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By Mohan K. Wali

This report, the first in a series of 13 reports, provides a summary of 11 major topics on which individual reports have been prepared. These major topics are: (a) Nature of coal mine spoils, topsoils, and unmined soils; (b) influence of macro- and microclimate on (c) plant production on spoils and topsoils; (d) prediction of aboveground biomass from plant cover; (c) mineral composition of plants; (f) controlled environment studies on plant growth response; (g) microbial communities (h) water chemistry and organism diversity of catchbasins; (i) vegetation and soil development on abandoned, and (j) topsoiled sites; and (k) viability and diversity of seed bank. Based on these investigations, general conclusions and some recommendations are presented.

Jan 1, 1982

By Joseph Grumer

An instrumented spherical vessel has been used for many years to study laminar combustion waves. Concurrent measurements of flame speed and pressure-rise rates have led to evaluations of burning velocities, the pressure dependence of the burning velocity, and the expansion ratios of the gases passing through the combustion wave. For the most part, these studies have involved flames initially at atmospheric or subatmospheric pressure. The old spherical vessel used by the Bureau of Mines was not designed for use at elevated pressures. Moreover, being made of wrought iron, it was susceptible enough to corrosion to prohibit its use with many combustible mixtures that figure in industrial research. In mid-1956, under sponsorship of the Office of Naval Research, the Bureau undertook the development of a stainless steel spherical vessel capable of withstanding explosions of gaseous mixtures at initial pressures as high as 20 atm. and initial temperatures as high as 250° C. The design called for a double array (cross) of closely spaced small windows for observation of the flame as it traversed the vessel and a piezoelectric transducer to measure concurrently pressure-rise rates. Because no commercial contractor was willing to bid on the construction of such a vessel, it was built at the Bureau's Bruceton machine shop.7

Jan 1, 1961

By Fred P. Giese

Southeastern reserves of titanium ores are large, widespread, and ample for anticipated demand. The leading titanium industries are mining and beneficiating sand deposits, principally in Florida, and manufacturing titanium pigments. Most of the mineral output is consumed by the producers themselves. In 1962, 20 percent of the national pigment capacity was in the Southeast.

Jan 1, 1964

By R. Pallini

The Franklin Research Center (FRO, a Division of The Franklin Institute was contracted by the U.S. Department of Energy to investigate the application of elastomeric materials for the purpose of smoothing loads on dragline thrust rollers. This report covers the design, fabrication, and demonstration of a portable- device for measuring roller circle track deviations and roller loadings. The results of this work are documented in this report. During December 1981, a field test group visited the Falkirk Mine, Underwood, North Dakota for the purpose of demonstrating the use of the designed and built device. The data collected indicates the practicality and usefulness of such a device for determining actual dragline roller circle roller loads, while the dragline is in service. The device was useful in determining roller load peaking that may be a contributing Factor in the premature failure of these thrust rollers. The device could be used for field evaluation of elastomeric cushioning materials used to eliminate these load peaks.

Jan 1, 1982

This Bureau of Mines report contains the proceedings of a symposium cosponsored by the Bureau of Mines and the University of North Dakota concerning utilization and technology of Western coals and lignites. The symposium, the sixth in a series, comprised 12 papers.

Jan 1, 1972

By D. A. Keefe, O&apos

The electrowinning of beryllium from beryllium oxide (BeO) using a molten-salt electrolyte composed of 56 LiF-37 BeF2-7 BeO (mole-percent) was investigated. Anodes made of porous carbon were found to be superior in current-carrying capacity and gave a lower cell voltage than other types of anode material tested. When porous carbon anodes were used) the resultant increase in anode area prevented anode passivation. The cell voltage was 3.3 volts) and electrode current efficiencies of 50 to 70 percent were obtained. The electrodeposited beryllium was recovered as beryllium powder or was coalesced to metal beads by heating to 1,300° C.

Jan 1, 1970

By R. Q. Shotts

Factors of geological structure and occurrence of coalbeds, plus the resulting mining conditions, have required more care in preparing coals in Alabama than in most other districts almost since mining Alabama coals began. For this reason, literature on these coals may be interesting to those in areas where prime coals have been mined out, and thinner and less regular beds must now be exploited. This literature review has been arranged in order of subject matter. Some references have been listed more than once, but each separate review is limited to the material pertaining to the subject matter being discussed. For those seeking specific information, the authors have indicated which items repeat material and which items are most complete or specific. Geology, preparation, and carbonization of coal have been reviewed the most frequently.

Jan 1, 1963

By J. D. Ramsdell

To obtain information on the effects of cobalt on microstructure and tensile properties of titanium-vanadium-cobalt alloys, the composition ranges of 4 to 16 percent vanadium with 1 to 4 percent cobalt have been studied. The beta phase was not completely retained with vanadium additions up to 16 weight-percent or in the same alloys containing up to 4 percent cobalt.

Jan 1, 1960

The strippable reserves of bituminous coal and lignite in the United States were calculated in accordance with the prevailing conditions of seam thickness and depth of overburden in each of the several coal-producing areas of the Nation. Within defined limits of seam thickness and depth of overburden, it is estimated that there was a remaining strippable resource of 118 billion tons of raw bituminous coal and lignite as of January 1, 1968. Because of topography, natural and manmade features, and other limitations, only 45 billion tons of the resource are strippable reserves. Of this, 32 billion tons is considered low-sulfur (less than 1 percent), 4 billion tons is medium-sulfur (1 to 2 percent), and 9 billion tons is high-sulfur (over 2 percent) coal. Owing to a cleaning loss affecting that portion of strip coal that is mechanically cleaned, the 45 billion tons of strippable reserves are reduced to 39.6 billion tons of marketable coal. A brief discussion is given for each coal-producing State, summarizing past and present production, historical background, and outlook. Appendix A contains reserve data by State, county, seam, and sulfur content. Appendix B contains the general information and requirements necessary to comply with the current strip mining laws covering 20 States.

Jan 1, 1971

By V. R. Miller

The Bureau of Mines developed and evaluated a detecting and sorting device to separate the copper-bearing portion from the barren portion of Michigan native copper ore in the minus 4- plus 1-inch size range. Small-scale sorting tests were also conducted on minus 1- plus 1/2-inch material from the Centennial No. 6 mine, using a previously developed system that was modified to increase sensitivity. Results showed that, with the added sensitivity, 85 to 90 pct of the copper in the minus 1- plus 1/2-inch material could be recovered in about 50 to 60 pct of the fraction. Sorting tests on minus 4- plus 2-inch and minus 2- plus 1-inch fractions from the Centennial mine were conducted with the large sorting system. Results showed that 86 to 93 pct of the copper was recovered in 43 to 64 wt-pct of the sorted fractions. Combining of concentrates from the two fractions resulted in a recovery of 90 pct of the Popper in 55 pct of the weight. The composite concentrate contained 2.40 pct copper, and the tailing analyzed 0.33 pct Cu; the head sample assayed 1.46 pct Cu.

Jan 1, 1978

By John C. Machisak

DATA ON INJURY experience at quarries and related plants of the United States are presented in this publication under the following general sections: A) General injury experience: Tables 1-4: Contain current data on number of injuries, injury-frequency rates, work location, accident agency, degree of injury, and related employment data. (B) Injury experience at different kinds of quarries: Tables 5-6: Current data on number of injuries, injury-frequency rates, work location, accident agency, degree of injury, and related employment data. (C) Injury experience by States: Tables 7-19: Current data on the number of injuries, injury-frequency rates, accident agency, degree of injury, and related employment data. (D) Selected injury data: Tables 20-30: Current data on various selected factors of operating conditions at different kinds of quarries, including employment size-groups, length of shifts, comparative severity of injuries, and injury data and related employment experience at dimension-stone and crushed and broken stone quarries, and underground quarries. (E) Mining methods and historical injury experience: Tables 31-32; Employment data and injury experience in the quarrying industries of the United States, by mining method and work location, 1953-58; and historical injury experience and employment data in the quarrying industry, 1911-58.

Jan 1, 1962

By V. R. Spironello

The Bureau of Mines is involved in research directed toward the utilization of municipal solid waste. One of the primary objectives is the recycling of the magnetic fraction of municipal solid waste (raw refuse). This is consistent with one of the Bureau's goals, which is to minimize the requirements for mineral commodities by maximizing metals recovery from secondary domestic resources, In this investigation, cupola trials were made using combinations of refuse scrap with shredded automobile scrap under basic and acid slag practices. Furnace operating information and the behavior of alloying and tramp elements was obtained. The research showed that it is possible to utilize up to 60 percent refuse scrap in the cupola under basic practice and 30 percent under acid practice, Aluminum in refuse scrap, present in bimetallic cans, increased the recoveries of silicon and manganese charged to the cupola. Increased use of refuse scrap provided iron of lower sulfur. The alumina resulting from oxidation increased the slag volume. The aluminum and tin contents of the iron increased with increasing levels of refuse scrap in the charge. Lead was not a problem with respect to contamination of the iron. In basic practice, operation of the cupola was satisfactory since all slags were adequately fluid. In acid practice, operation became troublesome above the 45-percent level. Under both practices, the cupola iron melting rate decreased. Particulates in scrubber water and stack condensate samples contained lead, zinc, and tin, and the dust load increased. The tensile and transverse strengths of the iron produced under both practices are reported.

Jan 1, 1980

Geophysical Abstracts 1 - 86 were issued in mimeographed form by the Bureau of Mines; Abstracts 87 - 111 were published in bulletins of the Geological Survey; Abstracts 112 - 116 were issued in mimeographed form by the Bureau of Mines as Information Circulars 7256, 7257, 7267, 7273 and 7285. 1. GRAVITATIONAL METHODS 7380. Dryden, H. L. A reexamination of the Potsdam Absolute Determination of Gravity. Jour. Research Nat. Bureau of Standards, vol. 29, No. 5, 1942, pp. 303-314.

Jan 1, 1944

This section presents highlights of world economic and mineral industry performance in 1982, a year characterized by continued recession, and selected 1983 forecasts of economic indicators of importance to the mineral industry, some of which indicate a modest improvement in the economies of the United States and Western Europe. The U.S. Economy in 1982 In 1982 U.S. gross national product (GNP) in current dollars increased at a rate of 4 percent, but GNP adjusted for inflation (real GNP) declined at a rate of 1.8 percent. Yearend 1982 real GNP was at roughly the same level as in 1980 (table 1). Thus no growth in real terms had taken place in the United States during the 1980-82 period.

Jan 1, 1983

By K. Thirumalai

This study forms a part of Bureau of Mines continuing research on thermal fragmentation of rocks. The potential of internal heating techniques for rock fragmentation is discussed. A concept of rock fragmentation with rapid inter¬nal heating of a localized inner volume of rock is advanced The energy required for rock fragmentation is made available by creating a required vol¬ume of localized heating. The fragmentation of rock using the proposed method is analyzed and qualitatively compared with the results of experiments with Charcoal granite, Dresser basalt, and Sioux Quartzite. High frequency dielec¬tric heating below 100 MHz is used in the study as an example to examine the working of the concept. The selection of operating conditions for the experi¬mental heating is explained. Fragmentation of Charcoal granite and Dresser basalt test rock blocks is achieved for localized heating below 550° C. The heated volume required for fragmentation is observed to be less than 2 percent of the test block volume and the electrical energy consumption is in the order of 3.5 to 6 5 kwhr/m3 The method offers a possibility for in situ fragmenta¬tion of rocks, favorable for internal heating. The method is highly dependent on rock properties governing internal heat generation The efficiency of dielectric heating in the experimental study is observed to increase with increasing dielectric loss of the rock material, ranging from about 10 percent in Sioux. Quartzite to about 50 percent in Dresses basalt

Jan 1, 1970

By John C. Gagliardi, Walter K. Utt

The U.S. Bureau of Mines, in cooperation with Carter Mining Co., conducted vibration tests of four off-road vehicle seats. The purpose of the tests was to determine which seat provided the best vibration attenuation under laboratory conditions. Laboratory tests were constructed to simulate the mining vibration environment within the limitations of the test equipment. The acceleration test levels and corresponding response of the seats were low compared to IS0 2631's fatigue-decreased-proficiency time limits. Two of the seats employed mechanical suspensions and two seats employed air suspensions. The seats were tested using a 22,241-N (5,000-lbf) electrodynamic shaker. Mechanical suspension seats were tested with various preload-to-mass ratios (PMR's) and cushion densities. Air suspension seats were tested with various air pressure levels and seat cushion densities. Air suspension seats provided good vibration attenuation if pressurized greater than 552 kPa (80 psi). Mechanical suspension seats' attenuation performance decreased if the PMR exceeded 9.8. Seat cushions of lower density provided less vibration damping.

Jan 1, 1993

By Galen G. Waddell

The Deep Creek zinc and lead mine afforded an excellent example of a relatively small underground mine operation that approached the low mining costs of large, highly mechanized mines, An open stope mining method incorporating sublevel benches and vertical long holes was used (fig. 1). Detailed descriptions are given on the exploration program, stope development, stoping procedures, and pillar removal. Pressure grouting was used to check the inflow of water and thus prolong the life of the mine. Statistics on mining costs and on electric power consumption, haulage from mine to mill, and milling costs are included.

Jan 1, 1963

By Z. J. Fink

Ultraviolet-visible and infrared emission spectra from propagating methane-coal-dust-inhibitor mixtures have been obtained in a 0.2-by 0.2¬by 5.3-m vertical duct over a range of flame speeds from 2 to 100 m/sec. Results serve as a basis for the design and evaluation of thermal radiation detectors for triggered barriers that suppress ongoing mine explosions. Of particular significance is the large continua superimposed on the methane-air spectra when small amounts of coal dust are present and the variation of emissivity with infrared (IR) wavelength in dust flames. In conjunction with the spectral measurements, studies of flame speed, particle size, gas sampling plus thermodynamics, and dust sampling are presented and discussed in order to gain insight into the more fundamental aspects of propagating explosions. Sampling results have shown that only a near-stoichiometric amount of dust is consumed in the flames studied even though initial concentrations are five times stoichiometric. Difficulty in propagating coal-dust inhibitor flames of realistic mine characteristics in a cold-walled laboratory duct has been encountered. A simplified analysis of the flame zone utilizing spectral and sampling results indicates that the stability of slowly propagating flames is more dependent upon thermal radiation than upon convection losses to the walls. It is predicted that thermal radiation losses will make any measurements of coal dust burning velocities, "quenching diameters," or flammability limits more apparatus dependent than those corresponding to gaseous fuels.

Jan 1, 1974

By G. Richards Gwinn

The mineral graphite, a form of carbon, has been known for hundreds of years, and, was first used commercially as a coloring agent. Its true identity, however, was not recognized until the end of the eighteenth century, and its commercial development did not become extensive until near the close of the ninteenth century.

Jan 1, 1943

By Seth C. Schaefer

The Bureau of Mines investigated the thermodynamic properties of Bi203 (bismuth sesquioxide) and Sn02 (stannic oxide). Standard Gibbs energies of formation (AGfO) of these compounds were determined with high-temperature electromotive force (emf) cells using stabilized Zr02 (zirconia) as the electrolyte. Potential measurements were obtained from the cell

Jan 1, 1984