rid of them. When the coal is of a coking quality, or when the slack can be used for steaming-purposes, these losses are not sustained, but many thousands of tons of what might be converted into usable fuel have been wasted every year simply because of the increased expense involved in its preparation.

Sep 1, 1907

By W. L. Dare

This information circular is one of a series published by the Federal Bureau of Mines in which the methods and costs of producing uranium ore on the Colorado Plateau are discussed. This report describes the three largest company-operated uranium mines of Climax Uranium Co. - the G-1, the Mineral Joe, and the Frank No. 1. Climax Uranium Co., a subsidiary of American Metal Climax, Inc., was [corporated] May 11, 1950, just 2 years after establishment of the domestic uranium program by the Atomic Energy Commission. Twenty-five years earlier Arthur H. Bunker, now chairman of the board, American Metal Climax, Inc., organized and operated the U. S. Vanadium Co. at Rifle, Colo.3/ Soon after Climax Uranium Co. was organized, it entered into a contract with the Federal Government to build a uranium-vanadium processing mill in Grand Junction, Colo. Under the contract Climax leased from the Federal Government certain uranium-bearing lands that had been withdrawn from public entry in 1948. From Minerals, Engineering Co. on June 12, 1950, Climax acquired other uranium-vanadium properties on Calamity, Outlaw, and Monogram Mesas in Colorado and on Polar Mesa and in the Yellow Cat area of Utah. To house the milling equipment, Climax leased the old Grand Junction sugarmill building of the Holly Sugar Co. Milling facilities, based on a then new process developed for treating both uranium and vanadium, were completed, and the plant went into production in 1951.

Jan 1, 1959

By Robert T. Davis

An award is a form of recognition given for superior performance in a special field of endeavor. Each year awards are given by the Joseph A. Holmes Safety Association and the National Safety Council to the coal-mining industry's underground and open-pit mines that have worked a specific number of man-hours without a lost-time injury. These awards have a dual significance in that they prove efficiency can be attained without injury to persons. Safety awards do not result from luck or good fortune but do result from sincere desire coupled with sufficient effort and cooperation to achieve a desired goal.

Jan 1, 1964

By Alfred Petrick

This study gives an analysis of the copper system byproducts and discusses the identification and classification of byproduct metals and their supply systems. Arsenic, platinum-group metals, silver, gold, selenium, tellurium, molybdenum, rhenium, uranium, aluminum, magnesium, and byproduct copper, lead, and zinc from complex ores are covered. The report describes several metallurgical systems, the marginal and incremental products costs of byproduct subsystems, industry structure and organization, and the historical data on price, consumption, and supply. Supply curves are presented for about one-half of the byproduct metals studied. The study develops a conceptual framework for analysis by reviewing the present concepts of byproduct supply and the related price theory. It gives the sources of supply of the individual byproduct metals to indicate the importance of the byproduct supply to the total supply. Mills, smelters, and refineries processing byproduct materials for their metal content are identified by geographic location and company ownership, The study also includes information on the reserves-resource base supporting byproduct output, reserve estimates, and the demand aspects of each byproduct metal.

Jan 1, 1973

By NEFE NONE

Possible New U.S. Half-Dollar. - Tile George Washington Commemorative Coin Act, H.R. 3133, was introduced in the House and approved by the House Banking Committee. It would allow the minting of at least 10 million commemorative silver half-dollars the size of the same coin produced before 1965. A companion bill, S. 1228, was introduced in the Senate. Taxes and the U.S. Minerals Industry. - The General Accounting Office completed a report to Congress on "Assessing the Impact of Federal and State Taxes On the Domestic Minerals Industry." the study presents a quantitative method to assess the effect of taxes on profitability, and suggests ways to use taxes or tax credits to help marginal mine operations and possibly to increase mineral production, Limited copies of the 139-page report are available free of charge from U.S. General Accounting Office, Documents Handling & Information Sevices Facility, P.O. Box 6015 Gaithersburg, Md. 20760.

Jan 1, 1981

In October, the Aluminum Company of America restarted the fourth of seven pot-lines at its Point Comfort, Tex. primary aluminum smelter. The price of primary aluminum ingot, as quoted by American Metal Market, was increased from a range of 60.5 to 63.0 cents per pound at the end of September to a range of 66.0 to 66.5 cents per pound at the end of October. BERYLLIUM On October 15, Brush Wellman, Inc., of Cleveland, one of two U.S. producers of primary beryllium products, announced a planned $6 million expansion of its extraction plant at Delta, Utah, increasing the plant?s capacity to extract beryllium from bertrandite ore by 25%. Another $5 million will be spent on two mine expansion programs in Jaub and Millard Counties, Utah. Other mineral claims and 1 eases he 1 d by The Anaconda Company will be taken over by Brush Wellman through lease or purchase. This expansion, when completed in 1981, will decrease U.S. dependence on imported beryl ore.

Jan 1, 1979

By AIME AIME

UNTIL recently, practically all geophysical prospecting in Australia was conducted by government departments, either by the Aerial, Geological and Geophysical Survey of Northern Australia or the New South Wales Department of Mines. At present, in addition, the Shell company is carrying out an extensive geophysical campaign in South West Queensland. The Northern Australia Survey has now been in operation for over six years, its work being carried out principally in the northern and central parts of Australia over an area of about a million square miles. At present this Survey is being brought to a conclusion but it appears certain that the geophysical section will be transferred to a Commonwealth Government department on a permanent basis. At present the officers of the Geophysical Section are preparing or have issued some 150 reports on their field work and also a special technical report on the geophysical practice of the Survey.

Jan 1, 1942

By C. Droun

"Low back pains account for about 13 per cent of all compensation claims made to the Quebec Workmen's Compensation Commission and cost the employers a sum exceeding ten million dollars. The frequency and cost of these health problems in Quebec metal mines are proportional to the provincial trends. An elaborate review of the literature on the causes, nature and prevention of low back pain is made in this presentation. A prevention program for low back pain has been designed in cooperation with a team of seven medical specialists and two physiotherapists for the Quebec metal mines. The program is especially designed for persons who have had low back pain, in order to prevent a recurrence, and for persons beginning to feel chronic difficulties. It is based on existing programs at the Hawthorne Plant of Western Electric Company and at Minnesota Mining and Manufacturing, but it requires a much different approach because of the nature of medical care available at the mining sites. The program is difficult because it involves a change of attitude for every employee and every supervisor. The program, so far, is beneficial because several men are now seriously engaged in an active program of reconditioning and because the problem of low back pain ie beginning to be seen from a new angle."

Jan 1, 1973

By Robert B. Francini

Longwall mining and pipelines have coexisted since longwall mining was introduced into the United States. How the pipeline operator reacts to longwall mining under their line depends on many factors. This paper outlines the process the pipeline operator goes through to determine the appropriate response when their pipeline is being undermined. Typical mitigation procedures are reviewed. Finally, the paper looks at current design practices for new pipelines that are expected to be undermined during their lifetime.

Jan 1, 2011