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By F. E. Block

The metallic reduction of vanadium chlorides was investigated by the Federal Bureau of Mines as a possible new route for preparing vanadium metal in an effort to develop a production process that would be adaptable to large-scale plant production and would yield metal of uniformly high quality. Vanadium tetrachloride was usually prepared by chlorinating vanadium pentoxide in the presence of carbon. Although oxygen-?free tetrachloride was difficult to prepare this way, it could be prepared by the direct chlorination of vanadium carbide. Lower valent vanadium trichloride was prepared by the thermal decomposition of vanadium tetrachloride. Vanadium dichloride was also prepared by the thermal disproportionation of vanadium trichloride.

Jan 1, 1961

By Larry G. Stolarczyk

An underground medium frequency radio communications system has been developed and demonstrated in both coal and metal/non metal mines. The principal advantage of the system are its low cost, ease of installation and the ability to provide radio communications to any vehicle or roving miner in the underground mine. The system provides high quality radio coverage in work areas and along manways with existing "wireplant" conductors. The conductors include AC power cable, telephone cable, metal water and high pressure air pipes, etc. The measured communications range from the base station to mobile transceiver exceeded 12,500 ft without the use of repeaters. A cost/benefit analysis shows that the initial cost of the equipment can be returned 2-6 times in the first year. The mine productivity increases by approx. 13 percent.

By Ronald T. Mayerle

In 1989, the U.S. Bureau of Mines conducted a mineral investigation of the Mallard study area near Elk City, Idaho. The study area comprises most of the original Mallard RARE II area (1-847) plus some additional lands. The investigation is part of an ongoing, multi-year study of north-central Idaho that is being conducted in cooperation with the Idaho Geological Survey and the U.S. Geological Survey (USGS). The only identified resources are rock suitable for road metal. Five lode prospects and a pyrite-bearing rock quarry, which is operated by the Forest Service for aggregate, were examined for metals. One of the prospects warrants additional exploration for silver in quartz veins, but the chance of finding an economically minable deposit is limited. Several rock and stream sediment samples were anomalous in various metals. Two of the more promising localities for gold and/or other metals are adjacent to a unit of the Frank Church-River of No Return Wilderness that the USGS classified as having a moderate potential for gold deposits related to fossil hot springs.

Jan 1, 1991

By H. R. Shell

Of three known compounds in the ternary system K20 - PbO - SiO2, one having the composition K2Pb4Si8021 crystallizes into a structure with asbestiform properties. This compound, whose silicon-oxygen ratio is between that of the layer silicates (for example, mica) and the double-chain amphiboles, crystallizes in the tetragonal system. It malts, apparently congruently, at 779° C. The fiberized product prepared from crystals is fluffy and closely resembles natural asbestos in appearance, but is more brittle and has less strength. However, potassium-lead silicate may be separated into fibers with a uniform diameter of 200-300 A.U., and the fibers show with the electron microscope the s criteria that have been interpreted as indicating a hollow tube structure in chrysotile asbestos. Since very few inorganic crystalline compounds have such a structure, the material has unusual scientific interest. Microcrystalline potassium-lead silicate was rapidly and completely formed when powdered glass of the same composition was heated to 650° - 700° C, but macrocrystals grew only slowly from the viscous massive glass. Maximum growth rate was 0.12mm. per hour at 700° C.

Jan 1, 1957

By W. H. Tomlinson

One of the more important functions of the Federal Bureau of Mines is conservation of the life and health of employees of the mineral and allied industries. Since its very beginning the Bureau has encouraged competition between mine rescue and first-aid teams as a means of stimulating interest in safety and accident-prevention work. In addition to sponsoring competition on a national and international scale during the past 45 years, the Bureau has also assisted State mining departments, mining companies, and mining organizations in holding State, district, company, and other local meets. This assistance includes providing instructors to train teams, judges, and other contest officials. The Bureau has also furnished problems and outlines for working them, judges I discount sheets (scorecards), contest rules, and problem judges. In fact, Bureau representatives participate in nearly all State, district, and company contests and have bad complete charge of some contests.

Jan 1, 1956

By L. A. Readdy

Pilot Hole "X" was drilled to test the formations through which the ventilation shaft for the proposed U.S.B.M. demonstration oil shale mine will be drilled. The history of the drilling of Pilot Hole "XI' is presented. This historical summary provides the details of method used during the drilling of this hole. Problems encountered during drilling are discussed. The quantities of drilling mud and other materials used to drill the hole are documented.

Jan 1, 1977

By R. B. Porter

Bench-scale tests were performed by the Federal Bureau of Mines on lignite and subbituminous coal at pressures to 1,000 p.s.i.g. (pounds per square inch gage) in atmospheres of hydrogen or nitrogen to obtain information concerning the influence of pressure on carbonization of normally noncaking coals. The distribution of gaseous, liquid, and solid products as a function of processing pressure was determined. Except for special experiments, the carbonization was at 940° F. In a hydrogen atmosphere above 400 p.s.i.g., agglomeration of the solid residue (especially with lignite) became noticeable and increased directly with the processing pressure. Although in some instances the solid particles fused together, the mechanical strength of the agglomerate was always low. On the basis of visual inspection, the coals agglomerated in the following order of decreasing intensity: (1) Steam-dried lignite; (2) lignite; and (3) subbituminous coal. Addition of lignite tar in quantities to 25 percent by weight of charge did not increase agglomeration or change the carbonization characteristics of the coal.

Jan 1, 1961

By W. W. Adams

Because of insufficient funds for printing, the Bureau of Mines was unable to publish its annual bulletin covering accidents at metal mines in the United States for the year 1933. A brief mimeographed summary of the principal statistical data for that year was released to the public late in 1934. Since then reports for 1934 have been received from the mining companies, and in order to avoid further delay in releasing this information to the mining industry and others interested in the prevention of accidents in mining, statistics for both years are presented in this publication with a minimum of interpretation and comment. The fatal-accident rate for the metal and nonmetallic mines (excluding coal mines) of the United States was more favorable in 1933 than in any previous year since 1911, the first year for which the Bureau of Mines obtained reports from the operators. Further progress was made in 1934, when the fatality rate was even lower than that of 1933. On the other hand, the nonfatal-accident rate, which had reached its lowest level in 1932, increased in 1933 and increased further in 1934, although not to such an extent as to prevent the rate for either of those 2 years from being better than that for any year previous to r1931.

Jan 1, 1936

By Vernon O. Markworth

This report contains the results of tests performed on three large diesel engines to determine their ability to meet selected criteria of the Mining Enforcement and Safety Administration Regulations for equipment used in gassy, non-coal mines. Study efforts were first directed toward determining the types of equipment expected to be used in underground oil shale mines. Three typical engines in the 800-1200 horsepower range were then selected for testing. Intake flame arresters, exhaust scrubbers, and water jacketed exhaust system were designed and built for each engine. During testing, each engine was evaluated for its gaseous emissions output, adequacy of the exhaust gas cooling system, ability to withstand internal explosions, and adequacy of the flame arresters. Surface temperatures of the engine and exhaust cooling system were determined under full load operation.

Jan 1, 1978

By James W. Wade

This paper describing the mining practices at the Tintic Standard mine is one of a series being prepared by the United States Bureau of Mines. In the preparation of this paper each subject has been presented by the engineer in charge. L. R. Dobbs wrote the part pertaining to tae technique of square-set mining, J. M. Snow the part on geology, and M. D. Paine, the part on ventilation. All of the drawings are the work of H. W. Waterfield of the engineering department. The statistics of the Tintic district ware prepared by A. G. MacKenzie. Each writer has attempted to show the difficulties that arise in operating and the practices used to overcome them.

Jan 1, 1930

By J. J. Shields

With the increased use of mechanized equipment in mining bituminous coal, production panels are mined out rapidly. To keep current with the rapid completion of production panels, development work must be speeded up also. Although the same type of equipment usually is employed in development as in production places in the same mine, past output per man for development usually was less than from production panels. A study of development practices in 14 mines reveals a tendency toward equalization of the output per man between development and production.

Jan 1, 1957

By Thomas A. Phillips

This publication is an economic evaluation of the Bureau of Mines electrolytic process for recovering lead from scrap lead-acid batteries. In this process, scrap batteries are crushed and separated into metal and sludge fractions. The metal fraction is cast as anodes and electro- refined. Lead in the sludge fraction is converted to lead carbonate by reaction with an ammonium carbonate-ammonium bisulfite solution. The lead carbonate is then dissolved in a fluosilicic acid electrolyte from which pure lead metal is electrowon. A cost estimate is presented for a plant capable of processing 10,000 scrap batteries per day. The fixed capital cost for this plant is estimated to he $14 million on a fourth quarter 1984 basis. Operating costs are estimated to be $0.15/lb Pb recovered. Assuming a lead selling price of $0.17/lb, the interest rate of return on investment after taxes is 11 pct. A lead selling price of about $0.21/lb is needed to obtain a 20-pct-interest rate of return.

Jan 1, 1986

By V. E. Edlund

Pyrometallurgical studies by the Bureau of Mines demonstrated the feasibllity of sintering and smelting a low-grade flotation concentrate made by pilot-plant processing 10-percent manganese ore from the Maggie Canyon deposit, Mohave County, Ariz. Under optimum conditions 85 percent of the manganese in a flotation concentrate that assayed 36 percent manganese was recovered as standard ferromanganese. A blend of this flotation concentrate with high-grade dithionate pilot plant precipitate was similarly processed with a recovery of 90 percent of the manganese. Thorough mixing and pelletizing of the charge before treatment on the sinter hearth was necessary to produce a well agglomerated product by single pass sintering. Although satisfactory sinter was produced from a variety of material combinations, best results were obtained on a charge that contained 80 percent flotation concentrate and 20 percent return sinter fines. This combination was mixed with 6 percent coke, based on weight of concentrate; and 12 percent moisture. Sintering such a charge yielded a well agglomerated product containing over 80 percent coarse material, The results of standard crushing tests showed that the product was physically comparable to iron ore sinters and manganese nodules.

Jan 1, 1962

By Jean J. Tancous

Chromium recovery from wet-blue offal trimmings and shavings can be done with substantial chemical cost gains by incineration at 600° C for 5 hr. Pretreating the offal with 0.5 M Na2C03 and air-drying prior to incineration produce Cr04 .By simply incinerating the offal, without pretreatment, an ash containing water insoluble Cr203 was produced. The Cr203 in the ash was purified by leaching with water. Chromium and crude protein were efficiently extracted from offal using 5 pct Na103, 5 pct H2S04, and 3 pct NaCl at 40° C. This procedure was effective but expensive. Satisfactory leather as to odor, appearance and shrinkage temperature was made from chromium recovered from wet-blue offal by incineration and by extraction. Chromium conservation is possible by recycling chromium liquors and by precipitating chromium from spent tanning liquors prior to combining these liquors with other tannery wastes. Combining chromium liquors with other wastes introduces contaminants that make chromium recovery and reuse difficult. Leaching sludges with H2SO4 produced marginal chemical cost gains. Leather tanned with these solutions had satisfactory shrinkage temperature but the sludge odors and iron contamination were objectionable.

Jan 1, 1979

By H. Winkelmann

The author, who himself has worked inn the field with various types of torsion balances, expresses in the article his experience with the recently marketed Haff-Torsion-Balance. The advantages of practical work with Haff?s s torsion balance as compared with other types are mentioned. In spite of low weight and corresponding small dimensions (Model M = 23.5 kg., Model Al = 11.5 kg.) the sensitiveness is not less than that in the largest instruments. It is at 1.10-9, which is proved by calculations. A comparison with the corresponding values of other types of torsion balances (Eötvös, Askania, Gepege) is given. The mechanical features of the instrument are briefly described, and the balance is illustrated by a, cross section of it. -- W. Ayvazoglou. DETERMINATION OF THE ELEMENTS OF THE MAGNETIC AND GRAVITATIONAL FIELDS INDUCED BY AN INFINITELY LONG HOMOGENEOUS CYLINDER By G. A. Gamburzeff Gerlands Beiträge zur Geophysik, Band 19, Heft 2/3 Leipzig, 1928, pp. 210-230. The present work is a. contribution to the quastion of the reason for the magnetic and gravitational anomalies in the government of Kursk (Russia).

Jan 1, 1929

By [F. P. ] Stambaugh

Results of research on the hydrothermal precipitation of zirconium oxide from the Bureau of Mines' zirconyl chloride-sulfate strip liquors indicate that nuclear grade material can be prepared by this process. Greater than 99% of the zirconium value can be precipitated at 250-260°C in short (5-10 minutes) reaction time without consumption of acid value of the liquor. Thus, precipitation of zirconium dioxide on a continuous basis, i.e., the zirconium dioxide is precipitated in a continuous mode of operation by pumping the strip liquor through a heated pressurized reactor and recycle of the acidic (spent) liquor to the process stage are favored. The results of accompanying studies of liquod/solid separation, product washing and dewatering, product purity, and chlorination of the product are presented and discussed.

Jan 1, 1980

By W. H. Blackburn

This paper describing the milling practice at the Tybo concentrator is one of a series of similar papers being prepared by the United States Bureau of Mines on milling methods and costs at the various mills in the United States. ACKNOWLEDGMENT A large part of this paper way prepared by H. M. Lewers, mill superintendent of the Tybo plant of the Treadwell Yukon Co., Ltd.

Jan 1, 1931

By G. E. Bobeck

The first year's work of a proposed three-year study of the effects of the exposure of coal mine roof rocks to the mine atmosphere has been completed. The project has been terminated. The goal of the project was to determine if possible the mechanism or mechanisms by which coal mine roof rocks interact with the mine atmosphere and weaken, and coupled with mechanical stresses, ultimately fail. The scope of the study was limited to the effects of environmental factors on the deterioration of the rocks. While mechanical stresses may play an important role in the interaction of environmental factors, stress effects were excluded from the study. In order to study the effects of environment on coal mine roof rocks, samples were obtained from several coal mines in the western states. The rocks forming the roofs of most of the mines visited were shales of varying composition. These shales were subjected to numerous tests to determine how the rocks changed with time after exposure. In addition, the identity of the minerals present in the shales was determined by x-ray diffraction analysis and by thermal analysis as well as by optical microscopy

Jan 1, 1973

By R. Barany

The heats of the glass-crystal transformation of nepheline (Na0.7794K0.2206AlSiO4) and wollastonite (CaSiO3) and the heat of formation of nepheline at 298.15° K were determined by solution calorimetry. For the glass-crystal transformations, the heat values were -9.0 ± 0.3 kcal/mole for nepheline and -8.1 ± 0.2 kcal/mole for wollastonite. The heat of formation of nepheline was -34.8 ± 0.6 kcal/mole from the oxides and -501.0 ± 0.5 kcal/mole from the elements.

Jan 1, 1966

By Louis C. Srichta

The rapid depletion of known high-grade ore deposits of the Tri-State district and the recognized need for development of additional reserves, together with increased interest in open-pit mining of low-grade zinc-lead ores led to Bureau of Mines examination of several abandoned mining areas for possible deposits adapted to strip mining. Examination of the North Empire tract in Cherokee County, suggested that mineralized zones contiguous to previously mined 2e deposits presented probabilities of meeting the requirements for an open-pit mine - hence the tract was selected for further investigation by churn drilling. The zinc-lead deposit on the property is in a sink-hole structure that has been subjected to intense deformation and silicification. Numerous shafts, mine dumps, and surface caves are evidences of exploitation of an extensive area. The reported active mining period was 1895 to 1905. No production records are available, but it is generally stated locally that the value of the mill products exceeded $2,000,000 which represents considerable production, considering the low metal prices of that epoch.

Jan 1, 1950