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By Ted C. Briggs

Equations for the elastic pressure distortion of the volumes of a Burnett compressibility apparatus are developed and presented in this report for volumes under internal and external applied pressures. An experimental method for the determination of the external pressure distortion coefficients is presented. Young?s modulus and the internal-pressure distortion coefficients are computed from the experimentally determined external-pressure distortion coefficients. The temperature dependence of the pressure distortion coefficients and of Young's modulus is evaluated for the temperature range 0° to 80° C.

Jan 1, 1968

By Thomas M. Barczak

The safety of mine workers depends on the proper installation of roof supports to prevent the ground from collapsing into the working areas of an underground mine. As new support systems are developed, they need to be properly evaluated to make sure that they are capable of providing adequate roof support before they are first used in a mine. In addition to making certain that the supports meet basic safety criteria, the limitations of the support need to be fully defined in order to avoid improper application of a particular support design. The National Institute for Occupational Safety and Health (NIOSH) operates a world-class facility called the Safety Structures Testing Laboratory. This laboratory contains a unique load frame, the Mine Roof Simulator, which is capable of simulating the ground behavior in underground mines for conducting full-scale evaluations of roof support systems. Safety performance testing protocols using the unique Mine Roof Simulator have been developed for both standing roof support systems and longwall shield supports. The purpose of this paper is to describe these test procedures. The protocol for standing roof supports incorporates seven test series:( 1) uniform loading baseline tests, (2) height evaluations, (3) asymmetric loading, (4) biaxial loading, (5) load rate studies, (6) active loading determination, and (7) static loading evaluations. For longwall shields, a four-series test program that accurately simulates in-service conditions on a longwall face is proposed. This test program consists of (1) transfer of horizontal load to the caving shield-lemniscate assembly (zero-friction test),(2) point loading of shield joints due to lateral movement or rotation of the canopy, (3) evaluation of leg socketand leg cylinder integrity, and (4) face-to-waste racking of the shield. In addition, an evaluation of the shield’s hydraulic components will be conducted prior to the performance testing. These protocols will provide state-of-the-art safety performance evaluations of emerging support technologies, as well as a means to assess the safety of both new and aging longwall shields. Hence, this effort will enhance the safety of mine workers by ensuring that critical support elements are properly designed and that aging supports are retired before their support capability is jeopardized.

Jan 10, 2000

By C. K. Rose

A hydraulic scaling rig was placed in operation at the Bureau of Mines oil-shale mine near Rifle, Colo., in 1953. The rig consists of a self-leveling platform mounted on a hydraulic-powered boom. The boom is mounted on the bed of a diesel truck. The equipment provides a movable work platform from which two men can work in safety and comfort while barring loose rock from the backs and walls of the rooms, pillars, and haulageways. INTRODUCTION As a part of its synthetic liquid fuels program the Bureau of Mines has developed a mine in the richer oil-shale beds of the Green River formation near Rifle, Colo. An important part of the work of the Oil-Shale Mining Branch is investigation of techniques for low-cost mining of oil shale on a commercial basis. It is evident that scaling loose rock from the high backs and walls of the mine represents a portion of the direct mining cost. This paper describes the development of a scaling rig for operation in the upper heading of the mine, which is 39 feet high.

Jan 1, 1954

By Hal H. Engel

This publication was written in response to numerous requests for information about the Federal Bureau of Mines' "Demonstrated Lecture on Flame Propagation and Permissible and Explosion-Proof Electrical Equipment." The requests came principally from: (1) Persons wanting to know more about the demonstration before requesting it for groups they represented; (2) persons wishing advance information to help publicize a meeting where the demonstration was to be given; and (3) members of audiences desiring something to help them remember the salient points, facts, and figures presented during the lecture and demonstration. The purpose of the demonstration that accompanies the lecture is to show: (1) Variations in flame speed and pressure at various percentages of flammable gas within the flammable range; (2) effect of flame speed on the "pressure piling" within the area confining the mixture; and (3) the application of flame speed and pressure piling to the combustion of surrounding gas and to the design and maintenance of electrical equipment used in hazardous locations.

Jan 1, 1960

By Terry S. Cory

This report is a comprehensive summary of the results of the propagation measurements program conducted for the US Bureau of Mines under Contract H0366028. Data was gathered in the MF frequency range from a cross sample of six mines representative of the industry having typical wireless requirements. From the raw data which was gathered, a logical method of data reduction is presented which culminates in a set of average attenuation characteristics for all mines visited. These characteristics define a typical MF wireless system when the communication range requirements are known. Direct through-the-earth propagation and the range enhancement mechanism due to coupling on and off conductors are evaluated and related to the planning of a typical wireless MF communications system.

Jan 8, 1977

By G. W. Murrie, W. P. Diamond, S. W. Lambert

A geologic study of the Mary Lee Group of coalbeds in the Black Warrior coal basin was undertaken to examine coal stratigraphy and determine regional trends and extent of the coalbeds. The area investigated encompasses 835 square miles in Jefferson, Walker, and Tuscaloosa Counties, Ala. More than 700 core logs were used to construct a structure map, coal, interval, and overburden isopachs, and cross sections. There is evidence that structure affected sedimentation. Coalbed isopachs indicate the Mary Lee Group was deposited in fluvial-deltaic and low-lying coastal plain environments. The Mary Lee coalbed is the only coalbed which is continuous throughout the area, commonly with two benches which have a combined thickness of 2 to 12 feet. The Mary Lee coalbed changes rank in the basin from high- through medium- to low-volatile coal. The methane gas potential of the Mary Lee Group coals is estimated to be greater than 1 trillion cubic feet. There is an excellent correlation between the orientation of surface cleats with those measured underground in the Mary Lee coalbed. The face cleats roughly parallel the axes of the area's folds and trend northeast-southwest.

Jan 1, 1976

By J. I. Paige

The Bureau of Mines, U.S. Department of the Interior, conducts research on methods to minimize the requirements for mineral raw materials through conservation, substitution, and increased minerals and metals recovery from primary and secondary domestic resources. To further this goal, prior Bureau research had devised a pyrometallurgical technique (RI 8211) to recover metallic iron and copper from molten copper smelting furnace slags by carbothermic reduction. As a continuation of this Bureau research on the carbon injection technique, reverberatory and electric furnace slags were treated in an 800-kva electric arc furnace by simultaneously top feeding the slag and injecting coke breeze into the bottom of the molten bath. Results of the tests show that 76 to 89 pct of the copper and up to 48 pct of the iron contained in the smelting furnace slag were recovered in a metallic phase, while 56 to 82 pct of the carbon injected into the sys-tem was utilized as the reductant. Laboratory evaluation has shown that the metal product, which contains 86.9 to 95.0 wt-pct iron and 1.3 to 4.1 wt-pct copper, will be a satisfactory medium for recovering copper by cementation. The expected energy consumption for the process is 110 kwhr per ton of molten slag treated and 520 kwhr per ton of solid material charged.

Jan 1, 1982

By d&apos, Kathleen J. Amico

THIS SUMMARY appears in Minerals Yearbook volumes I and III, which cover mineral production in the United States, its island possessions, the Canal Zone, and the Commonwealth of Puerto Rico, as well as the principal minerals imported into and exported from the United States. The several commodity and area chapters contain further details on production. A summary table comparing world and U .S. mineral production also is included. Mineral production may be measured at any of several stages of extraction and processing. The stage of measurement used in the chapter is normally what is termed ?mine output." It usually refers to minerals in the form in which they are first extracted from the ground, but customarily includes for some minerals the product of auxiliary processing operations at or near mines.

Jan 1, 1965

By G. E. McClelland

During the 1970?s, the Bureau of Mines investigated a particle agglomeration technique for improving the flow of leaching solution through heaps of clayey or crushed, low-grade gold-silver ores, wastes, and tailings. This technology has been adopted on a broad scale by the precious-metals-processing industry. This report presents information on five commercial operations that have benefited from agglomeration technology and that represent a cross section of current heap leaching practice. The technology is cost effective because of decreased leach times and improved precious metal recoveries.

Jan 1, 1983

By D. B. Dow

"In the natural-gas Gasoline industry, the methods used in determining the amount of gasoline in natural gas are many and varied; they include the specific-gravity test, laboratory tests involving absorption, charge in volume of the gas or in the absorption medium, absorption in charcoal with subsequent distillation, compression of the gas which results in the condensation of the gasoline, and the absorption of the gasoline vapors in an absorption oil, from which the gasoline is distilled and measured. Each of these various tests has advantages, and disadvantages. It is however, conceded in the industry that the tests in which the gasoline is obtained and measured as such are the more reliable.This paper deals with certain factors which should be considered in making absorption tests using ""mineral seal oil"" as an absorbent; this method of testing is widely used not only in the field, but in control work in absorption gasoline plants where the gasoline content of the intake and discharge gas is determined daily. In control work it is frequently found that the plant produces more gasoline than the tests show, which gives the plant the appearance of making more gasoline than is actually present in the gas treated, or in other words operating at more than one hundred per cent efficiency. Obviously then, the tests as made in these cases are in error, and in hope of correcting some of these variances, the following factors have been studied at the U. S. Bureau of Mines petroleum station at Bartlesville, Oklahoma."

Aug 1, 1920

By J. M. Stuve

Low-temperature adiabatic heat-capacity determinations were made by the Bureau of Mines in the temperature range from 5 to 300 K for the two crystalline modifications of zinc sulfide, sphalerite (ß) and wurtzite (a). The entropy at 298.15 K of sphalerite was evaluated as l4.02±0.04 cal/deg mole and wurtzite, l4.06±0.04 cal/deg mole.

Jan 1, 1974

By W. S. Anderson

The use of flexible liners for support of underground openings has been investigated by the Bureau of Mines. This report presents installation procedures and instrumentation results of a full-scale flexible liner field installation in the Burgin mine. The flexible liner is a part of the mine support system and has provided maintenance-free support for 22 months

Jan 1, 1975

By J. Davitt McAteer

Dear Mine Operator, Training for new employees, refresher training for new employees, refresher training, and new task training can mean the difference between life and death for workers. Part 46 spells out how you can develop a training program to protect workers for on-the-job hazards. Together, labor, industry, and the U.S. Department of Labor reached a milestone with the development and publication of Part 46. We want to continue working together toward the next milestone, October 2000, when the regulations take effect. We want to make sure you have all the information you need about these new training requirements. Throughout the next 12 months, MSHA personnel will be holding regional meetings across the country, delivering information and sample training plans to your operation, and offering you help to develop your plan. If you are among the many operators who are already providing training to your workers, keep up the good work. The rule will tell you exactly what is expected. If you currently have no training program, we can help you develop one. A brochure is being distributed, which highlights the main provisions of the rule. It is designed to introduce the rule to you. More detailed materials will be delivered to you. If you want information right away, simply call us, or e-mail us. We also welcome your comments, suggestions, and success stories. Part 46 will be successful and beneficial to miners through our combined efforts. Together, we can make our mines safe and healthier for everyone. Sincerely, J. Davitt McAteer, Assistant Secretary of Labor Mine Safety and Health Administration

Jan 1, 1999

By Kenneth C. Stewart

This contract was directed toward a study of the attenuating properties of earmuffs as worn by miners. Two attenuation measurement procedures were utilized. Human subjects were tested in a diffuse sound field according to threshold shift procedures recommended by the American National Standards Institute and a physical measurement procedure was accomplished in the same diffuse field on the same human subjects with microphones placed simultaneously on the inside and outside of the muffs. All measurements were obtained in one third octave of random noise. The results of the study indicated that physical and psychophysical attenuation measurements are in essential agreement at frequencies from 125 Hz to 2 KHz. Above 2 KHz the psychophysical measurement demonstrates larger amounts of attenuation than the physical measurement. The difference in attenuation ranged from approximately 7.0 dB to 9.0 dB at frequencies of 4 KHz and above. A possible explanation for the observed differences in attenuation has been presented.

Jan 1, 1980

By A. W. Deurbrouck

This Bureau of Mines report describes the washability characteristics of 14 coalbed samples collected in Wyoming. Such data is needed to evaluate the quality of the coals of the West where most of our low-sulfur-content coal reserves are found. Of the 14 samples included in this report 13 had a total sulfur content of 1.1 percent or less. All of the samples contained low per¬centages of ash or could be readily washed to a desirable ash level with minimal loss of yield. The coals ranged in rank from high-volatile B bituminous to subbituminous C, although 10 of the samples were high-volatile C bituminous. The coalbeds varied in thickness from 4.5 to an unknown thickness greater than 67.5 feet.

Jan 1, 1971

By Charles L. Kimbell

Available statistics on 1989 worldwide consumption of selected nonfuel minerals shown in table 5 show increases for 11 of 14 listed nonfuel mineral commodities with 1 unchanged from the 1988 level, a departure from the pattern of the past 2 years, in which each of the listed commodities registered gains. The 1989 results, however, were better than those for 1986 when only seven listed nonfuel mineral commodities recorded gains with one un- changed from 1985. Consumption of the two ferrous metal raw materials listed advanced as functions of increased output of pig iron and crude steel. The increase in iron ore consumption exceeded the increase in iron ore output, suggesting a slight drawdown of world iron ore inventories. The estimated in- crease in iron and steel scrap consumption was slightly greater than the minuscule increase in world steel production, but it is believed that there was little change in the ratio of iron ore to scrap in steel plant feed on a global basis.

Jan 1, 1992

By Robert E. Johnson

THE MILDEST recession of the postwar period ended in the first months of 1961, and the economy climbed steadily during the remainder of the year. The Federal Reserve Board (FRB) Index of Industrial Production climbed from a low point of 102 (1957=100) in February to 115 in December, a rise of 12.5 percent. But economic activity for the year as a whole was only 1.5 percent higher than the 1960 level, as measured by real gross national product (GNP). Although activity increased throughout 1961, much of it was merely regaining ground lost in the decline during the second half of 1960 and the first months of 1961. The FRB index did not re ain the July 1960 high of 110 until June of 1961. Mineral fuels did not fully share in the economic recovery. The (FRB) crude oil and natural gas index rose only 5 percent between February and December. Although the index of monthly coal production increased 11.5 percent during the year, the February level was so low that total production for the year was the lowest since 1954. Total production of energy measured in Btu's was up slightly (1 percent) during the ear. Coal production was down; production of crude oil and natural gas was up. Calculated consumption paralleled production-total up slightly, coal lower, and crude oil and natural gas higher. The most interesting product developments were in coke and residual fuel oil. Sales of coke showed a sharper drop than steel

Jan 1, 1962

By Martin Hertzberg

The Bureau of Mines 8-liter flammability system was used to study the effectiveness of a variety of powdered inhibitors in preventing the propagation of explosions of coal dust or methane in air. Over 35 different chemical additives were evaluated against Pittsburgh seam pulverized coal. The least effective inhibitors were the carbonates, which required mass additions in the range of two to three parts inhibitor to one part of coal dust in order to prevent propagation. The most effective inhibitors were the derivatives of ammonium phosphate, which were effective quenching agents at additions of only one part inhibitor to four parts of coal dust. Alkali halide powders were of intermediate effectiveness. These laboratory-scale results are in good agreement with full-scale mine experiments in all cases where detailed comparisons have been made. Data were also obtained for the effectiveness of several of the same powdered inhibitors against methane-air explosions. Their relative order of effectiveness and the concentration ranges required for quenching the gas explosion are comparable to those measured for coal dust explosions. Data are also presented for the effectiveness of N2 and CF3Br addition. Some preliminary data are also presented for powder addition to methane burner flames. Those data are compared with other burner data and evaluated in terms of their relevance to explosion tests.

Jan 1, 1982

By R. Barany

The heats of formation at 298.15° K of calcium tungstate, calcium molybdate, and magnesium molybdate were determined by solution calorimetry. For the heats of formation from the elements, the values obtained were calcium tungstate, -402.4 ± 0.5 kcal/mole, calcium molybdate, -369.5 ± 0.3 kcal/mole, -334.8 ± 0.2 kcal/mole. For the heats of formation from the oxides J the values obtained were calcium tungstate, -49.2 ± 0.4 kcal/mole, calcium molybdate, -39.6 ± 0.1 kcal/mole, and magnesium molybdate, -12.9 [ ] 0.1 kcal/mole.

Jan 1, 1962

By Francis R. Redfern

Newton's method of solving a nonlinear equation is employed to develop a least-squares acoustic emission source location method in which the spatial residuals of the location equations are minimized. These residuals, related to the distances from the least-squares source location perpendicular to the surfaces described by the location equations, permit location error to be estimated to first order along the spatial axes. The solutions obtained by this method are the best spatial solutions to the location equations in the least-squares sense. Also presented is a procedure by which the geometrical control of a transducer array can be evaluated using the rate of change of source location with fractional velocity change.

Jan 1, 1982