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The Bureau of Mines Minerals Information organization collects worldwide data on virtually every commercially important nonfuel mineral commodity. These data form the base for tracking and assessing the health of the minerals sector of the U.S. economy. This data collection activity was instituted by the 47th Congress in an appropriations act of August 7. 1882 (22 Stat. 329), to place the collection of mineral statistics on an annual basis. The most recent authority for the Bureau of Mines Minerals Information activity is the National Materials and Minerals Policy, Research and Development Act of 1980 (Public Law 96-479, 96th Congress), which strengthens protection for proprietary data provided to the U.S. Department of the Interior by persons or firms engaged in any phase of mineral or mineral-material production or consumption.

Jan 1, 1985

The Bureau of Mines Minerals Information organization collects worldwide data on virtually every commercially important nonfuel mineral commodity. These data form the base for tracking and assessing the health of the minerals sector of the U.S. economy. This data collection activity was instituted by the 47th Congress in an appropriations act of August 7. 1882 (22 Stat. 829) to place the collection of mineral statistics on an annual basis. The most recent authority for the Bureau of Mines Minerals Information activity is the National Materials and Minerals Policy, Research and Development Act of 1980 (Public Law 96-479, 96th Congress), which strengthens protection for proprietary data provided to the U.S. Department of the Interior by persons or firms engaged in any phase of mineral or mineral-material production or consumption.

Jan 1, 1987

Develop a lightweight, portable device for use in mines for non-destructive testing of resin grouted roof bolt bond integrity. Approach A unique, intrinsically safe, electronic instrument has been developed that determines the holding quality of a fully grouted roof bolt by testing the integrity of the resin bond to both the bolt and to the surrounding rock. How It Works A measured pulse of energy Is sent Into the bolt by a piezoelectric transducer, and the instrument listens for reflected energy. Where the bolt is properly bonded, the energy passes from the bolt, through the resin, and out into the rock mass. Where proper bending does not exist, a portion of the energy Is reflected back along the bolt. The Instrument measures the reflected energy and compares it to the original pulse. The amount

Jan 1, 1982

By Wilton Johnson

Native asphalt was produced by four companies in two States, Texas and Utah. Bituminous limestone, used primarily as a paving material for street and road repair, was produced by one firm. R. L. White Co., Dabney Quarry, Uvalde County, TX. Gilsonite, a solidified hydrocarbon found only in Utah and Colorado, was mined by three firms: American Gilsonite Co., a division of Chevron Resources Co. (a subsidiary of Standard Oil Co. of California); Ziegler Chemical and Mineral Corp.; and Hydrocarbon Mining Co. (a subsidiary of Oberon Oil Inc., a Utah corporation), from properties in Uintah County, UT. Gilsonite is used for a variety of purposes including automobile bodysealer, light-weight aggregate for cement used in oil well drilling, asphaltic building board, protective coverings, anticorrosive paints, and roofing compounds. Gilsonite production in 1985 declined 57% owing primarily to reduced oil well drilling activity. The value per ton was essentially unchanged.

Jan 1, 1987

By Gerrit V. R. Goodman, Fred N. Kissell, Charles D. Taylor

In This Chapter [Methane emission peaks Exhaust line curtain or duct The spray fan system Dust scrubbers with blowing ventilation Dust scrubbers with exhaust ventilation The ventilation of abnormally gassy faces Methane detection at continuous miner faces Ventilation and methane detection at bolter faces and Reducing frictional ignitions] This chapter gives guidelines for preventing methane gas explosions at continuous miner sections in coal mines, both at continuous miners and at roof bolters. The need to control peak methane emissions is particularly stressed. Emphasis is also placed on ventilation principles, monitoring for gas, and reducing frictional ignitions. METHANE EMISSION PEAKS Methane emission from the coal at continuous miner faces varies considerably. Plotted on a chart, methane emissions consist of a series of peaks and valleys corresponding to the cutting cycle of the mining machine, with the methane concentration spiking as the machine cuts into the coal (Figure 3–1) [Kissell et al. 1974]. These methane peaks can be substantial. For this reason, efforts to safely dilute the methane must focus on the level of the [ ]

Jan 6, 2006

By W. L. Staker

Alternatives were developed to the conventional ammoniacal carbonate leaching-steam stripping procedure for recovering copper as an oxide from contaminated scrap metal. By entraining air bubbles in the leach solution, the copper dissolution rate was increased to 1.5 g/in2 of copper surface per hour, compared to 0.5 g/in2/hr produced by conventional agitation in stirred tanks. Using entrained nitrogen gas bubbles for agitation in conjunction with powdered sulfur not only resulted in rapid dissolution but also simultaneous precipitation of the copper from solution as a high-grade cuprous sulfide.

Jan 1, 1971

By J. Roger Loebenstein

Demand for arsenic exceeded supply, and major domestic and foreign producers allocated available supplies to customers for the fourth consecutive year. Major demand for arsenic was about evenly divided between industrial chemicals and agricultural chemicals. Legislation and Government Programs.-Effective April 1, 1981, taxes were collected from companies producing and importing 42 chemicals and petroleum products designated as hazardous, The revenue was used to begin funding of the 5-year, $1.6 billion "superfund" being established under Public Law 96-510, the Comprehensive Environmental Response, Compensation, and Liability Act, designed to help clean up spills of hazardous substances throughout the United States. As hazardous chemicals, arsenic metal and arsenic trioxide were taxed at the rate of $4.45 and $3.41 per short ton, respectively.

Jan 1, 1982

Develop design and support guidelines for coal mine entry intersections based upon results of integrated field and numerical modeling analyses of structural parameters for improving ground stability. Background Underground coal mines contain a large number of entry intersections. Dome-shaped zones over the intersections are unstable and are often associated with roof falls. These roof falls may occur during mine development, trapping equipment and endangering miners. These high-risk areas of the mine account for 10 pct of the total number of ground-failure-caused fatalities. The falls, ranging from heights of 1 to 20 ft, cause high dilution and slow the advance rates. Stability at intersections is influenced by four structurally interrelated parameters: in situ stress, geological discontinuities and physical properties, intersection geometry, and roof span. Because of the complex interaction of these parameters, the actual mechanism of roof failure may vary considerably, depending upon the roof lithology, rock strength, and stress conditions.

Jan 1, 1990

By James W. Vogh

The report covers initial findings in an experimental program to identify diesel exhaust odorants and determine their contributions to diesel odor. The approach was to isolate selected component groups from exhaust and to evaluate the contribution of each group to exhaust odor. Results were obtained for those carbonyls and phenols that could be isolated from exhaust through inter-mediate conversion to oxime derivatives. Unsaturated aliphatic aldehydes and sterically hindered carbonyls were not included. Hydrocarbons intermediate in the diesel range were "also evaluated and an odor contribution was found from those of the aromatic group. The evaluated carbonyls, phenols, and hydrocarbons were found to account for about 20 pct of the total odor in exhaust from an indirect-injection engine during idle. For exhaust from the indirect-injection engine operating under load and from a direct-injection engine at no load, these compounds were found to have no significant levels of odor.

Jan 1, 1972

By Benjamin W. Haynes

The Bureau of Mines conducted research to devise technology for increasing the Nation's mineral supply by recovering valuable constituents from currently discarded waste materials. Municipal solid waste (MSW), presently a major disposal problem, represents a significant source of metals, glass, and a combustible fraction that can be used to supplement coal in generating heat and electricity. As part of the total metallurgical system to treat MSW, this study evaluates the combustible fraction of MSW to characterize the various combustible components and to identify the principal sources of elements that eventually may be objectionable from corrosive or environmental considerations. Several possible sources for cadmium, chromium, cobalt, copper, lead, nickel, and zinc have been tentatively identified. These sources are pigments, inks, paper stock, and additives to plastics. A correlation between industry consumption values and measured concentrations in MSW was found for several elements.

Jan 1, 1978

Develop a dry dust collector suitable for working faces and belt transfer paints. Approach A filter cartridge with a reverse-pulse, self-cleaning system has been mounted in-to a low profile unit requiring electric power only. How It Works Dust-laden air entering the in-let end of the collector passes through the two inline filter elements. When the elements load to a pre-selected pres-sure drop, they are automatically pulse-cleaned by a "backflush" method using compressed air. When the elements are pulse-cleaned, caked dust material on the filter surface is released, and falls away as lumps. Dust is removed from the collector by an auger mechanism. Features of the collector are: (1) unit is completely self-contained, (2) built-in air compressor for pulse-cleaning, (3) cleaning cycle initiates automatically at a preset restriction, (4) automatic auger discharge of collected dust, (5) detachable extension auger for transporting collected dust, (6) "dust leak" indicator light, and (7) "change filter element II warning light. The collector has been designed as permissible although approval has not yet been granted.

Jan 1, 1981

By Daniel Edelstein

Demand for arsenic trioxide increased markedly during 1984 as a result of increased use of arsenical wood preservatives and increased use of arsenicals in agriculture. The increase in agricultural demand was due to a return to production of land with-held from cotton planting under an agriculture program for acreage diversion for some 1983 crops. Supplies of arsenic trioxide were more than adequate to meet increased demand, and prices either declined from, or remained at, the low 1983 levels. In June, ASARCO Incorporated announced plans to close its Tacoma, WA, smelter by mid-1985. Domestic Data Coverage.-Refined arsenic trioxide was produced by two U.S. companies. The major producer voluntarily reported its production to the Bureau of Mines, but to prevent disclosure of proprietary data, the production data have been withheld.

Jan 1, 1985

By David Hoadley, Kenneth R. Maser, Ashok B. Boghani, James E. Billar, D. Randolph Berry, Mackenzie Burnett, Robert H. Trent

A. 4 Illustrative Simulations The capabilities of the program are demonstrated by simulating various evacuation cases in different situations for a particular mine. The mine selected for the illustrative simulations is the mine I C' , as described in Section 2, chosen particularly because of availability of mine characteristic data and mine evacuation results for test drills. These evacuation results can be used to verify validity of the predictions made by the program A.4 1 Mine Characteristics A schematic diagram of the mine is shown in Figure 19. The figure shows all the major shafts, drifts, raises and stopes of the mine in the form of a network. There are four hoists, Hoist No. 1 and Hoist No. 2 are assumed to be single drum hoists and Hoists Nos. 3 and 4 form part of a double drum hoist, with Hoist No. 4 being the main hoist (master hoist) The positions of the 133 miners, typically working in a day shift of the mine, are also shown in the figure. The miners are identified by a miner number, and their total number on each level is chosen from the data on the fire drill simulated as Case No. 1 in the illustrative simulations.

Jan 1, 1976

By Maria I. De Rosa, Charles D. Litton

The U.S. Bureau of Mines conducted experiments for predicting materials' ease of combustion (smoldering onset, smoldering, flaming, and decomposition rates) by means of submicrometer smoke particle characteristics for the development of a simple test method. The experiments were carried out in an approximately 20-L furnace, with a 10-L/min airflow through the furnace for a 14-min duration, at set furnace temperatures of 150°, 250°, and 1,000°C. The variables studied as a function of time were the onset time of smoke particles, time and duration of maximum smoke particle generation, average concentration of smoke particles, and particles' average diameter, mass weight loss, and furnace temperatures. Results show that the onset time of smoke particles is predictive of materials' ease of smoldering, and the time of maximum smoke particle generation and its duration, coupled with mass weight loss, are predictive of materials' ease of smoldering and flaming (depending on the experimental temperatures), and decomposition rates.

Jan 1, 1992

By A. W. Hall

A neutron meter was developed for monitoring the sulfur content of coal streams. Neutrons from 80 micrograms of californium-252 penetrate the coal, producing thermal neutrons that are captured by atoms of elements present in the coal. The excited atoms emit prompt gamma rays with energies characteristic of the capturing element. These gamma rays are detected with a 6-by 7-inch sodium iodide detector and processed by electronic equipment to produce a gamma ray energy spectrum of the elements. Tests of the meter at a commercial coal preparation plant showed that sulfur in moving coal can be determined to a precision of 0.05 percent sulfur within 2 minutes. Based on this report by the Bureau of Mines, reliability of the coal-handling system proved inadequate for long-term operation, however, and improvements are planned.

Jan 1, 1975

By Wilbur I. Duvall

The Bureau of Mines presents a theoretical solution for the stresses and displacements in an infinite elastic plate containing a circular hole whose boundary is subjected to applied shear loads over four separated arcs. The results for the applied shear loads can be superimposed on the results for applied radial loads, given in a previous publication, to obtain a complete two-dimensional approximation of the stresses and displacements induced in the rock by tunnel boring machines anchored in a circular tunnel by means of four props. Analysis of the various solutions shows that the tangential tensile stresses induced on the boundary of the circular tunnel by applied radial loads can be minimized in the roof and floor of the tunnel by the application of appropriate shear loads to each of the four props. Thus when planning tunnel boring operations, consideration should be given to the in situ stress field in the rock and the induced stresses in the rock resulting from the applied radial and shear loads produced by the props of the boring machine.

Jan 1, 1968

Perform laboratory tests to measure the vibration attenuation characteristics of off-road vehicle operator seats for various types of seat suspensions, cushions, and seat adjustment settings. Background A study was conducted by the U.S. Bureau of Mines to determine the probability of whole-body vibration (WBV) exposure for a large class of off-road machinery operating in surface coal mines. The study determined that mere than 40 pct of off-road equipment operators were exposed to WBV exceeding the standard fatigue-decreased-proficiency (FDP) level defined by the International Standards Organization in its guideline ISO standard 2631. The tire-terrain interaction of a moving vehicle generates vibrations that are transmitted through the ve¬hicle suspension, cab mounting, and seat. The final point of transmission of vehicle vibration to the operator is through the scat. A seat that provides good vibration isolation and allows good vehicle control is of prime importance to operator safety and health.

Jan 1, 1993

By Edward A. Barrett, Roberta A. Calhoun

Introduction This Instructor’s Copy contains most of the materials trainers will need in order to use Drill Rig Incident (DRI). It includes suggestions for using the exercise, performance objectives for the training, master answer sheets, a scoring key, and a set of discussion notes that provides additional subject information. Four appendices are also included. Appendix A is the complete exercise problem booklet. It may be reproduced so that every person in the training class has one. Appendix B contains answer sheet blanks. The blanks are furnished if you choose to have the invisible ink answers that appear in appendix C printed on them at your location.3 Answer sheets are consumable. One is needed for each group of three to five persons who work the exercise together. An alternative is for each individual trainee to have his/her own answer sheet. Appendix D contains the 24-question pretest / posttest that was used in the field evaluation of the DRI exercise. Acknowledgment The authors thank Linda J. McWilliams, Statistician, NIOSH Pittsburgh Research Laboratory, for her assistance in analyzing the experimental data in this document.

Jan 2, 2005

By Jack C. White

The Bureau of Mines, in its efforts to insure the continued viability of the domestic minerals economy, has been engaged for several years in research on the extraction of alumina from domestic, nonbauxitic resources. Hydrochloric acid leaching of kaolin is one of the more promising technologies being studied for recovering alumina for feedstock to existing aluminum smelting capacity; 93 pct of this feedstock is currently imported either as bauxite or alumina. Organics contamination of pregnant leach liquor, originating during solvent extraction for removal of iron from aluminum chloride solution formed during hydrochloric acid leaching, causes rapid deterioration of the semihard rubber lining of process equipment. These organics were removed by a skimming tank-coalescer-activated carbon adsorption system. Organic levels of less than 10 ppm from the coalescer and less than 0.5 ppm from carbon adsorption were achieved. Analytical methods employing CC14 extraction and infrared spectrophotometry were developed to determine the organic content of both the liquor and the carbon. Mass transfer zones delineated in the carbon columns provide adsorption data for the design of larger systems.

Jan 1, 1981

Reduce the dust exposure to the operator of a longwall shearer with a novel foam spray system. Approach Discharge foam through the nozzles of a shearer drum so that foam and coal are better mixed. How It Works Bureau of Mines research showed that two very important principles for successful application of foam are: (1) moisture distribution and (2) degree of mixing. Foam can distribute a given quantity of moisture much more evenly over a large surface area. Successful Bureau tests of foam for dust control always involve a high degree of mixing between the foam and the material, Mixing, permits a greater distribution of foam throughout the mined product. The most suitable location of foam application would be at the point where the dust is generated, before the dust becomes airborne. Foam nozzles located in the cutter drum (pick face foaming or ejecting foam through scroll sprays) will suppress dust close to its source.

Jan 1, 1989