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By John J. Henn

An evaluation is presented for an ammonium sulfate leaching process designed to extract manganese from Cuyuna, Minn., and Aroostook, Maine, deposits. In this process the manganese and iron in the ore are reduced to MnO and Fe 3 0 4 in a shaft furnace; the reduced ore is then leached with ammonium sulfate solution forming soluble manganous sulfate while leaving most of the iron undissolved. After filtration, the manganese and some impurities are precipitated from solution as carbonates which are then pelletized and calcined to form a product composed mainly of Mn3O4. The plants are designed to produce 100 tons per day of manganese contained in a product that is suitable for the production of ferromanganese. A byproduct credit, together with the extra processing cost, is included for the Cuyuna ore processing plants because Fe2O3 may be recovered for use in blast furnaces. The estimated operating costs per ton of manganese, excluding income taxes and return on investment, are: [ ] The process with or without byproduct recovery, when treating Cuyuna or Aroostook ores, is not economically competitive with ores available at $71.43 per ton of contained manganese.

Jan 1, 1968

To improve safety by making speed and direction control of a tracked vehicle simpler and instinctive. Approach A joystick control (which determines vehicle speed and direction of movement as well as the direction of any turning or pivoting) was developed and tested on a loading machine during a long-term underground demonstration. How It Works The control box actuated by the joystick lever contains two multiposition, multideck rotary switches. Fore-aft movement of the joystick rotates one switch through five positions to provide a neutral position and two speeds of travel in both

Jan 1, 1978

By F. R. Cattoir

This report presents the results of preliminary studies for the evaluation of some fused-salt electrolytes for refining tungsten metal, and describes the equipment used. Some impurities could be eliminated with electrolytes composed of sodium chloride, sodium iodide, or sodium tetraborate in combination with tungstic oxide or sodium tungstate. Electrolytes composed entirely of chlorides were unusable because of the volatility of tungsten chloride. Refining 96-to 98-percent tungsten to produce a commercial grade was more successful than further refining of 99.9-percent tungsten. No electrolyte tested yielded a product pure in all respects. Electrolyte temperatures of about 900° C were necessary to maintain a good dissolution rate at the anode and acceptable cell operation. Cathode current densities at the beginning of a deposition cycle were limited to approximately 1 ampere per square inch. Higher current densities resulted in a finely divided product that frequently failed to adhere to the cathode. The most conspicuous impurities in the tungsten produced were carbon, iron, and molybdenum; the former two came from the iron cell and the graphite cell liner. Electrolytes com-posed of tungstic oxide or sodium tungstate in sodium iodide, or 2Na, 0.B203, were capable of producing tungsten carbide.

Jan 1, 1963

By Frank Ruskey

This report describes a computer program devised by the Bureau of Mines to model coal-mining situations where one or more panels encounter oil or gas wells. The program seeks in several hundred trials to evade the wells if possible or to minimize their influence by shifting or skewing the mine plan and/or adjusting the centerline dimensions of the entryways. Upon completion of computations, the program sorts the hundreds of models which have been tested, and lists the 10 best with their associated parameters. It also draws a mine plan of the best configuration, showing the entryways and crosscuts along with the "lost" coal remaining in the barrier pillars surrounding the various wells.

Jan 1, 1972

By Roger L. King

The Bureau of Mines has developed probes to be used in emergency mine rescue operations by being lowered through a borehole drilled into an underground mine. Various probes can provide two-way voice communication with trapped miners, continuous mine atmosphere monitoring, temperature indication, and television searching capability. At present, an infrared imaging probe is being developed for "seeing" through coal smoke.

Jan 1, 1976

By Gregory J. Chekan

As part of the initial investigation and validation of a new boundary-element formulation for stress modeling in coal mines, the underground stresses and displacements at two multiple-seam coal mines with unique stress problems were modeled and predicted. The new program, LAMODEL, calculates stresses and displacements at the seam level and at requested locations in the overburden or at the surface. Both linear elastic and nonlinear seam materials can be used, and surface effects, multiple seams, and multiple mining steps can be simulated. In order to most efficiently use LAMODEL for accurate stress prediction, the program is first calibrated to the site-specific geomechanics based on previously observed stress conditions at the mine. For this calibration process, a previously mined area is "stress mapped" by quantifying the observed pillar and strata behavior using a numerical rating system. Then, the site-specific mechanical properties in the model are adjusted to provide the best correlation between the predicted stresses and the observed underground stress rating. Once calibrated, the model is then used to predict future stress problems ahead of mining. At the two case study mines, the calibrated models showed good correlation with the observed stresses and also accurately predicted upcoming high stress areas for preventive action by the mines.

Jan 5, 1999

By A. F. Colombo

Laboratory-scale tests were conducted by the Bureau of Mines on an argillaceous Michigan copper ore and mill tailing to determine the feasibility of leaching with acidified ferric sulfate solutions. The ore and tailings, containing 1.24 and 0.24 percent copper, respectively, were from the White Pine Copper Co., Ontonagon County, Mich. The investigation showed that ferric sulfate leaching of the ore and tailings followed a predictable pattern. Thus, with 4 hours of leaching, up to 58 percent of the copper in the ore was extracted, but prolonged leaching (2 to 3 weeks) was required to dissolve more than 90 percent of the copper. Similarly, about 50 percent of the copper in the mill tailings sample was dissolved in a few hours, but 8 days or more were required for extractions of over 90 percent.

Jan 1, 1962

By Claude W. Sill

In the course of a series of investigations on vanadium deposits of the western United States, the Bureau of Mines collected many hundreds of samples for chemical analysis. As uranium is often associated with these vanadium minerals, they were also analyzed for uranium, which was pound to be absent in a large percentage of the samples. Since the usual methods for determining uranium are laborious and time-consuming it is very desirable to have some simple qualitative test that can be applied prior to a quantitative analysis to determine whether uranium is present or absent and thus save the time and expense of applying the quantitative analysis to the large proportion of samples containing no uranium. To be acceptable, the test should be specific for cranium, sensitive enough to detect small amounts of uranium, and. simple enough to make it worthwhile to apply. The available methods for detecting uranium lacked one or more of the desired characteristics. Eventually, however, a method was worked out that satisfied all the requirements. This method is probably more specific and sensitive than the usual qualitative methods for uranium, and its simplicity and speed of application make it ideal for testing samples prior to quantitative analysis.

Jan 1, 1945

Develop personal computer (PC) based software for analyzing and/or filtering time- and frequency-domain attributes of seismic and electromagnetic signals from geophysical surveys for the enhanced interpretation of rock masses and subsurface geologic structure. The Problem Both mining and petroleum geophysicists utilize seismic signals to characterize rock masses for delineating subsurface stratigraphy and structural conditions. However, a vast amount of information available in seismic project evaluation data often is unavailable for interpretation unless these data are enhanced. New processing technology increases the quality of these signals for analysis and interpretation. Comprehensive signal processing software is mostly written for petroleum exploration companies. Commercially available signal processing programs are often limited to a single application or are restricted for use with specific hardware, e.g., a digital oscilloscope or a mainframe computer. The programs may use computer codes that are proprietary, restrict user modification to expand capabilities, or may be hard to interface. They may have insufficient documentation for easy use and be support dependent.

Jan 1, 1990

By W. M. Dressel

A simple field test for detecting the presence of germanium in rocks, coals, and flue dust has been developed by the Bureau of Mines. The method consists of dissolving germanium from the samples by either acid or fusion treatment methods, adding a few drops of hematein or phenylfluorone dye, and extracting the resulting colored complex with carbon tetrachloride. INTRODUCTION Germanium is obtained commercially as a byproduct of zinc production, as a coproduct of base-metal refining from germanium-bearing mineral, and as a recovered product from the ash of some coals. The growing use of germanium in the electronics industry has increased demand for this semiconducting metal to the extent that an intensive search for new sources of supply is necessary.

Jan 1, 1962

By D. S. Kimmel

The Bureau of Mines sponsored development of a system to remotely energize and de-energize the trolley wire in a section in response to demands from vehicles as they enter and leave the controlled section. The system developed utilizes a detector/actuator that controls a dc contactor at the outby end, and a 3 kHz oscillator at the inby end. A prototype system has been built and installed at the Bureau's trolley test site at Bruceton, Pennsylvania which has demonstrated the ability to also provide load discrimination for faults of 300 amperes or more. The system could readily be modified by locating the oscillator on the vehicle to provide automatic de-energizing of the trolley wire when the vehicle's pole is removed or the vehicle leaves the section.

Jan 1, 1978

To devise an economical, environmentally acceptable method for recycling scrap lead-acid batteries. Approach A combination electrorefining-electrowinning method for recycling lead metal and sludge from scrap batteries was devised which produces a 99.99 + percent pure lead product and eliminates the lead and sulfur oxide emissions that are the normal by-products of high-temperature smelting processes. How the Method Works Lead metal grids and lugs are separated from the battery sludge by washing and screening, and are melted and cast into anodes for electrorefining by the Betts process. The electrolyte used is fluosilicic acid, a large volume waste product generated during the production of phosphate fertilizer. During the electrorefining process, impurities in the anode are trapped and held in an adherent slime blanket on the surface as the anode dissolves while pure metallic lead is deposited on a lead cathode. The major problem in the past has been to recover the lead from the battery sludge which consists of approximately 60 percent lead sulfate, 21 percent lead, and 19 per-cent lead dioxide. In the flow sheet developed by the Bureau

Jan 1, 1983

Analyze variably saturated flow in mining and other environmentally sensitive settings through the use of personal computer (PC) based software. The Problem There is an increasing need for mining companies to quantify water contaminants and their migration in the unsaturated zone. New and innovative computer models are therefore necessary to more accurately assess the potential impact of mining activities on groundwater resources and the environment. Applications for unsaturated flow modeling include (1) assessment of the impact of surface or underground extraction mining on flow conditions; (2) assessment of various hydrologic designs for resource recovery, such as in heap leaching or in situ leach mining; (3) assessment of the transport of conservative nonrcactive constituents in response to migration from spoil piles, or acid mine drainage; and (4) assessment of any combination of the above to facilitate expeditious permitting for mining operations. Since the mid 1970's there has been a proliferation of mathematical models and procedures for solving unsaturated now problems; however, few of these approaches have been integrated into software for public use. Commercially available unsaturated flow software models typically are limited to a single application and have restricted approaches. For example, computer codes that solve the unsaturated flow problem based on an analytic expression arc restricted to a simple geometric shape, homogeneous and isotropic materials, and provide only information regarding pressure and flow conditions in specified wells. The variably saturated computer codes that take advantage of the finite difference or finite element approach arc often restricted to either steady state or transient solutions; utilize one specific moisture-retention relationship and moisture-dependent permeability function; do not account for hysteresis; and are used with specific hardware such as a mainframe or work station. This restricts their use because they arc hard to interface, and arc often poorly documented, support dependent, and expensive. The mining community needs a flexible, more broadly based, variably saturated fluid flow simulator for the PC-platform to more accurately predict fluid movement in the mining environment.

Jan 1, 1991

By H. B. Brunot, L. C. IlsLey

The chief object of the Electrical Section of the United States Bureau of Mines is the study of causes and means of preventing accidents resulting from the use of electricity in mines . A large part of this work for the last 20 years has been the inspection and testing of mining equipment under the provisions of schedules which give the minimum requirements considered essential for the safety of equipment intended for use at or near the working faces of dusty or gassy mines . During the first few years of this work , particular attention was paid to the explosionproof features of the various accessories such as motors , controllers , and other parts . The knowledge of the essentials necessary for safe designs of enclosures has since been augmented by field experience and by data obtained in testing a large number and variety of designs . With our present knowledge it would seem that a disproportionate stress was placed on making the various enclosures explosionproof , but not enough thought was given to the danger from wiring and connections outside of explosionproof enclosures . The list of equipment that has met minimum requirements for safety and has been approved as permissible by the Bureau of Mines includes storage - battery locomotives , power trucks , drills , loading machines , conveyors , cutting machines , room hoists , pumps , concrete mixers , and rock-dusting machines . The wiring on some of the machines is comparatively simple and sometimes , except for the trailing cable , may be entirely within the explosionproof enclosures . In general , there is outside wiring between enclosures , and on the larger machines the wiring may be extensive and complicated . In considering the safety of wiring for mining machinery , attention must be given the severe service and unfavorable surroundings imposed by mining conditions . Some of the matters that require consideration are : ground . The lack of care of the exterior wiring to be expected in the average mine . The lack of adequate periodic inspection of the wiring . The absence of adequate facilities for satisfactory inspection and repairs under- The severe conditions of moisture , dirt , mechanical injury , and low voltage encountered in mining service .

Apr 1, 1931

By R. F. Tenney

No detailed information has been published heretofore on the performance of small industrial-type anthracite stokers in building-heating service, apparently because of the difficulty of comparing the performance of one unit with that of another over an entire season's operation. Studies of competitive heating fuels have been similarly handicapped, and attempts to compare fuels are seldom technically sound in this investigation, the performance of a 60-in. Losch4 stoker burning rice-size anthracite in a standard commercial boiler was observed during a 4-month winter-spring season. It was used to heat two buildings at the Bureau of Mines' Anthracite Research Center at Schuylkill Haven, Pa., with the customary type of automatic pressure-range control. Attendance was limited to inspecting, fuel weighing, data recording, and ash removal. Results were computed daily and grouped by weekly periods to minimize daily irregularities. The same stoker-boiler unit had already been tested in a series of American Society of Mechanical Engineers (ASME) test code runs, with the stoker running continuously and with other conditions well stabilized A comparison of results from the code test and the building-heating tests provided information not available in the past for a single stoker unit, assisted in analyzing heat losses not computable in a cyclic operation, and established a basis for evaluating stoker performance in heating service.

Jan 1, 1963

By P. Kovalchik

The Bureau of Labor Statistics (BLS) classifies hearing loss as a separate illness category. Hearing loss accounted for 11% of all illnesses in 2005 (U.S. Department of Labor Bureau of Labor Statistics, 2006a). According to occupational data for coal mining provided by the Mine Safety and Health Administration (MSHA) from 2000 to 2005, operators that exceeded 100% noise dosage were from only seven types of machines: auger miners, bulldozers, continuous mining machines, front end loaders, roof bolters, shuttle cars (electric) and trucks (Title 30 CFR Part 62, 2000-2005). Roof bolting machine operators rank second among all underground machine operators that exceed 100% noise dose. There are approximately 600 underground coal mines with 3,930 roof bolting machine operators (U.S. Department of Labor, Mine Safety and Health Administration, 2005; U.S. Department of Labor Bureau of Labor Statistics,

Jan 1, 2008

By Robert W. Freedman

In the Bureau of Mines study, a filter with a 20-by 20-inch-square cross section was inserted into the exhaust ducting of a 4-stroke-cycle, 90-hp diesel engine, and the efficiency of removal of total particulate was measured gravimetrically as a function of time. Removal efficiencies were close to 90 pct during the main portion of several extended runs employing several combinations of filter beds. Variations in engine load had little effect on collection efficiency. Particle size as measured by a Bureau-developed online instrument centered on 0.07 m based on number count. Removal efficiency increased rather sharply for both larger and smaller particles.

Jan 1, 1979

By Dorsey A. Lyon

At the main experiment station of the U. S. Bureau of Mines , situated in Pittsburgh, Pa . , three phases of its work in behalf of the safety of the coal miner are the establishment of permissible explosives for use in gaseous and dusty mines , the development of electrical equipment that can be used with safety in mines of this character , and improvement in the safety of mechanical devices used in and about the mines . Also That these efforts are beginning to have a cumulative effect in lives. saved is evident from the fatality statistics of the industry . Although nearly 80,000 more men are employed in coal mining than ten years ago and much more coal is mined , the fatalities each year are considerably less than ten years ago . the amount of coal mined in a year for each life lost has risen between 60,000 and 70,000 tons . In 1909 , the year before the Bureau was created , the production of coal for each life lost was 174,416 tons . In 1920 , the production for each life lost was 285,000 tons .

Mar 1, 1921

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

Provide reliable, early-warning fire detection instruments, telemetry, and control systems for noncoal underground mines. Approach Industrial-grade fire detection instruments and signal telemetry equipment were modified for long-term exposure to harsh underground mine conditions, then were installed in four mines to evaluate long-term performance and reliability. How It Works The elapsed time between the onset of a fire and its detection is critical because fires tend to grow in size and intensity with time. Early fire detection and warning permit the initiation of a mine's emergency plan (evacuation, fire fighting, etc.) while the fire is still small, or ideally, while it is still in the incipient stage. Fire detection and warning systems, utilizing sensitive heat, flame, smoke, and gas analyzers, provide the most rapid and reliable indication of a developing fire.

Jan 1, 1987