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By Alan G. Mayton

The Bureau of Mines conducted one of the most extensive studies on surface mine illumination to date, to assess the illumination needs of mobile surface mining machinery with respect to the visual tasks required of machinery operators. Field Investigations were performed at 22 surface mining operations, coal and metal-nonmetal, within several mining regions of the United States. Visibility and illumination were measured for 159 visual tasks performed by equipment operators on or near 57 surface mining machines, including draglines, shovels, blasthole drills, bulldozers, loaders, haul trucks, graders, scrapers, and several service-type vehicles.

Jan 1, 1987

By R. H. Sprute

The Federal Bureau of Mines performed laboratory tests using direct current to dewater and densify fine-grained coal sludge in order to alleviate disposal problems and lead to recovery of high energy value often present in this waste. The laboratory tests described in the main body of the report were performed on thickened underflow (no flucculant added) from a northern Appalachian coal preparation plant. Solids in this slurry was very fine with 65 percent of the particles less than 0.1 mm in diameter. A variety of application procedures tested is exemplified by a test in which a soupy slurry (55 percent dry-weight moisture content) was converted into a firm dense material with a 20-percent dry-weight moisture content. These results were achieved in 3 hours with current density of 3.7 amp/ft2 and a power expenditure of 35 kwhr/yd3. The treated material has an average heating value of 10,400 Btu/lb. Varying current density, electrode configuration, and placement depth makes application of the treatment flexible. Two other types of sludge were tested briefly--thickener underflow from a southern Appalachian coal preparation plant with flocculant added, and sludge from an acid mine drainage treatment plant. The underflow responded well to the treatment, but response of the sludge from the acid mine drainage treatment plant was poor.

Jan 1, 1976

By Noel N. Moebs

This report summarizes 10 selected Bureau of Mines research contract reports produced from 1970 to 1980 which consist largely of geologic studies of coal mine roof support problems. Significant highlights from the contract final reports are discussed and presented in practical terms. The selected reports focus on the Appalachian and Illinois coal mining regions. In the Appalachian coal region, two geologic structures, roof rolls and slickensides, predominate over all structures as features that directly contribute to roof falls. Studies of these and other structures are reviewed, and improved methods of utilizing drill core and core logs to prepare hazard maps are presented. Among the reports described are several on the weakening effects of moisture on shale roof, as determined from both laboratory and underground measurements, and an assessment of air tempering as a humidity-control method. Also summarized are findings concerning the time lapse between roof exposure and permanent support installation as a factor in the effectiveness of roof bolting.

Jan 1, 1984

By J. H. Soulé

The Copper King copper-gold-silver deposit was discovered about 1880. Various individuals and companies have been interested in the deposit and considerable work has been done, although production, if any, has been small. The deposit is located in the western part of Laramie County, Wyo., and is favorably situated with respect to rail and truck transportation and high-tension power facilities. Mild summers and cold winters characterize the climate. Precipitation averages between 16 and 17 inches annually, with considerable snowfall in the winter. Permanent streams are small and most available water in being stored for use by Cheyenne, Wyo. Range grasses comprise the bulk of the vegetation, with small trees and shrubs common in the most rugged areas.

Jan 1, 1955

By Richard D. Miller

The helium resources base of the United States was estimated by the Bureau of Mines to be 961 Bcf as of January 1, 1983. These resources are divided into four categories in decreasing degree of assurance of their existence: (1) helium in storage and in proved natural gas re- serves, 271 Bcf, (2) helium in probable natural gas resources, estimated at 202 Bcf, (3) helium in possible natural gas resources, estimated to be 351 Bcf, and (4) helium in speculative natural gas resources, which makes up the remaining 137 Bcf. These helium resources are further divided into depleting, nondepleting, and stored classifications. The depleting resources are those associated with natural gas fields that are, or will be, produced for the natural gas they contain. All of the helium in potential (probable, possible, and speculative) natural gas resources is included in this classification. These depleting resources are estimated to contain 789 Bcf of the total helium resource base. Helium resources contained in nondepleting natural gas resources, those in shut-in, abandoned, or otherwise nonproducing natural gas fields, are estimated to total 134 Bcf. There is 38 Bcf of helium in storage in the Federal Government- owned Cliffside Gas Field near Amarillo, TX.

Jan 1, 1985

By James J. Olson

The Bureau of Mines recorded both particle accelerations and velocities from one-stick and production blasts at Eagle-Picher Industries' Shullsburg mine, Shullsburg, Wis., to test the effectiveness of square root scaling in grouping underground blast vibrations and to determine the effects of rock type and mine geometry on blast vibrations. Although the charge weights of subsequent delay periods sometimes exceeded the charge weight of the zero-delay period, both acceleration and velocity records showed that the zero-delay portion of the Shullsburg production blasts produced the highest vibration amplitudes. Because of the restricted range of charge weights in the Shullsburg experiments, no statistical determination of an appropriate scaling factor could be made. However, the square root scaled peak particle velocity data from the Shullsburg production blasts grouped well within the approximate band-width of vibration data obtained by the Bureau from quarry blasts in many different rock types. This indicates that scaling by some factor, perhaps the square root or cube root of the charge weight, may be an effective way to group and study vibration data from underground blasts. Further research is needed to determine which scaling factor is best for underground blasting.

Jan 1, 1970

By Charles B. Kenahan

Application of ultrasonics in the electrolytic deposition of metallic manganese and manganese dioxide from sulfate electrolytes had several effects. Ultrasonics produced finer-grained deposits of electrolytic manganese at all current densities than obtained in normal cell operation, but at high current densities it resulted in less adherent deposits. Ultrasonic radiation did not affect cell voltage or cathode current efficiency. In the electrodeposition of manganese dioxide at 70° C., ultrasonic-; increased the current efficiency and decreased the cell voltage at a current density of 9 amperes per square foot, but it had little effect at current densities above this. The decrease in cell voltage was caused by the depolarizing action of ultrasonics at both anode and cathode. Ultrasonic radiation produced a smooth, glossy, adherent, and pit-free deposit at all current densities and at each temperature. Radiation had no effect on current efficiency or cell voltage at 90° C. Ultrasonics was more effective than conventional agitation in producing all of these effects.

Jan 1, 1962

By Charles L. Kimbell

For a study such as this, which summarizes and amalgamates much information collected, compiled, and utilized by the numerous U.S. Bureau of Mines country specialists and branch chiefs for inclusion in the country and regional reports that comprise the five other sections of 1991 Minerals Yearbook-International Review, it is clearly impossible to cite all sources of information used in its presentation, but some recognition is due. Generally speaking, this study and its related detailed studies on countries and areas would be much more difficult, if not impossible, without the efforts of the personnel of national mining and geological agencies throughout the world. Information that they collect, compile, and then publish, either in their own volumes or those of central statistical agencies in their countries, are the foundations on which this work rests. Thus, appreciation is expressed to the multitude of persons employed by these agencies.

Jan 1, 1993

By Stephen Utter

This report summarizes the procedure and results of an investigation to determine the stresses in the rock around an underground opening in the Climax molybdenum mine, Climax, Colo. This study is part of an overall investigation conducted by the Bureau of Mines to determine the stresses induced by block-caving mining. The purpose of this study is to obtain estimates of the magnitudes and directions of the principal stresses, the location of the maximum stress concentrations, and the effect of topography on the stresses.

Jan 1, 1962

By Andrew B. Cecala, Edward D. Thimons

The Bureau of Mines has successfully tested a method to simulate methane (CH~) flows from face areas through the returns of noncoal mines. This technique' involves releasing a small quantity of tracer gas at a working area and sampling for that gas downstream in the re- turn airways. By measuring the dilution of the tracer gas, the dilution of any volume of CH4 released at the face can be calculated. This information is useful in selecting locations for CH4 monitors and in deciding the necessity for permissible equipment in the returns.

Jan 1, 1984

By Charles L. Kimbell

For a study such as this, which summarizes and amalgamates much information collected, compiled, and utilized by the numerous U.S. Bureau of Mines country specialists and branch chiefs for inclusion in their country and regional reports that comprise the five other volumes of the international studies of the Minerals Yearbook, it is clearly impossible to cite all sources of information used in its presentation, but some recognition seems due. Generally speaking, this study and its related detailed studies on countries and areas would be much more difficult, if not impossible, without the efforts of the personnel of our counterpart agencies throughout the world. Information they collect, compile, and then publish, either in their own volumes or those of central statistical agencies in their countries, are the foundations on which this work rests. Thus, we must begin by expressing our appreciation to the multitude of persons employed by these agencies for their contributions.

Jan 1, 1993

By T. Ruff

Researchers at the National Institute for Occupational Safety and Health, Spokane Research Laboratory, studied technology and methods that could reduce accidents involving surface mining equipment that collides with other vehicles or workers, or drives over an unseen road edge. These accidents are partially attributed to the lack of full visibility around these large pieces of equipment. Blind areas can be extensive and this report presents plots of blind areas for five pieces of surface mining equipment. Several technologies designed for detecting obstacles in blind areas and providing a warning to the operator were evaluated on off-highway dump trucks. These proximity warning systems included radar, sonar, GPS, radio transceiver tags, and combinations of radar and cameras. A summary of test results is presented in this report, along with guidance on effective proximity warning technology, installation and maintenance considerations, and recommendations for effective implementation. This study found several commercially available systems that could effectively warn an equipment operator of an impending collision. Several new technologies also show promise for reducing these accidents. In most applications, it is recommended that sensor-based systems be combined with video cameras to provide important alarming functions along with an actual view of the blind area.

Jan 6, 2007

By J. R. Hoskins

A recent survey of 23 vein-type metal mining operations in several western states discloses that some of the more serious deficiencies in ventilation technology are associated with inordinately high levels of mine resistance. This problem has progressively increased over many years of operation (without adequate remedial action) as mines have become extended in depth. Where two shafts form the downcast and upcast airways of a relatively deep mine, the whole of the mine air volume must pass through each shaft in turn. Since at least one of these shafts contains hoisting equipment, structural members are necessary to support the rigid guides and shaft walls. These offer high aerodynamic resistance. In some deep mines, a single shaft of this nature may represent upwards of one-half of the total mine resistance. The second shaft, depending upon its design, may represent an additional one-third of the mine resistance. Therefore, the various working levels throughout the mine contribute only the small remaining amount of the total mine resistance.

Jan 1, 1972

By G. B. Shea

The accident experience of the California petroleum industry for 1927 was characterized by a decrease it .the number of fatalities. The year closed with a total of 41 fatal accidents, as compared with a total of 54 for the preceding year. 3 In percentage, the figure for 1927 represents a decrease of 24 per cent from that of 1926 and evidences the promising results of organized safety work, in which the industry in California has taken an absorbing interest. The percentage of decrease for 1927 is the largest recorded in any one year since the compilation of the fatality record in the California petroleum industry was begun. Although good progress has been made during the past few years, much remains to be done to reduce still further the human and economic waste caused by accidents. This review is intended to show the employee, as well as the employer, the proximate and contributing cause of accidents. To increase the value of the report, preventive measures in various instances are suggested, on the theory that accidents of a similar nature will occur unless remedial action in taken to remove the cause.

Jan 1, 1928

By C. E. Jordan

Domestic cobalt resources are relatively large, but low grade. The full potential for cobalt production from domestic sources is at least 19.4 million lb of cobalt per year exclusive of offshore resources. A summary of the cobalt processing technologies for the major domestic resources is presented in this Bureau of Mines report. The processing technologies for the Blackbird, Madison Nine, Duluth Gabbro, iron ore pyrite, laterites, and manganese sea nodules are nearly complete, but the economics are not favorable. Research on these resources should be limited to approaches that promise to cut the total processing costs by at least 50 pct. The most promising sources of cobalt are the spent copper leach solutions and siegenite from the Missouri lead ores. Research on cobalt processing from these two sources needs to be completed.

Jan 1, 1988

By Martin H. Stanczyk

Freezing to dewater typical Florida phosphate rock slime as demonstrated in laboratory tests appeared to have potential commercial use because of indicated moderate energy requirements, good compaction of dewatered solids, and effective recovery of usable water. After freezing, thawing, decanting, and filtering, batch freezing of gallon-size 13.7 percent solids slime samples yielded 42 percent solids products. Cationic amine, used as a process additive, yielded 46.8 percent solids product with significant filter area reduction. Semicontinuous 8 stage freezing tests also produced thickened slimes. Cooling and freezing 13.7 percent solids slime from 30° to minus 10° C required removal of 183 Btu per pound of slime; Carnot cycle calculation indicated that the theoretical minimum energy to transfer this heat was 27.8 Btu per pound. To produce 1 ton of 44 percent solids slime from 13.7 percent sol-ids slime, the calculated theoretical energy required for cooling and freezing was 52.3 kilowatt-hours. During the research heat capacity and heat of fusion data were determined for the slime at various percent solids.

Jan 1, 1971

By Webster S. Anderson

Two series of tests were run with planer model 'BB": one at the Arickaree mine of the San Francisco Chemical Co., Rich County, Utah, and one at the Roslyn No. 9 mine of the Northern Pacific Railway Co., Roslyn, Wash. The tests at the Arickaree mine were started on June 25, 1958, and continued until September 30, 1958. Prior to these tests, an electrically activated remote-control system was installed, and other modifications were made on the planer. The tests showed that the planer in general and the remote-control system worked very well; however, the various cutting tools used would not consistently penetrate and cut the phosphate rock. This indicated that the cutterhead design had to be changed before the planer would operate efficiently in phosphate beds similar to the "A" bed in the Arickaree mine.

Jan 1, 1962

By Thomas R. Bur

Symmetry theory, based on ground work established in the study of single crystals and experimental procedures utilizing ultrasonic pulse velocities of spherical specimens plotted on equal area polar projections, enables the direct identification of a material's elastic symmetry system and the determination of its orientation, as well as the position of the elastic coordinate axes. The method is especially useful for elasticity studies of polycrystalline and amorphous materials for which this knowledge of symmetry is a prerequisite in determining the independent elastic constants. Projections based on theoretically derived velocities are given for a single crystal from each of the major crystallographic symmetry systems except the triclinic. Projections based on experimentally derived velocities are given for one brass and several rock spheres.

Jan 1, 1969

By R. J. Hundhausen

The continued worldwide shortage and strategic value of nickel place great importance upon the continued development and exploitation of new sources of nickel in the United States, The deposits of nickel-bearing minerals in Oregon and Washington have attracted considerable attention, particularly since the Hanna Development Co. has engaged in development work aimed at producing ferronickel from the Nickel Mountain deposit, near Riddle, Douglas County, Greg. The Red Flats nickel deposit in Curry County, Oreg., was first examined by the Bureau of Mines in dune 1945, but it was not until 1952 that the deposit was drilled and sampled. In 1953, a 15-ton sample of Red Flats material was procured and subjected to continuous smelting tests in the Bureau's Northwest Electrodevelopment Laboratory, Albany, Greg.

Jan 1, 1954

By D. R. Tesarik, F. M. Jones, J. B. Seymour, L. A. Martin, T. J. Williams

Determining backfill stress is an important part of evaluating mine safety, whether personnel are working in proximity to backfill or in other areas of the mine where backfill is an integral part of regional support. To assist in determining stress in backfill more accurately, researchers from the Spokane Research Laboratory of the National Institute for Occupational Safety and Health, Placer Dome, Inc. (Turquoise Ridge Mine), Peabody Energy Co. (Foidel Creek Mine), and Hecla Mining Co. (Lucky Friday Mine) used temperature readings recorded by thermistors to correct for the influence of temperature on stress data. These thermistors were positioned in the stems of earth pressure cells installed in backfill. Corrections were then calculated and compared using four different methods: polynomial equations fit to temperature-versus-stress plots before the pressure cells were loaded by overburden, a factor provided by the manufacturer, a theoretically derived factor, and a linear correction factor based on information collected during periods when no mining was taking place. To evaluate the accuracy of these methods, corrected stresses were calculated using each method and results compared to cumulative stresses caused by blasting at one of the mines. Results indicated that only a small percentage of the temperature effect on stress was corrected using the factor from the manufacturer because that factor accounted for only the pressure transducer and not the entire instrument body. Stresses adjusted with a linear correction factor based on information collected during periods when no mining was taking place were the most accurate. Stresses recorded at two other mines were corrected using the theoretical method and the polynomial equations method; the two methods produced similar results. For some time intervals, the results were identical.

Jan 4, 2006