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By D. R. Tesarik

Displacement and stress changes in cemented backfill and ore pillars at the Buick Mine, near Boss, MO, were monitored by engineers from the U.S. Bureau of Mines and The Doe Run Co., St Louis, MO. A test area in this room-and-pillar mine was backfilled to provide support when remnant ore pillars were mined. Objectives of this research were to evaluate the effect of backfill on mine stability, observe backfill conditions during pillar removal, and calibrate a numeric model to be used to design other areas of the mine. Relative vertical displacements in the backfill were measured with embedment strain gauges and vertical extensometers. Other types of instruments used were earth pressure cells (to identify loading trends in the backfill), borehole extensometers (to measure relative displacement changes in the mine roof and support pillars), and biaxial stressmeters (to measure stress changes in several support pillars and abutments). Two-and three-dimensional numeric codes were used to model the study area. With information from these codes and the installed instruments, two failed pillars were identified and rock mass properties were estimated.

Jan 1, 2010

During the period 1979 thru 1982, Multi Mineral Corporation conducted a mining research program at the United States Department of the Interior's Bureau of Mines Oil Shale Mining Environmental Research Facility in the Central Piceance Creek Basin, Rio Blanco County, Colorado. The program consisted of mining, environmental and geotechnical research data and the results are described in this report.

Jan 1, 1983

By Wesley T. Holmes

This report describes the first phase of an investigation aimed at obtaining a wider knowledge of the problems involved in smelting titaniferous magnetites. Liquidus temperature measurements were made on selected slag compositions in the titania-alumina-silica-calcia-magnesia system. Both the melting-holding-quenching method and the hot-stage microscope method were used in the tests. Liquidus temperatures of slags studied ranged from 1,217° to 1,667° C. The lowest liquidus temperature of the slags occurred when the difference between CaO plus MgO and Si02 was less than 12 weight-percent. Liquidus temperatures were also lowered when Si02 was substituted for Ti02 plus Al2O3 when CaO and MgO levels were held constant. Improved methods for the measurement of liquidus temperatures on very small samples are described.

Jan 1, 1968

Reduce face methane concentrations and help prevent miners from working under unsupported roof while moving the curtain. Approach Use water sprays on the continuous mining machine to move and direct air to the face, and also provide appropriate installation guidelines for the most effective use of the system. I n laboratory tests and under actual mining conditions, the spray fan has proved an effective means of ventilation. Recent observations in the field, however, have shown that not enough technical information is widely available on proper installation of the spray fan. This Technology News is designed to rectify that situation by providing a concise guide for spray fan installation. How the System Works Good ventilation is essential for methane control. The spray fan system repositions regular water sprays to help the normal exhaust face ventilation do a more effective job. The various water sprays help in many ways: 1. Side sprays bring clean air along the side of the miner into the off-curtain corner.

Jan 1, 1983

By E. G. Davis

This report summarizes an investigation to determine the occurrence and recoverability of heavy minerals in sand and gravel operations in the Southeastern United States. A total of 61 samples from 34 sand and gravel operations in Alabama, Georgia, South Carolina, and North Carolina were studied. Heavy minerals, in amounts ranging from 3 to 400 pounds per ton, were found in all of the samples. Eighty percent of the samples contained 20 to 40 pounds per ton of heavy min¬eral. Valuable heavy minerals, in order of decreasing amounts, were ilmenite, kyanite, zircon, rutile, and monazite. Large-scale concentration tests were made on five samples from four major producers. Gravity concentration by Humphreys spirals and tables resulted in bulk heavy mineral concentrates that graded from 82 to 98 percent total heavy minerals. Mineral recoveries ranged, in percent, as follows: Ilmenite 60 to 95; zircon 96 to 100; kyanite 37 to 77; rutile 89 to 100; and monazite 96 to 100. Separation studies on the gravity concentrates showed they would respond to high-tension and high-intensity magnetic separation techniques to produce individual mineral concentrates. The recovery of each individual mineral from fractionation of the heavy mineral gravity concentrates, in percent, was: Ilmenite 77 to 94; rutile 41 to 68; kyanite 62 to 79; zircon 49 to 83; and rare-earth products, monazite and xenotime, 42 to 96. The grade of each mineral concentrate was: Ilmenite 51.1 to 68.7 percent Ti02; rutile 93.7 to 94.3 percent Ti02; kyanite 55 percent A1203; zircon 58 to 61 percent Zr02; and rare-earth products containing 73.8 to 90.8 percent monazite and 4.8 to 12.7 percent xenotime.

Jan 1, 1971

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Jan 1, 1975

By A. C. Fieldner

In preparing this paper, an attempt was made to obtain results of plant-scale carbonization tests on washed and unwashed coal from the same mine. A letter. in which the following questions were asked was sent to some 50 coke-oven superintendents and others who might be interested; "What is the influence of washing coal on: (1) The chemical and physical properties of coke, as for example, the size the amount of breeze, the fracture, strength, cell-structure, etc. (2) The quantity and quality of gas and by-products. (3) The capacity of the ovens. (4) The composition of the coal. "Your general opinion, as well as any specific data or results of tests, on this important subject will be arc greatly appreciated."

Jan 1, 1930

By J. A. Cavallaro

This Bureau of Mines report describes the preparation characteristics of 10 coal samples collected from the significant coal-producing mines of Lucas, Mahaska, Marion, Monroe, and Wapello Counties in Iowa, with special emphasis on physical desulfurization. All 10 samples were of high sulfur content as received, ranging from 4.2 to 10.4 percent; the organic sulfur content ranged from 0.8 to 3.8 percent. The pyritic sulfur content of the samples could be appreciably reduced by crushing and washing and provided pyritic sulfur reductions ranging from 36 to 75 percent. Crushing to 3/8-inch top size and removing the sink 1.60 specific gravity material would provide float coal products containing 3.5 to 6.0 percent sulfur. However, these coals could be burned at utility plants utilizing SO2 removal processes with efficiencies ranging from 70 to 88 percent and still be in compliance with the current Federal SO2 emission regulations for stationary sources.

Jan 1, 1973

By Raymond P. Miller

This two volume report addresses slope stability of surface mine spoils within the Interior Coal Province. Sixteen (16) mines were visited, pertinent data and samples collected, and reported spoil instabilities back-analyzed. Laboratory test results are compared to back-analyzed material properties. Available methods of slope stability analysis are reviewed and evaluated with respect to application to mine spoil stability evaluation and prediction. Correlation and tentative relationships among spoil material properties, highwall conditions, mining equipment and procedures and empirical observations are presented. Slope stability sensitivity plots illustrate the relative significance of various input parameters on stability. Slope stability input parameters are correlated with site and mining conditions to identify the primary factors controlling spoil stability. Investigative methods, spoil stability enhancement techniques, spoil stability prediction procedures and future study areas are discussed. Appendices include a glossary of terms, annotated bibliography, details of mine visits, and detailed laboratory test procedures and results.

Jan 1, 1979

By Hendrik Gerritsen

The research to be described is directed to the construction of an instrument that detects methane in air. The principle on which it is based is that methane gas absorbs infrared radiation in the wavelength range of about 3.2 to 3.4 micron. Solid state p-n junctions of composition In, .97Ca.03As emitting radiation in a band centered at 3.3 micron were grown by liquid epitaxy on InAs. Fight separate growth cycles and a total of 200 diodes were measured to determine total power, wavelength peak, spectral. half width and reproducibility of the method. In order to compensate for temperature changes, dual emitter systems (one InGaAs, and one InAs diode) mounted on the same TO-5 header were made. These devices were imaged, using a folded optical path cell, on large area InAs detectors, grown by a planar diffusion technique. In the 0-50°C range the primary temperature sensitivity is in the InAs detector rather than in the emitters. Several methods to reduce the overall temperature sensitivity to within acceptable limits were demonstrated. Humidity was shown to have a negligible effect on the measurements.

Jan 1, 1976

By J. T. Popp

This Bureau of Mines study reviews the geological factors that affect methane in the Beckley coalbed in southern West Virginia, including overburden, coalbed structure, type of and changes in lithology above and below the Beckley coalbed, and presence of fractures in the coal and rock adjacent to the Beckley. Depending on the depth, the Beckley coalbed emits from 216 to 520 ft3 of methane per ton of coal mined, and the Bureau estimates that methane emission in a deep, extensively developed mine in this area may exceed 3,000 ft3 per day per ton of coal mined. Average face cleat and butt cleat trends in the Beckley coalbed measured underground are N 33° W and N 53° E, respectively. Close cleat spacing con¬tributes to the friable nature of the Beckley and provides easy movement for methane and water. Because rider coals, splits, and carbonaceous shales may contribute methane to mine emissions, predictions of methane emission based on gas content of the Beckley coalbed alone may be conservative. Beckley coalbed reserves in the study area are 234 million tons. The gas content of the Beckley coalbed averages 407 ft3/ton, and the coalbed gas reserves are 108 billion ft3.

Jan 1, 1976

By W. R. Reed

A computer model named the "Dynamic Component Program" (DCP) was specifically designed for predicting the dispersion off dust from haul trucks at surface mines. Validation of the DCP was completed by comparing its results with the results of the 1SC3 model and with actual dust measurements taken front two operating mine sires. Comparisons of the field measurements, predictions of the ISC3 model and the predictions of the DCP demonstrate that the results from the DCP represent, on average, an 85% improvement truer the ISC3 dust dispersion model results.

Jan 1, 2008

By John E. Conley

Of the three chemical elements most vitally essential for plant growth the United States, before World War I, had developed ample domestic supplies of but one-phosphorus. During and shortly after the war period, the fixation of nitrogen was greatly expanded in this country, as in many others, insuring a supply adequate for agriculture as well as for munitions. However, in spite of a search for sources of the third element, potassium, which began years before the war, attained almost frantic intensity between 1914 and 1919, and continued for 10 years thereafter, it was not until 1921 that the American Trona Corporation put its Searles Lake operations into continuous production. This company in 1926 became The American Potash & Chemical Co. but has never supplied much more than 15 percent of the potash consumed in the American market. Likewise, though discovered in 1921 in drill cuttings from oil wells, it was not until 1926 that domestic deposits of potassium salts adequate to render the United States independent of foreign sources of supply were proved to occur in the Permian Basin of Texas and New Mexico.

Jan 1, 1944

By M. Kanda, J. W. Adams

A system for measuring amplitude probability distributions (APD’s) of electromagnetic noise in coal mines is described and typical APD’s from an underground coal mine are presented. The APD is a basic statistic required for the design and analysis of communication systems, especially those intended for use in noisy environments, and where neither overdesign nor underdesign is acceptable. The rms and average field strengths are obtained by integration of the APD, and examples are shown at several frequencies. All field strength levels are given in absolute units. Selected frequencies cover the range from 10 kHz to 32 MHz.

Jan 1, 1973

Research workers From the Bureau of Mines and industry met with other government and industry representatives in Pittsburgh, Pa., on January 22, 1975, to discuss the results of research under the Bureau of Mines Noise Control Program. The program, aimed at reducing noise in mines, is functionally divided into three major areas: Instrumentation, personal protection, and noise abatement. This proceedings contains the opening remarks to the seminar and seven technical presentations based on various aspects of noise abatement and control.

Jan 1, 1975

By Herbert H. Einstein

This report contains the documentation for 11 computer programs representing the entire computer documentation for the eight-volume report entitled "Risk Analysis for Rock Slopes in Open Pit Mines." A detailed summary of the programs is included.

Jan 1, 1979

By A. J. Kraemer

The Bureau of Mines for a number of years has been carrying on an investigation of properties of crude petroleum from producing, fields in the United States and the Western Hemisphere, and has published a series of reports on these fields, including oil fields of Oklahoma2. Acknowledgements Thanks are due to R. R. Brandenthaler and Peter Grandone, of the Petroleum Experiment Station of the Bureau of Mines, at Bartlesville, Oklahoma, who reviewed the manuscript and contributed valuable suggestions. The samples were analyzed under the direction of E. C. Lane at the Bartlesville station of the Bureau of Mines.

Jan 1, 1927

By J. Owens

Advanced materials development ranks as one of the most important high-tech industries of the future in the United States. Recent breakthroughs can be attributed to advanced computer technology, powerful mathematical models, and more precise analytical tools that enable scientists to examine and control properties of materials as never before. Discoveries now being made are providing many industries with opportunities to improve product lines, fabrication techniques, product reliability, and so forth. More¬over, industries, such as space, medicine, and defense, which require stringent: design and perfomance specifications in highly competitive world markets, increasingly demand these new materials. The definition of advanced materials used here is one that has been adopted by the U. S. Bureau of Mines: Those materials which have been developed over the past 30 years or so, and which are being developed at present, that exhibit greater strength, higher strength-density ratios, greater hardness, and/or one or more superior thermal, electrical, optical, or chemical properties, when compared with traditional materials.

Jan 1, 1991

By Wils L. Cooley

Several aspects of mine safety grounding systems and equipment are studied. Electrolytic corrosion of test ground beds has shown a high incidence of stray current damage, while efforts to build a reliable continuous ground bed monitor continue. Laboratory and field investigations of trailing cable splices have yielded strong evidence that splices can contribute to stray current problems in the mines, but a method is suggested for discovering deteriorating splices before they pose a serious hazard. A prototype device has been constructed to evaluate the electrical resistance of rail bonds underground as a source of stray current. Theoretical modeling of ground electrodes, has advanced considerably, now covering measurements of large cylindrical electrodes, multiple-rod ground beds, rod electrodes in stratified earth, and measurement of connected beds. A prototype instrument design is given for a potential gradient plotter to quickly evaluate voltage gradients near earth electrodes. Additional ground-check monitor testing is reported.

Jan 1, 1977

By Frank A. Peters

A series of evaluations is being made to determine the relative processing costs of producing metallurgical-grade alumina from low-grade aluminous materials. These evaluations include the estimated operating and capital costs as well as recommendations for additional research and development to improve the processes and to lower their costs. The design for each process is based on published work. The three processes considered in this evaluation are designed to leach alumina as aluminum sulfate from calcined clay with sulfuric acid and to remove the silica residue by filtration. The filtrate from leaching is then purified by one of the following methods: Removal of iron in electrolytic cells using mercury cathodes; removal of iron by chemical precipitation through the formation of an iron-manganese complex; or precipitation of the alumina from an aqueous-ethanol solution, leaving iron in solution. Both the operating and capital costs for these processes are higher than those for the Bayer process. For plants producing 1,000 tons of alumina a day, the estimated operating costs per ton of alumina are: Electrolytic iron-removal process........... $81.35 Chemical iron-.removal process............... 82.08 Ethanol purification process............... 86.17 The investment in mercury is not part of the operating cost since this cost is considered equivalent to catalyst cost which would not be shown. The estimated capital investments for 1,000- ton-per- day plants on a Marshall and Stevens chemical equipment index basis of 240.0 are: Electrolytic iron-removal process...... $116,775,500 Chemical iron-removal process............... 99,418,900 Ethanol purification process................ 94,210,200 These investments include the working capital but not the land for each of the processes. Included in the electrolytic iron-removal process is an investment of $4,859,400 for mercury. Investigation of other methods for removing iron, of the decomposition operation, and of the leaching operation could reduce these costs.

Jan 1, 1963