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By David E. Van Dillen

This volume is a task-by-task review of work performed in modernizing the BMINES finite element code. Much of the discussion is accomplished by cross reference to the user?s guide, which is Volume I of this two-volume report. The computer program described in this report provides for the static, three-dimensional, linear and nonlinear analysis of structural and geologic systems by the finite element method. The nonlinear material properties currently available in the code include isotropic, anisotropic, variable modulus, plastic, viscoelastic, and viscoplastic. Load application capabilities include gravity loading, surface tractions, and initial stresses. The element library includes rods, beams, plane and axisymmetric quadrilateral elements, three-dimensional brick elements, thick shell elements, and plane, axisymmetric, and three-dimensional joint elements. Special features include the ability to simulate excavation and construction sequences by means of element activity. An automatic mesh generator is included in order to simplify input preparation.

Jan 1, 1981

By A. L. Engel

In the period of 1942-1945, medium-grade, oxidized, lead-silver ore was mined and shipped from the Diamond district near Eureka, Nev. An encouraging tonnage of low-grade ore was developed during these operations and partly blocked-out for future mining. If the low-grade ore could be treated profitably, further development of the district would result, and production of an important strategic metal might be increased. A representative sample of Diamond district ore was obtained through the Reno office of the Mining Division for the studies described in this report. The sample consisted of lumps and fines of a highly altered siliceous rock containing much earthy red hematite and some granular black hematite. Examination with the binocular microscope showed the lead carbonate mineral, cerussite, in seams and disseminated in the hematite. No zinc or silver minerals were identified, and no sulfide minerals were present. Analyses of the ore showed:

Jan 1, 1951

By S. A. Matthes

This Bureau of Mines report describes a system for the dissolution of metal and mineral samples using a microwave heat source. Samples and an acid mixture are placed in sealed polycarbonate vessels. The vessel contents are heated using microwaves, digested for 2 min, and quickly cooled. After the solution is brought to a final volume, the vessel contents are heated an additional 2 min in the microwave oven. Using this method, a slag, a feldspar, and a Ni-Cu alloy were dissolved and analyzed by atomic absorption spectroscopy. Values obtained for Na, K, Cu, Ni, Si, Mg, Mn, Ca, Al, and Fe agreed with certified values and had an average relative standard deviation of 1 pct. This system results in a significant savings in time and expense over traditional methods of sample dissolution, and is ideal for preparing solutions for analysis by atomic absorption, plasma optical emission, or X-ray spectroscopy.

Jan 1, 1983

By William A. Beck

Since bauxite mining began in the Irwinton District, Wilkinson County, Ga., in 1912, it has been on a small scale, as most of the deposits of high-grade ore are small. The bauxite has a high silica content, and its use has been largely limited to the chemical industry. Drilling under this project did not disclose any bauxite deposits of commercial value: However, numerous holes penetrated high-alumina clay deposits, but no attempt was made to delimit them, as the project was solely an exploration for bauxite. Bauxite was first discovered near Irwinton in 1907. The district covers virtually all of Wilkinson County and extends into the adjoining counties of Washington, Baldwin, and Twiggs. Mining was begun in 1912 by the Republic Mining & Manufacturing Co. on the Honeycutt, Parker, and Daniel properties, which are 1.5 miles from Wriley on the old Irwinton to Milledgeville Road.

Jan 1, 1949

By L. J. Prosser

The Bureau of Mines has completed an underground degasification project in which an underground piping system was used to transport methane from the coalbed to the surface. In a la-month period four horizontal holes were drilled to an average depth of 1,450 feet. All four holes were surveyed vertically and azimuthally. In 991 days of degasification, 255 MMcf of gas was drained from the coalbed. The underground piping system proved to be a safe and effective means of transporting methane from the coalbed to the surface.

Jan 1, 1981

By W. M. Deaton

[Knowledge of the ten?erat~rre to wkich n gas ullder3atur~ted xith re- srplc t to water vapor may be cooled before the water p?f 11 3egin to condense 8 is desirable .and frec-uently iq neceTsarp in nWy resenrch md industri~J activities. This tenperrture, the dew point, i s 2 nrrticulnrly innortmt factor in high-pressure gas transmission, PS water cox?-ensate any interfere i with the flow of gos in the line. Sonetimes this interfexnce is due only to the yresence of the liquid water. At other tfncs, under certain condi- tions of pressure and teriperature, the cogdense;? water cn!nhines with the 93 to farm solid .y2: hydrctes. These solid coar~ouncis ma:/ ccllect in sufficient quantit;. to rehce materially the c~xrying cap.citg of the pipe line or ever, to ply thc line coimletelp.]

Jan 1, 1938

By W. M. Deaton

[Knowledge of the ten?erat~rre to wkich n gas ullder3atur~ted xith re- srplc t to water vapor may be cooled before the water p?f 11 3egin to condense 8 is desirable .and frec-uently iq neceTsarp in nWy resenrch c~d industri~J activities. This tenperrture, the dew point, i s 2 nrrticulnrly innortmt factor in high-pressure gas transmission, PS water cox?-ensate any interfere i with the flow of gos in the line. Sonetimes this interfexnce is due only to the yresence of the liquid water. At other tfncs, under certain condi- tions of pressure and teriperature, the cogdense;? water cn!nhines with the 93 to farm solid .y2: hydrctes. These solid coar~ouncis ma:/ ccllect in sufficient quantit;. to rehce materially the c~xrying cap.citg of the pipe line or ever, to ply thc line coimletelp. ]

Jan 1, 1938

By E. Chilton

The National Institute for Occupational Safety and Health (NIOSH) has been conducting re-search to determine the influence of mining machine mounted water sprays on airflows and methane concentrations at the face when blowing ventilation systems are used. Tests were conducted in a full-scale ventilation gallery. Airflow speeds and directions were measured at several locations near the face with ultrasonic anemometers. Methane was released from the face and concentrations were measured in the entry at locations above the mining machine using fixed point methanometers. Changes in airflow speed, direction, and methane concentrations were correlated with water spray operations. The test results using different spray arrangements and water pressures showed that operation of the machine-mounted sprayers can improve face ventilation effectiveness by increasing the velocity of airflow moving toward and away from the face. The improved ventilation resulted in reduced methane levels near the face.

By G. L. Finfinger, J. Cervik, L. J. Prosser

The Bureau of Mines has completed an underground degasification project in which an underground piping system was used to transport methane from the coalbed to the surface. In a 10-month period four horizontal holes were drilled to an average depth of 1,450 feet. All four holes were surveyed vertically and azimuthally. In 991 days of degasification, 255 MMcf of gas was drained from the coalbed. The underground piping system proved to be a safe and effective means of transporting methane from the coalbed to the surface.

Jan 1, 1981

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 V. E. Homme

This report describes methods of using sodium for reducing titanic chloride, developed as part of Bureau of Mines activities at Boulder City, Nev., to improve the extractive metallurgy of titanium. Theoretical indications pertaining to the major chemical reactions and possible side reactions of the process are compared with experimental observations. Low-temperature reduction equipment is described, in which titanic chloride was reduced with sodium at temperatures between 97.5° C., the melting point of sodium, and 200° C. Techniques employed in making reductions in ball-mill and high-surface sodium reactors are given.

Jan 1, 1958

By Charlie Wyche

In 1980, gold, silver, and pit and quarry construction materials were the principal minerals produced in the Dominion of Fiji. The combined value of these minerals totaled some $7.2 million,2 over 85% of all mineral production, Production of cement, sand and gravel, and quarry products continued to increase, but gold and silver production from Fiji's only operating mine declined slightly from the previous year's level. Mineral exploration has been carried out by U.S., Australian, British, Canadian, West German, and South African companies since the early 1960's, and a high level of activity was maintained throughout 1980. At the end of 1980, some 40 mineral prospecting licenses covering over 4,300 square kilometers were in force, and 19 applications were under consideration by the Mineral Resources Department. Total expenditures by mining companies on land base projects exceeded $6 million in 1980.

Jan 1, 1982

By Lito C. Mejia

Diesel-powered equipment operating in a gassy underground mine could conceivably ingest a methane-air mixture from the mine atmosphere that could cause the diesel engine to overspeed, or exceed its rated speed. Engine overspeed, particularly if extreme (engine runaway), could result in personal injury, a possible mine explosion, and/or catastrophic engine failure. In this report, the Bureau of Mines reviews the literature on the potential hazards of methane-induced diesel engine overspeed. Also included are the Bureau's findings from consultations with representatives of the diesel engine industry to determine the specific engine behavior that could he expected under the overspeed condition. The report summarizes data on mine accidents involving methane, discusses results of tests on the compression ignition of methane in diesel engines, and examines fuel governors and intake-air-cutoff devices, two kinds of devices used to prevent overspeed. Analysis of the information gathered suggests that the conditions necessary to cause a diesel engine to overspeed uncontrollably are not likely to occur, particularly if the engine is equipped with flame-proofing devices. The available literature and lack of actual overspeed case histories suggest that the safety devices currently in use are sufficient to prevent diesel engine overspeed.

Jan 1, 1984

By Carlon S. Land

The Bureau of Mines investigated the influence of a free gas saturation on oil recovery by water drive. A digital computer was used to calculate the combined oil recovery from solution-gas drive to various states of depletion. Results of these calculations are compared and optimum conditions for the maximum oil recovery are found for various fluid-rock systems. For most of the fluid-rock systems, the calculations show an optimum gas saturation other than zero. Using fluid and rock properties as parameters, graphs are plotted showing the optimum gas saturation and increase in oil recovery brought about by the gas saturation. The effects of fluid properties and relative permeability on the optimum gas saturation are seen in these graphs. The graphs can be used as guides in connection with other considerations in determining the optimum time to start a waterflood. They should also be helpful in determining the MER of a water-drive reservoir. The effects of compressibility and solubility of the trapped gas saturation are investigated for select cases using a backward difference scheme to solve the partial differential equation of three-phase flow. From these calculations, it is observed that some benefit of a gas saturation remains for injection pressures up to 1.5 times the original bubble-point pressure.

Jan 1, 1974

By Sidney Speil

In the study of clays and related minerals, the analytical techniques commonly employed in mineral analysis are not always applicable. The X-ray examination of a clay sample usually will show the major constituents, but often minor· clay impurities will not be detected because of line broadening and the similarity of the main lines of clay· mineral diffraction patterns, The petrographic analysis of clay minerals with clay particles as small as a few microns is usually difficult. With still smaller particles, a gross effect often is noted in which a mixture of several constituents gives the appearance of a single constituent with the mean optical-characteristics of the mixture. 3/ The electron microscope has recently been used to study clay particle shapes of various aluminosilicates. 4/ However, this method has not yet been sufficiently explored. The Chemical method in which a mineralogical analysis is calculated from the oxide chemical analysis has been discussed by Wilson 5/ and others, and many of the shortcomings have been pointed out. It should also be recognized that the variable alkali and alkaline earth content of bentonites makes it inaccurate to assign these basic elements arbitrarily to feldspar or mica in any clay that contains appreciable bentonite.

Jul 1, 1944

By Joseph A. Sutton, John D. Corrick

The chemistry involved in the microbial dissolution of iron and copper from such sulfide minerals as pyrite, chalcopyrite, chalcocite, cove11ite, and bornite is described. The chemical criteria used to evaluate the activity of microorganisms on these minerals were changes in pH, ferric iron produced, and oxygen consumption. In a series of experiments in which a ferrous sulfate nutrient solution was percolated over small portions of the above-mentioned copper sulfide minerals for 56 days, the iron-oxidizing bacteria Ferrobaci11us ferrooxidans and Thiobaci11us ferrooxidans were capable of bringing about the dissolution of 23.7 percent of the copper from chalcocite, 56.3 percent of the copper from cove11ite, and 29.8 percent of the copper from bornite by the microbial production of ferric sulfate which reacted with these minerals. Laboratory tests have demonstrated that pure strains of the iron-oxidizing bacteria act as catalysts to the ferrous iron being oxidized by the Oxygen of a system containing pyrite and chalcopyrite. In a series of experiments during which nutrient solution was percolated over pyrite for 70 days, the ferric iron produced by the iron-oxidizing bacteria was 112 to 120 times greater than that produced atmospherically.

Jan 1, 1964

By E. J. Murphy

"INTRODUCTION This investigation is a continuation of previous work 3/4/5/ on the gaseous products of permissible explosives with and without sheaths. The range of oxygen balance of the explosives has been considerably increased. As has been shown previously, certain approximate relations exist between the volumes of gaseous products and the oxygen balance. Further systematization of the data is not feasible, since the method of theoretioal calculatln of the gaseous product is not yet satisfactorily developed. In a previously described method, 6/ it has been assumed that the explosion occurs at constant volume and that thermodynamic equilibrium is established. Apart from the presumably less important uncertainty of some of the thermodynamic data, it is not known how the confinement of the shots in the Bichel gage or the Crawshaw-Jones gage should be treated, or whether thermodynamic equilibrium is fully attained; nor can the extent to which the equilibrium composition changes during the subsequent period of expansion and cooling be judged with any reliability. Therefore, no calculations have been attempted. However, in anticipation of possible future theoretical interest and as an aid in answering practical problems, the new data are presented in the same minute detail as was done previously."

Mar 1, 1948

By J. Durkin

The Bureau of Mines has conducted field studies in coal mines throughout the United States to determine the effectiveness of electromagnetic techniques in locating miners trapped underground following a mine accident. Data from these tests have been used to generate models of expected signal and noise distributions as found above these mines. These distributions have aided in placing the expected performance of a through-the-earth electromagnetic communications technique into a probabilistic framework. Results show that at a 10% false-alarm rate, the expected probability o detecting a miner's signal" from a depth of 1000 ft is 54% at 500 ft it is 95%. These depths exceed the actual depths of 90 and 50%, respectively, of United States coal mines. Sensitivity studies have shown that at depth of 1000 ft, the probability of detection will improve approximately 2% for each dB of increase in signal-to-noise (SNR) ratio.

By H. W. St. Clair

In about 1930, Degussa applied for a patent on a process for the of oxides, carbides, sulfides, and other nonmetallic impurities by filtration in the molter state. The filtering media listed were wire screen, coke, and ceramic materials, and quartz. It was also suggested that filtration might be combined with chemical reaction between the metal and the filter medium or that might be added to the system. No patent was granted on the general scheme, but several years later a patent was granted on a continuous process purification of crude light metals, especially or alkali earth and their alloys. The melt was stirred at 1 temperature at which the impurities (such as oxides and salts) remained solid and the metal was drawn through a filter tube. The impurities collected under the filter and were removed by a screw conveyor. Crude sodium was purified by this process in Degussa's Knapsack plant. During the last war, when the refining of scrap became a very urgent Problem in Germany, experimental investigations were extended to separation of other metals and metallic compounds by filtration. Preliminary experiments seemed to confirm the opinion of Dr. L. Weiss that the principles of wet chemical filtration might be applied to a great extent in the purification of metal and alloys.

Jan 1, 1949

By T. L. Marchewka

As part of its program to conserve the Nation's natural resources by developing improved performance materials, the Bureau of Mines, U.S. Department of the Interior, in cooperation with the U.S. Department of Energy, has conducted an investigation of materials of construction able to withstand the high temperature and hostile environments encountered in coal gasification units. Refractory pipe liners are required when extremely hot gases or abrasive solids are transported between processing units in the gasification plants. One promising technique for producing refractory pipe (or refractory pipe liners) is centrifugal casting. For this study, the effect of processing variables such as workability, additives, reinforcement and spinning time, and centrifugal force were evaluated using four commercial refractory concretes. In addition, data on characteristics such as strength, density, abrasion, and spalling resistance of 5-inch-diam refractory pipe were developed. Techniques for forming large-diameter (19-inch) refractory pipe also were evaluated. The test results indicated that all four refractory concretes could be made into strong, homogeneous pipe, but that optimum casting parameters had to be determined for each specific composition. The investigation revealed that the major controlling factor in the production of the centrifugally cast pipe was the workability of the refractory concrete.

Jan 1, 1979