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By J. M. Stuve

Low temperature and high-temperature calorimetric measurements were made by the Federal Bureau of Mines on high-purity samples of Re02(s) and Re03(s) to determine heat capacities and enthalpies. The temperature range of heat capacity measurements was 5 to 310 K for Re02 and 8 to 309 K for Re03. High-temperature enthalpy measurements alone were determined for pure Re207(s,1). The derived standard entropies are S°298 = 11.43±0.01 cal/deg mole for Re02(s) and S298 = 16.55±0.02 cal/deg mole for Re03(s). High-temperature enthalpy equations expressed in calories per mole are as follows: Re02 (s) , H-H298.15 = 16.002T + 1.600 X 10-3T2 + 3.522 X 105T-1 - 6,095 (298 to 1,400 K); Re03 (s) , H-H298.15 = 20.293T + 3.238 X 10-3T2 + 3.950 X 105 T-1 - 7,664 (298 to 1,000 K); Re207 (s) , H-H298.15 = 38.437T + 10.309 X 10-3T2 + 4.315 X 105 T-1 - 13,824 (298 to 413 K); Re207 (s) , H-H298.15 = 30.181 + 17.713 X 10-3T2 - 10,612 (413 to 600 K) ; Re207 (1) , H-H298.19 = 66.101T - 10,092 (600 to 700 K). Gibbs energy of formation (?Gf°) data and related functions over the temperature ranges investigated are tabulated for the three oxides.

Jan 1, 1976

By William O. Vanderburg

This paper describing the methods and costs of milling scheelite ore at the Silver Dike concentrator of the Nevada-Massachusetts Co., Inc., is one of a series being prepared by the Bureau of Mines. In the Silver Dike mill tungsten ore which contains about 1 per cent of scheelite is treated at the maximum rate of 45 tens per 24 hours by tabling followed by magnetic separators to clean the table concentrates. Unusually high-grade concentrates are produced which average between 70 and 75 per cent of W03.

Jan 1, 1932

By Thomas C. Mowatt

Chemical and petrographic studies were carried out on selected tin-bearing rock samples of contact-metasomatic origin from the Cassiterite Creek and Brooks Mountain areas, Seward Peninsula, Alaska. The tin content of rocks ranged from 0.39 to 8.9 pct. Leaching with a 20 pct hydrochloric acid solution released from 19.3 to 67.9 pct of the tin. Cassiterite was not observed in the rock samples. These results are significant with regard to tin recovery and reserve delineation in these and similar occurrences. Part of this leachable tin may be associated with metasomatic borate minerals.

Jan 1, 2011

By Benjamin W. Haynes

Analytical procedures are described for the quantitative determination of 16 elements (As, Ba, Be, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Se, TI, and Zn) and 7 ionic species (NH4, C032-, CI-, F-, NO3-, P043-, SO42-), identification of major and minor mineral components, and measurement of physical properties associated with manganese nodules and nodule processing reject waste materials. Compound identification methods discussed include X-ray diffraction, infrared spectroscopy, scanning and transmission electron microscopy, selective area electron diffraction, and optical and reflected light microscopy. Methods for elemental analysis include atomic absorption spectrophotometry, inductively coupled plasma emission spectroscopy, neutron activation analysis, fluorescent X-ray spectrography, and ion chromatography. Thermal gravimetric analysis, ultraviolet-visible spectrophotometry, ion specific electrodes, and standard wet chemical procedures are briefly discussed. Physical properties determined in manganese nodule materials include grain size distribution, specific gravity, triaxial shear, permeability, maximum density, Atterberg limits, and slurry density. The results of a round-robin analysis of an ammonia process waste material and manganese nodule standards demonstrate the applicability of the discussed methods. Tests discussed for the evaluation of the waste materials for disposal options include the Environmental Protection Agency (EPA) EP toxicity test, the ASTM shake extraction test, and the U.S. Army Corps of Engineers EPA seawater elutriant test.

Jan 1, 1983

By J. D. Kalasky, Stephen Krickovic

A degasification experiment was conducted in a Pocahontas No. 3 coalbed mine in Virginia. It involved (1) drilling holes in the coalbed in the out- side headings of a set of five being developed in virgin area, and (2) conducting a methane emission rate study as mining progressed and additional holes were drilled. Degasification from all drill holes except the longest in each of the outside headings and the first three drilled (excluding the in-situ pressure hole), was erratic and inconsequential in methane emission rates. The two longest holes liberated 66 and 79 cfm of methane, which is significant for the coalbed, but such quantity lasted a relatively short time; the first three were uniform but low in methane emission.

Jan 1, 1972

By J. W. Jensen

Alloys of manganese and copper containing from 65 to 80 percent manganese possess mechanical strength and vibration-damping capacity in an unusually high degree. The success of their use in reducing vibration in structures depends, to some extent, on their fatigue properties. This report describes the results of fatigue tests on alloys of four compositions. Three metallurgical conditions were investigated for each alloy. Or the basis of the data in this report, the general rule that vibration-damping manganese-copper alloys are comparable to mild steel in hardness and strength may be extended to include fatigue strength. Methods for casting and fabricating these alloys were described in a previous report,4 which contained data on the mechanical and damping properties of the solid-solution alloys, and on alloys aged for 2 hours at 450° C. The aging heat treatment of solution-treated alloys results in optimum mechanical and damping properties throughout the range of specified composition. However, in the present work, measurements also were made on alloys aged for 2 hours at 500° C., because it was theorized that the additional precipitation of a-manganese under these conditions might have a pronounced effect on the fatigue strength of the alloy.

Jan 1, 1961

By F. P. Haver

The Federal Bureau of Mines investigated aqueous electrolysis as a means for reducing lead chloride prepared by ferric chloride leaching of galena concentrate: NaC1 PbS + 2FeC13 ? PbC12 + 2FeC12 + S°. During electrolysis, metal was produced from solid lead chloride in contact with the cathode rather than from lead in solution. Relatively high current densities--up to 300 amp/ft2--were possible when operating in this way. A very simple cell, having a horizontal lead cathode at the bottom and a vertical graphite anode at the top, was employed. Lead chloride crystals, covering the cathode, were converted to metal powder during electrolysis, and chlorine gas or FeCls was produced at the anode, depending on the electrolyte composition. Electrolytes tried included aqueous solutions of HCI, NaCl, NH4Cl, and FeC12-NaC1. Optimum results (96-pct current efficiency, 0.23 kwhr/lb Pb) were obtained with 20 pct HC1 at 25° C, using a current density of 15 amp/ft2 and an electrode spacing of 1 inch. When the current density was increased, the energy requirement increased also but only to 0.41 kwhr/lb at 150 amp/fr3 and 0.58 kwhr/lb at 300 amp/ft2.

Jan 1, 1978

By Wesley T. Holmes

In this final stage of a three-part investigation of the smelting of titania-bearing iron materials, the Bureau of Mines conducted semicontinuous smelting tests in a laboratory electric arc furnace on four concentrates and one are. The objective was to substantiate the significance of liquidus temperature measurements in predicting satisfactory slag compositions in electric furnace smelting of titaniferous magnetites to produce pig iron. Previously obtained liquidus temperature data were used in determining flux requirements. Self-fluxing pellets of either ore or concentrate plus fluxes and reductants were made to produce pig iron and slags containing 0.2 to 0.6 percent titanium. Individual constituents of the slags generally agreed within 5 percent with the value of the corresponding constituent of target composition. Liquidus temperature of furnace slags generally agreed within 50° C of the value obtained from corresponding nominal synthetic slag. The results of the three phases of the investigation may serve as guide-lines for determining flux requirements in smelting a wide variety of titaniferous magnetites and other titania and iron-bearing materials.

Jan 1, 1969

By A. J. Barry

An apparatus and procedure have been developed for testing the anchorage effectiveness of slotted-type bolts. The apparatus consists of: (1) A hydrualic Jack assembly for loading the bolt and (2) a device (extensometer or cathetometer) for measuring displacement of the bolt as it is loaded. This apparatus and procedure permit measurment of anchor slip for loads up to the yield load of the bolt. Two representative makes of slotted-type bolts (a total of 94 bolts) were tested in typical sandstone and shale mine roof. Analysis of the test results showed that (1) anchorage capacities up to the yield load of the bolts can be developed in either rock type; (2) the shape of the slotted end of the bolt affects the ease with which the bolt can be driven; (3) all bolts for which the driving distance was more than 1.25 inches produced satisfactory anchorage in both rock types (thus, driving distance can be used as a criterion for satisfactory anchorage); (4) for the group of bolts that was satisfactorily anchored the anchor slip was unaffected by the type of bolt but was considerably larger in shale than in sandstone; and (5) the bolt expansion, that is, the amount the wedge expands the prongs in excess of the diameter of the hole, can also be employed as a criterion for satisfactory anchorage. Although the bolt-expansion and driving-distance results do not differ appreciably, the latter is recommended because it is easier to determine.

Jan 1, 1954

By George H. Holmes

This paper is one of a series being prepared by the Minerals Division of the Bureau of Mines on mining and milling methods and practices at various mines in the United States. It describes such methods at the Caselton mine of the Combined Metals Reduction Co. The Caselton mine and mill are in secs. 28 and 29, T. 1 N., R. 67 E., M. D. B. & M., Lincoln County, Nev., about 10 miles by paved highway south- west of Pioche, Nev. (fig. 1). the history of the district and company This circular summarizos operations, describes physical features, labor and living conditions, the geology, ore deposits, and the ore. Prospecting and exploration methods are outlined, and shaft sinking, drifting and crosscutting, and raising are covered under development methods. In the soction on mining mothods, stoping and slushing are discussed, following which are descriptions of underground transportation, hoisting, ventilation, drainage and sampling, and surveying. The surface and crushing plants are described, and milling practices are presented in dotail with explanation of the filter plant and assay office. Safoty practices and the company organization are described in the concluding sections of the circular.

Nov 1, 1950

By John E. Kelley

The Bureau of Mines conducted a study to determine the feasibility of joining refractory metal compounds to each other and to oxide ceramics by a vacuum hot press-diffusion bonding method. Very satisfactory joins were made of ZrC to ZrB2, ZrN to ZrB2, ZrC to ZrN, and of ZrC, ZrN, and ZrB2 to Al203. Each of these join assemblies contained a mixture layer comprising 50 weight-percent each of the two end compounds. The mixture layer, sandwiched between each end compound, enhanced bonding and smoothed out the thermal expansion gradient between the two end members. Strength and thermal shock tests showed that the join areas of the ZrC, ZrN, and ZrB2 joins were stronger and more shock resistant than the parent materials. Also included in the joining tests was one each of TiC to TiB2, TiC to TiN, TiB2 to TIN, and TiC to ZrB2 joins. Each of these was well bonded, showing that the vacuum-hot-press method can be used for a variety of systems.

Jan 1, 1969

By E. J. HOFFMAN, J. c. W. FRAZER

The apparatus and methods described in the following pages were devised and used by the writers in connection with certain investiga- tions of the technologic branch of the United States Geological Sur- vey, especially those bearing on the improvement of furnace condi- tions and on efficiency in the use of fuel. The Bureau of Mines, which has charge of such analyses and tests of fuels as were formerly made by the technologic branch of the Sur- vey, is using the same apparatus and methods in connection with similar investigations that are being carried on at the testing plant of the bureau at Pittsburg, Pa. The furnace conditions prevailing both in small plants and in large industrial establishments in this country are frequently far from satisfactory. If such conditions are to be improved, they must be more thoroughly understood, and means must be found to insure complete combustion of the fuel, and yet to permit operation with such an excess of air as will result in the greatest efficiency. In this work the services of the chemist are indispensable. A very important problem is the determination of the small percentage of unburned combustible matter that escapes from the furnace in the flue gases. Under ordinary circumstances so little as 0.1 per cent of unburned combustible matter in a furnace gas is equivalent to about 1 per cent of the fuel used; and for the determination of such small percentages of gas more accurate and refined methods are required than have ordinarily been available heretofore. It is the purpose of this paper to describe some apparatus and methods which have proved satisfactory to those engaged in the chemical work of the investigations mentioned. While these methods and apparatus have been designed more particularly with regard to analysis of furnace gases, their use is by no means limited to that purpose. The reader will readily see their applicability to other uses in which the sampling and analysis of gases are involved.

Jan 1, 1911

By J. L. Kohler

Component failures in the electrical control circuits of mining machines account for a large percentage of the total downtime of the machine, Once a failure has occurred it is always a tedious and usually a time-consuming task to locate the failed component. Moreover, the pressure to quickly locate the cause of a delay can lead to compromises in safety. Thus an onboard diagnostic system, essential for an automated machine, would be a very useful addition to existing machines. This report details U.S. Bureau of Mines development of a generic procedure for synthesizing diagnostic systems for electrical-control-circuit failures in mining machinery. A continuous mining machine is used as the testbed to illustrate the application of the developed methodology. Substantive differences among mining machine control circuits made it impossible to achieve a generic diagnostic system, but a generic approach for the synthesis of the diagnostic system was possible. As the research progressed, it became apparent that an algorithmic approach was better than an expert-system-based implementation. A prototype system was constructed and used to evaluate the diagnostic system. Prototype implementation issues are also examined.

Jan 1, 2010

By M. M. Tilman

The Bureau of Mines conducted research to determine the feasibility of strengthening experimental magnesium-base sheet alloys by strain softening induced by controlled cold rolling followed by selective heat treatment. Relatively small alloying additions having potential for producing strain softening were selected from metals that are readily avail-able. Tensile properties comparable to minimum properties of the most commonly used magnesium-base sheet alloy AZ31B, in the H24 condition (strain-hardened and partially annealed), were obtained in an Mg-IMM (mischmetal)-O.5Mn alloy after strain-softening rolling followed by heat treatment. Tensile properties of the experimental alloys in certain conditions are also compared with minimum tensile properties of other standard magnesium sheet alloys. Incidental to the principal objectives, apparent superplastic behavior was observed in three experimental magnesium-base alloys containing MM, MM plus manganese, and MM plus zirconium.

Jan 1, 1985

By Frank J. Wiebelt

Work on the Abbott-quicksilver property was part of the general program of th~ Bureau of Mines in its investigation of domestic mineral resources, which are essential to national defense or industry and of which our present or probable future supplies are inadequate. The mine was discovered in 1862, and the intermittent production up to 1947 has totaled around 37,500 flasks of quicksilver. Output has come from ore shoots formed in the vicinity of fault intersections in a narrow zone composed of lenses of silicified serpentine breccia interbedded with shale. Work by the Bureau included the drilling of six diamond-drill holes aggregating 2,845 feet. Several possible ore zones were intersected by the drill holes. Field work was begun in April 1948 and concluded in October of the same year. This report gives detailed results of the diamond drilling and a brief account of the history and description of the ore deposits.

Jan 1, 1949

By W. L. Dare

This information circular is one of a series, published by the Federal Bureau of Mines, on methods and costs of mining uranium ore on the Colorado Plateau. This report describes the relatively small-scale operations of the Salt Wash miner: The mining method followed, the equipment used, and the production costs. It describes 10 lease-operated mines of Union Carbide: Nuclear Co. that are typical of Salt Wash operations on the plateau. These mines lie within the Uravan mineral belt3/ and arc in the Gateway, Bull Canyon, and Uravan mining districts. (See fig. 1.) Generally the ore bodies occur as irregular, discontinuous layers of ore minerals within sandstone beds in the Salt Wash member of the Jurassic Morrison formation. The ore bodies sometimes occur as rolls, pod associat with carbonaceous trash, or tabular masses. Their size and erratic distribution preclude the use of a prearranged and uniform stoping system. The mining method is simply to follow the ore and leave open scopes behind.

Jan 1, 1959

By R. A. Beall, S. L. Ausmus

The development of a completely water - free expendable graphite mold material , useful for reactive metal castings , has been detailed . Mixing and curing variables have been evaluated both by physical testing of the material itself and by castings of titanium , zirconium , and hafnium . The blend of powdered graphite , cornstarch , dextrin , cereal binder , linseed oil , and Carbowax -4000 is a successful mix when mulled in a carbon dioxide atmosphere , and properly cured and fired . The primary advantage of this material is its adaptability to standard foundry techniques ; i . e . , core blowing and hand ramming . Temperatures in the curing and firing cycles do not exceed 960 ° C , and no vacuum firing is required .

Jan 1, 1964

By Eugene T. Sheridan

The annual survey of the fuel-briquet industry by the Bureau of Mines, United States Department of the Interior, revealed that 21 fuel-briquet plants in 11 States were in operation and reported production in 1956. The demand for fuel briquets in the United States has gradually declined since 1948, and the number of operating plants has decreased from 36 to 21. Also, the annual productive capacity of the industry has decreased, although not a proportionate amount because most of the plants that were abandoned were small and in most instances had a designed capacity of less than 25,000 tons per year. In 1956 the 21 active plants had an annual capacity of 3.7 million tons (table 2), which was only 20 percent less than the total capacity of the 36 plants in 1948. This indicates that most of the larger plants have remained active, even though operating at reduced rates, and the average capacity of the industry has increased from 130,000 tons per plant in 1948 to 177,000 tons in 1956. Since 1948 operating rates have decreased from 67 percent to 41 percent of annual capacity.

Jan 1, 1958

By Richard H. Spencer

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.

Jan 1, 1975

By R. O. Dannenberg

Exploratory research was conducted to ascertain the feasibility of recovering beryllium from Spor Mountain, Utah, ore by the sodium fluosilicate (Na2SiF6) method used industrially for processing beryl. Na2SiF6 requirements to form water-soluble salts of beryllium were determined for three different samples--two clayey ores containing 0.6 and 1.3 pct BeO, respectively, and a calcareous ore containing 0.6 pct BeO. The ores were sintered with Na2SiF6 at 750° C for 3 hours. About 80 pct of the beryllium was rendered water soluble by sintering the 0.6-pct BeO ores with 30 and 40 lb Na2SiF6 per lb BeO contained in clayey and calcareous ores, respectively. The higher grade 1.3-pct BeO clayey ore required only 20 lb Na2SiF6 per lb BeO to solubilize over 80 pet of the beryllium. As the 0.6-pct BeO clayey ore was possibly the most representative of the deposit as presently delineated, leach liquor prepared from this sample was treated to recover beryllium salts. About 60 pet of the beryllium contained in the ore was recovered as beryllium hydroxide, which then was calcined to yield a 99-pct BeO final product by means of the following operations: (1) Sintering with Na2SiF2, (2) leaching with water, (3) precipitating crude Be(OH)2 by adding NaOH, (4) filtering to separate the hydroxide from the NaF solution, (5) redissolving the crude Be(OH)2 in excess NaOH, (6) filtering to reject caustic-insoluble impurities, and finally (7) boiling the Na2BeO2 filtrate from (8) to precipitate pure Be(OH)2. Reagent consumption was 49 lb Na2SiF6 per lb BeO recovered and 17 lb NaOH per lb BeO.

Jan 1, 1963