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By P. R. Tisot

Knowledge acquired from this research contributes to a better understanding of the physical structure of Green River oil shale and provides fundamental data and concepts that may serve to improve oil-shale technology. This study by the Bureau of Mines indicates that oil shale is a highly consolidated organic-inorganic system with no significant micropore structure, pore volume, or internal surface. This system is a form of physical structure that precludes rapid diffusion of either gases or liquids. The mineral matter consists essentially of nonspherical particles that tend to follow a log-normal size distribution. An excess of 99 weight-percent of these particles have equivalent spherical diameters of less than 44 microns--75 weight-percent are from 2 to 20 microns, and 15 weight-percent are less than 2 microns. The surface area (3 to 5 square meters per gram) of these mineral constituents is mainly external surface. The mineral constituents contain some micropore structure--pore radii ranging from 10 to 100 Angstrom--with the pore sizes randomly distributed. Distribution of the organic matter within the inorganic matrix is essentially interparticle and not intraparticle. The organic matter within the micropores of the mineral constituents is less than 4 percent of the total. Estimates made from surface area data suggest that perhaps only a small amount of the organic matter is bonded either physically or chemically to the mineral constituents.

Jan 1, 1963

By F. E. Block

The metallic reduction of vanadium chlorides was investigated by the Federal Bureau of Mines as a possible new route for preparing vanadium metal in an effort to develop a production process that would be adaptable to large-scale plant production and would yield metal of uniformly high quality. Vanadium tetrachloride was usually prepared by chlorinating vanadium pentoxide in the presence of carbon. Although oxygen-?free tetrachloride was difficult to prepare this way, it could be prepared by the direct chlorination of vanadium carbide. Lower valent vanadium trichloride was prepared by the thermal decomposition of vanadium tetrachloride. Vanadium dichloride was also prepared by the thermal disproportionation of vanadium trichloride.

Jan 1, 1961

By Ted C. Briggs

A special high-pressure Burnett-type compressibility apparatus was constructed and used to determine compressibility factors for pure helium, pure nitrogen, and nine helium-nitrogen mixtures containing 89.47, 79.04, 69.69, 60.09, 49.24, 41.02, 30.99, 20.53, and 10.67 mole-percent helium. A total of 161 runs were made consisting of 2,355 observed pressures. Data were obtained at 0°, 25°, and 50° C and at pressures to 1,000 atmospheres. A power series in the reciprocal volume, commonly called a Leiden series, is used to represent the compressibility factors. Three parameters in the series are required to represent helium, five parameters to represent nitrogen, and from three to five parameters to represent the mixtures. Compressibility factors are believed to be accurate to better than 0.1 percent over the entire pressure, temperature, and composition range.

Jan 1, 1972

By William J. Campbell

This Bureau of Mines report describes a study conducted to determine the relationship of mineral habit to particle size and shape characteristics for prismatic, acicular, fibrous, and asbestiform varieties of tremolite. Particle measurements were made with the petrographic microscope at X 1,250 and the scanning electron microscope at magnifications up to X 10,000. All of the varieties of tremolite, upon Wiley milling, produced a significant percentage of particles that meet the Federal regulatory criteria for counting as asbestos fibers. However, only the asbestiform variety gave milled particles that fell into a size range of >10 µm in length and <0.5 µm in width; some medical scientists consider this range significant for production of adverse health effects.

Jan 1, 1979

By Wiliam L. Crentz

The importance of Somerset County, Pa., as a coal producer is due in large measure to the presence reserves of low-volatile bituminous coals. Although many coal beds of minable thickness are present, the important reserves are to be found in those beds underlying the Pittsburgh bed. The Kittenning beds and Freeport beds, which are responsible for the bulk of the present coal production in Somerset County and contain the largest reserves to meet future coal requirements, are usually thin and entirely free from impurities. The Pittsburgh bed, which has been such an important coal deposit in the coal areas immediately west and south of Somerset County, is of secondary importance in this county. Although generally rather friable, Somerset County coals have enjoyed wide receptability as excellent coals and to some extent have been utilized in the metallurgical market.

Jan 1, 1951

By S. M. Shelton, A. L. Engel

"This report presents the results of investigations of ore-testing projects assigned to the Ore-Dressing Section, Metallurgical Division, Bureau of Mines, at the Mississippi Valley Experiment Station, Rolla Mo. During the fiscal year ended June 30, 1941.The manner of approving ore-testing projects has been explained in a previous reports. 4/ The testing procedures likewise have been described. 5/The treatment methods described are based upon laboratory experiments with small amounts of sample and naturally are subject to the inherent, normal, limiting conditions of such procedure. It is not intended to describe treatments in detail, but rather to indicate applicable methods. Local operating conditions, when the laboratory results are applied to plant operations, may require further study. Large-scale pilot-plant tests should be made before commercial operations are begun, so that translation from the experimental stage will yield satisfactory results."

Mar 1, 1942

By V. R. Miller

The Bureau of Mines conducted research on substitute brazing filler alloys with properties similar to those of silver filler alloys in an effort to conserve silver and reduce hazards from cadmium emissions. Experimental work was conducted first on the commercial silver brazing alloys BAg-I, BAg-la, BAg-2, and BAg-3 to establish criteria for evalu-ating the substitute alloys. Properties investigated included the wettability of copper, brass, and steel substrates, and the strength of joints made with the filler alloys. A series of experimental alloys containing 50 to 60 pct Cu, 20 to 28 pct Mn, and 17 to 30 pct Zn was prepared and evaluated, together with Cu-Mn-Zn alloys with 5 pct Pb or 2 pct Ni. Wetting properties and joint strengths were not as good as those for silver filler alloys, and the high application temperatures reduced the copper and brass base metal strengths. However, experimental alloys containing 70 pct Cu, 15 to 20 pct Mn, and 10 to 16 pct Sn had wetting and strength properties approaching those of the silver filler alloys. The application temperatures for these alloys were high-er than those for silver fillers, but not as high as those for the Cu-Mn-Zn alloys. With the Cu-Mn-Sn alloy fillers, copper alloy joint members are less deteriorated by recrystallization than when applying Cu-Mn-Zn alloys. The Cu-Mn-Sn system has potential for further devel-opment as a substitute brazing alloy system, particularly if the melting temperature can be reduced by the addition of other elements without decreasing the ductility and wetting.

Jan 1, 1983

By Thomas J. Albin

This U.S. Bureau of Mines report identifies potential causes of slip-and-fall accidents occurring during surface mine equipment maintenance and describes the relative roles of direct worker behavior and machine design. The relative roles of human behavior and machine design in the causation of slip-and-fall accidents were determined through analysis of accident records, observations of maintenance worker behavior, and evaluation of mine machinery. From these data, relative risk ratios were calculated. Behavior had a relative risk ratio of 1.5; machine design, specifically access systems design, had a relative risk ratio of 2.2. Of the access systems, ladders had the highest relative risk ratio, 7.0. This study suggests that accident intervention would be most profitably made in improving the design of systems used to access maintenance worker areas of mining equipment.

Jan 1, 1990

By Robert L. Anderson

A shaft or slope bottom is that portion of a mine that is contiguous to the bottom of the main hoisting shaft or slope. It includes the terminal tracks for loaded-and empty-car storage, locomotive run-arounds, locomotive shops, charging stalls, supply rooms, pump rooms, waiting rooms, and offices for dispatcher, weighmen, and foremen. This paper will deal principally with the arrangement of tracks and the handling of cars on the bottom, but includes other data that may be affected, directly or indirectly, by the bottom lay-out. All of the mines discussed are being operated in comparatively level coal seams.

Jan 1, 1937

By Michael G. Zabetakis, Aldo L. Furno, Henry E. Perlee

The Bureau of Mines conducted an experimental study with liquid and gaseous hydrogen to determine the hazards associated with the use of liquid hydrogen as an ionizing particle detector in bubble chambers . The glass window , the vacuum chamber , and the vent system were investigated . In addition , a study was made of the detection and ignition of escaping hydrogen and of the available electrical equipment for use in hydrogen atmospheres . Materials such as tempered glass , aluminum , and stainless steel are not penetrated readily by the small fragments formed when fully tempered glass is shattered and propelled by hydrogen at initial pressures up to 100 psig ; long , slender fragments from untempered glass may penetrate thin walls of relatively soft materials such as rubber gaskets and lead . Hydrogen can be vented satisfactorily from a vacuum chamber with a well - designed vent system . However , the rapid leakage of hydrogen into the surrounding air is a serious problem because the available detectors are satisfactory only when the accumulation of hydrogen is slow . Much of the electrical equipment currently available was designed for use in hydrogen- air atmospheres .

Jan 1, 1963

By J. R. Koehler

The U.S. Bureau of Mines (USBM) ground control research program includes several projects focused on developing design criteria for yielding-pillar-based longwall gate road systems. As part of this program, mining practices at the Sunnyside Mines, Sunnyside Reclamation and Salvage Co., Sunnyside, UT, are being documented to preserve the long history of yield pillar system evolution on the property. Published information describing the specific in-mine performance of the numerous gate road configurations utilized at the Sunnyside Mines is very limited. To overcome this deficit, USBM personnel interviewed 30 longtime mine employees representing nearly 700 years of mining experience at the Sunnyside operations. Mining conditions in 12 specific areas in the Nos. 1, 2, and 3 Mines were discussed in the interviews. Also, broad topics such as general mining practices, safety, and geology were often addressed during the discussions. Comprising the body of this report is an extensive record of the events and conditions experienced while mining the identified areas. In addition, eight significant conclusions were developed that accurately summarize the general opinions of the interviewed personnel regarding mining conditions and practices at Sunnyside.

Jan 1, 1994

By S. J. Page, P. Bolsaitls, W. E. Wallace, C. A. Hill, M. J. Keane

"Boiling respirable quartz dust in water for 10 to 40 minutes decreases the cytotoxicity for both erythrocyte hemolytic potential and pulmonary macrophage release of lactate dehydrogenase in vitro. The potential is reduced to near zero in the boiling concentration range of 1 to 10 mg quartz per ml water in boiling times of 20 to 40 minutes. Below this range the detoxification occurs over a longer boiling time. Above this range the hemolytic potential remaining after 40 minutes of boiling approaches native quartz potential with increasing concentration up to 30 mg quartz per ml water. Replacing the media with fresh at the midpoint of boiling results in full detoxification through 20 mg per ml. Pre—boiling the medium with quartz or silica gel reduces the effect of subsequently boiling test samples. Detoxification persists after mild drying at 110 C for 8 hours, and persists after three days of resuspension in water at room temperature. Additional data on persistence of the effect, on the use of acidic and basic media treatment, and on surface analyses are presented, with a discussion of a working hypothesis and research needs.IntroductionResearch underway to determine interactions of quarts and other mineral dust surfaces with pulmonary fluids and alveolar macrophages in culture led to the observation that when dusts were autoclaved in aqueous suspension, their cytotoxic effects on macrophages wore suppressed, in some cases fully and even after several days incubation with the cells. This finding was in direct contradiction to earlier results from both short term macrophage lysosaal enzyme release assays, as well as longer term cytotoxicity assays from macrophages in culture; in those studies, dusts were steam autoclaved at 121 121 ºC with no liquid water but with steam present. (1,2) However detoxification under boiling conditions has been reported in other research.(3). It was decided to use the hemolysis assay to further investigate these findings, because of its sensitivity, simplicity and cost."

Jan 1, 1988

By S. E. Khalafalla

In support of its goal to maintain an adequate supply of minerals to meet national economic and strategic needs, the Bureau of Mines has investigated a novel hydrometallurgical system with sulfur dioxide. Differential leaching with dissolved SO2 of manganese, nickel, and cobalt from their hydrous oxides was found to be very rapid and efficient--almost instantaneous and quantitative. In this method a given weight of mixed oxides previously ground to minus 200-mesh is slurried with a leach solution containing a specified quantity of dissolved SO2 for 10 minutes at room temperature and ambient pressure. An empirical leaching parameter, R, is defined as the ratio of the number of SO2 moles in the leaching solution to the weight of the metal oxide charge. Plots of the variation of metal extraction with the ratio R generate a series of sigmoidal-shaped curves, each of which is characteristic of a specific metal extraction. A threshold value of R is required to initiate the leaching of a given metal from the mixed oxides. Once this threshold is reached, the metal recovery can increase to more than 95 pct in very short times. For increasing values of R, the extractability of various metals by SO2 follows the order: Mn > Ni > Co >> Fe, Al, Cu. Differences in the threshold R values permit a variety of metal separations to be made simply by adjusting the quantity of SO2 in the contacting solution. Success in this leaching system depends upon comminuting the sea nodules to less than 0.149 mm (100-mesh). Above this critical size, leaching is slowed due to the inaccessibility of inner particle reacting groups to the SO2 leaching agent. This results in nonselective extraction and less extraction of preferred metal values. At or below 0.149 mm, leaching by SO, is possible with all its attributes of selectivity, sensitivity, and rapidity. Leaching with HC1 solutions of the same pH level as dissolved SO2 yielded mixed, slow, and incomplete metal extractions. This observation rules out any interpretation based on hydrogen ion as the leaching agent. The leaching curves resemble the complexometric titration curves of heavy metals with specific coordination species.

Jan 1, 1981

By William C. Cooley

A review was made of two Russian books and a chapter from a third book dealing with pipeline transport of coal. Emphasis was placed on hydrotransport of coarse coal in underground mines or surface pipelines. The books reviewed were: "Means of Increasing the Effectiveness of Hydrotransport," by V. N. Pokrovskaya (1972), "Parameters and Modes of Hydraulic Transport of Coal" by V. V. Traynis (1970), and the chapter "Calculations of Hydrotransport of Useful Minerals and Waste Rock" from the book "Hydromechanization of Opencast Workings" by G. A. Nurok (1970). All three are unique and useful additions to the world literature on hydrotransport. The Traynis book reveals the development and results of circular wheel stand tests to simulate hydrotransport in horizontal pipes, which is a potentially outstanding contribution to slurry pipeline technology. Graphical data and equations are presented which suggest that headlosses for coarse coal can be predicted with good accuracy for pipe sizes up to 14 inches in diameter. Wheel stands permit tests for pipe wear and lump degradation without recycling coal through pumps. Recommendations are made for wheel stand tests and for correlation of existing data.

Jan 1, 1976

By Clarence Karr

RESINS from a bituminous pitch, a bituminous coal, a lignite tar, a subbituminous pitch, and an electrode binder pitch wore investigated by the Bureau of Mines. The compositions of these resins were determined by four independent methods of structural detemination: (1) Molecular formula and ring analysis, including ring (2) infrared and ultraviolet spectra; (3) combined pyrolysis/gas chromatography, and (4) catalytic dehyrogenation followed by spectra and pyrolysis. The resin structure was correlated with coal structure, and it was concluded that pitch resins probably consist of essentially unaltered coal molecules carried over with the tar vapors in low-temperature carbonization.

Jan 1, 1966

By Arthur V. Petty

The Bureau of Mines has investigated the effect of refractory oxide additions, introduced in soluble form, on the refractory properties of 42-, 58-, and 70-pct-A1203 brick. Brick having porosities ranging from 12 to 16 pct were impregnated with solutions containing chrome, chrome-iron, zirconium, calcium, magnesium, cobalt, nickel, tin, and manganese ions. Additions of some of these ions provided dramatic improvements to such properties as hot modulus of rupture, hot load, and particularly slag resistance. These improvements can be related to reduction of porosity, amorphous grain boundary phases, formation of more refractory bond phases, and reduction of the wettability of Al203-containing refractories by metallurgical slags. Fifty-eight-percent-AI203 brick, impregnated with chrome, showed hot modulus of rupture, hot load, and slag resistance two to five times better than those of untreated 70-pct-AI203 brick. This could result in reducing the Nation&apos;s dependence on imported refractory-grade bauxite generally required for high-A1203 brick, as domestic alumina resouces could be used to produce the improved refractories.

Jan 1, 1984

Data recently released indicate substantial improvement in mineral industry performance for 1984. Business plans to increase plant and equipment spending in 1984 by 14.8 percent, according to a recent survey conducted by the Commerce Department&apos;s Bureau of Economic Analysis (table 1). In contrast, capital spending by all industries declined 4.8 percent in 1983 and 2.3 percent in 1982. The latest estimate of planned expenditures for 1984 is $2.2 billion higher than the comparable estimate based on the survey conducted in late January and February 1984.1/ [ ] Of particular significance to the U.S. mineral industries are the 15.5-percent increase in capital spending planned by manufacturing in 1984 and the planned 18.6-percent increase in spending by durable goods manufacturing, where the largest increases are planned in the transportation equipment (26.4 percent) and electrical machinery sectors (23.5 percent). Capital expenditures in manufacturing declined in both 1982 and 1983.

Jan 1, 1984

By Thomas V. Falkie, R. Venkataramani

Anderson, L. B., 1963, "Multiple Regression Techniques Correlate Experimental Data," Chemical Engineering, V. 70, N. 12, pp. 223-228. Aubert, E. J., Lund, I. A., and Thomasell, A. J., 1959, "Some Objective Six-Hour Predictions Prepared by Statistical Methods," Journal of Meteorology, V. 16, pp. 436-46. Barrett, A. L., 1958, "Alternating Current in Continuous Mining," Mechanization, V. 22, N. 9, pp. 83-86. Bower, A. B., Jr., 1970, "Bit Design: Key to Coal Cutting," Coal Age, V. 75, N. 7, pp. 70-72. Bower, A. B., Jr., 1971, Personal Communication dated April 29, 1971; General Electric Company, Mining and Metallurgical Products Department, Detroit, Michigan. Burt, C., 1950, "Group Factor Analysis", British Journal of Statistical Psychology, V. 3, pp. 40-75. Cady, L., Gertler, M., Gottsch, L., and Woodbury, M., 1961, "The Factor Structure of Variables Concerned with Coronary Artery Disease", Behavioral Science, V. 6, pp. 37-41. Cattell, R. B., 1965, "Factor Analysis: An Introduction to Essentials I. The Purpose and Underlying Models," Biometrics, V. 21, N. 1, pp. 190-215. Christensen, R. W., Heins, R. W., Babcock, W., and Tonn, R., 1971, "The Effect of Material Properties on Materials Handling Processes," Six Month Technical Report, (August 1971) to Advanced Research Projects Agency, U. S. Department of Defense; The University of Wisconsin. Collins, G., 1961, "Factor Analysis," Journal of Advertising Research, V. 1, N. 5, pp. 28-37. Cooley, W. W., and Lohnes, P. R., 1962, Multivariate Procedures for the Behavioral Sciences, New York: John Wiley and Sons, Inc. Cree, J. 0., 1956, "Power for Continuous Mining," Mining Congress Journal, V. 42, N. 10, pp. 49-52. Draper, N. R., and Smith, H., 1966, Applied Regression Analysis, New York, John Wiley & Sons, Inc. Griffiths, J. C., 1966, "A Genetic Model for the Interpretive Petrology of Detrital Sediments," The Journal of Geology, V. 74, N. 5, pp. 655-672.

Jan 1, 1972

By E. W. Parsons

Permanent support of the back is an important economic factor in maintaining a tunnel or other underground opening in condition to render the service for which it was driven. Timber has been most commonly used for support in tunneling and drifting because of its strength and ease of installation. Even when treated for decay, however, timber is subject to deterioration and, over a long period of time, should not be considered a permanent support. Concrete support or lining is permanent and has been used in tunnels of every size for many years but has been almost exclusively cast in place, a difficult, costly process. This report deals with the design and installation of precast concrete supports to combine the best features of both methods.

Jan 1, 1958

By Paul M. Tyler

Hafnium appears to be among the more abundant of the newly discovered elements . Though quite widely distributed in nature , its compounds chemically so resembled those of zirconium , its sister element , that it escaped detection until 1923 , when Coster and Hevesy announced the discovery of the element , to which they gave the name of " hafnium " , from Hafniae , the Latin name for Copenhagen , where their research work was performed . Hafnium has so far been found only as a minor constituent of zirconium minerals . Zirconium as an element was discovered more than 140 years ago , but only a few unimportant uses were found for the metal or its compounds until some 18 years ago ; it is still classed among the rarer commercial metals . It is not surprising , therefore , that hafnium has not yet found a definite place for itself in industry . Nevertheless it has commanded a considerable interest among scientists ; and in 1930 some 70 grams of perfectly pure oxide of hafnium were prepared in Europe . A commercial future for hafnium is already glimpsed in the radio industry , and its high melting point and electronic emissivity have already led to the taking out of patents for its use in radio tubes and incandescent electric lamp filaments and for the cathode surfaces of devices such as X- ray tubes and rectifiers .

Apr 1, 1931