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By Lester J. Crow

This study advances the use of elemental sulfur in structural materials by demonstrating its value in bonding high-strength, well-graded basalt aggregates to form sulfur-basalt concretes. Sulfur is an excellent bonding agent, and the strength of a thermoplastic sulfur-aggregate mixture depends, to a large degree, on the strength and grain-size distribution of the aggregate used. A 3-cubic-foot, electrically powered mixer with heat applied to the barrel was used to mix the sulfur and aggregate. Sulfur content of several mixtures was varied to obtain the best workability with a minimum of sulfur in excess of that necessary to fill the voids. The average grain sizes and grain-size distributions were also varied to determine their effects on strength. Unconfined compression tests of forty-five 6-by l2-inch cylinders yielded average strendths of 3,348 psi to 10,398 psi. The highest strength single cylinder was 10,717 psi. The cylinders were tested from 24 hours to 6 days after pouring; after 24 hours the rise in strength was very slight. From the results obtained it appears that sulfur can be a useful construction material. An evaluation was made of a high-vacuum application for sulfur concrete. Sulfur has a high vapor pressure at elevated temperatures, 50° to 100° C; consequently, significant losses by sublimation can be expected. At lower temperatures the losses are not significant; however, this factor will limit its use at a higher temperature.

Jan 1, 1970

By Zsuzsanna Zborovszky

[Certain chapters of the tentative document entitled, "Test Requirements for instruments & Apparatus to be Considered for MESA Intrinsically Safe Certification" are evaluated and supporting data are presented on certain key issues with the purpose of helping the regulatory agency in improving the above document. The subjects discussed in detail are: hot wire ignition with W and BeCu wires; the most sensitive methane-air :and propane air ratio; the ignition limits for inductive-resistive circuits in 8.3°; methane-air mixtures in the 24-OV, 100 mH-2 [ ]H range, the resistive ignition limit as a special case when L ? 0; the capacitive-resistive ignition limit representing a four ,dimensional problem is analyzed and discussed in general and the variation of the ignition limit using Vo and/or r2 as a parameter are determined experimentally. The ignition limit is also determined for the [r1 ,~ r2] = 0 case ("capacitor alone") and for the most dangerous capacitive resistive circuit combination. The ignition limits are below the limits proposed in the document. A survey of the different factors influencing the ignition is made as to their suitability to provide a constant safety factor. It is shown that a constant safety factor cannot be achieved. The best method for applying a safety factor appears to be the increase of initial pressure or use of other gas mixture. The revision of the safety factor concept and ignition limit curves is recommended.]

Jan 1, 1980

By Michael E. Meadows

The results of tests to determine the .regional applicability of four synthetic unit hydrograph models are presented. The SCS curvilinear (Haan), SCS single triangle, Williams and TVA double triangle unit hydrograph models were tested on 271 events from 38 USDA experimental watersheds in 14 physiographic provinces. Though inconclusive due to the limited number of events analyzed, the results indicated a regional tendency for each model, with the SCS curvilinear unit hydrograph method generally performing best overall. It outperformed the SCS single triangle by predicting better shape; they differed less than 2 percent in time of peak and peak rate predictions. The Williams model performed well at Oxford, Mississippi and Coshocton, Ohio, which suggests it may be applicable to surface mined lands within the Northern and Central Appalachian Plateau and Texas coal producing regions. The TVA model is applicable to the Appalachian Plateau, specifically the Cumberland Plateau. A second test using only the SCS curvilinear unit hydrograph on 11 small watersheds and 50 events was conducted to investigate the effect of the excesss rainfall pattern on simulation results. A Green and Ampt infiltration model was coupled with the SCS unit hydrograph model to determine if peak rate and timing errors noted in the regional test could be minimized with an alternate to the SCS curve number model for determining infiltration losses. The results confirm the curve number model is the better approach to determining the excess rainfall pattern for unit hydrograph simulation.

Jan 1, 1983

By Derek Ellis

Volume II of this two-part series on Submarine Tailings Disposal (STD) as a tailings management option for coastal and island mines contains descriptions of lesser known case histories. The Misima gold mine (Papua New Guinea) and the Black Angel lead-zinc mine (Greenland) are described in some detail as the best documented cases. Atlas copper mine (The Philippines) is less fully described due to relative lack of documentation. The Misima and Atlas STD systems are working to their design criteria. At Black Angel the system adopted did not prevent contamination for a number of reasons, which are now understood. Two cases are described where STD is being developed. They are the Cayeli Bakir copper mine Turkey), and the Toquepala and Cuajone mines (Peru). There is excellent documentation available for both cases. Three case histories are described where tailings have reached the sea either through beach or river discharge. In one case the STD option has been explored (Marcopper Mine, The Philippines). In the others we explore in hindsight whether STD might have been a viable alternative using the Screening Criteria that this Volume develops - see below. The mines are Bougainville Copper Mine in Papua New Guinea, and Jordan River Mine (Canada). There is potential for STD at all three sites. Finally, the Volume presents Screening Criteria for appraising STD, based on the experience in design, operation and environmental impact reviewed in the case histories.

Jan 1, 1994

By Chas. F. Jackson

This paper is one of a series dealing with special mining problems and forming part of a general study of mining, methods and costs being conducted under direction of the Bureau of Mines. A considerable part of the material assembled and discussed in this paper has been gathered from articles on individual mines written by consulting engineers to the bureau who are engaged in active mine operation at the properties described, while other data have been taken from the technical press or gathered from personal observations. OBJECT AND SCOPE OF PAPER C. F. Jackson4 ha[-] pointed out that underground transportation (tramming, haulage, and hoisting) absorbs an appreciable percentage of the total underground cost of most mines, averaging for different methods of mining 12.9 to 28.4 per cent of the total underground cost. In general the percentage of cost accounted for by transportation was shown to be highest for the low-cost mining methods.

Jan 1, 1931

By Graham W. Marks

Recently it was shown the total energy method of spectrochemical analysis is suitable for the quantitative estimation of many of the elements of which ores are composed. It was shown how this method can be applied to the determination of germanium, tin, and lead. Continuing, this work, the present report deals with analyses for beryllium, zinc, cadmium; and indium. There are three basic problems in these investigations. The first is to study the influence of those elements that make up the greater part of an ore sample on the spectral-line intensities of the elements for which analyses are being made, the latter generally being the minor constituents. The second is to develop proper methods for the preparation of standard spectrographic curves. Finally, we are concerned with improvement in equipment and procedure, so that greater accuracy can be achieved. As discussed previously, it is better to study as groups those elements that belong to the same group in the periodic table because their spectra are similar. Beryllium, zinc, and cadmium are thus related. Indium was included in this work because it is, associated with zinc and cadmium in zinc ores.

Jan 1, 1948

By R. L. Benner

The Bureau of Mines investigated the ZnO-Fe2O3-Fe3O4 system at 1,000°, 1,300°, and 1,400° C, with oxygen pressures between 1.0 and lx10-4 atmospheres. The results, divided into the thermodynamic properties as related to the spinel structure, and the thermodynamic properties as related to zinc concentrate roasting, were used to calculate the activities of ZnO, Fe2O4, and Fe3O4 within the spinel solid solution region of the ternary system, and the pseudo-binary activities of ZnFe2O4 and Fe304. The activities of both systems show large positive deviations from Raoult's Law, especially at high Fe3O4 concentrations. The free energies, the enthalpies, and the entropies of mixing for the binary system were calculated from the binary activities, and the entropies of mixing were compared with two statistical models, one representing an ideal solution, and one representing the mixing of a normal with an inverse spinel. The binary entropy of mixing seemed to be better represented by the latter statistical model, indicating that the tetrahedral and octahedral cations of the reactants tend to remain in the product, even at the high temperatures of the study. This comparison also indicated that the cations of the components are the major contributing factors to the thermodynamic properties.

Jan 1, 1966

By David White

Jan 1, 1925

By Theodore M. Katz, W. Stephen Brightwell, David E. LeGrande, Joseph J. Hurrell, Jane A. Lipscomb, Nancy Lessin, Lawrence R. Murphy, Michael J. Colligan, Steven L. Sauter, Richard A. Lippin

Revolutionary changes in the organization of work have far outpaced our knowledge about the implications of these changes for the quality of working life and for safety and health on the job. This gap in knowledge is one of the 21 priority areas for research under the National Occupational Research Agenda (NORA)—a framework crafted by the National Institute for Occupational Safety and Health (NIOSH) and its partners to guide research into the next decade. This report was developed under NORA as the first attempt to develop a comprehensive research agenda for investigating and reducing occupational safety and health risks associated with the changing organization of work. Research and development needs identified in the agenda include (1) improved surveillance mechanisms to better track how the organization of work is changing, (2) accelerated research on safety and health implications of the changing organization of work, (3) increased research focus on organizational interventions to protect safety and health, and (4) steps to formalize and nurture organization of work as a distinctive field in occupational safety and health.

Jan 4, 2002

By William Seymour, L. D. Schmidt

"FOREWORDAmong many problems created by World War II, the question of supplies and distribution of raw materials is of outstanding importance. One of the most critical of these raw materials is fuel, and of the fuels coal is of primary importance. The normal consumption of coal has increased greatly owing to the increased tempo of industry in general. It has been necessary to divert much of the fuel oil, gasoline, etc., ordinarily used for industrial and domestic purposes, to supply the enormous demands of mechanized warfare. Coal must be provided to replace this fuel. Furthermore, the enormous increase in the production of steel has increased the demand for coking coals to a critical point.The Solid Fuels Administration for War is encouraging the use of anthracite fines in the production of byproduct coke for blast furnaces for three reasons. First, the production of anthracite for domestic use; is hampered by the inability to find a market for the fines incidental to the production of domestic sizes. Second, the shortage of low-volatile coking coal is acute, and any action that will decrease the quantity of low-volatile coal required will relieve the situation. As will be seen in this report, there is some promise that use of anthracite fines in coke-oven mixes will lower the amounts of low-volatile coal required. Third, utilization of those anthracite fines will tend also to alleviate the general fuel shortage. It has been the privilege of the Bureau of Mines to cooperate with the Solid Fuels Administration in the technical problems involved."

Apr 1, 1945

By Alex C. Smith

This report describes laboratory studies conducted by the Bureau of Mines on the spontaneous combustion of U.S. coals. Approximately 11 pet of U.S. underground coal mine fires are attributed to spontaneous combustion. The relative self-heating tendencies of 24 coal samples were evaluated in an adiabatic heating oven. Minimum self-heating temperatures (SHT's) in the oven ranged from 350 C for a lignite and high-volatile C bituminous (hvCb) coal, to 1350 C for two low-volatile bituminous (lvb) coals. An empirical expression was determined predicting a bituminous coal's minimum SHT in the adiabatic oven based on the coal's dry ash-free oxygen content. Several factors that can affect the self-heating process were also evaluated. The self-~eating tendency of a coal increased when the coal was dried and exposed to humidified air, and was dependent on the particle size and oxygen concentration of the air. A new moderate-scale apparatus is described, in which the self-heating tendencies of larger coal samples, 3 kg, can be evaluated. The minimum SHT's of two coals were determined and the results were in good agreement with those found in the adiabatic oven. Finally, results of a test in the moderate-scale apparatus indicated a strong dependence of the self-heating rate of a low rank coal on the moisture content of the air.

Jan 1, 1987

By J. G. A. Stevenson

"IntroductionDURING the past quarter of a century diamond drilling, in all its phases, has increased in Canada to a very impressive total of more than 10,000,000 feet annually. Since the art of diamond drilling became recognized, some seventy-five years ago, there has been considerable improvement in both equipment and technique. The steam-powered drill rig and the hand-set diamond bit are things of the past.The purpose of this paper is to review some drilling trends •and practices over the past few years. In the preparation of the paper, the author wishes to acknowledge kind assistance of Mr. J. D. Cumming, Dr. C. H. Hitchcock, Mr. Robert H. Quintal, and many others, including staff members of the Longyear organization.Figures provided by the Dominion Bureau of Statistics for the year 1954 show that Canadian production of metallic and non-metallic minerals and structural materials had a value of $1,454.2 million, excluding radioactive products for which figures are not available. Approximately 61 per cent of this valuation comprised production of nickel, copper, gold, coal, asbestos, zinc, lead, and iron. It is certain that diamond drilling played a major role in the discovery and development of the orebodies from which these minerals were obtained.After the surface examination of an ore deposit, diamond drilling will automatically follow, in order to determine structure, grade, and tonnage.Footage drilled by mining companies and contractors on mineral exploration and blast-hole work since 1945, as reported by the Do-minion Bureau of Statistics, is shown in Figure 1."

Jan 1, 1955

By D. R. Kelland

A program has been carried out over the last two years to apply the technology of High Gradient Magnetic Separation (HGMS) to the problem of mineral beneficiation and specifically oxidized taconite iron ores. This program, supported by the RANN division of the National Science Foundation, has consisted of a laboratory program at the Francis Bitter National Magnet Lab- oratory at MIT and a pilot investigation at the Hanna Mining Company Research Laboratory. 1 The laboratory tests were conducted using several batch type high gradient separators and a continuous separator with a rotating matrix which was constructed at the beginning of the program. The high field magnets available at F.B.N.M.L. were used for investigations above 10 kG but most of the test work was performed in the range of this field value. Ore samples were contributed by several iron ore companies and consisted of oxidized taconites having goethite and hematite as their principal components.

Jan 1, 1975

By Dennis S. Kostick

Salt is a universal mineral commodity used by virtually every person in the world. Although a very common mineral today, at one time, it was considered as precious as gold in certain cultures. This study traces the material flow of salt from its origin through the postconsumer phase of usage. The final disposition of salt in the estimated 14,000 different uses, grouped into several macrocategories, is traced from the dispersive loss of salt into the environment to the ultimate disposal of salt-base products into the waste stream after consumption. The base year for this study is 1990, in which an estimated 196 million short tons of municipal solid waste was discarded by the U.S. population. Approximately three-fourths of domestic salt consumed is released to the environment and unrecovered while about one-fourth is discharged to landfills and incinerators as products derived from salt. Cumulative historical domestic production, trade, and consumption data have been compiled to illustrate the long-term trends within the U.S. salt industry and the cumulative contribution that highway deicing salt has had on the environment.

Jan 1, 1993

By R. W. Huber

A consumable-electrode arc-melting furnace was constructed at the Bureau of Mines Physical Metallurgy Laboratory, College Park, Md., for the production of uncontaminated titanium and titanium-alloy ingots. The furnace was designed to allow for evacuating to very low pressures and back filling with helium and argon mixtures for melting at or near atmospheric pressure. Vacuum melting at a few millimeters pressure was also used with a mixture of helium and argon gas sweeping the crucible. For research purposes a 25- to 30-pound ingot, 4 inches in diameter by 15 inches in length, was selected to provide, enough 1/2-inch plate for extensive tensile and impact testing of standard size specimens. Enough plate was also provided for testing by other Government laboratories. The homogeneity of several alloy ingots was determined, and excellent results were obtained. By using a large electrode-to-ingot-area ratio and high currents or power inputs to the arc furnace rather uniform ingots were routinely prepared.

Jan 1, 1957

By W. D. Hausel

Archean supracrustal rocks of the South Pass greenstone belt of western Wyoming have been the State's most prolific source of gold and iron ore. Actual gold production statistics are incomplete, but as much as 400 to 500 thousand ounces may have been mined with some silver and tungsten as a by-product. Iron ore was also mined from the greenstone belt for 22 years, and production totaled more than 90 million tons. Immediately south of the exposed greenstone belt in the Oregon Buttes area, Tertiary boulder conglomerate, which has been eroded from the granite-greenstone terrain, may contain a gold resource of 28.5 million ounces (Love and others, 1978). The amount of gold placered from stream alluvium derived from these Tertiary conglomerates is unknown.

Jan 1, 1986

By Hevina S. Dashwood

This paper proposes to build on my previous research (Dashwood 2012), which analyzed how and why the norm of sustainable development became institutionalized in the global collaborative corporate social responsibility (CSR) initiatives of major mining companies. Since the late 1990s, the majority of major global mining companies have employed the norm of sustainable development to frame their individual CSR policies and to inform industry collaboration at the global level through the International Council on Mining and Metals (ICMM). This paper proposal seeks to address lingering questions from that research, by developing an explanation for how the normative frame of sustainable development has translated into specific CSR standards adopted by the mining industry. Preliminary findings suggest that, although the global mining industry has reached broad consensus on the meaning of sustainable development in the context of mining, there remains considerable variation between mining companies in terms of which specific global standards they adopt. As members of the ICMM, major mining companies are required to report according to the Global Reporting Initiative (GRI) indicators relevant to mining, and there has been wide-spread up-take of the ISO 14,001 environmental management system standard. However, other global standards, such as the International Finance Corporation (IFC) Performance Standards and the Extractive Industry Transparency Initiative, have not been uniformly adopted by the mining industry. What explains this variation? The paper employs a three-level institutional framework (rational choice institutionalism, historical institutionalism and the ?new? institutionalism in organization theory) to explain the influences on the adoption of CSR standards in the global mining sector. Existing research confirms that institutional context is an important factor in explaining CSR adoption in the mining sector (Dashwood 2012). Are similar forces at work in explaining the variation in adoption of specific CSR standards? A three-level institutional analysis lends itself to uncovering influences both external to mining companies (such as pressures from stakeholders), as well as internal company dynamics (such as managerial discretion). Furthermore, the framework can incorporate dynamics operating at the global level (such as isomorphism), the national level (such as the regulatory regime) and the local level (such as community needs and environmental challenges). The theoretical significance of this framework is that the influences on CSR adoption are more complex than can be explained in a single approach (such as narrow rational choice/cost benefit explanations). On a practical level, insights into how global standards get interpreted and acted upon by individual companies could lead to the development of more appropriate and effective global standards.

Aug 1, 2013

This publication summarizes, for all interested parties, the research, development, and demonstration in-house projects programed by the Bureau of Mines for fiscal year 1981 (October 1, 1980 - September 30, 1981) under its Minerals Health and Safety Technology program. The objective of these projects is to provide an ordered and sequenced series of advances toward the Bureau's overall goal of providing the system technology required to create a healthier and safer working environment for the Nation's mining and minerals processing workers.

Jan 1, 1981

By Jr. Fish

As a part of a study of iron are resources in the Appalachians, 9 diamond drill holes aggregating 1,580.7 feet were drilled in a portion of the Butt Mountain area of northeastern Giles County, Virginia. Three hematitic sand-stone beds were intersected in the Clinton formation but only one was consistent in thickness and grade in all 9 drill holes. This bed averages 18.9 percent iron over an average thickness of 24 feet. The drill cores were logged and chemical analyses were made on 161 individual samples and 22 composite samples. Beneficiation studies were made of three composite hematitic sandstone samples each representing a separate bed containing 14.6, 19.8 and 20.0 per-cent iron. Major mineral constituents of the samples were hematite, quartz, and sericite.

Jan 1, 1967

By J. Y. Foley

Platinum-group elements (PGE) are preferentially associated with chromian spinels, including high-iron chromite, magnesian-chromian hercynite, and chromian magnetite in clinopyroxene-rich upper stratigraphic portions of the Tonsina ultramafic complex in southern Alaska. Ratios of Pt:Pt+Pd are proportional to chromium content in the associated chromian spinels. The maximum PGE content of geochemical rock samples from Dust Mountain is greater than 20.000 ppb (>0.6 oz/ton) with minor gold values. The maximum PGE content of tabled chromite concentrates is 3.430 ppb (0.1 oz/ton) at Dust Mountain. 1.029 ppb (0.03 oz/ton) at Sheep Hill, and 1,749 ppb (0.051 oz/ton) at Bernard Mountain. High-iron chromite at Dust Mountain yields tabled chromite concentrates with Cr:Fe ratios between 0.5 and 1.2. Lower PGE contents are found in more chromium-rich chromitites from Sheep Hill and Bernard Mountain that yield concentrates with Cr:Fe ratios between 1.0 and 2.8. Platinum-group minerals include amalgams. arsenides. PGE alloys, and sulfides. These minerals are between 3 and 40 microns in size and are concentrated along grain boundaries and fractures of metasomatically and hydrothermally altered chromian spinel grains.

Jan 1, 1987