Search Documents

By Arnold M. Lansche

Domestic Production.-Domestic production of white arsenic, AS,03, was derived entirely as a byproduct of smelting arsenic-containing copper ores by The Anaconda Company at Anaconda, Mont., and American Smelting and Refining Company at Tacoma, Wash. The Anaconda Company discontinued production of white arsenic in 1965. Arsenic metal was not produced. Consumption and Uses.-Most of the white arsenic produced in 1965 was consumed in manufacturing lead and calcium arsenate insecticides.

Jan 1, 1966

By Thomas R. Bur

Symmetry theory, based on ground work established in the study of single crystals and experimental procedures utilizing ultrasonic pulse velocities of spherical specimens plotted on equal area polar projections, enables the direct identification of a material's elastic symmetry system and the determination of its orientation, as well as the position of the elastic coordinate axes. The method is especially useful for elasticity studies of polycrystalline and amorphous materials for which this knowledge of symmetry is a prerequisite in determining the independent elastic constants. Projections based on theoretically derived velocities are given for a single crystal from each of the major crystallographic symmetry systems except the triclinic. Projections based on experimentally derived velocities are given for one brass and several rock spheres.

Jan 1, 1969

By Henry G. Dorsett

Dust explosion data obtained in laboratory tests by the Bureau of Mines are presented for 73 chemical compounds and mixtures, 29 drugs, 27 dyes, and 46 pesticides. Information is given on ignition temperatures of cloud and layer, minimum igniting energy, minimum explosive concentration, percent of inert dust required to prevent flame propagation, limiting oxygen concentration in the atmosphere to prevent ignition, and pressures and rates of pressure rise at dust concentrations of 0.1, 0.2, 0.5, 1.0, and 2.0 ounces per cubic foot. Explosibility indexes are computed where data are available to permit comparison of the relative explosion hazard. Variations of explosibility parameters with chemical composition are discussed. General means for minimizing the dust explosion hazard are reviewed.

Jan 1, 1968

By Noel N. Moebs

Coal mine roof failure is categorized according to character, trend, or pattern of occurrence. Two principal categories of failure are proposed--geology related and stress related. Geology-related failure includes both lithology and structure. Each of several subcategories reflects the probable cause of failure and thereby provides a basis for the selection of appropriate techniques for reducing the incidence of failure. These control techniques, depending on local conditions, may include supplementary support, destressing, reduction of mine air humidity, or a change in the customary support methods.

Jan 1, 1986

By V. R. Spironello

One of the primary objectives of the Bureau of Mines solid waste utilization program is the recycling of the magnetic fraction of municipal solid waste called raw refuse scrap. In this investigation, several types of scrap of differing quality, including refuse and turnings, were melted in a 1-ton electric-arc furnace in various combinations to produce steel in noncritical (construction) grades. In-formation on furnace operation and on the behavior of tramp and alloying elements was obtained. The research showed that it is possible to produce acceptable steel from a variety of steel scrap. Although some scrap is routinely used in steelmaking, it was found that up to 50 to 55 pct of the scrap charge can be ref-use, provided it is combined with higher quality scrap. The chemistry of the steels was generally acceptable, and all of them were rolled without difficulty. The specification (ASTM 615) for the steels produced was grade 40 or grade 60, containing 0.30 or 0.40 pct C, with mini-mum yield strengths of 40,000 or 60,000-psi, respectively. Most of the steels met the specification requirements. In-formation on typical microstructures of some of the steels is included. The composition of some furnace dusts showed high levels of Sn, Pb, and Zn.

Jan 1, 1981

By E. J. Ostrowski

The Bureau of Mines experimental blast furnace, Bruceton, Pa., was operated to determine the feasibility of replacing part of the burden coke requirements with solid fuels injected directly into the smelting zone. This report describes preliminary experiments and information resulting from such an interchange. These experiments were made on an all-sinter burden, using two parts sinter to one part fuel. Anthracite fines were injected intermittently into the smelting zone of the furnace by compressed air through auxiliary tuyeres. The interval between injection periods ranged from 5 to 15 minutes. A maximum of 28 percent of the stock column coke bur-den was replaced. This percentage replacement caused furnace malfunction, but the overall percentage of these experiments indicated that 20 to 24 percent of the coke requirements could be replaced in this way. The metallurgical coke consumption was decreased by as much as 377 pounds (25.3 percent) per ton of pig metal produced. Buckwheat anthracite No.4 was used in this experiment; however, such solids as bituminous coal or coke fines also could be used. The frequency as well as the quantity of solid fuel injected has a direct bearing on furnace performance.

Jan 1, 1960

By J. R. Nettle

The electrodeposition characteristics of seven binary alloys of titanium have been investigated. The object of the electrorefining experiments with an alloy was to determine the efficiency of titanium separation from individual alloying elements under established conditions. Reported results are only indicative. It is conceivable that numerous duplications of tests might give average maximums that would vary from those noted in this report; however, in the few tests that were repeated, the magnitude of transfer of the alloying elements was of the same order. The results detailed herein are for a given set of conditions. Many combinations of operating variables are possible, and the results achieved under different conditions probably would differ from those reported.

Jan 1, 1958

By D. E. Wolfson

Destructive distillation (carbonization) was shown to be a feasible method of disposing of scrap tires. The Bureau of Mines conducted tests under a variety of conditions. Solid, liquid, and gaseous products were produced, recovered, and analyzed. The quantities of the various products were shown to be quite dependent on the test temperature. Variability in composition of the liquid and gaseous products with changes in test temperature was also significant.

Jan 1, 1969

By Douglas A. Donato

This Information Circular presents the MULSIM/PC system of numerical modeling computer programs developed by the U.S. Bureau of Mines. This system consists of four programs: PREMUL, the preprocessor or mesh generator; MULSIM/PC, the actual numerical modeling program (number cruncher); MUL3D, a three-dimensional postprocessor; and MUL2D, a two-dimensional postprocessor. These programs were specifically designed to operate on IBM-compatible (MS-DOS-based) personal computers for easy transfer of this technology to the mining industry and academia. MULSIM/PC uses a subvariation of the boundary-element method, namely, the displacement-discontinuity technique, for linear-elastic geomechanical analysis of mine plans in one or two parallel underground tabular deposits. Results calculated by this technique include stresses and displacements as they relate to changing mine geometries and materials. In addition to describing the MULSIM/PC program and its features, and providing a detailed example model, this report also documents the associated preprocessing and postprocessing programs that are part of the MULSIM/PC system. User's guides for all the programs are contained in the appendixes following the main report.

Jan 1, 1992

By A. J. Barry

A method was developed for testing the anchorages obtained with 3/4-inch, expansion-type, headed bolt and shell assemblies. The apparatus is a modification of that used in testing -inch-diameter, slotted-type bolts. Four makes of expansion-type shells were used in 64 tests made in sandstone and shale roof. The results show that for 3 makes of shells the anchorage effectiveness is independent of the installed land, and for the fourth make of shell a better anchorage is obtained when instilled at a load of 8,000 pounds. The results also show that deformation of the expansion plug influences the majority of the anchorages obtained with two makes of shells. This deformation causes a larger increase in displacement for a given added increment of load. The data from 48 of the 64 tests were combined to establish a relationship between average displacement and increase in bolt load (above the installed load). This relationship can be used to evaluate the anchorage effectiveness of any 3/4-inch-diameter, expansion-type, headed bolt and shell assembly tested in the field.

Jan 1, 1956

By A. A. Giardini

This report represents the results of a literature study on boron nitride and related substances. The purpose of the study was to find Information that might be of value for production of a new, hard modification of boron nitride preferably in single crystal form. The report consists of a review of the major developments in boron nitride research, a discussion of the results, tabulations of physical and chemical properties;, conclusions drawn from the study, and a bibliography.

Jan 1, 1953

By J. W. Montoya

The chemical, mineralogical, and physical properties of berylliferous tuff from Spor Mountain, Utah, were determined in laboratory research conducted by the Bureau of Mines. Two beryllium-bearing minerals--a hydrated form of bertrandite and a berylliferous saponite--were found to be present in the tuff. Each of the beryllium mineral forms predominated in samples from certain areas of the district. The possibility of practicably separating the beryllium minerals from the tuff by physical methods appears remote because of the complexity and nature of the mineral associations. Beryllium mineralization in the region occurs in a rhyolitic tuff usually overlaid by unaltered rhyolite. The beryllium is distributed erratically throughout the tuff in individual mineralized bodies. Many samples of mineralized tuff were examined and found to contain from 0.2 to 1.8 percent BeO. All samples contained a hydrated form of bertrandite that was nearly cryptocrystalline, whereas samples from one area also contained a berylliferous saponite of variable beryllium content. Neither mineral has been previously reported, although related bertrandite-like minerals have been found in the U.S.S.R. and berylliferous minerals of the montmorillonite group have been synthesized. Most of the minerals of the tuff are finely crystalline, intergrown, and have similar densities. The complexity and intimacy of the mineral associations, the difficulty of achieving effective mineral liberation, and the highly friable nature are characteristics that lead to the conviction that tuff of the type examined cannot be effectively concentrated by gravity, magnetic, electrostatic, attrition, washing, sizing, or flotation methods.

Jan 1, 1962

By James Paone

The Bureau of Mines conducted laboratory drillability studies on nine rock types using two mining-type percussive drills. Percussive-bit action was simulated by dropping a known weight on a rock sample to obtain a coefficient of rock strength for each rock drilled. While no single physical property of a rock is completely satisfactory as a predictor of penetration rate, coefficient of rock strength showed a better correlation with penetration rate than did other physical properties. Results also indicate that over the range of energies investigated, energy per unit volume in a given rock is independent of blow energy. A drillability index for the percussive system is proposed that utilizes the coefficient of rock strength test to determine energy per unit volume for a given rock which, along with the work rate of a given drill and the bit diameter, is used to predict the penetration rate as shown in the following equation: [R = 4P pD2 E, where R = penetration rate, in/min, P = work rate, in lb/min, D = bit diameter, in, and Ev = energy required to produce a given volume of rock, in lb/in3.] Laboratory tests indicate this method's potential as a simple and reasonably accurate method of predicting penetration rates with any percussive drill and bit combination.

Jan 1, 1969

By Richard H. Spencer, Warren G. Bender

Since the passage of the Coal Mine Health and Safety Act of 1969, the Bureau of Mines has made many advances in mine communications. These efforts have resulted in the following developments and demonstrations: • Surface-to-surface electromagnetic transmission of baseband voice signals through overburdens as deep as 600 feet. This transmission was achieved with equipment from the Interim Mine Rescue and Survival System Program, and demonstrated that baseband voice communications could be obtained through these overburdens in the absence of mine-generated noise; that is, when the mine power system was shut off. However, during mine operational conditions, the mine-generated noise proved to be so large that effective baseband voice communications to the desired depths could not be effected. • The development of beacon transmitters for locating trapped miners. This work was again the outgrowth of the Interim Mine Rescue and Survival System. Extensions of this work have led to reliable detection and location of trapped miners to depths of 1000 feet. The system, which makes use of a loop antenna deployed where the trapped miner is located, uses low-duty-cycle, tone-burst transmission. Portable tuned receivers and loop antennas are used on the surface to determine the location of the trapped miner. An extension of this work has led to a call-alert paging system concept, wherein a transmitter, similar to that used in the trapped miner system, is used to audibly and/or visually alert key mine personnel carrying pocket receivers that they are wanted at the nearest mine telephone. In addition, a roof-bolt paging system has been developed, wherein commercial paging and mine carrier phone equipment are used in conjunction with a long-wire "roof bolt" antenna to page individuals and relay to them short voice messages.

Jan 7, 1975

By Joan T. May

Anhydrous methods were tested for the extraction of beryllium from low-grade source materials. The purpose of the investigations was to find new extraction processes that are applicable to domestic ores. Beryl, helvite, and phenacite materials containing from 0.1 to 2.8 percent BeO were used as starting materials for direct halogenation tests and pretreatment followed by halogenation. The results of the investigations showed that direct fluorination and carbide-chlorination are two practicable methods that can be applied to low-grade concentrates. Treatment of concentrate-carbon mixtures with anhydrous hydrogen fluoride extracted 99 percent of the beryllium in the concentrate; the soluble fluoride product, converted to an oxide, contained 70 percent BeO. Chlorination of beryllium-silicon carbide, prepared from low-grade concentrates, extracted beryllium into the volatile chloride product.

Jan 1, 1962

By John S. Berber

Bureau of Mines research on the production of phthalic anhydride by vapor phase oxidation of hydrocarbons began at Morgantown, W. Va., in October 1960. For these preliminary studies, a known solution containing naphthalene and 1-methylnaphthalene was used. In another series of tests, pure naphthalene was dissolved in different solvents. A series of investigations was conducted with the neutral oil fraction (210° to 270° C) of a low-temperature tar obtained from the Texas Power and Light Company's low-temperature carbonization unit. The neutral oil fraction was first dealkylated, and then the product was distilled into 210° to 250° C and 250° to 270° C fractions. These two fractions were then subjected to catalytic vapor phase oxidation. Although a number of catalysts was tested, most of the experiments were made using 9 percent vanadium pentoxide on inert alumina. The activity of this catalyst did not decrease after 162 hours at 1,030° F. Studies were conducted over a temperature range from 610° to 1,180° F. An operating temperature of 1,030° F yielded 47.50 percent of phthalic anhydride from a synthetic mixture of naphthalene and 1-methylnaphthalene. The highest yield (84.40 percent phthalic anhydride) was obtained with naphthalene dissolved in toluene and also with naphthalene dissolved in methyl ethyl ketone. With a 210° to 250° C fraction the highest yield of phthalic anhydride obtained was 12.32 percent at a temperature of 900° F, and, with a 250° to 270° C fraction, it was 15.80 percent at a temperature of 875° F.

Jan 1, 1963

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 A. J. Barry

Two methods of testing anchorages of headed expansion-type mine roof bolts were investigated by the Federal Bureau of Mines to determine whether they are acceptable for general use. In both methods a load was applied to a tightened bolt with a hydraulic jack. A total of 80 tests, 40 using each method, was conducted in 4 test areas in 3 commercial coal mines. Electric resistance strain gages were used in all tests to indicate true bolt load as the bolt was tightened and when an additional load was applied with the hydraulic jack. The results indicate that: 1. The relationship between the true bolt load and the jack load will vary according to the test method until the two loads become equal. The bolt load-jack load relationship below this point can be determined only with strain gages. 2. The point at which the two loads become equal can be estimated by noting the load when the hardened washer becomes loose in one method, and when the bearing plate becomes loose from the roof in the other. It also can be approximated for either method of testing by noting the load when the first abrupt change in the slope of the jack load-bolt displacement curve occurs. 3. The anchorage characteristics of the test bolt can be determined from the data obtained from either method by examining the slope of the jack load-bolt displacement curve above the point at which the true bolt load is equal to the jack load.

Jan 1, 1960

By F. M. Goodwin, John Campbell, G. W. Jones

"INTRODUCTION In previous reports 5 results were given of a manhole investigation carried out over a period from June 1929 to July 193C in cooperation with the Edison Electric Illuminating Co. of Boston. Mass., and during 1931 in cooperation with the Edison Electric Illuminating Co. of Boston and the Boston Consolidated Gas Co., to determine the general hazards of combustible gases and vapors in manholes and other underground openings owned by the Edison Electric Illuminating Co. and to develop methods of eliminating these hazards. These investigations have demonstrated that the detection, control, and elimination of combustible hazards in manholes can best be obtained by a close cooperation of the interested parties through a systematic and continuous inspection of manholes, under proper supervision.The investigation carried out during 1932 has been along lines similar to those conducted during 1929, 1930, and 1931 test crew consisting of two men, one an employee of the Consolidated Gas Co. and the other an employee of the Edison Electric Illuminating Co., was continuously employed during the year in the testing of gases in manholes served by the Edison system. The test crew was under the direct supervision of John Campbell, superintendent of the special service department of the Edison Electric Illuminating Co., and F. M. Goodwin, vice president of the Consolidated Gas Co.As in the previous investigations, all tests were numbered. The test-data sheets, on which the information regarding the tests was recorded, were prepared in triplicate, ono copy going to the Edison Co., one to the gas company, and the third to the Bureau of Mines at Pittsburgh, Pa. These test-data sheets were then filed (1) according to the town, (2) the street location, and (3) the manhole number; in this way a complete record of each manhole tested was immediately available. A typical test-data sheet was given in the 1931 report. These data sheets were found to entirely satisfactory and no changes were made during the 1932 investigation. The procedure of sampling manhole atmospheres, shipment of the samples to Pittsburgh, and method of analysis has been the same as that described in the 1931 report and need not be repeated here. Likewise, there has been no change in the method of calculation of explosibility of the samples analyzed or the use of charcoal filter tests given in appendix A."

Jun 1, 1933

By R. Blickensderfer

Test equipment that simulated frictional impacts between coal-cutter bits and mineral inclusions at a coal face during operation of a continuous coal mining machine was used by the Bureau of Mines in the laboratory to study the incendivity of impacts between various rocks, metals, and hard-metal alloys in an explosive mixture of air-7 pct natural gas. Quartzitic sandstone was found to be the most incendive of several rocks tested. Limestone concretions from a coal seam, known locally as "sulfur balls," sparked furiously but were not incendive. Among the metals tested, the type of steel used in commercial coal-cutter tools was the most incendive material tested. A l7-4PH stainless steel was less incendive and appears to be the most promising high-strength steel alloy, reasonably economical, for use in coal-cutter bits. Some hard-metal alloys, primarily titanium and zirconium diboride composites, were also evaluated as possible replacements for the conventional cobalt-bonded tungsten carbide used in the tip of coal-cutter bits. The metal-bonded diborides were generally less inc endive but more brittle than the conventional tungsten carbide. Carbonitride coatings on tool bits were also tested but found to have no advantage. The source of ignition during frictional impact between metal and rock was studied. Immediately after impact, a yellow flash was observed and a smear of metal near its melting point occurred on the rock. This hotspot on the rock, rather than the yellow flash or sparks or metal fragments, was observed to be the cause of the ignition.

Jan 1, 1974