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By Bertrand L. Johnson

Barite, the natural sulfate of barium (BaSO4), is the most important barium mineral. Normally it is white (opaque to translucent), but impurities sometimes render it yellow, gray, blue, brown, red, or black. Brown or red stains are commonly caused by iron oxide. Barite is unusually heavy (specific gravity, about 4.5); in fact, it is one of the heaviest of the nonmetallic minerals. It is brittle and fractures unevenly. The hardness of barite ranges from 2.5 to 3 but is usually about 3. It can be scratched by a copper coin. Pure barite contains 65.7 percent BaO and A.3 percent S03. Much of the crude barite ore mined, however, contains impurities; thus it has a lower content of barite and consequently less barium oxide. Commercial analyses show its total BaSO4 content. Barium also occurs in nature as the mineral witherite (BaCO3), which, however, is not common in the United States, and commercial deposits have been found only in California. Witherite is a yellowish-white, light-gray, or Kite mineral with a specific gravity of about 3, a hardness of 3 to 4, and an uneven to subconchoidal fracture.

Jan 1, 1941

By Karl-Heinz Frohne

This report presents the findings of a study of a portion of the Clover-Rush Run oilfield located in Roane County, W. Va. The study was made to investigate the possibilities of secondary oil recovery in the Big Injun sandstone underlying the William Kaufman lease. Reservoir properties, original reserves, and primary oil recovery are also presented. The investigation is based on a core analysis and related laboratory tests, well records, field production data, and subsurface information from the Kaufman property. A theoretical primary oil recovery of 9.7 percent of original oil in place is predicted for the reservoir. A waterflood performance prediction of a hypothetical pilot area was made by use of a computer. The prediction showed that, based on laboratory oil water relative permeability curves, the water-injection time needed to initiate oil production is excessive and that the stabilized water-injection and corresponding oil-production rates are very low. This precludes waterflooding the reservoir on an economic basis. A prediction for secondary oil recovery by gas injection was attempted but could not be completed because essential reservoir data were not available. In July 1965, the lease operator initiated, and is currently conducting, a gas-injection program, but there had been no increase in oil production up to November 1966.

Jan 1, 1967

By Jose P. T. Agapito

Several underground coal mines currently operating in the Beckley District of West Virginia are experiencing serious roof and floor problems. A significant portion of the estimated two billion tons of coal resources may be lost as a result of these ground control problems. Preliminary studies by the Bureau of Mines indicated that these problems are due in part to a high horizontal stress field. During this contract study, a field program was conducted to quantify the horizontal in situ stress. A total of 14 overcoring sites (using the Bureau of Mines strain-relief overcoring technique) in five mines were drilled producing 53 data sets. Analysis of the data was done to provide in situ horizontal stresses for each of the five mine, and for the district as a whole. Stress data indicate horizontal stresses far in excess of that predicted by theory and in some cases, up to six times the estimated vertical stress. In addition to the field testing, a detailed computer modeling study was conducted using finite element and boundary integral (displacement discontinuity) methods. Verification of in situ stresses was obtained by the models and analysis of various development geometries, mining methods and remedial techniques were conducted. Recommendations for reducing ground control problems and future studies are presented.

Jan 1, 1980

By Walter W. Kaufman

This report summarizes a study conducted to establish the nature and impact of regulations governing disposal of refuse from underground coal mines. The regulations affecting refuse disposal in eight major coal producing states are collected, summarized and reviewed. Federal regulations applicable to refuse generated by underground coal mines are also included. Common refuse disposal practices are discussed as are the refuse quantities generated annually in each study state. Technical requirements of regulations are discussed acid presented in appended tables. Economic implications are also assessed through cost analyses of three major types of disposal processes. The report also includes an assessment of future trends in regulation and refuse generation plus a series of recommendations concerning potential improvements in both the regulatory and refuse disposal processes.

Jan 1, 1978

By Avery H. Reed

RECORD production of marble, kaolin, scrap mica, and talc high-lighted the mineral industry of Alabama in 1962. Among the States, Alabama ranked second in scrap mica, third in the production of bauxite and native asphalt, and fifth in iron ore. The mineral industry of Alabama was dominated by mining and processing of coal and iron ore, and the manufacture of cement, which together comprised 73 percent of the total value of production, compared with 72 percent in 1961. Other important industries were the production of crude petroleum, and stone quarrying. Leading companies were Tennessee Coal & Iron, Southern Cement Co., Southeastern Electric Generating Co., Alabama By-Products Corp., and U.S. Pipe & Foundry Co.

Jan 1, 1963

By R. J. Matetic, David S. Yantek, David K. Ingram

The National Institute for Occupational Safety and Health (NIOSH) has investigated engineering noise controls to reduce sound levels in cabs on air-rotary drill rigs. A recent investigation revealed that some drillers are exposed to A-weighted sound levels exceeding 85 dB even though a cab is used. NIOSH studied the in-cab sound levels of one such rig. First, preliminary tests were conducted in a controlled environment using accelerometers and microphones with spectral analysis to identify the dominant noise sources for in-cab sound levels. The results indicate that vibration transmitted from multiple hydraulic pumps to the control panel produces a dominant spike in the sound level spectrum in the 400 Hz 1/3-octave band. Next, field tests were performed in a production environment to evaluate noise controls to reduce in-cab sound levels. It was found that utilizing hydraulic noise suppressors reduces the structure-borne noise transmitted to the control panel. Further, using hydraulic noise suppressors and enhancing soundproofing reduced the in-cab A-weighted sound levels by as much as 4 dB.

By E. M. Murphy

Comparative data from ASTM method of test E-162 and large-scale trials in the Experimental Mine show that the flame-spread quality of brattice cloth and other ventilation control materials can effectively be evaluated by either method. Materials having a flame spread index of 25 or less, as determined by the simpler and more economical laboratory test ASTM E-162, do not present a serious fire hazard when used in coal mines.

Jan 1, 1972

By R. D. Leitch

Spontaneous firing of coal during storage end even during shipment has long been a serious problem, especially in some regions and with some coals, and methods for preventing such firing have been investigated at intervals for more than 70 years. Spontaneous or other firing of coal waste, either outside or inside mines, has also been a problem probably for as long as mining has been practiced extensively. Much trouble has been caused by such fires, and much money has been spent in attempts to extinguish them. It is known generally that surface waste banks in bituminous-coal fields are very likely to take fire sooner or later, but it is not known so generally that anthracite refuse-bark fires also are common and that at least some of them are more serious in their effect and results than being regarded merely as a nuisance. There surface refuse fires probably would have attracted much more than local attention long ago had it not been that they usually cause no more serious trouble than air pollution. A few supposedly effective methods of preventing or extinguishing spontaneous fires have been reported rather recently. Unless one or more of these prove to be widely applicable, methods of solving these problems are no more certain today than they have been for many years.

Jan 1, 1940

By J. Bennetts

As part of its mission to develop technology that will help increase the supply of critical and strategic minerals from domestic resources, the Bureau of Mines has investigated methods for beneficiating platinum-group metal ores from the Stillwater complex, Montana. This report presents the result of a bench-scale study employing froth flotation to recover a sulfide concentrate containing platinum-palladium values from a mineralized gabbro. Best results were obtained with a flotation scheme utilizing a mercaptobenzothiazone collector and sulfuric acid. Rougher concentrates containing approximately 11 oz Pt-Pd/ton and 90 pct of the metal values in the ore were obtained. Subsequently, cleaner concentrates containing approximately 26 oz Pt-Pd/ton and between 80 to 85 pct of the Pt-Pd values in the ore were prepared.

Jan 1, 1980

By Worthen Bradley

This paper describing the metallurgical practice and costs at the reduction plant of the. Sulphur Bank Syndicate, Clearlake, Calif., is one of a series of papers on the treatment of ores being prepared by the Bureau f Mines. The reduction plant and mine of the Sulphur Bank Syndicate are on the eastern shore of Clear Lake, in Lake County, Calif., 4 miles from the town of Clearlake and 125 miles north of San Francisco.

Jan 1, 1931

By William F. Hahn

The Bureau Of Mines recognized the desireability of illuminating working places in trona mines. This report describes two illumination system designs, their demonstration and evaluation on a Jeffrey 120HR continuous mining machine in an active working trona mine in Wyoming.

Jan 1, 1980

By M. J. Spendlove

A progress report is presented on a research program in which an attempt was made to develop a practical sulfide-volatilization process for recovering tin from low-grade Bolivian ores. Shaft-furnace designs and operating techniques were studied in a series of experiments in which the objective was to sulfidize cassiterite to stannous sulfide, remove the stannous sulfide by volatilization, reconvert the stannous sulfide to stannous oxide, and collect the resulting fume. A shaft furnace was developed and operated in a final test in which many of the previous difficulties were surmounted. Since the supporting funds were exhausted at this point, the project was discontinued; recommendations for further improvements in furnace design and operation were made on the basis of interpretation of experimental results obtained in shaft-furnace experiments and other related studies.

Jan 1, 1955

By Donald W. Mitchell

Research shows that water neutralizes the explosion hazard of coal dust when present in sufficient quantity and when intimately mixed with the dust. The quantity of water required to neutralize coal dust and coal-rock dust mixtures is about equal to the limiting moisture adsorptive capacity of the dust; the adsorptive capacity increases with increase in the fineness and volatile content of the coal. Pools of water or high atmospheric humidity do not reduce the explosion hazard. Although wetted dust is less dispersible than dry dust, poor dispersibility cannot be relied on as the sole safeguard against explosion. Dust mixtures that contain water in excess of their limiting adsorptive capacity are dispersed and ignited by severe initiation sources. Pure coal dust adsorbs water with difficulty and retains water poorly; adsorption and retention is increased by the addition of rock dust the coal; the rock dust agglutinates wetted coal and assures that incombustible is present should drying occur. Therefore, it is advantageous to rock-dust wet areas in bituminous coal and lignite mines. When coal-rock dust mixtures are wetted and subsequently dried, the explosion hazard is about the same as for dust which was not wetted.

Jan 1, 1962

By J. F. McCoy

As mining develops into deeper and hotter regions, the safety and health of miners require that the workspace be cooled. Toward this end, this program has successfully developed a high performance, low maintenance spray cooler of 5000 cfm nominal capacity. Further, a series of four 25,000 cfm, nominal capacity, spray coolers has been built and mine tested with satisfactory results. The smaller coolers have been patented and become commercialized with 50 units currently in service. The concept has been developed independently overseas with an unknown number of units in operation.

Jan 1, 1984

By Andrew M. Leszcykowski

In 1984, personnel from the U.S. Bureau of Mines examined 41,550 acres of the North Fork Owyhee River Wilderness Study Area for mineral resources. This study area, in southwestern Idaho, is underlain by tuffs and basalt of Tertiary age. There are no known mines, claims, or prospects in or near the area. The northeast and southwest corners of the area are covered by oil and gas leases or lease applications, but no known exploration has been conducted. On Nickel Creek and Pleasant Valley Tables, in the southern part of the area, thin flows of vesicular, moss-covered basalt occur that are suitable for use as decorative building stone. The stone available for exploitation crops out over several square miles. However, more suitable material, outside the study area, is closer to potential markets.

Jan 1, 1986

By Ernest L. Corp

First in a projected series on the use of flexible liners for support of underground mine openings, this report presents information obtained from an extensive review of the literature on this subject. It also includes results of some preliminary test work by the Bureau of Mines. Investigations thus far indicate that flexible liners offer numerous advantages over rigid-type sup-ports, By deforming in the direction of the applied stress, the stresses are redistributed from the liner to the surrounding material. The corresponding buildup of passive resistance in the direction of diametric extension causes an equalization of stresses around the liner, thereby enabling the liner to carry loads in a more efficient manner. However, additional experimental data are needed to establish design criteria that will permit maximum utilization of the flexible liner concept in mining. Testing of small-scale models, accompanied by measurement of free-field stresses in material surrounding the model, is recommended as the most suit-able approach to the problem. The experimental procedures necessary to such an approach are outlined in detail and a statistical design for the experiments is proposed. The report also describes a device developed by the Bureau for measuring free-field soil pressures to 1,000 psi and a technique for evaluating the response of the device.

Jan 1, 1967

By Robert J. Dompe

The objective of this program was to develop a cost effective microprocessor-based electronic image sensor system for monitoring pit slope displacement to detect and/ or predict impending slope failure in surface mines. A background study and data analysis yielded a performance specification for candidate Video Slope Monitoring Systems. A design concept was developed based on using a pair of solid state video cameras located on precision pointing assemblies. The digital images from the cameras are compared and, using electronic triangulation, slope topology is calculated. The current and past locations of operator selected features are compared to determine pit slope displacement. A proof-of-concept test was performed using a laboratory model of a pit slope. Based on the successful results of that testing it is recommended that an in-mine evaluation be performed using a full-scale prototype Video Slope Monitoring System.

Jan 1, 1982

By William T. Boyd

Foreign mining publications describing successful hydraulic mining installations, and successful domestic hydraulic mining in a gilsonite bed, have prompted the Federal Bureau of Mines to conduct a literature survey of foreign publications to determine if the hydraulic mining method can be applied to domestic coal mining. Most foreign publications do not give detailed data about the water pressures, water capacities, and production and manpower requirements for successful hydraulic mining, However, they do provide enough general data on mining conditions, manpower, and equipment used to show that conditions in many bituminous coal deposits in the United States may be favorable for economical coal extraction, using high-pressure water jets. Therefore, the Bureau proposes to conduct a field investigation to determine the most appropriate natural conditions, water pressures, and equipment for successful hydraulic mining of coal beds in the United States with variable dip, thickness, and hardness. In the past, technical personnel reviewing foreign mining reports assumed that a steeply pitching coal bed was necessary for successful hydraulic mining. Although the structure of the coal bed may be a factor in gaining assistance from overburden pressures or help in an integrated hydraulic mining and transportation system, the coal is broken mainly by the action of high-pressure, water-penetrating cracks, fissures, or cleats; therefore, the slope of the coal bed is not necessarily a determining factor in hydraulic mining.

Jan 1, 1959

By H. J. Kelly

[This investigation of the refractory properties of seven Pacific Northwest chrome ores and concentrates has shown that five of the ores and one of the concentrates are suitable for making refractories and that all may be used in combination with high-grade chromite. The specific objectives of the investigation were to determine the inherent physic al and chemical characteristics, to shapes using each of the chrome ores and concentrates, to compare the refractory qualities of the laboratory-prepared with commercial chrome refractories. As far as possible, standard tests were used as criteria.]

Jan 1, 1952

By S. H. Ash

THE INVESTIGATION of barrier pillars in the Western Middle field is part of the comprehensive study of the mine-water problem in the anthra¬cite region of Pennsylvania by the Federal Bureau of Mines (1, 2, 5, 6, 7, 8,9,10,11,1,2,15,16).8 The Western Middle field is in Schuylkill, Columbia, and Northumberland Counties in eastern Pennsylvania. It has an area of 120 square miles, is 42 miles long from Delano on the east to Trevorton on the west, and is 2 to 5 miles wide. In the Western Middle field are 58 underground water pools containing 38 billion gallons of water (5). Some of the pools overflow to the surface, and the water from others seeps into adjacent mines through permeable barrier pillars separating them from abandoned mines. Several active mines are interconnected to workings in abandoned mines, which are partly filled with water. These mines are separated by barrier pillars that are considered effective only below the altitude of the connections. In some abandoned mines, pumping stations maintain the water at altitudes where the hydrostatic pressure against the barrier pillars is not excessive and does not endanger adjacent active mines. If water in these abandoned mines is allowed to rise to where it can overflow into the active mines, it must be pumped from the active mines at lower altitudes; this materially increases the cost of pumping. It is estimated that from 1944 to 1948 approximately 30 percent of the water pumped to the surface was from abandoned mines.

Jan 1, 1953