Search Documents

By J. C. Fowler

[This i.untra t hds bmii III c'IIILt fur till- past 1':?:u yrlr;, Till-- wurir pnrfor rw:it '. ,JS hlui.rn dawn Ilttf lit Iu i eel i ih?IS( S. 1 hesrt aIII, Phase I Candor tlri I a lest It) donurnSlrale SeiSrrlir nurihudS to hu USi!d lot ttlr? rti?tei thin and Iu" ainnl ul trapped rrlinc:rs hitting (-)it the roof with a harnrner, Phase I' Design and cunStrur.t a permanent Seismic monitor System to rrlunrtur roof (ails arm r:xploslun', III ,r 'Vol king mine. Phase III - Ire dII an an i i irr for sVstl rtl Ii i`'Smltur air quality in till, niitii iiH II ? ir,iti tin; niln !III ;I I ,, i; Phase I V - Conduct 11(21 d tests of the seismic IT IUnit UT ieq system fur a period nl two 11IUIIIIIS. Phase, V - Condirct three test periods of the seismic system over a period of six mimilis. Detailed reports covering the wurk. done in Phases I, 11, and IV have been i : . r tr I - i t report will, therefore, cuni.entrate on the work perfurmed in Phases III anti V.]

Jan 1, 1975

By Steven J. Page

Since 1982 standard calibration materials recommended for respirable crystalline silica analysis by the Mine Safety and Health Administration (MSHA) P7 Infrared Method and the National Institute for Occupational Safety and Health (NIOSH) X-ray Diffraction (XRD) Analytical Method 7500 have undergone minor changes in size distribution. However, a critical assumption has been made that the crystalline silica in ambient mine atmosphere respirable dust samples has also remained essentially unchanged in particle size distribution. The objective of this work, therefore, is to compare recent particle size distributions of underground coal mine dust and the silica component of these dusts with estimated aerodynamic particle size distributions of calibration standard materials MIN-U-SIL 5, Berkeley 5, and SRM 1878 used by two crystalline silica analysis techniques. This work provides resolution to a previously reported discrepancy involving the proper sample dilution for the particle sizing method used. Dust impactor sampling data for various locations in 13 underground coal mines were collected between 1991 and 1998 and analyzed for the respirable mass median aerodynamic diameters. The data suggest that the MSHA P7 Method will underestimate the silica content of the sample by at most 8.5 % in the median size range of 0.9–3.6 µm and that it is unlikely one would obtain any significant error in the MSHA P7 Method analysis when the method uses Berkeley 5, MIN-U-SIL 5, or SRM 1878 as a calibration standard material. The results suggest that the NIOSH Analytical Method 7500 would be more appropriate for a dust sample that is representative of the total (no cyclone classifier) rather than the respirable airborne dust, particularly since the mass fraction in the size range below 4 µm is usually a small percentage of the total airborne dust mass. However, the NIOSH Analytical Method 7500 is likely to underestimate the silica content of an airborne respirable dust sample by only 5–10 %. The results of this study also suggest that any changes that may have occurred in the median respirable size of airborne coal mine dust are not significant enough to cause any appreciable error in the current methods used for respirable crystalline silica analysis.

Aug 3, 2005

By C. Lurie

This final report describes the work performed by Gulton Battery Corporation under USBM Contract No. HO-112033, entitled "Research and Development on Lithium-Nickel Fluoride Batteries For Mint Life Support Equipment". The lithium-nickel fluoride couple was chosen For this investigation because of its high theoretical energy density (626 Wh/lb), its ability to operate at ambient temperatures and the fact that it showed promise as a secondary system. The theoretical energy density of the lithium-nickel fluoride couple is ten times greater than that of the widely used lead-acid battery and three times greater than the silver-zinc battery which has the highest theoretical energy density of the commercially available secondary systems. The experimental program first evaluated the cell components individually. The results of these studies then formed the basis for investigations of cell performance using experimental three-plate cells. These cells consisted of one nickel-fluoride and two lithium electrodes. All work was performed in a glove box under an argon atmosphere which was sufficiently pure to maintain the shiny appearance on freshly prepared lithium surfaces. The major portion of the work effort was concerned with the nickel fluoride electrode. Binder, conductive diluent, fabrication technique, as well as the nickel fluoride active material itself, were considered. Criteria for binder materials were established and six classes of materials encompassing thirteen binders were evaluated. The candidate materials were initially screened for appropriate chemical and physical properties and finally evaluated in three.-plate cells, Two epoxy powders emerged as the most promising binders. Two types of conductive diluent were evaluated. The first is a carbon black of low bulk density and high surface area. This material is a good conductive diluent; however, electrodes fabricated with it lacked good mechanical strength. It was hypothesized that a uni¬form, small particle size, low specific surface area would improve the mechanical properties of the electrodes. Therefore, two samples of graphicic materials, milled to uniform powders in the one-to-ten micron range were evaluated. Electrodes prepared with the graphitic materials had superior mechanical properties, However, their electrical performance was significantly poorer and voltage losses of 0.2 to 0.3 volts were observed. Several electrolyte solutions were evaluated. N-Methyl-2-Pyrrolidone was tested but found to be incompatible in the presence of lithium. Lithium perchlorate, lithium hexafluoroarsenate, and lithium bromide were tested as two-component electrolytes in propylene carbonate solvent and their performance compared with that of the single electrolyte solutions, Lithium perchlorate gave the best performance. Lithium hexafluoroarsenate was also evaluated in methyl formate and appears to give equivalent performance. The lithium perchlorate-propylene carbonate system is preferred as it is easier to handle and less expensive.

Jan 1, 1973

By August J. Kwitowski

This report presents the results of a joint Bureau of Mines-U.S. Department of Energy project that evaluated a newly developed low-coal mining system: the 4M miniminer system. The evaluation took place from April through October 1981 and determined potential health, safety, and productivity factors for the mining system using the surface test facilities at Bruceton, PA. The planning, testing, results of testing, and a summary evaluation of the 4M miniminer system are included in the report. The miniminer system was found to be a very good concept with future potential for safe, healthful, and economic production in thin-seam mining. The mining system was also judged to have considerable potential for use in some coal seams that are presently considered unminable by other existing mining equipment. The preproduction, prototype version of the miniminer system that was tested suffered from several safety and production problems. These problems are also described, along with suggested remedies.

Jan 1, 1989

By Jerry J. Gray

Transportation charges for mineral commodity movements in western Oregon and western Washington were determined mainly by a stratified random sample canvass of producers. Total 1965 mineral production value for this area was $53.3 million; the cost or charge to move this production from the mine to the consumer or to the point of consumption was determined to be an additional $38.7 million. Thirty seven companies were contacted as a sample out of a total population of 349; the statistically expanded sample production value deviated 3.6 percent from that obtained by the Bureau's annual canvass. The agreement between the sample results and the canvass totals demonstrated the effectiveness of the sampling method for obtaining data with a predesigned level of accuracy. For comparison, the north-central Idaho and western Montana area was studied, A random sample experiment was designed, but because of the dominance of a few major companies, a random sample technique would have required more visits to producers than if only the larger firms were contacted. Eighty-four percent of the 1966 mineral value ($198.6 million) was accounted for by interviewing 27 firms out of a total population of 199. Total transportation costs or charges for the area were $26.7 million. The significant difference observed between the relationship of minerals production value and transport charges between the two areas investigated can be attributed to the difference in the minerals produced. The western Oregon and western Washington region is a nonmetals-producing area as opposed to the predominance of metals production in the Idaho-Montana region.

Jan 1, 1968

By W. H. Somerton

The basic objective of this project was to determine the permeability of coal fracture systems as a function of effective stress. The detailed steps in accomplishing this objective are given in Article I of the contract under which the work was conducted as follows: Sec. 1.1 The objective shall be to determine the permeability of the coal fracture system as a function of effective stress. At least three bituminous coals shall be studied and at least five samples of each coal shall be tested. The sample size shall be as large as possible to be representative of coal found in the seam; a minimum of four inches is preferred.

Jan 1, 1974

By Thomas J. Peters

A mineral survey of the Sill Hill RARE II area (No. 5304), covering 5,200 acres (2,100 ha) of the Cleveland National Forest, San Diego County, California, was conducted by the U.S. Bureau of Mines and the U.S. Geological Survey. This survey was in conformance with the Resource Planning Act (RPA) of 1974, as amended by the National Forest Management Act of 1976, to provide mineral resource information for study area classification. Bureau of Mines personnel made an economic appraisal of mineral deposits by searching pertinent geological and mining publications as well as U.S. Bureau of Land Management, U.S. Forest Service, and U.S. Bureau of Mines files and records. Known mines, prospects, and mineralized localities were examined during 1981, and sampling and mapping were done where warranted. The Geological Survey 'did geologic mapping, geochemical sampling, and geophysical surveys to aid this study.

Jan 1, 1983

By Walter W. Kaufman

This report summarizes a study conducted to determine the state of the art of various rock removal systems and their capabilities. The objective of the study was to determine if currently manufactured equipment can adequately accomplish rock removal in surface mine reclamation applications. Evaluations of state reclamation regulations, with regard to topsoil rock content, were made to determine the rock removal requirements. The major categories of equipment studied are rock pickers and rock rakes. The impact of rock removal implementation on the reclamation operations is discussed in detail.

Jan 1, 1979

By John R. Benham

In 1979 and 1980, the U.S. Bureau of Mines and U.S. Geological Survey conducted a mineral survey of the 20,500 acre Black Butte RARE II area (No. 5102) in the Los Padres National Forest (fig. 1). The work by the Bureau of Mines indicates that the potential tor mineral resources in the area is low. Samples of outcrops and stream channels contained no economic minerals. A mercury deposit near a granodiorite-sedimentary rock contact occurs 2 mi northeast of the study area, but similar deposits have not been discovered within the area. Geothermal potential exists near Tassajara Hot Springs, but no thermal springs occur in the area; nor have oil, gas, or coal resources been found.

Jan 1, 1982

By R. V. Ramani

This report is volume 3 of an eleven-volume final report for a Grant completed by The Pennsylvania State University for the Bureau of Mines to develop a dynamic general purpose computer simulation model for underground coal mining. The simulator developed under the Grant has a wide range of possible applications in the design and evaluation of underground coal mining systems from the standpoints of health and safety, productivity, and mine environment. The Master Design Simulator consists of nine free-standing function-oriented subsystem models linked together into an integrated, comprehensive model of an entire mining system. The subsystems comprising the Master Design Simulator include geology and reserves, methane generation, roof support, subsidence, production, rail haulage, cost, water generation,' and ventilation. This volume of the final report describes the Methane Generator subsystem of the Master Design Simulator. This subsystem is used to determine methane emission rates into the mine environment. These flow rates are then used by the simulator in planning primary and secondary ventilation systems, planning a methane drainage system, and analyzing complex ventilation networks. Both steady state and unsteady state gas flows are included, and have been modeled as second order nonlinear partial differential equations. Finite difference equations are used to obtain numerical solutions to the models using a central differencing scheme. An application of the model is presented. The appendices include derivation of the gas flow equations used in the model as well as a users manual for the computer program.

Jan 1, 1974

"Requests are frequently received by the Information Service of the Bureau of Mines for published information on the coals of different foreign countries, as compared with coals mined in the United States. The analyses of various coals from several countries on the Pacific, which were submitted to the Fuels Division for certain tests between the years 1913 and 1916, may be of interest, and are shown below: Results of Analyses of Various Coals from China, New Zealand, Japan and Australia."

Sep 1, 1925

By Paul C. Hyndman

The U.S. Bureau of Mines investigations of the three subunits (fig. 1) of the Homestead RARE II area (No. 6291) revealed no evidence of mining activity or mineral deposits in the area. The Iron Dyke Mine, 3 mi (5 km) outside the study area produced ore between 1916 and early 1982 from a volcanogenic massive sulfide deposit in the Permian volcaniclastic Hunsaker Creek Formation of the Seven Devils Group. The Hunsaker Creek Formation does not crop out in the RARE II area, but extends into the area beneath Miocene flows of Columbia River Basalt. The abundant basalt in the area could be used as aggregate or dimension stone, but equivalent deposits exist closer to markets. INTRODUCTION Location and Access The Homestead RARE II area (fig. 1) encompasses 6260 net acres (253U ha), in three units, of the Wallowa-Whitman National Forest in Baker and Wallowa Counties, Oregon. Two small units of 160 and 300 acres (65 and 120 ha) are 5 mi (8 km) north and east of the main study area. Homestead, Oregon, on the Snake River, is about 3 mi (4 km) south of the two small areas, and about 3 mi (4 km) northeast of the main study area. Peripheral access is provided by State Highway 86, U.S. Forest Service Road 39, and ancillary roads and trails.

Jan 1, 1983

By Phillip R. Moyle

A cobalt/manganese occurrence in Clark County, Nevada was the subject of a site-specific mineral investigation by the U.S. Bureau of Mines in 1988-90. The study site is in the northern part of the Million Hills (wilderness) study area which is administered by the Bureau of Land Management. Field work during a period of one week consisted of geological mapping and sampling of workings and outcrops, and geochemical and geophysical surveys conducted on four transects totalling 7,600 ft. Although the concentrations of cobalt (0.1 to 0.5 percent) detected in samples from the fissure zones are within the range of grades associated with world-class economic deposits, the volume of material enriched in cobalt at the study site is insufficient to warrant consideration as a potential resource. Concentrations of manganese, nickel, copper, lead, zinc, barium, and thallium, although anomalous, are too low for economic consideration. At the study site, workings consist of three trenches and nine pits. The exploration history is unknown, and no production is reported.

Jan 1, 1990

By C. M. St. John

A series of analyses of possible mining excavations associated with the development of copper nickel deposits of the MINNAMAX site in Northeastern Minnesota is presented. Specific areas such as roof and pillar stability and excavution orientations are addressed. The majority of these analyses were conducted using a boundary element method but some cases were also analyzed using the finite element method. Comparable results were obtained using the two methods but the boundary element method required less data preparation time and computer run time. Results of the analyses, as well as indicating the capabilities of geotechnical numerical models, provide some insights into behavior around multiple excavations in jointed rock.

Jan 1, 1979

By B. V. Johnson

The Federal Bureau of Mines has conducted research in support of the National Aeronautical and Space Administration's (NASA) Apollo program to acquire fundamental scientific and engineering knowledge of lunar-mineral resources for NASA's Office of Advanced Research and Technology. Equipment and techniques were developed to conduct soil shear tests in a simulated lunar environment. Shear tests performed with this equipment in ultrahigh vacuum and controlled laboratory atmosphere showed that simulated lunar soil increased in strength in the simulated lunar environment.

Jan 1, 1973

By Steven W. Schmauch

A mineral survey by the U.S. Bureau of Mines and U.S. Geological Survey indicate the Blanco Mountain RARE II area has low potential. Lode deposits consist of small, mineralized quartz or quartz-gossan veins. The veins are sparse and widely separated and lead, silver and gold content is restricted in amount and concentration. No gold or other potentially economic minerals were found in a placer deposit. There is no evidence of industrial mineral, geothermal, or energy resource potential in the study area. INTRODUCTION A mineral resource survey of the Blanco Mountain RARE II area (No. 5059), Inyo and Mono Counties, California was conducted in July 1981. This report summarizes the results and interpretations of the Bureau of Mines investigation.

Jan 1, 1982

By J. V. Batty

Radioisotopes of selenium (se78) and tellurium (Te123) were successfully employed by the Bureau of Mines as tracers in metallurgical research directed to developing improved methods for volatilizing these elements from low-tenor raw materials. Prior research, guided and controlled by conventional analytical methods, was seriously hampered by inconsistent selenium and tellurium analyses, by the slowness of the conventional chemical methods, and by the poor accountability of these volatile elements in test products. Methods were devised and evaluated for admixing the radioactive tracer with typical raw materials and then following the deportment of the selenium and tellurium by radiometric methods with occasional chemical analysis checks. These techniques were found unusually effective in (1) quantifying the completeness and the rate of volatilization of selenium and tellurium while heating the raw materials at different rates to different temperatures and (2) accurately tracing and quantifying the distribution of minute amounts of these volatile elements in the several products made by high-temperature treatment and in the several units comprising the experimental equipment.

Jan 1, 1962

By L. R. Herrmann

The most fundamental feature of fracture is that it involves separation. Such separation can arise by either separation of molecules, more or less along the line joining their centers (tension), or by d sliding separation roughly perpendicular to that line (shear). Theoretically, a perfect crystal could never be broken by the application of perfectly axial compressive stress (until some sub-molecular actions occur). In tension fields the calculated forces between molecules are extremely high. Consequently, calculations based on the forces known to exist in materials at the molecular and crystalline levels always lead to strengths which are two or three magnitudes higher than the strengths obtained in service or in the laboratory. It has been a major problem, therefore, to explain: (a) How fracture can occur in compressive stress states. (b) Why the observed strength of a material is always much lower than its calculated strength.

Jan 1, 2012

By Eric E. Unger

Results are presented of a census of the machines used in surface coal mines in the United States. The numbers of each machine type and model reported to be in use are tabulated for large and small mines in the Eastern, Central, and Western regions. Also tabulated are the average daily usage times of the major machine categories and the numbers of machines that have acoustical and other cabs. Projections of the total numbers of primary production machines are given. It is found that heavy tracked dozers and wheeled front end loaders constitute the most prevalent machine types, and that generally a very few models of machines made by one or two manufacturers constitute a major fraction of the population in each machine category. About 70 percent of all machines are reported to have some kind of cab, and about half of these are reported to be acoustical gabs; it is noted that acoustical cabs generally came into significant use since about the early 1970's. It is observed that the percentage-wise mixes of equipment types used in the various categories of mines differ significantly for only a few types of machines, notably for heavy dozers and loaders, and for haulers, highway trucks, and internal-combustion engine-powered shovels and draglines.

Jan 1, 1977

By Chris Nelson

Two pieces of European Union (EU) legislation together establish requirements for protection against risks from vibration at work. The vibration directive1 specifies duties of employers to protect workers from risks from exposure to vibration; the machinery directive2, specifies duties of manufacturers and suppliers regarding the safety of machinery marketed in the EU. This paper discusses both directives and the standardisation programmes that support them. It also addresses the implementation of these requirements in Great Britain. Employers’ duties: the vibration directive This directive requires employers to assess and control risks to health and safety arising from hand-arm vibration (HAV) and whole-body vibration (WBV). Member States were required to implement the directive in national legislation by 6 July 2005. Employers are required to eliminate vibration risk at source, or reduced to a minimum. The duties include: assessing risk and exposure; planning and implementing the necessary risk control measures; providing and maintaining suitable work equipment; providing workers with information and training on risks and their control; and monitoring and reviewing the effectiveness of the risk control programme. Daily exposure exceeding a specified action value triggers a requirement for a programme of technical and organisational measures to minimise vibration exposures and the resulting risk, and the provision of health surveillance. Exposures above a specified limit value are prohibited. When conducting their risk assessments, employers are required to “assess and, if necessary, measure” the vibration exposure of workers, for comparison with the action and limit values. Vibration measurement in the workplace is not expected in all cases and the use of vibration information from equipment manufacturers is specifically mentioned. This provides a link with the machinery directive (see below). Manufacturers’ and suppliers’ duties: The machinery directive The machinery directive, first introduced in 1989, is intended to remove barriers to trade. It puts duties on manufacturers and suppliers who place machinery on the European market to design their products to eliminate or reduce risks to health and safety and to warn the user of any residual risks, providing information required for safe use (for example, operator training, maintenance and selection of consumables). There are specific requirements for minimising risk from vibration in the design and construction of the machine and, in the case of hand-held, hand-

Jan 6, 2006