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Develop a user-friendly computer program that permits those interested in mine health and safety to access and analyze on a personal computer (PC) employment, production, and accident data for U.S. coal and metal-nonmetal mines. This software is being designed with a major focus on flexibility and case of use. The Mine Accident Decision Support System (MADSS) will be available for distribution in mid-1994. Currently, the U.S. Bureau of Mines (USBM) is seeking volunteers willing to pilot test a preliminary version of the software and to provide suggestions for its improvement. Background Since 1975, the Mine Safety and Health Administration (MSHA) has compiled large data bases of information about U.S. mines and the reportable accidents, injuries, and illnesses that have occurred in those mines. Employment and production data arc collected on a quarterly basis from each mine and accident information is collected on an incident -by-incident basis. The USBM has compiled estimated costs for each of these accidents using computer models. All of this information is potentially useful to mine health and safety researchers. However, it has been underutilized because it is stored in large mainframe data bases that arc inaccessible to many users and/or are cumbersome and difficult to use.

Jan 1, 1993

By Elizabeth G. Baglin

Research was conducted by the Bureau of Mines to determine the feasibility of using electrokinetic densification to dewater Bayer process red mud, magnetic black mud prepared by pressure digestion of red mud in the presence of ferrous sulfate, and magnetic black mud formed by simu-lated Bayer digestion of Jamaican bauxite with added ferrous sulfate. Tests showed that the solids content of presettled muds could be increased from 25 pct to approximately 40 to 48 pct by gravity draining followed by electrodewatering for approximately 48 h. Electrodewatering may not be practical because of increased reagent and processing costs and because the muds must be thoroughly washed prior to electrodewatering to remove dissolved ions and decrease mud conductivities.

Jan 1, 1988

By N. S. Dalal, X. Shi

"SUMMARYElectron spin resonance (ESR) measurements provide direct evidence for the involvement of the glutathionyl radical, as well as an isolable Cr(V)-glutathione intermediate in the Cr(VI) glutathione redox reactions. These results indicate a new mechanism for the reduction of Cr(VI) by glutathione in relationship to cellular environment and suggest that synergistic reactions of Cr(V) and GS· might be responsible for the (unexpected) increase in the Cr(VI)-induced DNA-strand breaks at high glutathione levels.INTRODUCTIONWhile the reduction of Cr(VI) by glutathione (GSH) is thought to be a critical' step in the pathogenesis of the Cr(VI)-exposure related carcinogenesis1- 4, the exact reduction mechanism is not yet understood. The following reaction steps have been suggested :(A) Initial step:Cr04 2- + GSH - GSCrOa - (1)(B) At high GSH levels:GSCroa- + GSH - Cr( IV) + GSSG (2)(C) At low GSH levels: GSC rO a - - Cr ( V ) + GS ·(3)Thus far, however, in these reactions, the GS· radical has eluded spectroscopic detection, while the evidence for the Cr(V) formation has been reported positives as well as negative2·. Her~ we present spin-trap ESR evidence for the formation of the GS· radical, and a definitive ESR detection of an isolable cr(V)-GSH intermediate in Cr(VI)-GSH reactions.MATERIALS. AND METHODSESR spectra were obtained at X-band (-9.7 GHz) using a Bruker ER200D ESR spectrometer. The magnetic field was calibrated with a self-tracking NMR Gaussmeter (Bruker, Model ER035M) and the microwave frequency was measured with a Hewlett-Packard (Model 5340A) frequency counter. The spin probes, a-(4-pyridyl-1-oxide) -N -tert-butylnitrone (4-POBN) and 5,5-dimethyl~1-pyrroline-1-ox1de (DMPO) were purchased from Aldrich, K2Cr201 from Fisher and used without further purification. All experiments were done at room temperature."

Jan 1, 1989

By Sean Gallagher, Thomas G. Bobick, Diane M. Doyle-Coombs, Richard L. Unger

The U.S. Bureau of Mines has developed an in-house facility to evaluate selected effects of whole-body vibration (WBV) levels experienced by underground mobile equipment operators, Vertical vibration data were collected from a coal haulage vehicle via a uniaxial accelerometer attached to the machine frame under the operator&apos;s seat. Data were analyzed and processed so a computer-controlled platform could approximate the vibration signals. Eight men (35.5 yr 2 6.5 SD) participated in a pilot study to evaluate the effects of shock and kBV on heart rate (HR), blood pressure (BP), and subjective discomfort. Subjects were exposed to vibration for 30-min periods while seated in a typical seat (backrest angle at 90° or 130°) &apos;that was plain steel or modified with 2 in foam padding. Subjects repeated the same protocol on a separate day, without the vibration. Results indicated the vibration significantly increased the HR (Q< 0.01), systolic BP, mean BP, the number of times subjects reported discomfort, and overall subjective discomfort rating (pc 0.85). When seated in the steel seat, the overall discomfort rating (E< 0,081) ad the number of times discomfort was reported (p< 0.05) increased significantly. Seatback angle had no significant effect on any of the dependent measures.

By R. E. Campbell

Uranium metal of improved purity was prepared by electrorefining commercial magnesium-reduced uranium in a molten sodium chloride-uranium trichloride electrolyte. The best operating conditions for the preparation of refined metal were established as follows: an electrolyte containing 8.7 to 13.3 weight-percent uranium; initial cathode current densities from 300 to 1,500 amp/sq ft; and a molten salt temperature of 860° C. Ingots produced from electrorefined uranium crystals prepared with these operating conditions were substantially free of metallic impurities. The only impurities in the refined and consolidated metal were present in low or undetectable amounts.

Jan 1, 1965

By Guy A. Johnson

Despite the use of warning alarms to alert miners to the backward movement of large mining equipment, miners still are injured too frequently in backup accidents. Currently approved backup alarm technology consists of continuous sounding alarm systems. New technology has developed a warning system that initiates an alarm only if there is an object close behind the vehicle. This advancement eliminates constant exposure to the alarm because a warning is given only in case of a potential collision. Adoption of this development can improve safety and reduce damage, especially for front-end loaders (FEL&apos;s). It will also eliminate a source of nuisance noise in urban and residential areas. This Bureau of Mines report describes the general characteristics of infrared (IR) light, ultrasonic wave, and Doppler radar technology as used for backup alarms, and reviews the testing of the most promising detection devices.

Jan 1, 1986

By A. T. Coumbe

The first national survey covering sales of fuel oil by States and principal uses was made in 1926 by E. B. Swanson of the Bureau of Mines (then under the U. S. Department of Commerce) under a cooperative agreement with the American Petroleum Institute. This annual study, covering the market for fuel oil, was made through 1930 with the financial help of the institute bat has since been continued by the Bureau up to the present time. The scope and coverage of the survey have gradually changed over the years as new uses for fuel oil have been found and new products have come into importance resulting in market expansion. Range oil (No. 1 fuel oil or kerosine) came into use for cooking and space-heating daring the depression era in New England, and it was first reported as a total in the 1931 survey. In 1934 the sales were compiled on a State basis. State totals for distillate fuel oil, Diesel fuel, and residual fuel-oil sales were first shown for 1934 and by principal uses and States in 1937. Kerosine deliveries by States and main uses were also released for the first time in 1937.

Jan 1, 1952

By Michael E. Henderson

Presented in this report are the experimental results of coarse coal slurry degradation data obtained from the Hydraulic Transport Research Facility (HTRF) at the Pittsburgh Research Center (PRC), Bruceton, PA. The facility is operated by Boeing Services International, under Bureau of Mines Contract No. J0333956. Presented in this report are the experimental results of coarse coal slurry degradation data obtained from the Hydraulic Transport Research Facility (HTRF) at the Pittsburgh Research Center (PRC), Bruceton, PA. The facility is operated by Boeing Services International, under Bureau of Mines Contract No. J0333956. This particle degradation report is a summary of the particle distribution data obtained at the HTRF for the period 26 November 1982 to 1 October 1983. The testing covered herein is for coarse Pittsburgh Seam coal in the 6-in (150 mm) and 12-in (300 mm) pipelines, at velocities ranging from 5 to 18 ft/s (1.5 to 5.5 m/s), and at concentrations by weight ranging from 15 to 55 pet. Particle size distribution samples were taken systematically throughout the testing.

Jan 1, 1985

By D. E. Redmon

Linear programing provides a mathematical technique by which activities can be planned in such a way that an optimal result is obtained. Routine applications of linear programing require only a knowledge of algebra. However, a complete understanding of the fundamentals of linear programing requires a knowledge of advanced mathematics. The purpose of this publication is clarification of terminology and illustration of applications in comparatively simple mining problems. Two mining situations are considered: Mine stopes from which ore is to be produced at a minimum production cost; also, uranium mines from which ore is transported to one mill, a maximum monetary value is desired. The details of data arrangement for solution by linear programing are described and the solutions are presented. Results of these solutions indicate successful applications of linear programing to mine production scheduling.

Jan 1, 1964

By P. J. Remington

Field measurements utilizing a seat pad accelerometer were made on 61 surface coal mining machines in order to quantify the vibration levels experienced by the operators. Those data were combined with information on the statistics of the operating times of those machines in order to compare the operator&apos;s vibration exposure to the criteria in ISO 2631, ?A Guide for the Evaluation of Human Exposure to Whole Body Vibration.? The comparison showed that about ha]f of all surface coal mining machine operators can be expected to be exposed to vibration exceeding the fatigue decreased proficiency criterion, whereas only on the order of 15% would be expected to experience vibration exceeding the exposure limit. Detailed exposure statistics are presented and the implications of the results are discussed.

Jan 1, 1983

By K. K. Kershner

Sulfide ore concentrates containing cobalt, nickel, copper, lead, and iron were salt roasted and leached on a laboratory scale. More than 95 percent of the cobalt, nickel, and copper was recovered. Heating patterns for salt roasting different concentrates were established. More cobalt, nickel, and copper were recovered from a bulk concentrate composed of a mixture of copper concentrate and iron concentrate. This mixture corresponded roughly with the mixture of these materials in stockpiles in southeastern Missouri. A temperature range of 375° to 400° C. was best for salt roasting. Metal chlorides were leached at a pH of 1 from chloridized charges of concentrates, Although the amounts of cobalt, nickel, and copper extracted were high, the amount of iron dissolved simultaneously interfered with subsequent separation and recovery of these metals. The amount of dissolved iron was reduced substantially by steam treating chloridized charges of bulk concentrate at 300° C. In this way, the ratios of cobalt, nickel, and copper to iron in leach liquors permitted satisfactory separation and recovery of these metals. INTRODUCTION The Federal Bureau of Mines is experimenting with chloridizing reactions.4 5 6 7/ Salt roasting of sulfide ores and concentrates, or their calcines, to form metal chlorides has certain advantages. Chlorides of

Jan 1, 1961

By R. J. Tocher

Uniaxial testing was performed on coal specimens to determine the time-dependent response. The testing was carried out on coal from six mine sites throughout the Western United States and Pennsylvania. Testing configurations were varied to allow analysis of moisture dependency, stress level and specimen orientation. Several theories were presented for the behavior of coal due to moisture diffusion. Experimental results showed the correlation between the theories and the actual material response. Coal deformation was found to be highly dependent on the moisture level of the testing environment. Moisture migration causes drying and shrinkage which lead to progressive degradation of the material. The coal tested experienced a rebound if saturated after a period of drying. This type of time-dependent behavior overshadows the dependence on the applied stress level, which, however, still produces a noticeable creep behavior. Analysis of one series of creep test results was performed. A relationship was developed on the basis of a simplified rheological model to describe the coal response to uniaxial stress. Previous empirical formulations in the form of power laws were compared and their deficiencies pointed out.

Jan 1, 1980

By R. W. Stahl

A survey of firefighting facilities and practices in coal mines conducted by the Bureau of Mines3/ showed such variations in equipment and apparent attitude toward fire protection that a comparison with other industry seemed advisable. Although other industry is confined generally to surface operations and the hazards probably are not as great, the same general methods of extinguishment are employed, so that the cost and protection at least should be comparable. An investigation of industry other than mines revealed a generally greater emphasis placed on fire-combating equipment, fire-brigade training, fire-fighting facility inspection, and fire-hazard elimination, as well as a greater average expenditure for fire protection.

Jan 1, 1959

By Alla D. Mah

The energies of combustion of zirconium carbide and hafnium carbide were measured by combustion calorimetry and the heats of combustion and formation. of zirconium carbide and hafnium carbide were derived . The results are-- ZrC AH298.15 ( combustion) = -308.60 ± 0.55 kcal /mole , AH298.15 ( formation) -47.0 ± 0.6 kcal /mole , AH298.15 = HfC (combustion ) = -306.08 ± 0.20 kcal/mole , AH298.15 ( formation) -52.3 ± 0.4 kcal /mole . = INTRODUCTION This report contains the results of calorimetric measurements to obtain the heats of formation of zirconium carbide ( ZrC) and hafnium carbide ( HfC) . The work was conducted as part of a Bureau of Mines program for determining the heats of formation of oxides , carbides , and nitrides by combustion calorimetry . Combustion calorimetry is one of the most precise calorimetric techniques . The chief obstacle to obtaining accurate heat of formation values for carbides , and the chief reason for the variation in the results of different investigators , is the lack of purity of the carbide samples . Corrections for impurities always involve assumptions which lead to uncertainties . In general , a large impurity correction is accompanied by a large uncertainty in the final result .

Jan 1, 1964

By F. P. Haver

Because of increasing concern with air pollution, the Bureau of Mines has developed a hydrometallurgical procedure to obtain elemental sulfur from chalcopyrite (CuFeS2) by means of the following reaction: CuFeS2 + 3FeCl3 ? CuCl + 4FeCl2 + 2S. Under optimum conditions, 99.6 percent of the copper and 71.6 percent of the iron were extracted in 2 hours from a typical mill concentrate containing 75 percent CuFeS2 and 15 percent pyrite (FeS2). At the same time, 68.2 percent of the sulfur in the concentrate was oxidized to the elemental form. The leach was highly selective; gangue minerals, including pyrite, were not attacked, thus accounting for the relatively low recoveries of iron and sulfur. To obtain these results, the concentrate was ground to 98.9 percent minus 325 mesh, and 300 grams was treated with 1 liter of boiling ferric chloride (FeCl3) solution. The FeC13/CuFeS2 ratio was 2.7. Cement copper containing 99.9 percent copper was recovered from the leach solution by cementation on sponge iron. Excess iron, dissolved during leaching and cementation, was removed from the stripped solution by crystallization. Ferrous chloride (FeCl2?4H2O), obtained as a byproduct, was converted to high-purity ferric oxide (Fe203) and HCI by an oxidizing roast. The hydrochloric acid was then electrolyzed to obtain chlorine, which was used to regenerate the leach solution. The leach residue, which contained ~50 weight-percent elemental sulfur, was treated with an organic solvent to recover the sulfur and cyanided to reclaim gold and silver.

Jan 1, 1971

By H. H. Dewing

The U.S. Bureau of Mines characterized Hg-containing wastes and used a thermal-desorption process to remove and recover the contained Hg. The wastes were generated by an electrical-parts plant engaged in the assembly of Hg-containing switches and contained phenolic resins and paper insulating materials mixed with soil. The average Hg content was 396 ppm. Numerous characterization tests showed the Hg was tightly absorbed and could not be removed or concentrated by leaching or gravity separation techniques. Laboratory retort tests showed the Hg content reduced to < 16 ppm in 2 h at 400 °C; rotary-kiln, thermal-desorption tests required 4 h at 450 °C. Airflow through the retort im¬proved thermal-desorption efficiency, but vacuum operation only slightly reduced the temperature needed for thermal desorption. Offgases from decomposition of organic materials were burned in a high-temperature afterburner and subsequently cooled in a heat exchanger to condense water vapor. Finally, the Hg vapor was condensed and absorbed from the offgas by activated charcoal. Mercury recovery was over 99.99 pct of the desorbed Hg. Thermal-desorption processes have had wide application to many Hg-containing wastes, and historical experience in Hg mining has demonstrated its potential cost effectiveness.

Jan 1, 2010

By Gregory B. Beacher

Analyses have been performed on geotechnical properties of copper, uranium and phosphate (gypsum) tailings materials, with the intent of identifying typical measures of variability within and among sites, and of characterizing such variability for use in reliability modeling of tailings embankments. In all, data from approximately 41 sites were analysed. Fairly consistent results were obtained for within site variabilities. However no one probabilistic model was found to be applicable to all sites. The distributional forms for most of the data sets are regular, and tend toward Normality when spatial trends are removed. At many of the sites sufficient in situ data were available to allow estimates of vertical autocorrelation distances and measurement noise. Available data indicate that variability in pore pressures may have a more important effect than strength property variation. A major problem in interpreting available strength property data results from the unknown drainage conditions during testing.

Jan 1, 1983

By Slavoljub D. Maksimovic

At some coal mines, methane gas is released during raise drilling. At the request of the Mine Safety and Health Administration (MSHA), U.S. Department of Labor, the Bureau of Mines conducted ventilation surveys at different raise drill sites to assess various methods of reducing methane concentration. The resulting data indicate that raise drill shaft cavities are ventilated by air compressors, vacuum pumps, auxiliary blower fans, and free intake air from the surface. The compressors, pumps, and fans operate simultaneously or separately. At the bottom of the shaft cavities, ventilation is controlled by regulators and airlocks. Methane is monitored, measured, and periodically sampled on the surface, at the bottom, and at different levels in the shaft cavities. Maximum concentration of 3.5 percent was measured in one shaft in West Virginia. Air velocity down the raise drill shafts is always very low, Maximum recorded air down the drill stem was 3,000 cfm, which can be increased by adding air compressors. The best way to ventilate shaft cavities is through the simultaneous use of air compressors and vacuum pumps. If the methane concentration cannot be reduced with additional compressors, then the inside diameter of the drill rod should be increased, or larger pilot hole drill bits should be used.

Jan 1, 1981

By Everett A. Sondreal

Data are presented on the characteristics of lignites with emphasis on the composition and fusion properties of the ash. Differences in the analyses of commercial-grade lignites are related primarily to variations in moisture and ash contents. Lignite ash is generally characterized by high concentra¬tions of alkaline earth oxides and a greater tendency for retention of sulfur in the ash than higher-rank coals. Composition of ash varies significantly within and between mines. The differences within mines are significant for short distances and may be eliminated under certain circumstances by normal mixing occurring during mining. The sulfur in lignite averages 0.6 percent and is found primarily in the organic or pyritic forms with only a trace of the sulfate. During the stan¬dard laboratory asking procedures, from 60 to 100 percent of the original sul¬fur is retained in the lignite ash. Trace elements, such as uranium and germanium, in the ash from commercial¬-grade lignites are present in low concentrations, but others, primarily copper and silver, are present in specific samples in concentrations approaching those found in some commercial ores.

Jan 1, 1968

By Zsuzsanna Zborovszky

Study of the energy transfer from an inductive circuit to the discharge under the conditions of the minimum discharge voltage being smaller than the source voltage. Analysis of the effect of the electrode separation speed on the duration and maximum power amplitude of the discharge. Recommendation for optimal electrode setting. Experimental data on the variation of maximum discharge power required for ignition as a function of volumetric gas content for methane-air and propane-air mixtures. Experimental determination of the ignition limit for discharges derived from a 24, 15, 10 and 6v inductive-resistive circuit in 8.3% methane-air mixture by using the PTB breakflash with Cd disc and W wires, and also with Cu disc and BeCu wires. Method for calculating ignition limits for other source voltages.

Jan 1, 1978