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Contract No. H0110929 was awarded by the U.S. Bureau of Mines in February, 1971, to DeTer Company, Incorporated, of Mountain Lakes, N. J. The contract provided for the modification of the contractor's Model 5000 Pressure Foam Generator to fit it for the suppression of coal dust in mines, a detailed testing program in a working coal mine, and for additional modifications and testing for the suppression of fires in coal mines. The contractual program was completed in April, 1972. The results of the dust suppression tests showed conclusively that the modified DeTer equipment effectively reduced the level of respirable dust in a working coal mine well below the present and future acceptable levels set by the Mine Health and Safety Act of 1969. The fire tests, carried out in a simulated mine entryway erected on the surface, demonstrated the ability of the DeTer equipment in suppressing fires of varying degrees of severity within an acceptably short time.

Jan 1, 1972

By Wilbert J. Huff

The organization of the'Explosives Division is indicated by the accompanying chart (fig. 1). As this has been discussed in a previous report3/, it will not be considered further in this report. The activities of the various units are outlined below. I. INFLAMMABILITY OF GASES AND VAPORS4/ Determination of the Explosion Hazards of Combustible Gases and Vapors Found in Mines and Industries The Explosives Division maintains, at the Pittsburgh Experiment Station, a laboratory specially equipped for the determination of the explosion hazards of combustible gases and vapors. Of particular importance, is the determination of the chemical composition within which explosions may occur and beyond which there is no danger of explosion, combustion or inflammation. These limits, known as the limits of inflammability, as determined by this and other laboratories, have been compiled in Bulletin 279 of this Bureau. The last revised edition (1931) of this bulletin has been exhausted. Since it was published, the Pittsburgh laboratory has determined the limits of about 40 combustibles and has ascertained more precisely and accurately many previously published limits.

Jan 1, 1938

By W. A. Stickney, J. W. Town

Batch and continuous - circuit flotation , leaching , precipitation , and electrodeposition studies were made by the Bureau of Mines to determine optimum conditions for treatment of complex mercury - antimony sulfide and mercury- arsenic sulfide ores and concentrates . On the Red Devil ore sample over 95 percent of both the mercury and antimony sulfides were recovered in a flotation concentrate containing 35.6 percent mercury and 21.0 percent antimony . By selective flotation a mercury concentrate containing 71.0 percent mercury and 2.9 percent antimony was obtained with a mercury recovery of 90.4 percent . Leaching results show that , with 150 grams per liter of sodium sulfide and 50 grams per liter of sodium hydroxide , 95 to 99 percent of the mercury , antimony , and arsenic sulfides could be extracted from the concentrates treated . Sodium hydroxide reagent consumption was based on the sulfides generated in the dissolution of the sulfide minerals and on the method of metal recovery used . Selective leaching of the antimony and arsenic sulfides with potassium sulfide dissolved more than 95 percent of either of these two sulfides and 0.5 to 5 percent of the mercury sulfide present . Methods for recovering mercury and antimony from solution were electrodeposition of mercury followed by electrodeposition of antimony , aluminum precipitation of both mercury and antimony , or antimony precipitation of mercury followed by antimony electrodeposition . The method used in recovering the mercury depended on the mercury- antimony content of the solution being treated .Batch and continuous - circuit flotation , leaching , precipitation , and electrodeposition studies were made by the Bureau of Mines to determine optimum conditions for treatment of complex mercury - antimony sulfide and mercury- arsenic sulfide ores and concentrates . On the Red Devil ore sample over 95 percent of both the mercury and antimony sulfides were recovered in a flotation concentrate containing 35.6 percent mercury and 21.0 percent antimony . By selective flotation a mercury concentrate containing 71.0 percent mercury and 2.9 percent antimony was obtained with a mercury recovery of 90.4 percent . Leaching results show that , with 150 grams per liter of sodium sulfide and 50 grams per liter of sodium hydroxide , 95 to 99 percent of the mercury , antimony , and arsenic sulfides could be extracted from the concentrates treated . Sodium hydroxide reagent consumption was based on the sulfides generated in the dissolution of the sulfide minerals and on the method of metal recovery used . Selective leaching of the antimony and arsenic sulfides with potassium sulfide dissolved more than 95 percent of either of these two sulfides and 0.5 to 5 percent of the mercury sulfide present . Methods for recovering mercury and antimony from solution were electrodeposition of mercury followed by electrodeposition of antimony , aluminum precipitation of both mercury and antimony , or antimony precipitation of mercury followed by antimony electrodeposition . The method used in recovering the mercury depended on the mercury- antimony content of the solution being treated .

Jan 1, 1964

By R. H. Reist, R. D. Dey, V. Castranova, J. P. Durham, Y. Rojanasakul

"Silicosis is a fibrotic pulmonary disease produced by inhalation of silica-containing dusts (Peters, 1986). Chronic silicosis may develop 20-40 years after initial exposure to crystalline silica, and the disease may progress from a simple to a complicated form. Few symptoms are evident in simple silicosis with pulmonary function being relatively normal. However, chest radiographs reveal small rounded ·opacities in the upper lobes of the lungs. These silicotic nodules consist of collagen arranged in a distinctive circular pattern. As fibrotic changes become more severe, the disease progresses to complicated silicosis (progressive massive fibrosis). Complicated silicosis is associated with shortness of breath and decreases in pulmonary function characteristic ofrestrictive lung disease. Chest x rays reveal numerous large silicotic nodules which may be associated with scar emphysema. Several mechanisms have been proposed to explain the cellular events which result in silica-induced lung damage and fibrosis (Lapp and Castranova, 1993). They include: ( l) direct cytotoxicity of silica, (2) activation of oxidant and enzyme release from alveolar macrophages, (3) recruitment and activation of polymorphonuclear leukocytes, and (4) stimulation of fibroblast proliferation and collagen synthesis.Tetrandrine is a bisbenzylisoquinoline alkaloid derived from the Chinese herb Radix Stephania tetrandra. It has a molecular weight of 622.73 and an empirical formula of C38H420 6N2. The chemical structure of tetrandrine has been published previously by our laboratory (Castranova et al., 1991 a). Its structure is characterized by methoxy groups at C7 and C12 , uncharged nitrogens at N2 and N’2 and two 17-carbon ring members connected by a double oxygen bridge between Ca-C7 and C11-C12. Tetrandrine has been shown to reduce both silica-induced fibrosis and the elevation of lung collagen content in rats (Huang et al .. 1981; Yu et al., 1983; ldel, 1987). Furthermore, tetrandrine has been used as an antifibrotic agent in Chinese clinical trials (Li et al.. 1981 ). Preliminary results suggest that administration of tetrandrine to patients with silicosis results in substantial improvement of symptoms, increases in diffusion capacity, and decreases in the size of shadows on lung x rays."

Nov 1, 1995

By I. L. Feld

This report describes an attrition-grinding process and equipment for grinding coarse kaolins to the 2-micron particle-size range. The research was undertaken by the Bureau of Mines to devise an acceptable method for converting coarse kaolins, such as paper-filler-grade clays, to paper-coating-grade clays, thereby increasing the value and extending the life of the southeastern paper-clay deposits. The attrition-grinding process is basically the intense agitation of a slurry composed of the material to be ground, a granular grinding medium, and a suspending fluid. This process gave better particle-size reduction than that obtained by several other grinding methods. Results of batch tests in 5-and 10-inch-diameter attrition grinders demonstrated that a coarse kaolin containing about 13 percent minus 2-micron, equivalent spherical diameter (e.s.d.) particles was readily ground to give a product with 88 percent minus 2-micron e.s.d. material. Power consumption was reasonable in view of the increased value of the ground material. Comparison of particle-size reduction with power-consumption data for the two units indicated that better performance was obtained with the larger machine.

Jan 1, 1960

By G. S. Scott

The Bureau of Mines is engaged in research to assess the hazards associated with the handling, storage, and use of combustible gases, vapors, and. liquids encountered in mines and in industry. As a part of this general pro-gram, numerous limits of flammability and ignition temperatures are being investigated for a wide variety of combustible materials, and methods are being developed to minimize the explosion hazards of these combustibles. The Bureau receives numerous requests for information on the explosion hazards of specified combustible mixtures under various conditions of use. This information circular has been prepared to assist those who may have similar requests. Destined primarily for the layman with a limited technical knowledge of the subject, it considers rather briefly the numerous factors that enter into the general problem of gaseous explosions and their prevention.

Jan 1, 1951

By S. J. Gasior

A method for destroying the caking properties of bituminous coal was developed by the Bureau of Mines. Coal is treated in a fixed bed by heating through its plastic range under controlled temperatures in mildly oxidative atmospheres composed of inert gas and/or steam containing about 1 volume-percent oxygen. High-volatile A (hvab) and high-volatile B (hvbb) and low-volatile bituminous (lvb) coals in the size range 1/8 to 1-1/2 inches were successfully treated at 0 (atmospheric pressure) to 300 psig in static beds 6 to 18 inches deep. Conditions of treatment depended on the coal and ranged from 80 to 200 minutes at 350° to 510° C. Char produced in this manner from hvab coal was gasified with steam at 800° C and 100 psig in a fixed bed in one series of tests and in other tests was exposed to hydrogen in a dilute co current free-falling-bed system at 750° C and 3,000 psig without agglomerating.

Jan 1, 1965

By K. D. Luxbacher

Understanding methane emissions in underground coal mines is critical for a safe and productive mine. In addition to reasonable estimation of initial coalbed reservoir parameters, it is also crucial that changes in effective stress due to mining and pore pressure reduction are taken into account due to their effects on porosity and permeability. Primary parameters for estimation of emissions or modeling of the mining environment for this purpose are porosity and permeability which can change dramatically as a result of stress redistribution associated with mining and gas desorption from a large coal volume. These parameters affect the emission rates and ventilation requirements, as well as water inflow into the working environment. Stopping leakage, on the other hand, is a secondary stress dependent factor in estimation of emissions, as convergence of the roof and floor strata, compromising the integrity of the stopping, may result in leakage, making prediction of ventilation requirements difficult. This paper aims to examine the effects of porosity and permeability changes of the coal seam on methane emissions in an underground continuous miner section. The models were developed and executed in a dynamic fashion to simulate an advancing section. Through this process, the changes of effective stress in coal, particularly their change paths, on porosity and permeability were incorporated into the models and methane emissions, concentrations, air requirements, water inflow and possible leakage from the stoppings were investigated using a conventional coalbed methane reservoir model.

Jan 1, 2009

By F. R. Cattoir, T. A. Sullivan

Commercial uranium metal was electrore fined to a high- purity product using molten- salt electrolytes in an inert atmosphere cell . Electrorefined uranium that contained , after consolidation , less than 30 ppm of metallic impurities was prepared . A method of leaching the electrolyte crystals to remove the salts was developed . Cathode current efficiencies from 90 to 100 percent were obtained . Two molten- salt electrolytes were prepared and evaluated : (1 ) lithium chloride - potassium chloride - uranium trichloride and ( 2 ) sodium chloridepotassium chloride - uranium trichloride . Very little difference was found in the purity of the uranium metal produced in either system . The lithium chloride - potassium chloride - uranium tri - chloride electrolyte was preferable from an operational standpoint .

Jan 1, 1964

By C. J. Chindgren, L. C. Bauerle, J. B. Rosenbaum

Modifications of the conventional method of preparing ductile vanadium metal by calcium reduction of V2 05 in a bomb were explored for clues to a more economical procedure . The modifications examined included ( 1 ) omitting the gas purge of the bomb ordinarily used for eliminating atmospheric nitrogen , (2 ) using low- grade vanadium feed materials , ( 3 ) using alternative reductants , such as aluminum , magnesium , and silicon , and reductant mixtures , and ( 4 ) bomb refining of aluminothermic metal produced in open- vessel reductions . The most promising modification appeared to be bomb refining , using calcium to purify vanadium metal -- of low aluminum but high oxygen content-- prepared by open- vessel aluminothermic reduction of vanadium pentoxide .

Jul 1, 1960

By A. Baldwin

This report describes the engineering feasibility and economic advantages of a unique new mining machine using cutting bits that take a constant-depth linear cut in the coal face. The studies show that this innovative new cutting concept, being developed by the Bureau of Mines, can be designed into the basic continuous mining machine. The resulting miner would be attractive to mine owners because coal could be mined with minimum generation of airborne respirable dust, substantial increases in productivity, and elimination of methane ignition due to cutting.

Jan 1, 1977

By Bill Linville

Producing oil, gas, and coal in sufficient amounts to satisfy U.S. demands for fuels, electrical power, and chemicals promises to be one of the country's major challenges during the 1970's. Adding significantly to this challenge is the urgent task of satisfying soaring fuel and power demands without destroying the natural environment or jeopardizing long-range requirements for resources. The Bureau of Mines, U.S. Department of the Interior, is engaged in a comprehensive program of research to help industry meet this challenge. This report reviews the aims of the research program and accomplishments in 1970; the first 11 sections cover coal programs, nine sect ions are then devoted to petroleum, and the concluding five sections deal with oil shale research. Figure 1 shows the nationwide distribution of Bureau of Mines energy research installations; Full addresses are given in appendix A. Many of the publications resulting from the Bureau?s energy research efforts are discussed throughout the report; others are listed in appendix B.

Jan 1, 1971

By David A. Monaghan

On January 14, 1974 a fire occurred in the 3 East mains of the Joanne Mine of Eastern Associated Coal Corp. in Rachel, West Virginia. The mine was evacuated without injury and sealed completely at the surface within 24 hours. It was decided by the coal company along with the U, S, Bureau of Mines, the West Virginia Bureau of Mints and MESA that remote sealing of the fire zone would be attempted. This report summarizes the remote sealing effort and those activities directly related to the remote sealing effort. This chapter provides a brief history of previous remote sealing attempts, a description of the recently developed remote sealing system and a description of the Joanne Mine operation as it related to and affected the remote sealing effort.

Jan 1, 1975

By H. L. Burmeister

This report describes the mining and milling practices used by the Eastern Magnesia Talc Co. at its Johnson, Vt., operation. The report also contains a description of the local geology and all available information on cost and performance data. Since 1925 the mine has produced continuously at an average annual rate of 54,000 tons, and the ratio of ore hoisted to finished product is roughly 2 to 1. Ore is stoped by a combination of shrinkage and sublevel methods. In any 24-hour period the mill produces an average total of 14 grades of finished talc product, 9 by dry grinding and air classification and 5 by wet grinding and flotation methods. The mine operates one shift per day, 5 days per week and the mill operates on a 3-shift, 5-1/2-day-per-week basis. Operating costs for 1958, on a percentage basis, were mining, 22.34; milling, 54.77; ore haulage, 2.89; and all other, 20.00 percent.

Jan 1, 1963

By G. T. Fisher

The material requirements of carbide cutting tools for machining steel and cast iron are dependent on WC bonded with Co, with additions of TaCand TiC. The Bureau of Mines is conducting research to devise substi-tute materials, based on Ni-alloy-bonded TiC, for C-5-grade cutting tool applications. This substitution would result in less dependence on foreign sources for Co, Ta, and W, and use of lower cost materials. In this preliminary study, the Bureau investigated the effects of composition and processing variables on the transverse rupture strength and hardness of Ni-alloy-bonded TiC to identify compositions that exhibit promising mechanical properties. Further systematic modification of these compositions by soild-solution strengthening additions would subsequently be evaluated to obtain cutting tool materials with requisite properties and performance for C-5 applications. Compositions for evaluation were prepared by a powder metallurgy method of cold-pressing and liquid-phase sintering. Complementary analysis of compositions included chemical analysis, X-ray diffraction, energy-dispersive X-ray spectro-scopy, and density measurements. Based on results of this investigation, promising compositions were determined to be 59.37TiC-25Ni-5Mo-lO.63Mo2C, 59.68TiC-25Ni-3.33Mo-1.77Mo2C-6.67W-3.55WC, and 59.35TiC-25Ni-l.67Mo-3.54Mo2C-3.33W-7.1WC.

Jan 1, 1987

By V. E. Edlund

Pyrometallurgical studies by the Bureau of Mines demonstrated the feasibllity of sintering and smelting a low-grade flotation concentrate made by pilot-plant processing 10-percent manganese ore from the Maggie Canyon deposit, Mohave County, Ariz. Under optimum conditions 85 percent of the manganese in a flotation concentrate that assayed 36 percent manganese was recovered as standard ferromanganese. A blend of this flotation concentrate with high-grade dithionate pilot plant precipitate was similarly processed with a recovery of 90 percent of the manganese. Thorough mixing and pelletizing of the charge before treatment on the sinter hearth was necessary to produce a well agglomerated product by single pass sintering. Although satisfactory sinter was produced from a variety of material combinations, best results were obtained on a charge that contained 80 percent flotation concentrate and 20 percent return sinter fines. This combination was mixed with 6 percent coke, based on weight of concentrate; and 12 percent moisture. Sintering such a charge yielded a well agglomerated product containing over 80 percent coarse material, The results of standard crushing tests showed that the product was physically comparable to iron ore sinters and manganese nodules.

Jan 1, 1962

By F. D. Everett

The exploration work on a seleniferous tuff deposit near Lysite, Wyo., was confined chiefly to an area of approximately 1 square mile selected on the basis of prior examination and sampling work by the Bureau of Mines. This area was superficially explored by digging and sampling over 2,000 feet of trenches and 15 test pits. The surface sampling indicated that the deposit might contain a multimillion-ton reserve of easy-to-mine volcanic tuff assaying more than 0.01 percent Se. Later, 11 holes, ranging in depth from 57 to 135 feet and totaling 929.4 feet, were drilled under contract using a dry rotary drill. Samples for assay were cut at 5-foot intervals or at noticeable physical changes in the formation being drilled. Of the 206 samples assayed from the drilling, only 8 contained more than 0.005 percent selenium, and 2 of these assayed as high as 0.012 percent Se. Chemical analyses of samples obtained from six holes drilled by the Nugget Coal & Timber Co. to the south of the area explored by the Bureau of Mines showed that no selenium-bearing formations were encountered in that work. Two of 72 samples taken from 42 validation pits dug by claim holders contained more than 0.005 percent selenium. The exploratory work established that the selenium mineralization is erratically distributed in small irregular bodies and is not confined to any one tuff bed. Because of the lack of correlation between the infrequent showing of low-grade tuff, neither the extent nor grade of the reserves could be calculated.

Jan 1, 1957

By Ruth F. Brinkley

Principle activities of the Bureau of Mines Explosives Research Laboratory from July 1, 1960 to June 30, 1961 are reviewed briefly in Part 1. Part 1 also includes data obtained in connection with several minor investigations which are not sufficient to warrant separate publications. Part 2 gives brief abstracts of publications that appeared during fiscal year 1961; in general, the research reported in these publications antedates this period.

Jan 1, 1963

This Bureau of Mines report summarizes the research, development, and evaluation demonstrations conducted by the Bureau of Mines under the Health and Safety Act of 1969 to improve the means of notifying miners underground, who are away from their own phone, that they are being called.

Jan 1, 1977

By Alvin Kaufman

Increased exploration in Alaska has resulted in many requests to the Bureau of Mines for facts about the mineral resources and mining conditions in the Territory. This report presents information about the minerals of Southeastern Alaska and the factors that affect development of a mining industry in that area. Southeastern Alaska is a narrow coastal strip of rugged mountains and many islands. The climate is mild, with an average annual temperature of 40° and heavy rainfall. Geologically, the region is favorable for deposition of ore; geographic-ally, it is difficult to prospect and to develop, except along areas immediately adjacent to the coastline.

Jan 1, 1958