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By Arthur W. T. Grimley

Hydraulic coal mining is being successfully practiced in China, U.S.S.R., Japan and Canada and in each country, excepting Japan where suitable sites are not available, the system is being expanded to either existing conventional mines or new mines. Productivity levels and economics at these mines are in all cases better than the productivities achieved in conventional mines in the same general localities. In the U.S.S.R. face productivities approaching 50 tons per man shift have been reported while in Canada the latest statistics show average face area productivity levels are in the region of 200 tons per man shift production monitor. In the United States hydraulic mining has not been actively pursued to the same degree and consequently there are no full scale hydraulic coal mines in operation or construction. Because many of the coal measures in the Western U.S.A. are generally somewhat similar to those being successfully hydraulic mined in Western Canada and parts of Siberia it is realistic to believe that successful hydraulic mines can be designed and developed in the Western U.S.A. Particularly if the vast technological base that already exists is used to improve on other people's ideas, systems, methods and equipment.

Jan 1, 1983

By J. R. Long

The investigations described herein are concerned with a portion of a systematic research, by the Federal Bureau of Mines on ductile titanium. The Bureau's work on the metal has resulted in development of a semi commercial process for the preparation of titanium and has also made available significant information on the fabrication and physical properties of this new strong, light, corrosion-resistant metal. Considerable interest has been aroused by this work, and a number of other laboratories have begun similar investigations. However, the necessity for Consolidating titanium by normal powder metallurgy methods presents difficulties in producing commercial forms and shapes on a large scale. This investigation was therefore undertaken for the purpose of improving the technique for consolidation of titanium powder into solid nonporous metal.

Jan 1, 1949

By Michael Gobla

"Since 1994 the Bureau of Reclamation (BOR) has used risk analysis to evaluate dams. Risk considers both the likelihood of failure and the expected consequences should failure occur. Risk analysis relies on the detailed formulation and critical analysis of all possible potential failure modes. Potential failure modes are formulated by describing the sequence of events that must occur to result in failure, where failure is defined as the uncontrolled release of the impounded reservoir. Failure occurs in response to loadings such as water seepage through a dam (static forces), shaking from an earthquake (dynamic forces), sudden flood inflows (hydrologic forces), or accidental overfilling (operational errors). Reclamation has, to a limited extent, applied risk analysis to inactive and abandoned mines to evaluate tailings dams, pit lakes and flooded underground mines. Case histories of potential failure mode analysis, as applied to mine impounded water, illustrate what critical technical information is needed to determine if failure is likely, what the consequences of failure are likely to be, and what are the highest risks that should be addressed first.IntroductionImpounded water and high water content wastes at mining and industrial processing sites are potential threats to public safety and the environment. Recent failures such as the TVA Kingston flyash impoundment failure in Tennessee in 2008 (4.1 million m3 or 5.4 million cu yd) release, the Mt. Poly Tailings Dam failure in British Columbia in 2014 (4.4 million m3 or 5.8 million cu yd) release, and the Samarco Fundao Tailings Dam failure in Brazil in 2015 (59 millon m3 or 78 million cu yd) release have renewed attention to this issue. Potential risks from impounded water at mining and industrial sites originate not only from tailing dams, but also from water in process ponds and conveyance pipelines, sediment retention dams, water retention dams, mine pit lakes and flooded underground mine workings.Conventional water retaining dams also have a record of failure. Notable examples of failure include Vajont Dam in Italy in 1963 (2,600 lives lost), Banqiao and Shimantan Dams in China in 1975 (171,000 lives lost), and Machhu-II Dam in India (10,000 lives lost). After the 1976 Teton Dam failure in Idaho, the U.S. Bureau of Reclamation (BOR) established a Dam Safety Program. By 1984, the agency developed and began using risk analysis methods. BOR operates and maintains an inventory of hundreds of aging dams which were designed and constructed over a period of 100 years. Many of these facilities were designed and constructed prior to the development and adaptation of modern soil mechanics in dam engineering. Diligent observational monitoring, detailed site investigations and the application of risk evaluation to the BOR dam inventory has identified many deficiencies resulting in significant demands on available funding for remediation efforts. The application of risk analysis has allowed the agency to rank sites by risk. By giving priority of remedial efforts to high-risk sites, significant improvements to dam safety have been achieved."

Dec 1, 2016

By Qingming Feng, Bo Huang, Dongbo An, Jinhong Zhang

A study of the application of mine tailings as precast construction materials through alkali activation has been carried out, focusing on efficiently activating mine tailings, reducing alkali consumption, decreasing curing time and improving compressive strength. Firstly, the effect of temperature on the alkali activation of mine tailings was studied. Secondly, the impact of additives, i.e., calcium hydroxide and aluminum oxide, on the compressive strength of samples was investigated. Thirdly, the impact of forming pressure on sample strength was studied. Test results showed that unconfined compressive strength (UCS) of 40 MPa was achieved with the geopolymerization products through optimization. Finally, to elucidate the geopolymerization mechanism of mine tailings, microscopic and spectroscopic techniques including SEM/EDX, XRD, and FTIR spectroscopy were used to investigate the microstructure and the elemental and phase composition of the geopolymerization products. The findings of the present work provide a practical method for applying mine tailings as precast construction materials through alkali activation.

Jan 1, 1967

By P. O. Osifo, K. Premlall, X. Goso, R. H. Matjie, M. R. Mulaudzi, J. R. Bunt, K. Mphahlele

This study investigates the transformation of pyrolytic spent tyre-derived char and crumb rubber into high-performance activated carbon chars for industrial wastewater remediation. Utilising an in-house macro-thermogravimetric analysis system under an argon atmosphere, spent tyre-derived activated carbon char were synthesised via physical temperature activation and aqua regia demineralisation. Comprehensive characterisation using x-ray diffraction, Raman spectroscopy, and scanning electron microscopy, revealed a predominantly amorphous structure with nanoscale crystallites (~1 nm) and active surface functional groups. Proximate analysis confirmed that both crumb rubber and leached tyre crumb rubber with aqua regia derivatives achieved favourable compositions (ash ≈ 9.6%; fixed carbon ≈ 84%), comparable to commercial activated carbon (AC). At an optimal activation temperature of 850°C, the char of tyre crumb leached with aqua regia variant exhibited a significant surface area of 300 m²/g. Crucially, the tyre crumb char produced at 850°C variant developed a pore volume of 0.8 cm³/g—effectively doubling that of commercial activated carbon (0.4 cm³/g)—facilitating the sequestration of large organic molecules. In application tests using high-strength starch wastewater, char of tyre crumb leached with aqua regia and tyre crumb char, both produced at 850°C, achieved total organic carbon removal efficiencies of 60% and 50%, respectively, bridging the performance gap between waste-derived and commercial adsorbents. These findings validate waste tyres as a viable, low-cost precursor for industrial-grade adsorbents, offering a sustainable circular economy route for tyre valorisation and reduced industrial disposal costs. Future research will focus on kinetic modelling and the recovery of zinc from spent tyre-derived activated carbon char residues.

Mar 30, 2026

Despite the media's use of the mining industry as a whipping boy over its perceived attitude towards the environment, the facts remain that the only legislated requirement in the SA Statute Books for any form of environmental impact-assessment prior to development is to be found in the Minerals Act in the form of an EMPR. Not only is our industry complying with this requirement, but moves are afoot to set up environmental management systems for existing operations in preparation for seeking accreditation under ISO 14001 when published towards the end of this year. On how broad a front are we advancing? ? Is the industry equipped to handle these challenges? ? Does it have the determination to overcome its problems? ? Do we realise that failure may mean the loss of markets overseas to competitors who can meet the international standards? ? Where are the shortcomings and when must our efforts be focussed?

Jan 1, 1996

By Edward Keller

The work covered by this report was undertaken at the request of Dr. J. A. Holmes, late Director of the Bureau of Mines, to whom the writer had been recommended by C. W. Goodale and E. P. Mathewson, of Butte and Anaconda, Mont. The director's offer was accepted for the honor it conferred and for the useful results that might be promulgated by the work in the technical field covered. The investigation was facilitated by permission to visit various works and sometimes by contributions of important definite information on a given subject. It is therefore with pleasure that acknowledgment of courtesies is made to the following corporations and gentlemen: Anaconda Copper Mining Co., Raritan Copper Works, Baltimore Copper Smelting & Rolling Co., United States Refining Co., American Smelting & Refining Co., B. B. Thayer, A. C. Clark, A. L. Walker, William H. Peirce, E. A. Cappelen Smith, H. H. Alexander, F. C. Newton, S. Rolle, R. "V. Deacon, N. W. Pierce, O. C. Martin, C. N. Sappington, James K Thomson, W. G. Derby, and the assistants of the writer, K. 1V.McComas and W. L. Raup. In this report considerable space has been devoted to general and theoretical principles on the ground that under modern conditions the best results in any field of activity can be attained only with the aid of an adequate knowledge of the best theories underlying the practice. The diffusion of such knowledge in the field of sampling metallic metallurgical materials appears to have been quite insufficient, and it is felt that when the principles involved are once thoroughly comprehended their universal application will be appreciated, so that it will make no difference whether pig iron or gold bullion is offered for test. It may further be noted that a discussion of the theories underlying practical methods is placed under the caption "Practical Sampling," with the idea that no one can be a practical sampler unless he is capable of analyzing his methods. No attempt has been made to advocate anyone method, but it is hoped that the analyses of all of the methods in use will show where each may be correctly and safely applied. The fact that it is possible to demonstrate the theoretical correctness of several methods indicates the invalidity of the claim that any single one of them is the standard.

Jan 1, 1916

By M. Misra

The coral contaminated with plutonium at Johnston Atoll UA) was subjected to gravity and flotation separation processes at the Soil Washing Laboratory (SWL) and also at the Johnston Atoll UA) site. Tests were conducted with the contaminated coral fractions referred to as the "HP-l" ( hot particles) and the "sludge". The gravity process tested was centrifugal gravity separation and the flotation processes were conventional Denver mechanical flotation and tall column flotation. Flotation tests were conducted using both fresh and sea water. Industrial fatty acid (anionic collector) was chosen as collector to make plutonium-enriched particles hydrophobic. The use of flurosilicic acid and sodium silicate made the clean coral hydrophilic. The results show that each of the processed when tested with appropriate size fraction and operating conditions resulted in passing the success criteria. It was possible to obtain more than 80% weight of the original coral as "clean sand" having activity below the JA site "soil screening level" of 13.5 pCi/gm. The field tests spiked with plutonium particles showed remarkable success. The effect of depressants, flotation medium and the coral pretreatmentis described. Finally, a flowsheet developed by the University of Nevada, Reno to treat 8000 tons of HP-l pile presently stored at JA is presented.

Jan 1, 1996

By Oliver Bowles

In its geologic sense the term marble is applied to rocks consisting of crystallized grains of calcite or dolomite or a mixture of the two. Although limestone has the same chemical composition as marble it differs in that the component particles of calcium or magnesium car- bonates are granular and noncrystalline. In marble the crystals may be intimately intergrown, whereas limestone is an aggregation of unrelated particles cemented together into a solid mass. In its commercial sense the term marble has a much wider applica- tion. As susceptibility to polish is one of its chief commercial assets, all calcareous rocks capable of polish are classed as marbles. Lime- stones that show little crystalline structure may, if they take a good polish, be classed as marbles. Furthermore, serpentine rocks, even if they contain little calcium or magnesium carbonate, are classed as marbles, as they are commercial substitutes of true marbles.

Jan 1, 1916

Another major aluminum company announced intentions to follow other domestic producers recent price actions by raising its unalloyed ingot quotes by 3¢ to 44¢ per pound, effective June 1, 1976. COBALT: All final data for 1975 are included in the table for cobalt on page 23. Demand in March increased significantly for the second month in a row, signaling a recovery from the previous year's relatively low demand levels. Imports of cobalt tripled in March over those of February. This should partially offset reduced sales of cobalt excesses from the National Stockpile. Import projections for the next several months have been lowered because transportation difficulties in Zaire are expected to result in reduced shipments.

Jan 1, 1976

By D. Pappas

Over the past decade, the number of contractors working in underground coal mines has nearly doubled; however, the effect this has had on the industry's injury rates has been the subject of much speculation. The confusion exists because the U.S. Mine Safety and Health Administration (MSHA) database does not assign contractor hours to the individual mining operations where they worked. To better understand the safety record of the contractor segment of the industry, the National Institute for Occupational Safety and Health (NIOSH) undertook a comprehensive analysis of the data contained in the MSHA database. The first part of the study compared overall contractor and operator trends from 1983 to 2009 related to employment, hours worked and injury rate. One unexpected finding was that the larger contractors tended to have higher injury rates than the smaller ones. The second part of the study directly addressed the role of contractors on the safety record of 10 large underground coal mines. A detailed analysis provided both injuries and estimated contractor hours worked at these mines for the period 1992-2007. Comparison between the estimated contractor injury rates and the reported operator injury rates at these mines indicated that the contractor injury rates were significantly higher at most of the operations studied. However, the industry-wide data indicates that contractor and operator injury rates have converged since 2005 and are now equivalent. Mining Engineering, 2011, Vol. 63, No. 11, pp. 73-79. Official publication of the Society for Mining, Metallurgy and Exploration, Inc.

Jan 1, 2011

By Henry S. Washington

I. INTRODUCTION. DURING the last twenty years or so the chemical investigation of rocks has made great advances, and it is now generally recognized that a knowledge of the chemical composition is as essential as that of the texture or mineral composition-if not more so-for the proper classification of rocks and study of their origin and relationships. Rock-analyses have vastly increased in numbers and, what is of greater importance, in quality. New and improved methods permit of greater accuracy than was possible in the early days, and the list of chemical constituents frequently determined has risen from the seven or eight of the greater part of the nineteenth century to twenty or more. Indeed, rock-analyses with determinations of so many constituents are now commonly made by the chemists of the United States and Australia, while in Germany, Great Britain, France, and Italy the rarer constituents are determined more frequently than formerly. As a consequence of this modern, accurate work, it has been discovered that some elements which were formerly supposed to be rare are of wide-spread occurrence and are often present in considerable amount. The fact is further being developed that the elements tend to show certain relations of occurrence or abundance in connection with each other. This is a fact which is applicable to the rarer elements, and which also finds a broad geological and petrological expression in the recognition of petrographic provinces. We are beginning to obtain some definite, though as yet rudimentary, knowledge of the distribution of the elements among igneous rocks. Some of the results along these lines obtained by study of the vast accumulation of analytical data now available are well known to petrologists, while others do not seem to be so gener-

Sep 1, 1908

By A. T. Coumbe

The first survey 3/ covering sales of liquefied petroleum gases was made in 1930 by the Bureau of Mines, which at the time was under the United States Department of Commerce. This original canvass covered national totals for 1922 through 1929, and most of the supply came from natural gasoline plants. The 1930 report showed approximate totals for butane and propane and for butane-propane mixtures and pentane grouped together. No attempt was made to breakdown the national sales by various uses until 1931, when the quantities for domestic or household consumption, gas manufacturing, and industrial requirements, including miscellaneous uses were indicated. As the market for these liquid petroleum gases expanded and as new uses came into importance, their respective quantities were shown separately in the annual survey. Sales for internal-combustion engine fuel and for raw material for chemical plants were first taken out of the industrial total in 1936. During World War II liquefied petroleum gases became important as feed stock diverted to synthetic rubber plants, and consequently the survey was broadened to cover this particular demand, beginning in 1944. Pentane was dropped from the survey after 1943, as, being liquid at atmospheric pressure, it is not considered as one of the liquefied petroleum gases and furthermore, the quantity reported made up less than 1 percent of the total sales. Thirteen producing companies reported to the Bureau in the first survey made in 1930, and in the 1952 canvass about 130 producers--petroleum refiners and natural gasoline companies--and about 1,300 dealers cooperated by filing schedules showing a breakdown of their sales. Their 1952 deliveries of approximately 4.5 billion gallons of liquefied petroleum gases were equivalent to about 3.4 billion gallons of gasoline or 3.1 billion gallons of distillate fuel oil.

Jan 1, 1954

By F. M. Goodwin, John Campbell, G. W. Jones

"INTRODUCTION In cooperation with the Boston Edison Co. and the Boston Consolidated Gas Co. of Boston, Mass., a survey has been conducted continuously since 1929 by the Bureau of Mines to determine the general hazards of combustible gases and vapors in manholes of the Boston Edison Co. The New England Telephone & Telegraph Co. also has cooperated in the investigation, and tests have been made in its manholes from May 1, 1933, to October 15, 1937. Yearly reports. 6/ on the results obtained since the beginning of the survey have been published.The methods and procedure of conducting the survey in 1937 were the same as heretofore."

Jan 1, 1939

By Arístides Sotomayor

El presente texto señala la importancia del oro a nivel financiero y minero ya que los inversionistas suelen utilizar este metal para obtener ganancias debido al mínimo riesgo existente en la pérdida de su valor comparado con otras divisas. Así, se estima que en el Perú, existen 480 unidades mineras de oro, de las cuales 28 concentran cerca del 90% de la producción nacional, como la Minera Yanacocha, Minera Barrick, Compañía de Minas Buenaventura, Consorcio Minero Horizonte, Aruntani y Aurífera Retamas. Entre las dos regiones que producen mayor cantidad de oro está: Cajamarca y La Libertad ( 38%) y la tercera región es Arequipa, seguida por Madre de Dios (9%).

May 1, 2016

By Donald E. Redmon

This Bureau of Mines report reviews injury experience in the metallic mineral industries for 1966-67. For each of the years, 27 tables summarize disabling work injuries by department, source of injury, extent of disability, part of body injured, and nature of injury. Correlative information on employment, worktime, and operating activity is also presented.

Jan 1, 1973

By C. E. Baltzer

This is the fourth in a series of coal technology reviews being prepared. in accordance with a recommendation voted by the Coal Division C.I.M. in session at the Jubilee Meeting, Vancouver, 1948, that the Department of Mines and Resources be requested to arrange for publication by the proper Government authority of a Quarterly Review of Coal Technology for distribution among those concerned in the production and use of coal in Canada. Copies of the first review, which appeared in the November, 1948, BULLETIN, pp. 612-614, of the second review in the June, 1949, BULLETIN, pp. 272-275, and of the third review in April, 1950, BUL-LETIN, pp. 1,9?3-196 (also, respectively, in Transactions, Vol. LI, 1948, pp. 262-264 Vol. LU, 1949, pp. 117-120, and Vol: LIU, 1950, pp. 133-136), were distributed by the Dominion Coal Board and are still available on request. In this review, the first in the series in the field of combustion, development and trends during the period approximately from World War II to the present time are described and therefore the presentation is general. Later reviews will particularize developments in relation to the range of coals available in Canada.-ED. INTRODUCTION THE utilization of coal in heat and power producing equipment has become of paramount importance to the coal industry in maintaining stable and profitable markets. In the past, the chief concern was with mining, transportation, and overall supply problems, but modern conditions demand interest in and knowledge of all phases of the product, from coal in situ to its ultimate disappearance in the form of products of combustion. Even the last mentoined factor has caused complications, as is shown by current widespread activity in the field of smoke abatement

Jan 1, 1951

By Cínthia Toshimi Ogata

Processos de fundição de ligas de alumínio com altos teores de Mg são um desafio da indústria, uma vez que diferentes taxas de resfriamento ocorrem em geometrias diversas. Este trabalho tem como objetivo caracterizar a liga de alumínio AA5052 com variações em teores de Mg por meio de experimentos de solidificação direcional transitória, e compreender seus efeitos com relação a evolução de parâmetros térmicos, microestruturais, e propriedade mecânica. As leis experimentais de evolução do espaçamento dendrítico primário (?1) com relação a taxa de resfriamento resultam em: ?_1=640 ?T ?_L?^(-1/4) para a liga 5052 com 2,4%Mg e ?_1=300 ?T ?_L?^(-1/4) para a liga com 3,2%Mg. As leis de crescimento de espaçamento dendrítico secundário (?2) com relação a velocidade de solidificação resultaram em: ?_2=27 ?V_L?^(-1,1) para a liga 5052 com 2,4%Mg e ?_2=15 ?V_L?^(-1,1) para as ligas com 2,6%Mg e 3,2%Mg. Maiores teores de Mg na liga AA5052 proporcionaram uma expressiva redução no valor de ?2 para uma determinada VL. A evolução da dureza mostrou-se diretamente relacionada ao tamanho e a distribuição dos intermetálicos presentes, sendo ?2 o fator predominante neste controle.

Oct 30, 2017

By Alla D. Mah

Compilation of data on materials of metallurgical interest is one of the important activities of the Berkeley Thermodynamics Laboratory of the Bureau of Mines. Recent renewed interest in metallurgy of vanadium renders the present compilation a timely guide for experimentation to improve present methods or to develop better methods of extractive metallurgy. Thermodynamic data for vanadium and its inorganic compounds have been critically surveyed, selected, and compiled into one convenient reference from which information can be readily obtained for evaluating heat balances, determining trends, and establishing limits of metallurgical processes. By indicating the direction of experimentation, this report enables the saving of time, effort, and expense which would otherwise be necessary for trial and error experimentation. Much of the data has been obtained experimentally at the Berkeley laboratory. Other data were collected through an extensive survey of worldwide literature through April 1965. Estimates were made when no data were avail-able. Data on the vanadium halides was sparse, and the results derived from existing data were at times divergent. Some of the selected values for the halides may need modification as more or better experimental data become available.

Jan 1, 1966