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By J. Roger Loebenstein

Demand for arsenic trioxide exceeded supply in 1978 and 1979, and the major domestic and foreign producers allocated available supplies to customers. Major demand has been from the cotton-growing and wood-preserving industries. Ample supplies of arsenic metal produced in the United States and Sweden were available in 1978 and 1979. Major demand for metal was from the automobile battery industry in Japan, Europe, and the United States. Legislation and Government Programs.-The Occupational Safety and Health Administration (OSHA), promulgated the final standard on the occupational exposure to inorganic arsenic, effective August 1, 1978.2 The need for the standard was a result of OSHA's conclusion that inorganic arsenic is a human carcinogen. The purpose of the standard was to minimize the incidence of lung cancer among workers exposed to inorganic arsenic. The maximum exposure to arsenic was lowered from the previous ceiling of 500 micrograms per cubic meter of air to 10 micrograms per cubic meter over an 8-hour time period. OSHA had originally recommended a ceiling limit of 4 micrograms per cubic meter in January 1975. Provisions of the new standard require exposed employees to wear respirators and undergo continuous medical monitoring. Other provisions establish regulated areas limited to authorized employees and require the construction of special lunch-room and worker hygiene facilities and the posting of signs and labels warning of the presence of arsenic. The new arsenic standard will have a significant economic impact on copper, zinc, gold, and lead smelters as well as consumers of arsenic trioxide. A number of copper companies have joined together to contest the standard in court. However, measures to comply with the standard have been initiated by ASARCO Incorporated at its Tacoma, Wash. plant.

Jan 1, 1980

By D. E. Wolfson

This report presents 900° C BM-AGA carbonization and related data for coals from the principal beds of Nicholas, Randolph, and Webster Counties, W. Va. Thirty-three samples from nine coal beds in three counties were car-bonized at 900° C in the l8-inch-diameter BM-AGA retort, data from which have been correlated with industrial production. Host of the samples were chemically suitable for metallurgical use, and their coking properties were satisfactory. Except for four of the Lower Kit-tanning samples, the ranges of constituents in the coal seams were 1.8 to 9.0 percent ash and 0.4 to 1.1 percent sulfur, values within the range of accept-ability for metallurgical coals. Coke strength indexes were normal for Appalachian coals of similar rank, and the tumbler stability indexes of the coke ranged from 35 to 57.

Jan 1, 1969

By S. R. B. Cooke, J. Bruce Clemmer, F. P. Diener

"The limestone deposit utilized by one of the plants of the Universal Atlas Cement Co. is covered in part by a stratum of cherty limestone. If this overlying deposit could be utilized by removing the excess of chert economically, quarry costs could be reduced and the amount of rock economically available would be increased greatly. On account of the distribution of flint and limestone, a product fairly free of flint can be obtained until the quarry face is about 50 or 55 feet high. As the face is worked farther back into the hill, the comparatively clean stone is overlain with a constantly increasing amount of high-flint limestone. If this flint remained with the limestone, there would be a prohititively high silica ratio in the finished cement; if the flinty layer were removed as overburden a very large tonnage would be handled and much good stone lost. Consequently it was felt that means should be devised for separating the flint from the limestone after it reaches the plant.The investigation was undertaken by the Mississippi Valley Experiment Station of the United States Bureau of Mines in cooperation with the Universal Atlas Cement Co. and the Missouri School of Mines and Metallurgy, Rolla, Mo.CONSIDERATION OF PROCESSESMany schemes for the separation of Minerals are based on differences in the specific gravities of the minerals to be separated. In this case the flint has a specific gravity of approximately 2.62 while the limestone averages about 2.70. This differential is not large enough to permit separation by any method based on specific gravity. Furthermore, all the limestone particles in any given sample are not alike; usually about 10 percent of them have a specific gravity the same as, or lower than, the flint."

Mar 1, 1935

By A. A. Cochran

Bureau of MinesThe Bureau of Mines studied the development of practical methods for recovering manganese from the extensive domestic resources of low-grade ores and open hearth slags. A one-step operation was developed on a laboratory scale in which manganese and iron compounds are treated with chlorine, volatilized, and separated by selective condensation. Manganese recoveries of 90 to nearly 100 percent were obtained from 9 of the most important domestic ores. Analyses of the manganese chloride product indicated that it was suit-able for aqueous electrolysis with little additional purification. A complete, integrated process that provides for the recovery and recycling of chlorine is proposed. This process appears to have distinct advantages over previously proposed manganese recovery processes, and, in sharp contrast to leaching procedures, it is applicable to practically any manganese-bearing material.

Jan 1, 1967

By C. J. Thompson

Two sulfur compounds--the 2,2,5-trimethyl- and the 2,2,5,5-tetramethyl derivatives of thiacyclopentane--were identified in Wilmington, Calif., crude oil, using microdesulfurization and gas-liquid chromtography techniques.

Jan 1, 1963

By M. J. Ferrante

Relative enthalpies of high-purity disodium hexatitanate (Na2Ti6013) were measured at the Bureau of Mines to provide new thermodynamic data needed to advance the technology of materials. Measurements from 298.15 to 1,478 K were made by drop calorimetry with a copper block. Tabulated values are listed for the standard relative enthalpy, heat capacity, en-tropy, and Gibbs energy function between 298.15 and 1,500 K. Enthalpy data are also given in equation form and are combined with thermodynamic data from the literature to derive values of standard enthalpies of formation, Gibbs energies of formation, and logarithms of the equilibrium constants of formation. Similar calculations were made for the reaction of Na20 with Ti02.

Jan 1, 1986

By Gerald V. Gibbs

As a part of the Bureau of Mines long-range program in asbestos, synthetic asbestiform compounds and minerals were prepared and described. Fundamental structural data on two such compounds are given in this report. Crystallographic data are provided for the synthetic isotypic compounds potassium-lead silicate, K2.Pb4 -Si8021 (I), and lead-aluminum silicate, Pb2. Pb4 .Al2Si6O21 (II). The space group symmetry 14/mmm was assigned provisionally to I and II on evidence of single crystal and piezoelectric measurements. A statistical evalua¬tion of indexed powder diffraction data revealed the cell edtes of I to be a 11.816 and c 7.932A and those of II to be a 11.723 and c 8.044A. The phases are uniaxial with observed refractive indices eD 1.790, an ?D,699 and eD 1.884, cusp 1,807, respectively. The atomic structure of I and II may be based on a complex of chains of silicon-oxygen tetrahedra lying along the c cell edge similar to the type of chain structure postulated by Pauling for scapolite. K2.Pb4.Si8021 and Pb2.Pb4 Al2Si6021 were first described by Geller and Bunting (5, 6)4 as fibrous compounds similar in crystal habit to asbestos. These authors gave powder diffraction data, although no attempt was made to find the cell edges or to index the powder diffraction patterns. Later, Shell and others (9) conducted a crystallochemical study of these fibrous silicates in search of a substitute for strategic asbestos. Their single crystal data revealed K2.Pb4 -Si8021 to be tetragonal body-centered with cell edges a 11.66, c 7.95 A. Pb2.Pb4 Al2Si6021 was concluded to be isotypic with K2.Pb4 -Si8021 on the basis of similar powder diffraction patterns, chemistry, and physical properties. No attempt was made, however, to index the powder diffraction record nor to determine the appropriate space group of either compound.

Jan 1, 1962

By Thomas Varley

"During the past few years, since flotation has become the paramount treatment method for most all kinds of ores, the Bureau has gathered the data on consumption of reagents used in the flotation treatment. The first report was issued in 1916. A brief review of such reports shows the progress made in the art of flotation, and each year brings forth development of new reagents or combinations of reagents that seem sure to survive, but research and progress spell their defeat, if not by entire elimination, at least subjects them to considerable modification. Fortunately, close cooperation between the Bureau and the operators has been the means of an exchange of ideas in research work, and the development, in plant practice, of such research work on a commercial basis, is one of the outstanding features in milling today.In past years flotation has been referred to generally as ""oil flotation""— today it might be more properly called ""chemical flotatioin"" Minerals can be floated today without oil. Chemicals alone will do the work, showing how little was truly known about the process heretofore. The term ""regents as used herein, includes both chemicals and oils. The total pounds of oils and reagents consumed during the year was greater than shown in the 1925 report. The 1926 total was 201,711,795 pounds as compared with 81,688,967 pounds for 1925. The equivalent in pounds of reagent use& per ton of ore for 1926 was 3.933 as compared with 1.7972 for 1925. This increase is due largely to the amount of lime which is added in the alkaline circuits particularly in the mills treating coppers ores, which accounts for the larger tonnages."

Jan 1, 1928

By Fieldner. A. C.

"In preparing this paper, an attempt was made to obtain results of plant-scale carbonization tests on washed and unwashed coal tram to 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 testa, on this important subject will be greatly appreciated.""Of the 45 replies received, 24 stated that they had never used washed coal; 11 had used washed coal but had no comparative data on similar coals washed and unwashed; 7 answered some of the questions based on their general experience; and 3 gave some test data on Pittsburgh bed coal from western Pennsylvania. In none of the three tests did the washed coal come from the same mine as the unwashed. The washed coals in the three tests were from the same washery - one of modern construction in which the operations are under careful technical control in order to give a uniform product containing a minimum of surface moisture. The unwashed coals which were previously used in these plants were from different nearby mines in the same coal bed, and were supplied by the same company. Obviously, no sweeping or finale conclusions can be drawn from these few tests on coal from a single washery. Therefore, the writer vas obliged to consult the literature, coal-carbonization and coal-washing engineers, and other authorities to supplement the fragmentary information gleaned from the questionnaires in order to present a picture of chat gas engineers may expect from the use of washed coal in a carbonizing plant."

May 1, 1930

By J. A. Ruppert

The Bureau of Mines investigated methods of refining iron-contaminated zinc to marketable quality and developed a laboratory-scale process in which aluminum, added as a refining agent, reacted with the iron, forming solid Fe2Al which floated to the surface of the melt. Solids were separated by both filtration and centrifugation, using a unique type of "dipping" centrifuge devised during the work. Typical zinc recovery was 95 percent, and iron content of the metal was lowered from 0.37 to 0.02 percent.

Jan 1, 1967

By J. Hamilton Duffy

This is the first of, a series of papers describing dredging methods and costs in recovering sand and gravel from the beds of rivers throughout the United States and deals directly with the methods employed and costs obtained by the Ohio River Sand Co. near Louisville, Ky. ACKNOWLEDGMENTS The author wishes to acknowledge the assistance of J. R. Thoenen, mining engineer of the Bureau of Mines, in the collection of data and compilation of this report.

Jan 1, 1931

By J. E. Berg

This paper3 describing the mining methods at the Page mine operated by the Federal Mining & Smelting Co., is one of a series being prepared by the United States Bureau of Mines on mining practices, methods, and costs in the various mining districts of the United States. The Page mine is the most westerly of the producing lead-silver-zinc mines in the Coeur d'Alene mining district of Idaho, being situated 5 miles west of the city of Kellogg and at an elevation of 2,677 feet above sea level. It may be classed as one of the new active producers, of the district and owes its present activity largely to the development of floatation.

Jan 1, 1930

By Larman J. Heath

Liquid incendiaries were burned within the interstices of several different types of sandstone cores to determine the technical feasibility of increasing sandstone permeability by this method. Fuel-oxidant mixtures were tested in 186 cores; six cores exploded when ignited. In virtually all instances, the explosion completely pulverized the sandstone cores. In addition n those cores damaged by explosions, 24 cores were fractured so severely that permeability tests were impossible. Although combustion gener¬ally increased the permeability, specific mixtures at given pressures were inconsistent in their ignition and burning behavior. Tests indicated that the heat of burning incendiaries significantly increased sandstone permeability. The improved permeability ratios were usually less than 2, but one was 10.3. Permeability alteration by other in situ methods was not as effective as that by flame propagation.

Jan 1, 1971

By J. P. Hansen

In order to help assure an adequate domestic supply of minerals essential to the Nation's economy and and security by developing more efficient minerals extraction technologies, the Bureau of Mines Tuscaloosa Research Center examined the application of autogenous microgrinding to calcium carbonate minerals. Treatment of minus 8-mesh Alabama marble resulted in a product 80 pct minus 5 micrometers (µm) at a power consumption of 70 to 80 kwhr/ton, This study shows that coarse particles of calcium carbonate minerals are effective as the grinding media for the autogenous attrition grinding of these minerals. The minus 8- plus 30-mesh fraction is an effective grinding medium (sand) for particles smaller than 30 mesh. A 40-pct-solids slurry and a sand: marble ratio of 2.5 appeared to be near optimum. For residence times above 13 minutes, products were greater than 80 pet minus 5 µm and greater than 54 pct minus 2 µm. Power consumption was uniformly low, ranging from 50 to 100 kwhr/ton of product depending upon the feed rate. One marble sample from Georgia was shown to be the most persistent grinding medium, with losses of less than half those of the other materials tested.

Jan 1, 1980

By A. L. Engel

[This report describes preliminary tests of samples from six deposits of oxidized copper ores .in Nevada. The tests for the most part were confined to laboratory-scale acid leaching to extract the copper.'The exceptions consisted of flotation tests to demons' ate the possibilities of treating the ore by that method. The samples tested were representative of oxidized copper ores from six counties in all parts of Nevada. The results obtained by the preliminary tests described were indicative of the extractions of copper to be expected, In the five leaching experiments, the approximate consumption of acid was also indicated.]

Jan 1, 1953

By H. H. Schrenk, W. P. Yant, P. H. Mautz

"In a study of the chemistry and pathology of chronic benzene poisoning, which was conducted cooperatively by the United. States Bureau of Mines, the Barrett Co., and the producers of benzene, it was necessary to make quantitative determinatious of the abzorption, distribution, and: fate of benzene in the organism. Although methods for determining benzene in relatively large amounts were available no satisfactory method was found for removing and determining the small amounts that are present in the tissues or excretions after exposure to conditions which ultimately cause chronic poisoning. This no doubt accounts for the lack of information in the literature on this particular phase of benzene poisoning.The writers have found in work that will be described in a subsequent publication that the amounts of benzene present in the tissues and excretions under conditions of exposure which produce chronic benzene poisoning arc of the order of a fraction to a few milligrams per 100 grams of tissue. This report describes a method developed and found satisfactory for these determina¬tions.RÉSUMÉ OF PERVIOUS METHODSA method for the determination of benzene in tissue was developed by Joachimoglu. 5 In the Joachimoglu procedure the ground organs are mixed with water and acidified with diluted sulphuzic acid, and the benzene is distilled into a receiver containing carbon tetrachloride. The benzene is nitrated in the carbon tetrachloride, the carbon tetrachloride evaporated, the acid mix¬ture neutralized, and the dinitrobenzene extracted with ether. After removal of the ether the dinitrobeuzene is determined gravimetrically. Joachimoglu reports that this method is about 55 to 60 percent quantitative."

Aug 1, 1935

By James C. Cawley

This report presents results of recent Bureau of Mines research to establish the probability of spark ignition as a function of current (or voltage, for capacitor circuits) for resistive, inductive, and ca-pacitive circuits in 8.3% methane-air atmospheres. The data presented quantify the explosion hazard created when low-power electronic devices catastrophically fail in an explosive mine atmosphere. Previous litera-ture dealt with levels of probability between 10-3 and 10-4. This re-port extends the probability data to levels as low as 10-7. This study has verified that when the probability of ignition, PI, is plotted on a log-log coordinate system versus the current (or voltage), a continuous, straight-line relationship is formed. An interesting result that can be statistically hypothesized is that at some low level of igniting current the ignition process ceases altogether.

Jan 1, 1988

By E. A. Hewitt

This paper describing the mining practices at the Park Utah mine in the Park City district is one of a series being prepared by the United States Bureau of Mines on mining practices, methods, and costs in the various mining districts of the United States. The Park Utah mine is situated at Keetly, Utah, about 5 miles east of Park City. The Park City district lies on the eastern slope of the Wasatch Mountains, 25 miles southeast of Salt Lake City. The district embraces a tract located between the crest of the main range on the west and the mountain meadows along the eastern foothills. The elevation of the Union Pacific Railroad station at Park City is 7,000 feet above sea level. The town and mines are served by two railroads; one 28 miles long is a branch of the Union Pacific Railroad and connects with the main line at Echo Junction, east of Ogden; the other is 35 miles long and joins the Denver & Rio Grande Western Railroad at Salt Lake City. The district and mines are also accessible by excellent automobile roads from Salt Lake City and surrounding points (fig. 1).

Jan 1, 1930

By Thomas M. Barczak

This U.S. Bureau of Mines (USBM) report evaluates the load supporting characteristics of grout columns used as point supports for mine subsidence abatement. The cone-shaped columns were constructed with sodium silicate and cementitious grout in both wet and dry environments. The scope of work included the testing of seven full-scale grout columns in the USBM's Mine Roof Simulator from which the load-deformation and failure characteristics were determined. The performances of grout columns are analyzed with respect to (1) the amount of roof contact established during column construction, (2) shape effects produced by the truncated cone geometry, (3) size effects in reference to grout strength and full-scale column capacity, (4) the effect of wet environments on grout strength, (5) the effect of the sodium silicate on the grout strength and full-scale column behavior, and (6) the stiffness of the grout column. Limited tests were also conducted on cylindrical columns constructed in fabric bags. Recommendations for point support construction using sodium silicate technology and the need for additional research to develop improved containment devices for column construction are addressed in the report.

Jan 1, 2010

By M. M. Tilman

The objectives of this research were to determine the practicability of using cobalt as a means of controlling the amount of ferrite in the micro-structures of semiaustenitic stainless steels, and to determine the effects of reduced ferrite content on mechanical properties of these steels. Cobalt additions of up to 3 weight-percent were made to type 17-7 PH2 (AISI 631) stainless steel. Ferrite contents were determined for alloys in the aged condition, and for alloys quenched from the hot working temperature. Ferrite can be completely eliminated from the microstructure of 17-7 PH stainless steel by additions of cobalt, but complete elimination of the ferrite phase results in lower tensile strength, yield strength, and hardness. Tensile properties, hardness, and impact strength were determined for aged material. A subzero temperature treatment before heattreating was necessary to obtain maximum strength in the alloys containing cobalt. Addition of 2 weight-percent cobalt enhances mechanical properties of 17-7 PH stainless steel.

Jan 1, 1968