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By A. L. Engel

This report is a compilation of results of preliminary concentration tests of seven manganese-ore samples. Six of the seven samples were submitted through the Mining Division, and 1 from Mexico was submitted by H. A. Doerner, formerly chief metallurgist, Region III. These investigations were made to assist development of mineral resources and particularly to aid economical exploitation of marginal or complex ores, from which strategic or critical minerals may be recovered.

Jan 1, 1953

By Gerald T. Homce

Data from the U.S. Bureau of Labor Statistics show that 89 water well drillers died on the job between 1992 and 2002, and 28 of these deaths were electrocutions (Figure 1). In fact, elec­trical accidents are the leading on-the-job killer of water well drillers. The use of electricity is such an integral part of our lives that we usually take it for granted, but if we don?t understand or choose to ignore the hazards associated with electricity, the results can be deadly. Why is electrical shock so dangerous? If the voltage (of a shock) is sufficient to drive electrical current through your body, just 10 milliamps of cur­rent (1000 milliamps = 1 amp) can cause muscles to contract and prevent you from releasing an energized wire or tool in your grip. As little as 30 milliamps of current can paralyze your breathing, and 75 milli­amps can cause your heart to stop pumping blood (ventricular fibrillation). As a comparison, a small bedroom night-light draws about 30 to 60 milliamps. Other factors influence how severely you?ll be shocked if you touch a live electrical circuit, such as the path electrical current takes through your body and how long it flows, as well as your body weight. How much voltage is needed to drive electrical cur­rent through your body? Not much! Generally, any power source at 50 volts AC or higher is considered dangerous.

Jan 1, 2008

By J. C. Gerdeen

This project was a supporting effort with research contract H0230016 at White Pine Copper Company. Creep properties of White Pine rock were determined. These and properties for bolted joints were used in finite element analyses of sections of the White Pine Mine which included analysis of bed separations in the roof and sloping faults. In-situ experimental measurements were made of tension, compression, and bending of resin bolts by use of strain-gaged bolts. Evaluations of bolting effectiveness and comparisons of predicted and measured roof behavior are given.

Jan 1, 1976

By D. Denton, M. Stickney, R. Langston

The National Institute for Occupational Safety and Health and the Stillwater Mining Company worked cooperatively with the Montana Bureau of Mines and Geology to develop a system that would collect seismic data at the Stillwater and East Boulder mines. The purpose was to obtain baseline information on the magnitude and location of mining-induced seismicity to determine if the mines needed multi-channel in-mine monitoring systems. Seismic data recorded at field sites near the mines are being telemetered via FM radio through a series of repeaters to a central recording site where the seismic signals are digitized using an Earthworm data acquisition system. The Earthworm system performs several data analysis tasks in near-real time and places raw seismic data, preliminary hypocenter locations, and magnitudes on a Website within 5 min of a seismic event. Such rapid access to seismic data allows personnel at the Stillwater Mine, Spokane Research Laboratory, and Earthquake Studies Office to evaluate seismic events quickly and respond in ways that may improve the safety of mine personnel underground. Installation of the system also broadened earthquake coverage to south-central Montana, a region previously not covered by the seismograph network.

By Homer J. Ballinger

"SUMMARYDuring December 1945, the Bureau of Mines began churn drilling the Winchester zinc deposit, 11 miles south of Joplin in Newton County, Mo. The deposit lies in a virgin area northwest of the Seneca fault. It is one of several deposits partly proven by drilling but never developed.Logs of 28 privately drilled holes had indicated a substantial tonnage without delimiting the deposit. It appeared that additional drilling might increase this reserve sufficiently to justify mining. A, total of 6,33 feet of churn drilling was completed in 17 holes drilled by the Bureau of Mines. Twelve of the holes penetrated minable ore extending the length of the known deposit and materially increasing its estimated tonnage.INTRODUCTIONDuring May 1943, the Winchester property in Newton County, was visited by an engineer 3/ of the Bureau of Mines, accompanied by Dr. A. N. Winchester, owner, and Charles Keith, lessee of the property. At the request and with the assistance of these gentlemen, examination of the property was undertaken. Logs of 28 churn-drill holes were collected, hole locations were surveyed, and available historical data were obtained. It was concluded that although existing drill holes indicated considerable reserves, additional drilling might increase the tonnage substantially. In addition, it was believed that better knowledge of this ore deposit could be obtained by drilling further, and this knowledge could, in turn, be applied to other less proven deposits in the same field."

Jul 1, 1947

By L. W. Kelly

The purpose of this paper is to describe several methods that have been employed in successfully recovering roof bolts in Indiana, Illinois, and western Kentucky coal mines, the States where successful roof-bolt recovery was started. As far as is known, the first bolts were recovered in a mine in western Kentucky in January or February 1951. In April 1951 a meeting was held at that mine to discuss the recovery of roof bolts. The meeting was attended by A. D. Sisk, former Chief, Kentucky Department of Mines and Minerals; and L. W. Kelly, Federal Bureau of Mines; and officials of the coal company. Inasmuch as roof bolting was in its infancy, the thinking regarding roof bolts at that time was on the problem of getting them in, not getting them out; consequently, the thought of recovering them was revolutionary. The subject was discussed at length from all angles, and it was finally agreed that, if certain safeguards were taken, no agency represented at the meeting would oppose the practice. That this decision was sound has been proved, as thou-sands of bolts have been recovered in the Middle West without a lost-time accident. Recovering roof bolts is a simple operation; consequently, no complicated equipment had to be designed or built for this purpose. However, about 5 years ago, officials of the Traux-Traer Coal Co. conceived the idea and constructed a mechanical device for recovering bolts that has been very successful and has been copied widely in this area. This device will be discussed in detail in part II of this paper.

Jan 1, 1958

By James J. Dowd

The investigation to evaluate the reserves of coking coal is being made by the Bureau of Mines in three parts: (1) To estimate known (measured plus indicated) recoverable reserves of all coking coal; (2) to upgrade marginal coals through effective preparation; and, (3) to study the carbonizing properties of coal and coal blends not now widely used for metallurgical coke. This is the third of a series of reports giving results of studies by counties under part (1) of the investigation. This report covers Pike County, Ky., which comprises parts of the Harold, Williamson, Matewan, Gilbert, Pikeville, Regina, Hurley, Pound, and Clintwood quadrangles. (See fig. 1.) A base map for each bed in each quadrangle was made to the scale of 1 inch equals 1,200 feet. Maps of mines, locations of drill holes, bed and total coal thicknesses, and the outcrop of the bed were plotted on the maps. With all available data plotted, isopach lines were drawn to limit areas of known unmined reserves in beds 0 to 14 inches thick, 14 to 28 inches thick, 28 to 42 inches thick, and over 42 inches thick. These areas of coal reserves also were divided into "measured" and "indicated" categories. All areas in each thickness range and in each category, mined-out areas, areas excluded from the estimate but which may contain reserves based only on geologic inference, and areas outside of the outcrop were measured by planimeter on the base maps. Estimates of total reserves 14 inches and more thick and maps for individual beds were prepared from these data.

Jan 1, 1951

By M. J. Ferrante

The Bureau of Mines determined the enthalpies of Ni3S2 relative to 298.15 K to provide new thermodynamic data for advancement of mineral science and technology. Enthalpies were measured with a copper-block calorimeter from 298.15 to 1,197 K. A solid-solid transition was found at 834±1 K, with an isothermal heat absorption of 13.32 kcal/mol. The temperature of this solid-solid transition was accurately measured by differential scanning calorimetry. Because Ni3S2 does not melt congruently, the heat of fusion of 4.70 kcal/mol was obtained by extrapolation of enthalpy measurements from the solid and liquid phases to approximately 1,064 K. Tabulated values are given for the relative standard enthalpy, heat capacity, entropy, and Gibbs energy function between 298.15 and 1,800 K. Enthalpies are also given in equation form and combined with data from the literature to derive values of standard enthalpies of formation and Gibbs energies of formation. Similar calculations were made for the reaction of crystalline and liquid nickel with gaseous diatomic sulfur for Ni3S-2(c, l).

Jan 1, 1982

By B. K. Cantrell, K. L. Rubow

"Two source apportionment techniques have been applied by the U.S. Bureau of Mines to aerosol measurements in diesel-equipped underground noncoal mines. The first technique is based on size-selective sampling and the premise that the diesel exhaust fraction of the aerosol is predominately submicrometer in size while the mineral dust fraction of the aerosol is mostly supermicrometer in size. The second technique, chemical mass balance (CMB) modeling, was used to referee the analysis of diesel and mineral dust aerosol concentrations with the size selective method.The size-distribution data were modeled using a lognormal regression to parameterize the submicrometer and supermicrometer fractions of the sampled aerosol and to estimate the mineral and diesel contributions to each. Using this analysis, 97 ± 2 pct of the submicrometer aerosol mass was attributable to diesel exhaust aerosol.The CMB analysis, applied to both fractions of the respirable mi11e aerosol, yielded the amount contributed to each by the diesel and dust aerosol sources. On the basis of this analysis, 94± 10 pct of the submicrometer fraction was diesel exhaust aerosol. As much as 20 pct of the diesel aerosol, however, was found in the supermicrometer fraction, requiring a correction of the submicrometer fraction results to account for the missing diesel mass. More accurate measurements will require a carbon-specific analysis of the aerosol.INTRODUCTION Measurement of the contribution of diesel exhaust to respirable aerosol in mine environments has become increasingly important because of current concerns over the occupational health effects resulting from exposure to diesel emissions. In response to this, the U.S. Bureau of Mines is developing and evaluating new sampling methods for measuring diesel aerosol in underground mines. Two such techniques are being studied by the Bureau, size selective sampling and CMB modeling. These techniques use measurable physical or chemical characteristics of a mine aerosol sample to infer the amount of diesel particulate material contained in the sample."

Mar 1, 1992

By F. W. Hoertel

The Bureau of Mines investigated the use of depleted uranium as a sacrificial anode for the cathodic protection of submerged and underground structures of iron , steel , and copper . Uranium-metal couples were tested in simulated marine environments of varying oxygen contents at pH values between 5.5 and 8.5 and under simulated boiler service condition in Rolla , Mo. , city water . Similar couples were tested in samples of Missouri soils to simulate underground service . Uranium remained anodic to iron , steel , and copper in the simulated marine environments and under simulated boiler service if the electrolyte was oxygen- free city water . Uranium appeared to offer limited protection to iron , low- carbon steel , stainless steel , copper , and zinc in the simulated underground tests . Uranium anodes offer a space advantage because 1 cubic inch of uranium gives approximately the same protection as 2 cubic inches of magnesium or 1-1 /2 cubic inches of zinc .

Jan 1, 1963

By J. H. Hedges

During the World War Leadville was an important producer of manganese and maganiferous ores for then steel industry. Normally, the market for these ores is limited to the requirements of the local steel mill at Pueblo for low-grade ores used in making, basic pig iron containing 1 to 2 percent Mr and spiegoloison containing 20 percent Mn, but during the war and a brief period of postwar readjustment, a good deal of 25- to 40-percent manganese ore qua shipped to in-stern steel-manufacturing centers. Throughout the active life of the camp, manganiferous iron ore carrying a little silver and lead and sometimes as such as 35 percent Mn was chipped to load smelters for flux. The total reordered production is 936,024 tons of metallurgical ore shinned to steel mills and 2,576,514 tons of fluxing ore, much of it of metallurgical grade.

Jan 1, 1940

By H. H. Schrenk, L. B. Berger, W. P. Yant, F. A. Patty

"The use of small such as canaries and white mice, for detecting carbon monoxide depends primarily on the fact that the volume of respiration of these animals in proportion to their volume of blood is much higher than for man. Accordingly, when animals and men are simultaneously exposed to a given concentration of carbon monoxide the animals will absorb it more rapidly and attain serious poisoning in less time than men. Prom a practical viewpoint the use of the animals depends on the margin of time between observable symptoms in them and serious poisoning in man, during which man can return to fresh air or use respiratory protection. It should be remembered, however, that during the time the animal is incurring a detectable degree of poisoning, man is also absorbing some carbon monoxide, and the margin of time is not very wide. Experience with canaries has shown that an occasional specimen may have a tolerance above the average of the species and fail to exhibit symptoms before man incurs a very discomforting and possibly a serious degree of poisoning.It is also well known that physical activity increases the demand for oxygen by the body, and the respiratory exchange and circulation of the blood are increased to meet the demand. This sets up a vicious condition if carbon monoxide is present in the air because the rate of absorption of carbon monoxide is not only increased by the increase in respiration and circulation, but the absorption of carbon monoxide decreases the capacity of the blood for carrying oxygen at a time when the demand is high. These facts, together with the increase in respiration and circulation which attend excitement, underlie the caution to be calm and to walk slowly and to reduce physical exertion to a minimum when exposed to carbon monoxide. For these same reasons, when using animals for detecting carbon monoxide it is endeavored to keep them active, thereby tending to increase the response of the birds and widen the time between observable effects in the birds and effects in the man. As rule canaries are kept fairly active through fright at the unnatural surroundings and in their endeavor to remain on the perch of the cage when carried into the atmosphere to be examined. They also experience an excitement stage with oncoming carbon monoxide poisoning. Sometimes, however, especially if the air is cold, they tend to be inactive and quiet. Ordinary mice and white mice become inactive with use and also with oncoming poisoning. They huddle in the corner or the cage, and thereby not only reduce their sensitivity but make it difficult to observe signs of poisoning."

Oct 1, 1930

By R. V. Ramani, W. Miola

"A relationship exists between the quartz contents in the underground coal nine airborne dust samples and those in the coal and host rocks that are mined [17, 18, 19] The prescribed method for quartz analysis in respirable airborne coal dust samples is the MSHA P-7 method. Accurate quartz analysis procedures are needed for bulk samples in order to predict the potential quartz content in airborne nine dust, which in turn will aid the design of quartz dust control procedures during mining. thereby reducing the airborne quartz dust in underground atmospheres. The requirements of this method are that the amount of quartz is the sample be less than 250ug, and the total sample weight less than 2,500 ug. Unlike with airborne dust samples, there are no limitations to the available mass of bulk samples. However, these are no standard procedures for the preparation of bulk samples for scanning or prescribed methods for quartz analysis. The NIOSH and MSHA methods are certified for roped* dust and the acceptance of these methods for bulk samples assumes that the bulk samples will be reduced to the conditions specified for respirable dust samples. An alternative method is X-ray diffraction, which provides higher average quartz values than those obtained from P-7 method for the same samples.An investigation was carried out to determine the optimal procedure for preparing the bulk samples for the IR and XRD analyses. In this paper, the investigations on the effects of calibration, particle sizes, matrix composition, interferrous, and behavior of the filter substances on IR, XRD and FTIR results are presented. The error introduced by the presence of kaolinite and a new sample asking procedure to reduce it are discussed. The problems experienced with conventional sample holders for scanning were eliminated with the design and development of a new hollow sample holder. Quantitative comparison of quartz determinations by IR, XRD and MR methods on coal, roof and floor rocks, and airborne dust samples are presented. The important factors affecting the results of quartz analysis methods are: 1) bulk sample preparation for obtaining representative and homogeneous analysis samples: 2) particle size distributions of the analysis samples and calibration standards; 3) qualitative matrix composition of the analysis sample; 4) matching calibration standards to analysis sample; 5) substrates for sample deposition during analysis sample preparation; 6) procedures for analysis sample mounting; 7) selection of proper portions of she response profile for insanity measurement; and 8) interferences of spurious phases with the critical analyses. The recommendations of this study are important to enable comparisons and interpretations of analysis and research results."

Nov 1, 1995

By L. A. Neumeier

The Bureau of Mines evaluated the properties of zinc alloys containing 25 to 40 wt pet Al and 0 to 0.7 pet Mg. Microstructures, hardness, and tensile properties were evaluated for material as extruded at 285° C, solution treated at 300° to 400° C, and subsequently aged at 100° to 200° C. The alloys without magnesium are characterized by low hardness and strength with high tensile elongation and reduction in area. It was verified that magnesium effectively retards the Zn-Al eutectoid transformation below 275° C and markedly increases hardness and strength with decreases in ductility. Solution treating at 350° C results in large grain sizes and gross embrittlement. Subsequent aging of the Zn-Al-Mg alloys at 200° C restores ductility substantially and stabilizes the structures, but strengths are considerably reduced. Combined strength and ductility properties are better for the as-extruded condition than for any heat-treated condition. There is usually little advantage in overall tensile properties from increasing magnesium above 0.1 pct.

Jan 1, 1971

By Arnold M. Lansche

DOMESTIC OUTPUT of white arsenic, As2O3, was derived entirely as a byproduct of smelting arsenic-containing copper ores by The Anaconda Company at Anaconda, Mont., and American Smelting and Refining Company at Tacoma, Wash. Arsenic metal was not produced. Consumption, and Uses.-Most of the white arsenic produced in 1964 was consumed in manufacturing lead and calcium arsenate insecticides. In the 12 year period since 1951 the production of lead arsenate insecticide has varied between 7,800 tons and 4,900 tons, indicating that lead arsenate has maintained its position in competition with organic insecticides.

Jan 1, 1965

Develop technology that can reduce the dust exposure of a mine worker at the tailgate end of the longwall face by providing him with a clean split of air. Approach Use the jet spray air mover (JSAM) developed under a Bureau of Mines contract (refer to Technology News No. 117 for details on the development), to clean a small portion of the face air and to discharge the clean air behind a brattice partition. How It Works At most longwalls, air flows along the face from head-to-tail. Most of the airborne respirable dust generated along the face during mining is transported to the tailgate with the airflow. Any miner required to work at the tailgate is exposed to this dust. The only practical means of removing airborne respirable dust is with a scrubber. Simplicity and size made the JSAM the best choice for cleaning a portion of the tailgate air. The scrubber has no moving parts and is operated by water at low flow rates (<10 gpm) and fairly high pressures (250-500 psig). Many longwalls have sufficient water systems to supply the JSAM with adequate water pressures and flow rates. Also, the JSAM&apos;s size (4&apos;x 2&apos;x 1&apos;) allows it to be hung on one of the tailgate&apos;s shields or at some other convenient location. A clean split can be maintained at the tailgate by discharging the cleaned air behind a brattice partition at the work area. This should effectively seal off the clean air from the dusty air and provide the tailgate worker with a less dusty work environment.

Jan 1, 1983

By Steven A. Fechner

The U.S, Bureau of Mines is conducting a four-year (1987-1990) study to assess the mineral resources and mineral development potential of the Valdez Creek Mining District in southcentral Alaska. This study is part of the Bureau&apos;s ongoing statewide mining district evaluation program. This report summarizes the Bureau&apos;s site specific evaluations of two areas (Tyone and Peters Creek) of the district that were investigated to determine the bedrock sources of gold and PCM in the alluvial gravel of both areas. In the Tyone Creek area, grains of gold (up to 0.0212 oz/yd3) and platinum group minerals (PCM) were recovered from alluvium and weathered conglomerate of the Jurassic Naknek Formation and Tertiary age using placer sampling techniques, Platinum and palladium were detected in the heavy mineral concentrates recovered from placer sampling the alluvium, and Naknek Formation and Tertiary conglomerates. In the Peters Creek area, grains of gold (up to 0.014 oz/yd3) were recovered from the alluvium and Tertiary Sterling Formation conglomerate. The Bureau&apos;s evaluations indicated that drainage basins containing conglomerate are the most favorable targets for placer gold and PGM exploration; and Tertiary conglomerate represents a high volume, low grade gold resource.

Jan 1, 2011

By Michael J. Sapko, Kenneth L. Cashdollar

In This Chapter [Methane ignition as initiation source for much larger secondary coal dust explosions Rock dusting requirements to prevent coal dust explosions Dangers of hybrid mixtures of methane and coal dust] Although methane explosions are dangerous, those that involve coal dust are even more so. If exploding methane disperses and ignites the coal dust that has accumulated on the mine ribs and floor, the burning coal dust immeasurably increases the strength of the explosion. Such methane-dust explosions are prevented by inerting the coal dust in a way that prevents the exploding methane from igniting it. This chapter discusses the dust hazard and how it is pre-vented in U.S. coal mines. METHANE IGNITION AS INITIATION SOURCE FOR MUCH LARGER SECONDARY COAL DUST EXPLOSIONS The typical scenario for coal mine explosions starts with the ignition of a flammable methane-air atmosphere near the face. The turbulent winds from the primary methane explosion then disperse the coal dust. If there is insufficient rock dust (usually limestone), a secondary coal dust explosion then propagates throughout large sections of the mine. These scenarios have been studied extensively at the Bruceton Experimental Mine (BEM) and the Lake Lynn Experimental Mine (LLEM) of the NIOSH Pittsburgh Research Laboratory. The minimum quantity of methane required to initiate a coal dust explosion was studied in 1930 in the BEM [Rice et al. 1933; Nagy 1981] and then later in the LLEM, whose cross-sectional area (130 ft2) is over twice that of the BEM [Sapko et al. 1987a]. Studies conducted in the BEM closely simulated conditions that existed in operating mines in the early 20th century. The later tests in the 20-ft-wide entries of the LLEM simulated the geometries of modern mines with advanced roof support technology. The data from the BEM tests show that 13 ft3 was the minimum quantity of methane at the face that, when ignited, would disperse and ignite coal dust. In the BEM, this amount of methane was mixed with air to form a total flammable volume of about 140 ft3 of a 9% methane-in-air mix-ture. In the wider entries of the LLEM, about 37 ft3 of methane was required to disperse pure coal dust and start a self-sustained coal dust explosion. This amount of methane was mixed with

Jan 6, 2006

By Thomas J. Peters

In 1987, at the request of the U.S. Bureau of Land Management, the Bureau of Mines studied the 350-acre Henry?s Lake Wilderness Study Area (ID-035-077) in order to evaluate its identified mineral resources. The Wilderness Study Area is located in northern Fremont County, ID, approximately 140 air miles north-northeast of Pocatello and 3 miles south of the Montana border. The Wilderness Study Area is near the north shore of Henry&apos;s Lake at the foot of the southwest-facing slope of Black Mountain. Archean hornblende gneiss, the main rock type present, crops out northeast of the Madison Range Fault, which trends northwest across the southwest corner of the Wilderness Study Area.

Jan 1, 1988

By Donald J. Keefe

The Remote Working Level Monitor (RWLM) is an instrument used to remotely monitor the Rn-daughter concentrations and the Working Level (WL). It is an ac powered, microprocessor based instrument which multiplexes two independent detector units to a single central processor unit (CPU). The CPU controls the actuation of the detector units and processes and outputs the data received from these remote detector units. The remote detector units are fully automated and require no manual operation once they are set up. They detect and separate the alpha emitters of RaA and RaC&apos; as well as detecting the beta emitters of RaB and RaC. The resultant pulses from these detected radioisotope; are transmitted to the CPU for processing. The programmed microprocessor performs the mathematical manipulations necessary to output accurate Rn-daughter concentrations and the WL. A special subroutine within the program enables the RWLM to run and output a calibration procedure on command. The data resulting from this request can then be processed in a separate program on most computers capable of BASIC programming. The calibration program results in the derivation of coefficients and beta efficiencies which provides calibrated coefficients and beta efficiencies.

Jan 1, 1977