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By T. F. Mitchell

During the investigation or the occurrence of manganese deposits in western United States, Bureau of Mines' examining engineers collected samples from four manganese properties in the Death Valley region, California. These were supplemented by samples submitted by owners of two other properties in the same area. Extensive laboratory tests were made to determine the, amenability of the ores to standard ore-dressing concentration methods. A small sample of high-grade oxide manganese ore from the McWhinney property, San Bernardino County, Calif., was submitted by the owner. Although the sample would sinter directly to plus 48 percent manganese grade, it appeared probable that the ore, if mined in quantity, would be lower in grade and would require beneficiation. Therefore, testing was conducted to remove the chief gangue constituent, calcite. The National Resources, Inc., property (also known as the old Owl Hole mine) is in the Owl Hole Springs district, I mile from Owl Hole Springs, San Bernardino County, Calif., near the southwest corner of Death Valley National Monument. The ore deposits occur as small lenses or ,pockets, evidently .replacements in limestone and granite. Laboratory work was done on a representative sample of orb procured by Bureau engineers.

Jan 1, 1949

By Wm. O. Vanderburg

This paper describing the milling methods at the Hughesville concentrator of the St. Joseph Lead Co., Hughesville, Mont., is one of a series of similar papers being prepared by the U. S. Bureau of Mines on practices at the various mills in the United States. The writer expresses his thanks for the courtesies extended by the officials of the company while visiting the property and acknowledges the assistance and helpful suggestions given by R. H. Willcomb, general manager, and Carl Martin, mill superintendent, of the Hughesville Division f the St. Joseph Lead Co.; and E. D. Gardner, supervising engineer, U. S. Bureau f Mines, Southwest Experiment Station, Tucson, Ariz., in gathering and compiling the data herein presented.

Jan 1, 1931

By J. P. Morris

A diphenyl ether calorimeter for measuring high-temperature heat contents of ferrous alloys and iron-and steelmaking slags was constructed and calibrated with specimens of molybdenum, alumina, and platinum that were heated to temperatures ranging from 1,720° to 1,875° K. The standard deviation of the calibration measurements was 0.37 percent. By measurements of the enthalpy of delta and liquid iron, the heat of fusion of iron was found to be 3,298 ±100 cal per mole.

Jan 1, 1966

By D. W. Frommer

Mineral dressing research was conducted by the Federal Bureau of Mines under a cooperative agreement with the St. Joseph Lead Co., on three samples of iron ore from the Pea Ridge deposit in central Missouri. The objective was to provide information on how to upgrade these submarginal ores and produce marketable concentrates. Samples were prepared from drill-hole cores of similar composition and character to produce (1) a medium-grade mixed hematite and magnetite, (2) a high-grade mixed hematite and magnetite, and (3) a high-grade magnetite. In all three ores phosphorus and sulfur constituted objectionable impurities; excessive amounts of silica were also present in the medium-grade ore.

Jan 1, 1960

By A. Visnapuu

The Bureau of Mines, as a part of its goal to minimize occupational hazards associated with mining and mineral processing operations, has developed and field tested a compact exhaust air muffler for mechanized, jumbo-mounted pneumatic rock drills. The muffler is constructed of 1/8-inch sheet steel and has nominal dimensions of 1-3/4 by 9 by 13 inches. A directed air passage, flexible neoprene baffles, and an expandable slit-type outlet are incorporated to reduce drill exhaust air noise and eliminate muffler icing. Field tests in actual mining operations showed a l5-dbA reduction in exhaust noise and an 8-to 12-dbA reduction in overall drilling noise with no icing problems or decrease in drill performance. Data are presented on muffler construction, laboratory, and field test results.

Jan 1, 1979

By Gus Pantages, Bernard D. Blaustein, Charles Zahn, Irving Wender

Oils from coal hydrogenation have been examined at the Bureau of Mines to learn whether any centers of the optical activity reported in coal would survive catalytic hydrogenation at 450-525 ° C and about 8,000 psig pressure , and , if so , to obtain information about the nature of the active products . Oils from carbonization tars also were examined . Optical activity was found in the majority of the distillate fractions of the hydrogenation oils and in almost all distillates from the carbonization tars . No activity was observed in the tar - acid and tar - base fractions examined . Methods for isolating optically active concentrates included distillation through a packed column , liquid chromatography on silica gel , and adduction with urea . For the materials so processed , the optical activity segregated mainly in the paraffin - naphthenic and the hydroaromatic fractions . Although the specific compounds responsible for the optical activity were not isolated , experimental and spectrometric findings indicate that alkylsubstituted cycloalkane , cycloalkene , and hydroaromatic structures are most likely responsible for the optical activity of the concentrates . The optically active centers probably derived mainly from the steroids and terpenes in the biological materials that participated in the formation of coal .

Jan 1, 1964

By E. G. King

This publication presents original thermal data for a typical variety of perlite and supplies basic information for use in computing energy requirements in processes for expanding perlite. Perlite has been defined by Raiston 4/ as any silicious lava containing dissolved water in sufficient amount to errand into bubbles when the material is quickly heated to a suitable point in the softening range." The uses of expanded perlite in) the construction and ceramic industries have been discussed by Ralston 4/ and King. 5/ The work described here had a dual purpose: (1) It was desired to ascertain quantitatively, using a typical variety of perlite, just how firmly the contained water is held, and (2) it was desired to obtain basic thermal data sufficient for energy-requirement calculations in processes for expanding perlite.

Jan 1, 1948

By R. O. Dannenberg

The Bureau of Mines conducted laboratory investigations with the objective of developing an alternative process for recovering cobalt and copper from complex sulfide concentrates. Processes currently used depend largely upon precipitation techniques to remove impurities and recover cobalt from sulfate liquors prepared by oxidative pressure leaching of the sulfide concentrates. The Bureau conducted bench-scale research on a process for treating cobaltite concentrates, comprising (1) oxidative pressure leaching, (2) jarosite precipitation followed by H202 oxidation and pH control to remove iron and arsenic, (3) copper solvent extraction with a mixed hydroxyoxime-amine extractant, (4) copper electrowinning from recirculating acidic strip liquor, (5) selective cobalt extraction from copper solvent extraction raffinate with a phosphinic acid extractant, and (6) electrowinning of cobalt from a recirculating weak acid strip liquor. Overall cobalt and copper recoveries were 91.7 and 84.1 pct, respectively. Electrowon products assayed 99.8 pct Co and 99.89 pct Cu.

Jan 1, 1987

By C. C. Hwang

The Bureau of Mines formulated a method for calculating the concentration of entrained dust from a dust deposit by a turbulent gas stream. In particular, a diffusion equation is used to calculate dust concentrations in a channel following an explosion. Dust leaving the channel walls was treated as originating from stationary or moving, and single or multiple material sources. Formulas and sample computations for various types of dust sources in circular and rectangular channels are given, based on experimental entrainment rates. The analysis predicts the dust concentration as a function of time and channel space. The results appear to agree with the physical characteristics of explosion-driven dust dispersion in a O.6-m-diameter, 50-m-long explosion tunnel. The analysis is also applied to simultaneous and consecutive dispersion of coal and rock dust from simulated coal mine surfaces (walls, floor, roof, and ribs).

Jan 1, 1974

By Roy L. Soderberg

Ground support for metal, nonmetal, and coal mines was examined through fill placement with a pneumatic stower to increase extraction, reduce ground pressures, and improve general mine safety. Several pneumatically stowed stope-fill products were tested to determine the effects of specific gravity, gradation, moisture, and impact velocity on the in-place density of the stowed fill. Hydraulic sand filling has now served the mining industry for several decades but because of the low density does not always provide ample support to the hanging wall; therefore, the sill and crown pillars sometimes build up excessive stresses that are detrimental to mining. Cementation of a dense fill adjacent to a pillar to allow 100-pct extraction of the pillar, or a fill that can be placed without the use of water and where water is a detriment to rubber-tired mining equipment, was found to be a possible use of pneumatic fill. Placing of coal mine washery products into abandoned underground workings is another possibility in order to completely eliminate surface impoundments.

Jan 1, 1976

By H. Kato, G. Asai, R. Blickensderfer, R. Siemens

Some relationships were established among crystallographic orientation , rollability , deformation texture , annealing behavior , slip planes , and ductile- brittle bend transition temperature of molybdenum single crystals . Six large molybdenum single crystals obtained from an ingot melted by electron beam were oriented by X - ray diffraction and rolled on crystallographic planes of low indices in a known direction . During room temperature rolling , cleavage occurred on 100 type planes . At 300 ° C the crystals were rolled to 95- percent reduction in thickness . The crystals ( 001 ) [ 110 ] and ( 011 ) [ 100 ] were most easily rolled . Pole figures were used to correlate the deformation textures of the rolled crystals with the initial crystallographic orientation . Several of the textures which developed could be explained as a rotation about a < 110 > axis of symmetry . The cube crystal ( 001 ) [ 100 ] retained much of its " cubic " orientation . The (001 ) [ 110 ] crystal developed the simplest texture , whereas the ( 211 ) [ 113 ] and ( 211 ) [ 120 ] crystals developed the most complex textures . The 1 - hour recrystallization temperature of the crystal ( 211 ) [ 113 ] was 700 ° C , which is about 300 ° C lower than that of commercial polycrystalline molybdenum . The poles of the slip planes ( as determined from gross slip lines at relatively low magnification ) tended to lie within 20 to 60 degrees of the pole of the rolling plane . The Knoop hardness was slightly dependent upon crystallographic orientation but more dependent upon rolling direction . The ductile- brittle bend transition temperature was dependent upon the rolling orientation and the dislocation density .

Jan 1, 1964

By Kenneth H. Johnston

This report describes an in situ combustion project and three waterflood projects in Allen, Anderson, and Wilson Counties, Kansas, that will be visited during the 1964 annual tour of the Kansas-Oklahoma Waterflood Association. Among the unique features of the projects are the movement of heavy crude oil through the reservoir and into the wellbore with energy furnished by burning s portion of the crude oil therein. Another feature is the simultaneous injection of C02 and water, through separate tubing into input wells during early development, to increase injectivity at moderate pressures, Discussion of individual projects includes information on their early history, source and treatment of injection fluids, oil production-decline curves, and the results of water injection on oil production.

Jan 1, 1964

By Harold Bailie

The purpose of this Bureau of Mines report is to furnish information on mining practices applied to flat-bedded fluorspar deposits in southern Illinois. It presents new and improved operating procedures and specialized techniques applicable to deposits of this type. All of the operating mines of the Ozark-Mahoning Co. in this area have been opened by vertical shafts which connect with levels consisting of haul-age ways, stopes, and loading stations. The stoping practice used locally called room and pillar, is open stoping with pillars left at different distances and diameters. To facilitate haulage and drainage, the mines are worked from openings turned off the main haulage drift on a grade to conform with the dip of the ore beds. The ore is predominantly fluorspar with smaller amounts of galena and sphalerite that contain traces of cadmium and germanium. The principal gangue minerals are limestone, calcite, shale, barite, and sandstone. The rock hardness ranges from relatively soft shale to hard, abrasive sandstone.

Jan 1, 1960

By D. L. Yopps

In research conducted by the U.S. Bureau of Mines, platinum-group metal (PGM) flotation concentrate from the Stillwater Complex, MT, was subjected to biooxidation using Thiobacillus ferrooxidans in an effort to break down the sulfide minerals and liberate the associated PGM&apos;s for subsequent chemical leaching. Bacterial preleaching oxidized up to 94 pct of the sulfide present, destroyed the PGM-bearing pentlandite [(Ni,Fe)9S8] mineralization, and dissolved most of the nickel in the concentrate. Cyanidation at 80° C proved to be the most attractive chemical leachant, removing 34 pct of the platinum, 76 pct of the palladium, 94 pct of the rhodium, and 97 pct of the gold from the biooxidized concentrate. Research also indicated that increased sulfide oxidation during the preleach phase led to improved PGM recovery in the subsequent chemical leaching phase.

Jan 1, 2010

By Graham W. Marks, Clyde A. Bridger

"INTRODUCTION An electrolytic process for the preparation of metallic cobalt has been developed recently in the Bureau of Mines Experimental Station at Boulder City, Nev. Chemical analysis shows this cobalt to contain impurities in small percentages, chief of which is nickel. It is desirable to be able to determine these impurities spectrographically. This report is concerned with a procedure for the spectrochemical determination of nickel in cobalt.Previous spectrographic work on cobalt was done by Breckpot and Mevis,/ who used the method of homologous pairs of lines. However, it was felt that a more detailed investigation was needed, employing the method of internal standards.ACKNOWLEDGMENTWe are indebted to B. G. Knickerbockor and his staff at the Boulder City, Nev., station of the Federal Bureau of Mines for their cooperation, and particularly to Richard W. Lewis and Robert G. Sanderson, who prepared nickel-free electrolytic cobalt for us."

Feb 1, 1948

By G. L. Humphrey

Although thermodynamic data for ferrous oxide are among the most important in extractive metallurgy, adequate values have not been available until quite recently. The older data suffered not only from the usual experimental difficulties but especially from lack of the knowledge that ferrous oxide of stoichiometrical composition does not exist as a single, thermodynamically stable crystalline phase under any circumstances. This paper reports new experimental data on the heat of formation of ferrous oxide by two methods (combustion calorimetry and solution calorimetry), employing material of unequivocal composition. The results are compared with values obtained from data for the hydrogen reduction, carbon monoxide reduction, and disproportionation reactions of ferrous oxide, and a best value is selected. A table of heat and free energy of formation values of ferrous oxide to 2,000°K is given. These values are combined with available data for water, carbon monoxide, and carbon dioxide to obtain theoretical heats and free energies of reduction corresponding to the selected heat of formation. Hydrogen and carbon monoxide reduction equilibria are compared, and the differences in trend with temperature and the percentage utilization of the reductants are considered.

Jan 1, 1952

By John C. Feeley

This paper is the result of a field study of prospect drilling in the Florida phosphate fields. The objective is to describe the drilling methods employed . . Since the general policies of the operating companies in the land - pebble area do not permit the dissemination of prospecting information and costs thereof , the writer has carefully avoided mentioning names and locations except by reference to existing publications ,

May 1, 1949

By E. J. Kloos

One phase of the work of the Bureau of Mines in health and safety is promoting the use of safe, satisfactory, and reliable respiratory-protective devices. To insure that such devices will be available, the Bureau has established schedules of minimum-performance requirements for the approval of self-contained breathing apparatus (1),4/ gas masks (2), supplied-air respirators (hose masks, air-line respirators, and abrasive-blasting helmets, hoods, or masks) (3), dispersoid (dust, fume, and mist) respirators (4), and nonemergency gas respirators (chemical-cartridge respirators) (5). Approval tests of self-contained breathing apparatus are conducted by Health and Safety District B; approval tests of other types of respiratory-protective devices are conducted by the Branch of Health Research. Manufacturers of respiratory-protective devices may submit their equipment to the Bureau of Mines for approval under the requirements of these schedules. If the device, when tested by the Bureau, meets the schedule requirements, a certificate of approval will be granted, which not only states that the equipment has passed the schedule requirements but also gives information about the limitations of the device. If it is found at any time that approved devices do not meet the requirements of the pertinent schedule, the Bureau may rescind approval.

Jan 1, 1959

By T. E. Gray

This report describes preparation characteristics of the significant coalbeds in Marion County, W. Va., as determined by the Bureau of Mines. It is one in a series telling what coals are suitable for producing metallurgical coke, either as mined or after beneficiation. Over 9.4 million tons of coal was produced in Marion County, W. Va., in 1958, of which almost 6 million tons was cleaned mechanically in nine cleaning plants. All of the coal mechanically cleaned came from the Pittsburgh bed. The Bureau of Mines estimated that 1,578 million tons of recoverable coal remained in the county in beds 28 inches or more thick as of January 1, 1955.

Jan 1, 1960

By S. F. Mauser

This report describes the study of factors which affect medium voltage (661 - 1000 volts) trailing cable splices used in underground coal mines. Improvements in quality, dependability, and design of splice kits and shop splices are presented in the study results and recommended guidelines and regulations. Recommended research programs are included which describe approaches for development of the recommended guidelines and regulations for medium voltage trailing cable splices. The basis for the conclusions and recommendations presented in this report is included in three appendices which describe a survey, splice examination, and general requirements development prepared during the progress of this study.

Jan 1, 1977