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By R. S. Fowkes

Jetstream pressure distributions and coal cutting rates were determined for a number of nozzles and under different operating conditions. The jetstrearn pressure distribution data were fitted to an assumed curvilinear equation by the utilization of a numerical least-squares technique with the aid of a digital computer. Subsequent manipulation of the approximation equation showed that the total force of the jetstream, rather than its maximum pressure or total kinetic energy per unit Lime, was the most significant quantity affecting the coal cutting rate. A shorter method for assessing the ability of a nozzle to cut coal was found.

Jan 1, 1968

By John L. Nieber

This information circular describes a computer program called VARSAT2D, a comprehensive unsaturated fluid flow simulator developed by the U.S. Bureau of Mines. VARSAT2D solves for either a vertical or horizontal, transient or steady-state solution in variably saturated, heterogeneous, anisotropic porous media using the Galerkin finite-element approach. Simplex triangular elements are used. Moisture retention characteristics are described by specifying either the Brooks and Corey, Brutsaert, or Van Genuchten power functions, with hysteresis described using the Maulem independent domain model. Boundary conditions may include any combination of time-varying seepage, pressure along solution domain, boundaries and/or at internal node points, unit hydraulic gradient at the lower boundary, and a uniform source and/or sink. This program should be a welcome addition for mining and environmental hydrologists, researchers, and engineers interested in modeling unsaturated fluid flow.

Jan 1, 1994

By John H. Hild

"INTRODUCTION Alunite occurs within a radius of 10 miles of Marysvale, Piute County, Utah, in veins and as replacements of igneous rocks. A number of each type of deposit was explored by the Bureau of Mines, in cooperation with the Geological Survey, under the Strategic Minerals program during 1942. The exploratory work comprised geologic and topographic mapping, diamond drilling,,bulldozer and hand trenching, sinking test pits, rehabilitation of old workings, sampling alunite exposures, and constructing and repairing roads.ACKNOWLEDGNENTSIn its program of exploration of mineral deposits; the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, R. G. Knickerbocker, chief, analyzes samples and performs beneficiation tests. Both these branches-are under the supervision of Dr. R. S. Dean, assistant director.With particular reference to this publication, acknowledgment is given to Richard E. Mieritz and William E. Young, who assisted on the project at various times; P. T. Allsman, chief. Salt Lake Division, Mining Branch, who advised on exploratory problems and gave valuable assistance in preparing the report and illustrations; A. P. T. Schumann, for preparing the illustrations; and to Gordon L. Bell, Max Willard, and Eugene Callaghan, of the Geological Survey, who cooperated as representatives of that agency."

Nov 1, 1946

By Franklin H. Persse

Domestic bismuth supply was projected from production figures for the ores in which it occurs--copper, lead, zinc, and tungsten. Published and unpublished data concerning host ores were examined to determine bismuth reserves and resources, and mine production. Potential recoverable bismuth occurring with reserves and resources of copper, lead, and zinc was estimated to be 36.3 million pounds. A bismuth availability diagram was developed from quantity estimates and ratios of production cost to value for these host ores. Additional recoverable bismuth occurring with domestic tungsten reserves was estimated to be 1.5 million pounds. Domestic byproduct production of bismuth will approximate 1.3 million pounds annually by 1980. This quantity will provide about 37 percent of the 3.5-million-pound estimated requirement for that year. Known world supply of bismuth appears to be sufficient for world demand to the end of this century. The study indicates that bismuth reserves and potential resources in the rest of the world have not been adequately reported.

Jan 1, 1970

By E. R. Palowitch

A centrifugal float-and-sink test procedure has been developed by the Bureau of Mines to reduce the time for the gravimetric separation of coals finer than l4-mesh from as long as 24 hours to less than 1 hour. Comparative tests indicated that centrifuging a minus 14-mesh Pittsburgh-bed coal for 20 minutes at 1,500 revolutions per minute produced results that compared favorably with static float-and-sink test results. Standard deviations of the mean recovery and ash content of the float obtained centrifugally ranged from 1.31 and 0.04 percent, respectively, at 1.30 specific gravity to 0.21 and 0.05 percent, respectively, at 1.60 specific gravity. As in static separations, retreatment of the products separated at low specific gravities was required.

Jan 1, 1961

By N. L. Kozlinsky, B. W. Gandrud

"The Marvel mines 1 and 3 of the Roden Coal Co. are located in the Cahaba field in Bibb County, Ala., nearly southwest from Birmingham, an airline distance of roughly 30 miles. The coal of the Clark seam at this point has some coking properties, but at present it is sold exclusively as a domestic and steaming coal.This paper, which is the second of a series on the washability of Alabama coals, like its predecessor dealing with the Mary Lee seam,5 contains screen-sizing and float-and-sink tests of a representative sample of the raw slack, and slotted-screen tests showing the proportions of flaky particles in certain selected sizes; inasmuch as this coal is not used for coke manufacture, no crushing tests have been made. These data have been obtained in connection with an exhaustive study of coal preparation in Alabama, now being conducted by the United States Bureau of Mines and the University of Alabama with the cooperation of the different coal operators. As the work progresses, other papers will follow containing further data on Alabama coals and giving results obtained in preparing these coals by various methods.The only published investigative work on the Clark seam is that of Forbes,6 who gives a number of sections of this seam in Marvel No. 3 mine with proximate and ultimate analyses of face samples taken in the mine and also some analyses of delivered coal.The available information on this coal indicated that the preparation problem was one of ash reduction. In order to substantiate this information a complete analysis of the 3/4 by 3/16 inch size, and sulphur determinations and ash-fusibility tests of the float-and-sink fractions have been made; these results are given in Tables 1 and 2. As these results also indicate that the preparation problem is one of ash reduction, the tests and discussion have been devoted to that subject."

Jun 1, 1930

By H. Dolezal

A laboratory study of acid-ferrous sulfate treatment of low-grade manganese ores from the Cuyuna range, Minnesota resulted in 93-percent extraction of manganese as manganese sulfate with consumption of 3.8 pounds of H2S04 per pound of extracted manganese. Two types of ore were treated in consecutive stages. The first are contained carbonate minerals of manganese and iron, both soluble in H2S04 solution. The second ore contained manganese oxide minerals, insoluble in straight acid solution but soluble in the ferrous sulfate solution obtained from treating the first ore. Leaching data were obtained by countercurrent percolation of coarse (minus-1/2-inch) ore particles at room temperature and by agitating minus-65-mesh ore particles in heated solution. Extraction of manganese and acid consumption were the same, but the percolation leach required 6 days compared with 1 hour for hot agitation. Variations in the size of ore particles treated, leaching time, acid concentration, solution temperatures, and method of applying ferrous sulfate solution to the oxide ore were studied. The effects of several reagents for removing iron from solution and improving filtration were also studied.

Jan 1, 1959

By Irving Hartmann

At the 9th International Conference of Directors of Safety in Mines Research a paper6/ was presented describing the initial phases of research by the Safety in Mines Research Establishment at Buxton, England, on the remote control of timber fires with high-expansion foam plugs in a rock tunnel. The work received extensive publicity, and great interest was aroused by the implied possibility that the method might be used successfully to control coal-mine fires, which for various reasons cannot be approached and attacked by standard fire fighting measures and frequently require sealing extensive, valuable coal properties and lead to loss of production and coal reserves and occasionally loss of lives. To investigate the practicability of the foam-plug technique under American min¬ing conditions, with room-and-pillar-type extraction and multiple entries, the Bureau of Mines in 1957 began an investigation at its Experimental Coal Mine, Bruceton, Pa, In preparation for this work it was necessary to rehabilitate and reinforce an elliptical tunnel in the mine where studies had been made, many years ago, leading to development of a ventilation system used in the Holland Tunnels between New York and New Jersey, and in many other vehicular tunnels.

Jan 1, 1958

By Stephen Gerard Sawyer

A Fortran IV computer program entitled WAVE, which employs an explicit finite difference scheme for solving the one-dimensional wave equation for a time-dependent inelastic rock has been developed. The viscoelastic properties of the rock are represented in terms of a generalized Voigt model. The theory on which the computer program is based is rederived and a short description of the program is given. The computer program input instructions, a listing of the computer program, and example problems with required input and subsequent printed output are presented in appendixes. In the example problems) calculated results are free of spurious oscillations which occur in certain other methods of numerical calculation) notably the extended Ritz method.

Jan 1, 1972

By Robert W. Freedman

Vacutainers are employed by the Bureau of Mines and the Mining Enforcement and Safety Administration for sampling mine air and other atmospheres containing fixed gases, low-molecular-weight hydrocarbons, and products of combustion. Tests were conducted to study shelf life of evacuated samplers prior to sampling and also to check the stability of sampled gases prior to analysis. An unexplained phenomenon, slow accumulation of carbon monoxide in evacuated samplers, occurred after a few weeks' storage; levels were low but increased with time and could pose a problem for critical applications. Accordingly, attempts to halt CO release by additional means of treatment were made, and storage at low temperature was found to be effective.

Jan 1, 1978

By K. J. Miller

Electrophoretic mobility measurements of coal and pyrite particles in distilled water revealed a difference between the migration speeds of the two materials toward the anode in a dc electric field. This information led to the development of a laboratory electrophoresis column for separating fine pyrite from coal by utilizing the electrokinetic and the specific gravity differences between coal and pyrite. The study demonstrated on a laboratory scale that pyrite and other impurities can be separated from fine coal by electrophoresis using a stage separation technique. In a cost analysis, electrical power for electrophoresis was extrapolated to about $1 per ton of clean coal product. But, since the only successful tests ever made were in the laboratory with prewashed samples of minus 100-plus 325-mesh coal in distilled water, the cost figure derived is not representative of conditions prevalent in commercial coal cleaning operations. True conditions would reflect costs many times as great. In the course of the work, several scale-up techniques were considered but their feasibility became academic in view of the physical and economic problems associated with electrophoretic separation of pyrite from coal. Although the process and apparatus were finally deemed impractical for commercial coal preparation, the electrophoresis column may have some application as a laboratory device.

Jan 1, 1974

By Albert W. Deurbrouck

This report describes the preparation characteristics of the Pittsburgh and Upper Freeport coalbeds in Hancock , Brooke , Ohio , and Marshall Counties , W. Va . Over 4.5 million tons of coal was produced in these four counties in 1962. Most of this production came from the Pittsburgh coalbed . Twelve coal samples were collected for this study , 11 from the Pittsburgh bed and 1 from the Lower Freeport bed . Two of these samples could be upgraded to produce metallurgical - grade coal . The sulfur content of the Pittsburgh- bed coals was generally excessive --as high as 4.9 percent in the raw coal and 3.19 percent in the float 1.30 specific gravity fraction . The rank of the coals in this area ranges from high-volatile A to high-volatile B bituminous .

Jan 1, 1964

After nine years of negotiations, the U.N. Conference on the Law of the Sea approved a Law of the Sea Treaty text in April. Israel, Turkey, the United States and Venezuela voted against the text and 17 other nations including Belgium, the Netherlands, Italy, the Soviet Union, the United Kingdom and West Germany abstained. These nations still have the option of joining the treaty when it is opened for signing in December. However, the Reagan Administration has stated that several provisions of the deep seabed mining portion of the text are unacceptable and it seems unlikely that the United States, at least, will change its position. ALUMINUM Reynolds Metals Co. has criticized an Oregon state plan to relax air pollution standards for aluminum plants. The company feels that relaxation of the rules does not go far enough. Reynolds officials say that they have spent about $31 million at their Troutdale plant for state-of-the-art pollution control equipment, and if they are required to make the pollution reductions called for in the 1986 rules, Reynolds would be forced to close the 40-year-old plant.

Jan 1, 1982

By Larry A. Haas

The chemistry of current or potential SO2 removal processes can be placed into four categories: (1) reduction, (2) Liquefaction, (3) direct dissolution, and (4) oxidation. Methods that involve reducing SO2 to elemental sulfur appear promising since this product can be easily handled, shipped, and stock- piled. Unfortunately, SO2 cannot always be reduced directly when other oxidizing agents are present. Thermodynamic data indicate that some oxidizing reagents will also consume reductant at the reduction temperature. A two- stage process can be applied to waste gases that contain excessive quantities of oxygen, nitrogen oxides, and water vapor. The best sorbent for the first stage appears to be a nonalkali or nonalkaline earth medium since this medium more readily releases the SO2 for reduction in the second stage.

Jan 1, 1973

By Stephen D. Hill

The Bureau of Mines devised and constructed a modified Knudsen effusion apparatus, permitting a constant measure of the weight of effusing vapor, to determine the equilibrium vapor pressure of metal halides at temperatures up to 1,200° K and over the pressure range 10-5 to 10-2 torr. The reliability of the apparatus was established by determining the vapor pressure of potassium chloride. After correcting for partial dimerization of the vapor, data obtained on solid KCl between 750° and 950° K can be expressed by the following equation:

Jan 1, 1966

By Margaret R. Egan

The Bureau of Mines experimentally burned Pittsburgh Seam coal and other combustible materials found in mines in order to obtain a better knowledge of their emission products. These experiments were conducted in the Bureau's intermediate-scale fire tunnel, which simulates environ-mental conditions in underground mines. Smoke characteristics, gas concentrations, mass loss, and ventilation were measured. From these values, heat-release rates, particle sizes, obscuration rates, combustion yields, and production constants were calculated. This information was sought as part of a comprehensive study of combustible materials that will ultimately advance the design of more efficient fire detection and suppression systems. The coal combustion measurements presented in this report, together with previous analyses of wood and transformer fluid fires form a data base by which future studies of other mine combustibles can be compared.

Jan 1, 1987

By J. E. Tiffany, N. A. Tolch

The Pittsburgh Experiment Station has made a survey of the properties and characteristics of the brands of fuse manufactured in the United States ; 25 samples were procured from 4 manufacturers representing the different brands offered on the market when the investigation was begun . It is believed that the field was completely covered except for special fuse made to order for a particular job .

Jun 1, 1934

This manual provides instructions for installing, operating, and maintaining a protective canopy on the Galis Mfg. Co. roof drill. The instructions are based upon two actual installations: one made in a mine on roof drill, model 300, and one in the factory. The parts list and engineering drawings for the protective canopy are included at the end of the manual. And a discussion of some alternative design concepts is also included. The manual can also be used for retrofitting other roof drills with similar protective canopies. Skilled mechanics can determine if the instructions herein would be applicable to the other roof drills and can determine any necessary modifications if they are not.

Jan 1, 1973

By E. G. Noble

The effects of HBr concentration and temperature on the solubility and hydration state of AlBr3,' CoBr2, PbBr2, MnBr2, KBr, and NaBr were investigated by the Bureau of Mines. Saturated aqueous solutions of the AI, Pb, K, and Na bromides were sparged with HBr gas at 20°, 40°, and 60° C, and saturated solutions of Co and Mn bromides were sparged at 20° C. Increased HBr concentration caused decreased salt solubility because of the common ion effect for all the investigated bromides except PbBr2. Aqueous solubilities at 20° C were, in percent, 51.7 for AlBr3, 53.2 for CoBr2, 1.1 for PbBr2, 59.6 for MnBr2' 39.5 for KBr, and 47.4 for NaBr. At 60° C, the solubilities were, in percent, 53.3 for AlBr3, 2.2 for PbBr2' 46.0 for KBr, and 53.8 for NaBr. Solubilities in solutions sparged to HBr saturation at 20° C were, in percent, 0.5 for AlBr3, 42.0 for CoBr2, 32.2 for PbBr2, 21.0 for MnBr2, 0.6 for KBr, and 0.3 for NaBr. At 60° C, the solubilities at HBr saturation were, in percent, 1.8 for AlBr3, 41.4 for PbBr2, 1.3 for KBr, and 0.4 for NaBr. CoBr2 precipitated out to a minimum solubility of 27.2 pct at 28.7-pct-HBr concentration. Further increases in HBr concentration increased CoBr2 solubility because of the formation of bromide complexes. PbBr2 in-creased in solubility as HBr concentration increased.

Jan 1, 1988

By Frank E. Cash

The compensation-insurance rates for quarrying in North Carolina are 11 times higher than for the State?s major industry, textiles. Some operators are willing to accept this as representing the ratio of existing hazards. This was not true of the management of the Southern Aggregates Corporation, and in 1935 it tools definite steps to correct the idea of its local officials and employees that loss of life and limb in quarries is inevitable. ACKNOWLEDGMENTS The authors acknowledge gratefully the assistance and information concerning these operations furnished by H. M. Shaw, safety director (also secretary and treasurer), Southern Aggregates Corporation, Raleigh, N. C.; by the following superintendents: J. H. Rodgers, Blair Quarry, Blair, S. C.; J. D. Lane, Greystone and Rolesville Quarries, Henderson, N. C. ; J. H. Arthur, Guilquarry, Stokesdale, N. C.; J. H. Watkins, Rockton Quarry, Wendell, N. C.; P. A. Wellenborne, Reidsville Quarry, Reidsville, N. C.; and J. L. Kirchin, Woodleaf Quarry, Woodleaf, N. C.; by the various foremen at the plants, and by Murry Id. Grier, safety engineer, North Carolina Department of Labor, Asheville, N. C.

Jan 1, 1940