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By Gordon H. Dechman

This Bureau of Mines report presents an iterative approximation method for microseismic source location that was developed to adapt microseismic techniques for rock structure analysis to investigations of surface problems, such as slope failure in an open pit mine. The source location method and two derivative location algorithms are described in detail, and the speed and accuracy of the two algorithms are compared.

Jan 1, 1977

By W. P. Diamond, John C. LaScola, D. M. Hyman

In 1972, the Bureau of Mines developed a direct-method test for measuring the gas content of virgin coal core samples for coal mine health and safety considerations. Since that time, approximately 1,500 coal samples from more than 250 coalbeds in 17 States have been collected for gas content determination. The gas content data, when combined with geologic and engineering studies, can be used as a basis for a preliminary estimate of mine ventilation requirements, and to determine if methane drainage in advance of mining should be considered. The data are also critical in delineating coalbed methane resources and in utilization feasibility studies. This report makes the Bureau's extensive data base of gas content data more readily available to the coal and gas industries. The data are presented in tabular form, alphabetically by coalbed name and by State. The components of the total gas content (lost, desorbed, and residual gas) are given, Location (State and county), sample depth, coalbed or formation name, and coal rank are included for geographic and geologic identification.

Jan 1, 1986

By Gertrude N. Greenspoon

Legislation and Government Programs.-The Occupational Safety and Health Administration (OSHA) held public hearings in early 1975 on proposed standards for exposure to inorganic arsenic. The findings obtained at the hearings will be considered to promulgate emission standards. Domestic Production.-Arsenic trioxide (As203) was produced domestically only at the Tacoma, Wash. copper smelter of ASARCO Incorporated. Production data cannot be published. Output rose 9% over that of 1974, shipments were less than half those of 1974, and stocks rose 31 %. Production of arsenic metal, begun by ASARCO in August 1974, continued in 1975.

Jan 1, 1977

By J. T. May

The Federal Bureau of Mines investigated the extraction of lithium from hectorite-type clay deposits found on the Nevada-Oregon border. Two clay samples were used in the investigation; one contained 0.36 pct Li and the second contained 0.64 pct Li. The purpose of this laboratory-scale research was to determine how these clays responded to different extraction techniques. Extraction techniques investigated were sulfuric acid leach, sulfuric acid bake-water leach, and roast-water leach procedures with cholorides, sulfates, carbonates, and combinations of these reagents. The processing characteristics of the clay samples showed significant variations, and no one technique was effective for both materials. Lithium extractions near 90 pct were achieved during these exploratory studies.

Jan 1, 1980

By Jamie Girard Dwyer, Edward McHugh, Stanley Miller, Jeffrey Whyatt

This user's guide covers the operation of a suite of three computer programs-Bplane, Bstepp, and Bwedge. These programs can be used to evaluate the potential for plane shear, step-path, and wedge failures along the crest of a slope bench. Such failures reduce the width of a catch bench and may compromise the bench's ability to catch rolling or sliding material before it reaches miners working below. The Bplane and Bwedge programs address sliding of blocks defined by continuous planar joints. The Bstepp program examines sliding of blocks defined by more complex failure surfaces that include steeply dipping cross joints and may even include breaks across small bridges of intact rock. The programs are applicable to jointed rock masses where the joints are small relative to the overall slope and form a number of sets with uniform statistical characteristics within a slope sector. The theoretical basis, application, and operation of these programs are described.

Jan 3, 2007

By S. J. Page, J. A. Organiscak

Dust surveys were conducted around small truck-mounted rock drills operating at surface coal mines to assess their airborne respirable dust generation and in-service dust control methods. Of four out of seven drills sampled, respirable dust concentrations measured around the drill deck ranged from 8.68 to 95.15 mg/m with3concentrations ranging from 1.37 to 2.69 mg/m at distances 12.2 to 30.5 m downwind of these drills. The other3drills had noticeably lower respirable dust concentrations measured around the drill deck at or below 1.30 mg/m.3Rotoclone-type dry dust collectors were commonly used with dust being emitted from around the drill deck shroud, collector exhaust, and collector fines dumping. Wind speed and direction was also a factor in the dust concentrations measured on the bench. Dust control modifications were made to three rock drills to reduce their airborne dust emissions. Dust controls tested included water injection into the Rotoclone exhaust, Rotoclone exhaust extension, improved sealing of drilling deck shroud, shrouding the Rotoclone hopper dump process, and wet drilling. These control techniques showed noticeable improvement in dust concentrations measured around the drills. Finally, repositioning the drill operator showed that operator dust exposure can be improved by avoiding the dust cloud around the drill.

Jan 1, 1995

By Isaac A. Zlochower, Michael J. Sapko, Ronald S. Conti

This paper describes a U.S. Bureau of Mines investigation of large-scale coal dust explosions in an experimental mine using a high speed electro pneumatic mechanism for the rapid grab-sampling of gases and dusts. This technique enables the monitoring of pyrolysis and charring in fuel dust particles, and the collection of gaseous combustion products, in both large and small-scale explosions. Data obtained from full-scale dust explosion tests at the Bureau of Mines Lake Lynn Test facility show the following: Rapid sampling appears to "freeze" the burned gas compositions at the flame temperature values. Gas samples taken entirely in the flame zone consist of pyrolysis and combustion products with very low residual oxygen. The particles collected in the flame zone show signs of extensive pyrolysis and charring. Measurements of gas concentrations and particle flame temperatures suggest that char burning may have occurred in the flame zone.

By W. J. Wenger

Results of the analyses of 151 crude oils from 123 oilfields in the Williston basin are presented. Production statistics are compiled by geographical areas within the basin, by geological age of the producing zones, by States, and by field for the nine fields with the greatest production. Characteristics of the oils are tabulated, and correlations are included to show relationships between properties of the oils and some factors in the environment. Properties of the oils in some instances imply that there has been migration and mixing of the oils between productive formations of different geological time periods.

Jan 1, 1968

By Manuel Gomez

The purpose of this study was to evaluate the feasibility of using statistical response surface regression analysis to predict the sulfur and ash distributions and the washability characteristics of coal along a seam in advance of mining. Prediction equations were developed with experimental data from channel, bench, and core samples from the Pittsburgh coal seam in Greene County, Pa. It was not possible, with the available experimental data, to construct mathematical models to predict ash and sulfur concentrations between sample points. In the authors' opinion, however, the good agreement between experimentally determined and predicted values at given sample points demonstrates the usefulness of the method. More input data, such as geologic information, seam characteristics (rock-to-coal ratio), petrographic analysis, and chemical data, would perhaps make it possible to predict sulfur and ash concentrations and washability characteristics between sample points.

Jan 1, 1970

By R. J. Hundhausen

The continued worldwide shortage and strategic value of nickel place great importance upon the continued development and exploitation of new sources of nickel in the United States, The deposits of nickel-bearing minerals in Oregon and Washington have attracted considerable attention, particularly since the Hanna Development Co. has engaged in development work aimed at producing ferronickel from the Nickel Mountain deposit, near Riddle, Douglas County, Greg. The Red Flats nickel deposit in Curry County, Oreg., was first examined by the Bureau of Mines in dune 1945, but it was not until 1952 that the deposit was drilled and sampled. In 1953, a 15-ton sample of Red Flats material was procured and subjected to continuous smelting tests in the Bureau's Northwest Electrodevelopment Laboratory, Albany, Greg.

Jan 1, 1954

By H. Billmayer

This report covers the period from June 17, 1974 to February 20, 1975, and describes the work performed in compliance with the requirements of Contract No. H0346102 and Modification No. 1 thereto. The purpose of the contract was to design protective canopies for an Elkhorn Scoop, a Lee Norse Miner, a Wilcox Miner and a Wilcox Bolter; to construct mockups of the canopies; and to obtain machine operator evaluations of the canopy designs by assessing the mockups while installed on their machines in the mines. The overall program objective was to achieve protective canopy designs for the four machines which would be acceptable to the operators.

Jan 1, 1975

By F. W. Lane

[The rapid expansion of the petroleum industry, the steadily growing use of oil fuel or steamships, the increasing transportation of oil in tankers and the extensive use of petroleum oils for many land industries, has resulted in pollution of our coastal eaters by these oils. On account of the great importance of this problem to the petroleum and shipping industries its, the Bureau of Mines, in cooperation with the American Petroleum Institute and -he American Steamship Owners Association has undertaken to ascertain the extend of petroleum oil pollution along the coasts of the United States and to indicated the principal so arcs of such pollution. Certain typical methods and devices in use and proposed for the separation of oil from water, and for the disposal of oily castes from ships and industrial plants have been studied. An attempt has also been made to point out the nature of the fire hazard resulting from oil pollution and to indicate the effect of such pollution on bathing beaches.]

Jan 1, 1924

By J. T. Schimmel

The purpose of this investigation was to obtain complete information on some of the uses of a 24-inch-diameter auger in the underground mining of pitching anthracite beds. The auger was placed in operation early in 1958 to drive ventilation connections between coal gangways driven by a continuous miner. Although designed to drill rise holes only, it was used also to drill dip holes. The latter holes were drill id from an adjacent gangway to avoid interference between the auger and the continuous miner. These holes established immediate ventilation returns when intersected by the continuous miner. Bureau participation in the project covered 361 working days. The auger was used on 288 shifts, usually one 7-hour shift per day, and drilled 3,246 feet, of which 493 feet were reamed. The longest hole was 87 feet; hence the maximum drilling depth of the machine (rated at 100 feet) was not required. Holes drilled normal to the strike of the bed ranged from 30 to 66 feet deep, averaging 45 feet. The continuous miner drove gangways on 575 shifts. Thus, the auger worked one shift for each two worked by the continuous miner and was used on less than 80 percent of the workdays. The auger drove 24-inch holes 10 times faster than the larger, conventional openings could have been driven by usual mining methods and exceeded the workload for which it was purchased. Augering eliminates exposure to the hazards encountered in driving chute-work by conventional methods and provides adequate circular ventilation openings, which are strong in self support and are adaptable to reaming when required. With alterations, the auger may have limited use as a production machine in thin-bed pitch mining but cannot compete with established methods of thick-bed pitch mining.

Jan 1, 1962

By T. T. Campbell

Research conducted by the Bureau of Mines demonstrated the feasibility of preparing columbium and tantalum metals by the application of Kroll-process techniques. Yields in excess of 95 percent were obtained in a modified Kroll-process reduction apparatus constructed from nickel and Inconel.4 Operating conditions during reduction and distillation were determined. Optimum temperatures during sodium reductions ranged from 650° to 750° C and for magnesium from 700° to 800° C with retort pressures ranging from 3 to 7 psig. Undesirable vapor phase reactions occurred when temperatures exceeded 750° C during sodium reductions or 850° C with magnesium. Vacuum distillation at 850° C effectively removed volatile salts and excess reductant from the reduced metals. Calculations based on the results obtained in small scale tests indicate that reaction rates of up to 34 lb/hr could be obtained during columbium reductions and up to 60 lb/hr during tantalum reductions in production scale reac¬tors. The small, laboratory-scale techniques used in this study could be adapted to commercial practice. The reduced powder or sponge metals can be consolidated by conventional arc-melting techniques, and the arc-melted metals can be fabricated into ductile sheet at room temperature. Analyses of arc-melted buttons prepared from Kroll-process tantalum or columbium showed that tantalum of greater than 99.8-percent purity was obtained and that columbium purity exceeded 99.7 percent. A significant purification of the reduced metals occurred when they were consolidated by electron-beam melting, and the purity and ductility of electron-beam-melted Kroll-process tantalum and columbium compared favorably with the commercial metals. After electron-beam melting, the purity of the tantalum exceeded 99.95 percent, and columbium purity was approximately 99.9 percent.

Jan 1, 1962

By M. L. Whisman

The Bureau of Mines developed a radiotracer method for detecting the contribution of selected components and additives to thermally induce deposits of turbine aircraft fuels. Fuels were examined before and after 52 weeks of storage at 130° F. Of particular concern was the influence of aromatic hydrocarbon fuel constituents on thermal-stability quality of jet fuels during storage. A microfuel coker test apparatus was used to thermally stress the test fuels and blends, and the resultant contribution to deposits of selected fuel components, labeled with carbon-14, was determined by radioactive-counting techniques. Ninety-one blends of five test fuels with carbon-14-labeled fuel additives or components were prepared, tested, stored for 52 weeks at 130° F, and reanalyzed for deposit-forming tendency. These additives included two anti-oxidants, a metal deactivator, and a corrosion inhibitor. Of the labeled hydrocarbon fuel systems studied, the greatest reaction was observed in blends containing methyl-and ethyl-substituted indenes. Other aromatic types also showed some contribution to the deposits. Three of the additives showed a marked tendency to degrade and react during storage and thermal stress. A cresol antioxidant, however, barely contributed to deposit formation. Oleic acid interacted with cadmium present in aircraft fuel systems and produced deleterious effects upon the thermal-stability quality of the fuel.

Jan 1, 1971

By Paul E. Loustaunau, Devah Galloway, Catherine Wetherby

This report describes a project in which Development of a Supervisory and Management Training Program for the Underground Coal Mining Industry was developed and evaluated. The project was carried out in two phases. The first phase was a research effort to develop specifications for the program. The second phase was a development and evaluation effort. In the second phase, training programs for first-line supervisors (section foremen) and for middle managers (mine/shift foremen and mine superintendents) were prepared in accordance with the specifications and evaluated by members of the industry. This report describes the project and presents the conclusions drawn there from.

Jan 5, 1983

By D. E. Shanks

The Bureau of Mines investigated the effects of HCI concentration and solution temperature on the solubility and crystal form of the chlorides of Co, Mn, and Ni when sparged with HCI gas at temperatures of 20°, 40°, and 60° C. Increasing HCI concentration in solution caused the chlo-rides of Co, Mn, and Ni to crystallize (salt out) because of the common ion effect. The salting-out crystallization was most effective for NiCI2, which had a solubility of 0.7 pct at 20° C and maximum HCI concentration. COCl2 salted out to a minimum solubility of 9.4 pct at 20° C and 22 pct HCI concentration and increased in solubility at greater HCI concentrations because of the formation of chloride complexes. MnCl2 was intermediate in behavior. The effect of temperature on solubility was greatest for CoCl2 and least for NiCI2, 15 and 7 pct change, respectively, over the temperature range of 20° to 60° C. The salted-out chlorides of cobalt and nickel formed the hexahydrates and those of manganese formed the tetrahydrate in saturated metal chlo-ride solutions at 20° C and low concentrations of HCI. Increasing the temperature or the HCI concentration caused a 108s in waters of hydra-tion. At 60° C, the salted-out crystals of NiCl2 formed the tetrahydrate in HCI concentrations up to 18 pct and the dihydrate at higher concentrations, while cobalt and manganese chlorides formed the dihydrates, even in water.

Jan 1, 1985

By Stephen W. Lambert, Michael A. Trevits

The Bureau of Mines examined the wellbore of a vertical gas drainage well in the Mary Lee coalbed to determine the results of specific completion procedures in coal. A jet-slotting tool was used to cut four vertical slots through the casing about 1 ft below the coalbed. Even though stimulation treatment pressure was excessive, hydraulically induced channels were contained entirely within the target coal zone. Sand-filled, induced channels were horizontal, inclined, and vertical, and were propagated in directions similar to bedding planes, rock joint, and coal cleat directions measured in the mine. Variable gas flow rates, recorded during the productive life of the well, were attributed to chronic downhole pump malfunction and the slotted casing below the production zone.

Jan 1, 1978

By Martin H. Stanczyk

Freezing to dewater typical Florida phosphate rock slime as demonstrated in laboratory tests appeared to have potential commercial use because of indicated moderate energy requirements, good compaction of dewatered solids, and effective recovery of usable water. After freezing, thawing, decanting, and filtering, batch freezing of gallon-size 13.7 percent solids slime samples yielded 42 percent solids products. Cationic amine, used as a process additive, yielded 46.8 percent solids product with significant filter area reduction. Semicontinuous 8 stage freezing tests also produced thickened slimes. Cooling and freezing 13.7 percent solids slime from 30° to minus 10° C required removal of 183 Btu per pound of slime; Carnot cycle calculation indicated that the theoretical minimum energy to transfer this heat was 27.8 Btu per pound. To produce 1 ton of 44 percent solids slime from 13.7 percent sol-ids slime, the calculated theoretical energy required for cooling and freezing was 52.3 kilowatt-hours. During the research heat capacity and heat of fusion data were determined for the slime at various percent solids.

Jan 1, 1971

By Curtis H. Elder

In studies conducted by the Bureau of Mines, two test areas were hydraulically stimulated and exposed by mining: One in the Pittsburgh coalbed at the Vesta No. 5 mine, Washington County, Pa.; and one in the Illinois No. 6 coalbed at the Inland mine, Jefferson County, Ill. Induced fractures were contained totally within the coalbed with no adverse effect on the stability of associated rock strata. Induced fractures were vertical and were propagated normal to the direction of least residual tectonic stress. Gas production was increased fivefold to twentyfold by hydraulic stimulation.

Jan 1, 1977