Search Documents

By Frank B. Fulkerson

Of the about 60 million pounds of aluminum used in the Pacific Northwest in 1960, 40 million pounds or two-thirds was used by 10 companies. One of these companies made airplanes and missiles; one manufactured roofing, siding, and tubing; three produced truck tractors, truck bodies, or truck trailers; two made architectural metal products; one made irrigation and industrial products; one was a general foundry; and one was a shipyard. These companies contributed to regional growth by developing markets outside the area; some have worldwide sales. Aluminum consumption increased at an average rate of 7 percent annually from 1954 to 1960. Airplane manufacture, formerly preeminent in aluminum use, no longer was in first place in 1960. By industrial group, the leading users were manufacturers of building products, 30 percent; airplanes and missiles, 22 percent; truck tractors, truck bodies, and truck trailers; 17 percent; general foundries, 5 percent; ships and boats, 4 percent; mobile homes, 4 percent; other transportation equipment, 3 percent; and irrigation equipment and all other products, 15 percent.

Jan 1, 1962

By John C. Holtz

Interest in the possibility of using Diesel6/ engines for haulage power in mining and tunneling is increasing in the United States, owning largely to the reported successful use of Diesel locomotives in European coal mines and to the comparatively recent development of automotive Diesel engines in this country. The extent of this interest has been evidenced to the Bureau of Mines by numerous requests for information as to the factors that must be considered if Diesel engines are to be used safely underground.

Jan 1, 1940

By John C. Holtz

Interest in the possibility of using Diesel6/ engines for haulage power in mining and tunneling is increasing in the United States, owing largely to the reported successful use of Diesel locomotives in European coal mines and to the comparatively recent development of automotive Diesel engines in this country. The extent of this interest has been evidenced to the Bureau of Mines by numerous requsts for information as to the factors that must be considered if Diesel engines are to be used safely underground.

Jan 1, 1940

By H. H. Dewing

The Bureau of Mines constructed a process research unit (PRU) to demonstrate new technology for extracting zinc from sphalerite concentrates. Up to 9 kg/hr of sphalerite (ZnS) concentrate was reacted at ambient pressure in the PRU with 80 pct sulfuric acid at 160° to 180° C to produce zinc sulfate and elemental sulfur. The PRU consisted of a three-stage glass reactor system: a 4-liter premix stage in which feed was slurried with 78 to 82 pct H2S04, a 40-liter stirred reactor, and a ISO-liter settling stage in which high reaction conversions were effected and excess H2S04 for recycle was separated from insoluble ZnS04 and sulfur. Evolution of sulfur-containing gases was minimized by sub-surface addition of acid feed slurry to the stirred reactor and by exclusion of air from the reactor to prevent the oxidation of elemental sulfur. Conversion of zinc to zinc sulfate averaged over 99 pct at the optimum acid concentration of 80 pct. Total sulfur losses (primarily S02) were less than 2 pct of the sulfur in the sphalerite. Elemental sulfur remained in the insoluble portion of the settled reactor product after leaching with simulated spent zinc electrolyte containing sulfuric acid. The sulfur residue contained 75 to 89 pct sulfur. Neutral zinc sulfate, required for zinc electrowinning processes, was separated from the sulfuric acid leach solution by crystallization at -15° C as zinc sulfate heptahydrate (ZnS04?7H20). The crystallization operation simultaneously effected a partial concentration of the recycled electrolyte solution by removing water.

Jan 1, 1982

By John A. Johnson

For the purpose of comparing the amounts of dust produced by various mining operations, samples of atmospheric dust were collected during a complete cycle of drilling, blasting and mucking at or near the face of the Bureau's Mount Weather testing adit while the efficiency of several types of stemming in metal-mine blasting was being investigated. ACKNOWLEDGMENTS All gas samples were analyzed in the laboratory of the Bureau of Mines Gas Section at Pittsburgh, Pa.

Jan 1, 1939

The objective of this study was two-fold: 1. To perform a world literature search pertinent to the analysis, selection and design of hoisting systems and their components and to codify the search into a literature compendium. The search resulted in a technical data file of over 1500 hard copy items. The compendium index was also suitable for establishing a comprehensive computer-loaded data base on the subject. 2. To develop a comprehensive system of guidelines to cover salient aspects of analysis, selection and design of electrical, mechanical and structural components of a hoisting system with a view to establish parameters for maximum safety and efficiency of operation, installation and revision of the system. 3. Considerations in the mine shaft layout, design, sinking, outfitting, testing and commissioning are set forth against the background of requirements of applicable parts of Code of Federal Regulations, Title 30.

Jan 1, 1988

By W. L. Acherman

The Bureau of Mines found the chemical and galvanic corrosion behavior of the TZM and molybdenum-30 tungsten alloys to be generally equal or superior to that of unalloyed molybdenum in many aqueous solutions of acids, bases, and salts. Notable exceptions occurred in 1 [N] nitric acid, where both alloys corroded appreciably faster than molybdenum. In mercuric chloride solutions, the TZM alloy was susceptible to a type of crevice corrosion which was not due to differential aeration. The alloys were usually not adversely affected by con-tact with dissimilar metals in galvanic couple experiments, but the dissimilar metals sometimes corroded galvanically. Both alloys were resistant to substitute ocean water spray at 60° C.

Jan 1, 1968

By E. Kamon

This report summarizes completed research pertaining to the reaction of human subjects exposed to Self-Contained Breathing Apparatus (SCBA) stressors during escape conditions (viz., resistance breathing, C02 breathing, hot air breathing, and static positive facepiece positive pressure breathing) and the development of an automated breathing and metabolic simulator (ABMS). Volume I contains summarizes of the studies performed under this contract. Volume II is an appendix which contains more detailed descriptions of these studies.

Jan 1, 1984

By W. L. Dare

Tri-axial strains in pillars, created by pillar robbing, were measured in an experiment at the Dysart No. 1 uranium mine near Grants) New Mexico. At this mine, room-and-pillar stoping is used on the advance, and pillars are recovered on the retreat. The are deposit is, for all practical purposes, horizontal. Measuring devices were installed in pillars approximately 90 to 200 feet from the break line, and strains were recorded over a 4-to 6-week period. The measurements indicate that, in general, the algebraic magnitude of vertical strains increased, and the horizontal strains decreased, in turn, indicating that vertical (or near vertical) loads on the instrumented pillars lessened as pillars were recovered.

Jan 1, 1962

By K. E. Robinson

This study is the extension of an investigation of reclamation of floodplain areas in the Coeur d'Alene Mining District, Idaho, that are unuseable in their natural condition, by construction of landfills with mill tailings. The study develops a valley-wide tailings disposal plan to utilize 20 potential landfill sites on floodplain areas and presents measures for reclaiming the sites for subsequent productive use. Field and laboratory testing on a test section and two abandoned impoundments support the use of hydraulically deposited tailings for landfill construction. Hydrological testing has shown that controlled discharge from tailings impoundments results in contaminant levels in the discharge below regulated standards. Additional testing indicated that compacted soil liners and pond management provide adequate contaminant abatement where acid-generating tailings are encountered. Mechanical compaction, including surcharge loading, upgrades foundation support capacity so that construction on the surface of tailings deposits is feasible. On completion of the testing program, the test sections were abandoned and rehabilitated. Details concerning potential landfill sites have been refined. At recent production rates, the 20 sites would result in 680 acres of reclaimed land, while providing a minimum of 40 years of tailings storage capacity. A general design has been developed for the retention dikes. Aspects of embankment stability, including liquefaction are discussed, and are shown to provide an adequate factor of safety under the anticipated range of operating conditions.

Jan 1, 1983

By Richard J. Mainiero

The Bureau of Mines conducted research to evaluate the optimum design for a rock-breaking explosive charge that could be fired unconfined in a gassy or dusty coal mine without the danger of igniting the flammable atmosphere. Charges of various shapes, with and without cavities, were tested in a gallery using 3-by 3-by l-ft concrete blocks as simulated boulders. For these tests the optimum charge, in terms of cost, weight, and convenience in handling, consisted of a flat l-1/2-lb charge of permissible explosive seven-eighths of an inch thick and 7 in in diameter encased in a l/2-in thick layer of fine salt (NaCI). This work demonstrated that it should be possible to produce an inexpensive explosive rock-breaker charge that would be safe to use in underground coal mines.

Jan 1, 1982

By T. N. Rushton

Rate minima are encountered in the reduction of magnetite with hydrogen. In a certain temperature zone, the reaction rate decreases with rise in temperature. This is inexplicable by classical kinetic theories; neither is a transition in reduction mechanism suitable for interpreting the observed behavior, This anomaly can be fully explained by hypothesizing two species of chemisorbed hydrogen with different adsorption coefficients and activation energies for adsorption. Competition between two energetic states of adsorption occurs with temperature rise, with the low energy state predominating below the anomalous temperature zone and the high energy state above it. The presence of two possible adsorption sites appears to be characteristic for oxidic adsorbents.

Jan 1, 1968

By M. J. Sapko

A moderately scaled apparatus was developed by the Bureau of Mines to determine the fire resistance characteristics of mine conveyor belts and similar type materials. The design of the apparatus was based upon data obtained in full-scale fire tests and features a radiant panel to preheat the belt and a methane-oxygen ribbon burner to ignite the sample under ventilating condi¬tions in a rectangular duct. The test method overcomes the limitations of existing laboratory-scale methods and provides a measure of both ignitability and flammability in quantitative terms. Flame propagation depended upon such variables as air velocity, ignitor heat flux, and belt width and height in the test chamber. Data are presented for nine belt materials and fire resistance ratings are proposed in terms of the flame spread rate, heat release rate, and the critical ignitor heat flux. The ratings discriminate between the fire hazard posed by different fire-resistant belts and tend to be in reasonable agreement with those obtained in full-scale fire tests.

Jan 1, 1981

By H. F. Yancey

About 65 percent of the more than 400 million tons of coal produced annually in the United States is mechanically cleaned to remove the inorganic impurities before being sent to market. The impurities, principally shale and clay with some pyrite, average about 20 percent of the raw coal treated. Nearly 95 percent of the tonnage is treated by wet processes, in which water, suspensions of solids in water, or occasionally calcium chloride solutions are employed. Difference in density of coal and impurity is the basis of these processes. Of major importance in the separation is the competency of the impurities, that is, the resistance of the impurities to size disintegration in water. In general, the impurities are more resistant in geologically older coals or those in effect made older by metamorphism. If the impurities suffer reduction in particle size when immersed in water, the separation of organic from inorganic material becomes more difficult, Recently the Scientific Department of the National Goal Board (Great Britain) undertook fundamental research into the interaction of shale and water and also developed an empirical method of assessing shale breakdown or disintegration. 6

Jan 1, 1962

By David A. Hill

This volume contains a summary of the results of past analyses on U.S. Bureau of Mines Contract No. 80122061 which are relevant to electromagnetic location in mine rescue situations. The analytical results indicated that detection of a trapped miner equipped with a special transmitter is feasible in most situations. Location of the miner by surface measurements is also generally feasible within certain errors. The feasibility of miner detection and the accuracy of miner location have been examined theoretically for a wide variety of situations. Agreement with experimental results is generally good in cases where measurements are available. Personnel involved in the investigation include J.R. Wait (Principal Investigator), D.A. Hill (Co-Principal Investigator), K.P. Spies, A.Q. Howard, and Lana Slusher (Administrative Assistant).

Jan 1, 1974

By W. A. Calhoun

The purpose of this investigation was to develop economical mineral dressing processes for removing objectionable quantities of impurities, such as quartz and pyrite, from refractory clay deposits in east central Missouri. The presence of excessive quartz in these clays causes crazing. Pyrite causes bloating and unsightly dark blobs on the surface of fired refractory brick. The iron concentration in the proper state of oxidation may also act as nucleation centers for carbon crystal growth which can result in bursting of the refractory. Numerous deposits, representing a very large tonnage, have been examined and prospected by various refractories companies and found to contain impurities in objectionable quantities. Upgrading these clays would greatly extend our reserves of high-quality refractory clays. Wet-tabling and wet-cyclone concentration were found to be effective for removal of impurities from clays. Of the two methods, wet-cyclone concentra¬tion would be cheaper and more effective. Although wet-tabling improved the refractory properties of each clay, beneficiation by wet-cyclone produced clays of superior quality. Clay recoveries by wet-cycloning ranged from 56.1 to 81.8 percent of the weight of the crude samples, and the beneficiated clays contained from 71.9 to 94.4 percent of the total alumina. The pyrometric cone equivalent (PCE) was increased from 1 to 3 cones by wet-cycloning. The beneficiated clays also met the reheat shrinkage requirements on refiring to 1,400° C. Missouri is one of the major domestic sources of fare clay. In addition to deposits of high-grade refractory clays, there arc many deposits that contain small percentages of impurities, which render the clays unfit for the production of high-heat-duty firebrick. Development of methods to beneficiate these submarginal clays to usable materials would greatly increase commercial fire clay resources.

Jan 1, 1961

By Paul G. Swanson

This investigation was conducted to identify the principle causes of spoil instability problems in the Eastern Coal Province. The study was also conducted to develop a matrix to predict the strength and groundwater parameters necessary to conduct stability analyses on a proposed reclamation scheme. Suggestive methods to reduce spoil instability potential are also included. Numerous physical property, strength, compressibility, chemical and mineralogical tests were conducted on mine spoil samples obtained from 11 different surface mine sites. Site characteristics that influence the position of the post reclamation groundwater table were identified. Distinct regions within the Eastern Coal Province with high incidences of surface mine slides or high landslide susceptibility were identified. The application of the predictive matrices developed in this study is for surface mine sites mined and reclaimed in general accordance with the Surface Mine Reclamation Control Act of 1977. A review of current mining practices and the relative effect on spoil stability is included.

Jan 1, 1983

By Michael J. Sapko, Gregory M. Green, Kenneth L. Cashdollar

The National Institute for Occupational Safety and Health (NIOSH) and the Mine Safety and Health Administration (MSHA) conducted a joint survey to determine the range of coal particle sizes found in dust samples collected from intake airways of US coal mines. The last comprehensive survey of this type was performed in the 1920s. The size of the coal dust is relevant to the amount of rock dust required to inert the coal dust, with more rock dust needed to inert finer sizes of coal dust. Dust samples were collected by MSHA inspectors from several mines in each of MSHA's 10 bituminous Coal Mine Safety and Health Districts. Samples were normally collected in several intakes at each mine. The laboratory analysis procedures included acid leaching of the sample to remove the limestone rock dust, sonic sieving to determine the dust size, and low-temperature ashing of the sieved fractions to correct for any remaining incombustible matter. The results indicate that particle sizes of mine coal dust in intake airways are finer than those measured in the 1920s. This finer size coal dust in intake airways would require more incombustible matter to be effectively inerted than the 65% incombustible specified in current regulations.

By Jonathan S. Kelly

Effective control of respirable dust is one of the most serious problems associated with longwall mining in the United States. This report describes the development and the underground evaluation of ventilated cutting drums, on a double ended ranging drum shearer. The ventilated drum uses high pressure (1,500 psi) water sprays to draw air (3,500 cfm) through 12 airmoving tubes mounted in the drum hub. The sprays draw dusty air from the face side of the drum, scrub the air, and discharge the clean air on the gob side of the drum against a deflector plate. During a three week underground evaluation, the cutting drums reduced shearer generated dust levels at the shearer operators position by 40%, at the shield operators downwind of the shearer by 55%, and at the tailgate by 55%. Cutting and loading performance of the drums were superior to the mine?s conventional drums. After the evaluation, the mine continued to use the ventilated drums to finish mining the panel. During this 3 month period, there were no mechanical or seal failures demonstrating excellent system reliability.

Jan 1, 1987

By James H. McCutchan

The small and remote mine operators must comply with the Federal Mine Safety and Health Administration regulation requiring them to train and maintain mine rescue teams. The alternative is for the operators to contract with established teams within two hours travel time of their mine. Many of these remote operations are too far away from established teams and have too few employees to make up the necessary teams. Many cannot comply with the regulation either from a manpower or economic standpoint. The Office of Arizona State Mine Inspector, under the direction of the Honorable James H. McCutchan, State Mine Inspector, entered into a contract with the Bureau of Mines to develop the concept of a volunteer mine rescue program. This program with the assistance of the mining industry and volunteer rescue organizations, has planned and instituted a statewide volunteer mine rescue organization. The trained and equipped volunteers are stationed throughout the state and can respond to a mine emergency within the time constraints.

Jan 1, 1984