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By S. C. Termes

The Bureau of Mines has used Fourier transform infrared spectroscopy (FT-1R) to study in situ reactions of aqueous solutions of potassium ethylxanthate with CU(II)-and Pb(II)-activated sphalerite plates, in which the plates were both the infrared-transparent windows and the reacting surfaces. A copper (I) ethylxanthate formed predominantly with Cu(II)-activated sphalerite, regardless of the activation time. The products formed on Pb(II)-activated sphalerite depended on the activation times; a short activation time (30 min) yielded a lead ethylxanthate-like product, but a long activation time (90 min) yielded a considerable amount of dixanthogen.

Jan 1, 1986

By Charles B. Kenahan

The effects of ultrasonic radiation on the electrodeposition of copper-zinc, copper-cadmium, and copper-tin alloys from cyanide baths were investigated by the Bureau of Mines at frequencies of 18.5 and 38 kilocycles per second, and at acoustic intensities up to 0.5 watt per cm3. Significant changes occurred in the composition of the deposited alloys; some of these deposits were brighter, harder, more adherent, or of finer grain size than nonirradiated deposits. The irradiated deposits were also smoother and less porous, and they afforded better corrosion protection for the substrate metal in sodium chloride solution. The limiting current densities of the cyanide baths were increased by the application of ultrasonics. Anode and cathode current efficiencies also were increased, and cell voltages were lowered; the relationship of these effects to current density is discussed. Electrode potential measurements showed significant depolarization effects at both electrodes during ultrasonic irradiation. The resulting decrease in cell voltage was due chiefly to depolarization at the anode, and the anode became less passive.

Jan 1, 1967

By Shirley F. Colby

Much interest has been shown recently in the possible utilization of dolomite as a source of magnesium metal, a large production of which is deemed essential for national defense. As a result, many inquiries have been received by the Bureau of Mines as to sources of dolomite. This report has been prepared primarily to augment the Bureau's present published information on the occurrence of high-grade dolomite deposits in the United States. To supplement such data, the report also defines dolomite and related rocks and describes their properties and uses. The uses are covered in some detail in Information Circular 6524 entitled "Utilization of Dolomite and High-Magnesium Limestone," published in 1931 but now out of print. All essential data on uses contained in that report have been incorporated herein, and. have: been supplemented by data developed during subsequent years. DEFINITION Dolomite is a mineral composed of calcium end magnesium carbonates combined in equal molecular proportions, expressed by the formula CaMg(C03)2. Dolomitic limestones contain considerable dolomite but also include either

Jan 1, 1941

By L. C. IlsLey, E. J. Gleim, F. CRAVEN

Electrical apparatus and circuits began to be used in mines about 50 years ago. A search of the literature on mining reveals that in 1882, umping was being done by electricity in some aines of England. One account tells of a small electric locomotive being used in 1882 "to drive eight corves loaded with coal" in a mine near Dresden. In an account of his visit to some English mines, en American in 1892 mentions that he saw underground electric signals, lights, pumps, hoists, and one revolving- cutter-bar 19wall mining machine,. Among the carl electrical installa- tions in the United States was an electric locomotive in the Lykens Valley Coal Co. mine at Lykens Valley, Pa., in 1887. In 1889 the Sperry electric coal digger was being tried out. Tarce mining machines were placed in the Prospect mine, East Palestine, Ohio, in 1890. An electrical pumping plant was put in oneration during 1892 in the Woodward mine of the Delaware, Lacka- rahma & Western Railroad Co. Thus we Almost coincident with the proposed use of this new servant in under- ground workings, came the thought of making it safe in gassy mines. find an account of a design for a protected stationary electric mine lamp proposed by Edison in 1831. Enclosed-type motors rere developed in the United States and shiped to English collieries about 1903. From those early beginnings there has been continuous progress until to-day one finds hundreds of pieces of specially designed electrical apparatus distributed in American coal mines and in mines of nearly all important coal-producing countries. Along with introduction of this equipment grew the idea of the necessi- ty of government aid, in standardization. In most coal-mining countries to- day the governments either directly or indirectly have a considerable in- fluence in guiding the design of electrical equipment intended for use in Pasay mine

Jan 1, 1933

By B. W. Madsen

The Bureau of Mines conducted a large-scale (6.4 t), long-term (2,165 days) test to gain a better understanding of the leaching characteristics of chalcopyritic ores. An ore sample containing 0.77 pct Cu was leached in a fiberglass column by downward percolation of acidified ferric sulfate solutions. Three sets of leaching conditions were investigated: (1) ambient temperature leaching, (2) elevated temperature (50° to 60° C) leaching, and (3) elevated temperature leaching after inoculation with thermophilic bacteria. Leaching at ambient temperature resulted in a copper extraction rate of 0.44 pct per 100 days. Increasing the temperature to 50° to 60° C resulted in decreased activity of natural mesophilic bacteria, and the leaching rate decreased to 0.22 pct per 100 days. The pH was lowered from 2.0 to 1.6, and nutrient solutions that contained thermophilic bacteria were added. This procedure resulted in an increase in the ferric-to-ferrous iron ratio and an increase in the copper leaching rate. However, the increased leaching rate was not sustained, and 120 days after inoculation the bacterial activity declined, the ferrous iron content increased, and the copper leaching rate decreased.

Jan 1, 1983

In September 1985, the Chairman of the Transportation, Aviation and Materials Subcommittee of the House of Representatives requested that the Director of the Bureau of Mines address the issue of South Africa and critical materials dependency in testimony before the Subcommittee. Subsequent to the testimony, the Bureau has prepared a technical report focusing on the importance of South Africa and, in some cases, its neighboring countries as suppliers of six key materials. The report includes a qualitative analysis which examines the supply shortfall resulting from a potential disruption, options that are available for mitigating the impact, and their likely effectiveness, and quantitative analyses which estimate the economic impacts in the chromium and manganese markets resulting from peacetime disruption scenarios specified by the Subcommittee Chairman. The concluding section treats the role and capabilities of the Bureau of Mines in dealing with mineral supply disruptions.

Jan 1, 1986

By W. M. Dressel

The Federal Bureau of Mines has obtained data by differential thermal analysis of the various minerals that represent the nation's resources in manganese. These data are supported by X-ray diffraction analysis, chemical analysis, mineralography, and optical mineralogy, and provide fundamental information on the response of each mineral to thermal treatment in oxidizing, reducing, and neutral atmospheres. The information can be applied advantage¬ously in the identification of manganese minerals. Its greatest potential value, however, lies in the application of the quantitative data on the reaction temperatures, rates, and products to the more efficient extraction of manganese from U.S. ores. Thermal analysis curves are presented for certain manganese minerals, namely hausmannite, bixbyite, braunite, pyrolusite, lithiophorite, cryptomelane, hollandite, manganite, rhodochrosite, and rhodonite. The original minerals and the products of their thermal decomposition were identified by X-ray diffraction analysis, supplemented by chemical analysis and mineralogical identification.

Jan 1, 1961

By Maria I. De Rosa

The U.S. Bureau of Mines performed experiments to determine if primary gas toxicities that evolve during the early (~300° C) and later (~.400° C) combustion stages of polyvinyl chloride and chlorinated brattices could be predicted by a smoke particle characteristic, which could be used as a simple and inexpensive test parameter. The experiments were conducted in an approximately 20-L furnace at set furnace temperatures of 2500 and 1,0000 C, for 14 min duration, with an airflow through the furnace of 10 L/min. The variables studied, as a function of time, were the hydrogen chloride (HCl) and carbon monoxide (CO) concentrations, sample and furnace temperatures, the sample mass weight loss, the average smoke particle diameter (dg and number concentration (no), and the product of the average smoke particle diameter and concentration (dgno)' Results show that the inverse of the smoke particle diameter-concentration (l/dgno) correlates directly with the primary gas toxicities evolved during both stages of combustion.

Jan 1, 1989

By W. W. Agey

This report summarizes results of bench-scale metallurgical studies by the Federal Bureau of Mines on three composite samples representative of the low-grade manganese ores purchased by the General Services Administration (GSA) and stockpiled at Deming, N. Mex., and Wenden, Ariz. Bench-scale flotation tests at the Salt Lake City Metallurgy Research Center showed that all three composites could be beneficiated by flotation to recover 88 to 90 percent of the manganese in concentrates that assayed from 38.5 to 39.0 percent Mn, 10 to 12 percent insoluble, 5 percent CaO, 3 to 5 percent Fe, and 1.3 to 1.7 percent combined Pb plus Zn plus Cu, Sintering studies indicated that specification-grade material could be made from these concentrates by sintering above 1,000° C, and adding either sodium or calcium chloride to the charge to insure removal of enough lead and zinc to meet the specifications.

Jan 1, 1962

By Frederick W. Lee

List of contributing editors of Geophysical Abstracts:

Sep 1, 1932

By Donald F. Reed

During the first 6 months of 1948 the Bureau of Mines investigated the titania, deposit on the Wynn 0. Christy property in northern Hot Spring County, Ark. The property is situated in Magnet Cove, about half a mile north of the Magnet Store and U. S. Highway 270 (fig. 1). The purpose of the investigation was to determine the extent and grade of the ore body and to obtain a representative sample of the ore in as nearly natural condition as possible for use in metallurgical testing. All of the titania that has been marketed from Arkansas mines has been in the form of rutile from a deposit about 2 miles west of the Christy property. The titania in the Christy property occurs principally as brookite, which, with fragments of novaculite, quartz, and limonite, is imbedded in red clay. It is difficult to recover a core of the material. Three types of drills - a diamond drill, a bucket drill, and a Baker cable-coring tool operated on a churn rig - were employed in an effort to procure proper samples in their natural state. The Baker tool was found to be the most efficient and to be capable of drilling to a depth of 150 feet, making 80 to 100 percent core recovery (fig. 8). Total footage drilled was 1,536.9 in 21 holes, of which 7 were diamond-drill holes, 13 were bucket drill holes, and one was drilled with the Baker tool. The ore body was found to be 900 feet long, 500 feet wide, and more than 141 feet deep and contained 5.8 percent TiO2 and 0.52 percent 1720. Most of the deeper drill holes bottomed in ore, and there is a possibility that the ore may persist to a depth of several hundred feet. The Metallurgical Division of the Bureau of Mines is conducting experimental work at the Mississippi Valley Experiment Station at Rolla, Mo., for the purpose of developing methods of concntrating and utilizing the ore.

Jan 1, 1949

By Charles Vaught, Henry J. Kellner, Michael J. Brnich, Henry P. Cole, William J. Wiehagen

In 1985, U.S. Bureau of Mines and University of Kentucky researchers began a series of studies relating to self-contained self-rescuer (SCSR) donning proficiency. During the next 5 years investigators examined a number of factors that have a bearing upon miners' ability to put on and use the apparatus in an emergency: the procedure being taught; availability and utilization of training models; opportunities to practice; hygiene; and on-the-job training. This report presents an overview of that research. It is concluded that companies should adopt a hands-on training protocol that allows them to integrate SCSR donning practice into other workplace routines such as fire drills.

Jan 1, 1993

By Oliver C. Ralston

Fluorescence is of growing interest to the mineral industry because certain minerals may be detected thereby and because, as shown in figure 1,4/ many minerals (natural or synthetic) are needed in tubes and lamps. The use of fluorescent lighting is expanding, and large numbers of lamps of many sizes and shapes are being made and used in works, factories, stores, offices, homes, and in photography. Fluorescent tubes, as distinguished from clear tubes filled with neon, argon, or other rare gases through which a current of electricity passes, fluoresce owing to specially, selected and prepared minerals placed in the tubes. Luminous chemicals and paints also contain special minerals and are used in similar applications; therefore, these also will be considered in this report. Although the quantity of minerals (in tons) that are used for fluorescent purposes is small, and probably will continue to be so, this use is significant because it exemplifies a requirement for "pure" minerals in which a trace of contaminant as" minute" as one part in ten million may distinguish between the acceptance or rejection of a particular material. This extreme purity makes synthetic minerals almost essential, and natural mineral's are now little used.

Jan 1, 1944

By Young W. A.

The Eagle Silver mine is in the Rush Valley mining district, Tooele County, Utah, and is now operated by the Hampton Mining Co. The property, originally referred to as the Argent, is reported to have been one of the first discoveries in the district. The early operators mined ore to a depth of 850 feet, at which point the property was abandoned because of excessive water. During 1905 the Honerine tunnel was driven into the area approximately 1,800 feet below the collar of the Argent shaft. This tunnel served to drain the levels above and operations were resumed. Ore deposits in the Eagle Silver mine occur in the Galena King lime-stone, a 20-to 60-foot member of interbedded quartzite and limestone in the Oquirrh formation of Pennsylvanian age. This member has been faulted along the bedding, forming the Galena King gouge. Mineralization commonly occurs in or near this gouge area in a brecciated, highly altered, pipelike zone. The known ore shoots occur in association with the breccia pipe, commonly adjacent to cross faulting and porphyry intrusions. In general, two ore shoots have been mined on the upper levels of the mine, one lying to the east and the other to the west of the breccia zone. The Bureau of Mines diamond-drilling program was begun during the latter part of 1948 and completed early in 1949. Nine holes were drilled, aggregating 852.8 feet. Sludge and core samples from mineralized sections were analyzed in the Salt Lake City laboratories. A total of 87 sludge, 71 core, and 11 chip samples was submitted for analysis.

Jan 1, 1950

By K. K. Kershner

Nickel having a purity of more than 99.99 percent with reference to metallic impurities was electrodeposited at the Rolla Metallurgy Research Center of the Federal Bureau of Mines. The production of high-purity nickel is in keeping with the current trend in technologies for producing metals with lower and lower percentages of impurities. To understand more fully the role to be played by nickel by itself and as a component in many alloys, the element must be in a state of high purity. Procedures are outlined for purifying nickel solutions by precipitating and filtering off impurities. Details are given for using the purified solutions as electrolytes in depositing high-purity nickel. The elecneleposited nickel contained 0.0005 to 0.002 percent each of cobalt, copper, aid iron together with spectrographically detectable traces of aluminum, magnesium, and silicon. The deposits were smooth and dense; the crystalline structure was typical of an electrodeposited metal. Some preliminary experiments for purifying nickel solutions by liquid-liquid extraction are also described in this report. Tests of this type were limited since more encouraging results were obtained by other methods of purification.

Jan 1, 1961

By K. R. Dorman

To further investigate the potential of precast concrete sets as a support medium for underground mines, the Bureau of Mines designed a five-piece precast concrete drift set for a small opening and tested it to destruction in a straining frame. Twenty-seven tests were made with three sizes of members using three loading conditions. In addition, six tests were made with sets in a distorted configuration, Test results and typical failure patterns are presented. A comparison of results with those previously reported for the three-piece set shows the five-piece set supports considerably larger total loads than does the three-piece set of equivalent cross section designed for the same size of opening. Recommendations are made for improvements in design.

Jan 1, 1969

By Jon K. Ahlness

The Bureau of Mines conducted laboratory and field experiments to determine tne amount of permeability reduction in uranium sandstone after its exposure to different drilling fluids. Seven polymer and two bentonite fluids were laboratory-tested in their clean condition, and six polymer fluids were tested with simulated drill cuttings added. Sandstone cores cut from samples collected at an open pit uranium mine were the test medium. The clean fluid that resulted in the least permeability reduction was an hydroxyethyl cellulose polymer fluid. The greatest permeability reduction of the clean polymers came from a shale-inhibiting synthetic polymer. Six polymer fluids were tested with simu-lated drill cuttings added to represent field use. The least permeability reduction was obtained from a multipolymer blend fluid. A field experiment was performed to compare how two polymer fluids affect formation permeability when used for drilling in situ uranium leaching wells. For this test, the polymer fluid with the best laboratory results (multipolymer blend) was compared with a commonly used polymer fluid (guar gum) that gave poorer laboratory results. When fluid injection rates for the four wells drilled with the guar gum were compared with those for the four drilled with the multipolymer blend, no statistically significant difference was found.

Jan 1, 1984

By W. W. Staley

This paper discusses the design of small head frames that will fill the needs of prospectors and small operators whose operations are conducted through shafts. The head frames considered were designed to handle relatively small tonnages. It was assumed that the shafts in which buckets are used would not exceed 300 feet in depth and that not over 60 tons of rock would be hoisted, in, 14 hours. In the design of the larger head frames, a hoisting capacity of about 250 tons per 6 hours from a depth of 300 to 500 feet was assumed. Under these conditions, hoisting speed, rate of acceleration, and weight of rope have a negligible effect on the head frame design and, therefore, have been ignored in the following, discussion. Because timber is relatively cheap and easily obtained in most mining areas, the discussion has been confined to timber construction.

Jan 1, 1937

By Laurence G. Britton

Accurate flammability and ignitability data for chemicals form the cornerstone of procedures used to assess the hazards associated with commercial chemical production and use. Since 1967 the ASTM E27 Committee on the Hazard Potential of Chemicals has issued numerous, widely used consensus standards dealing with diverse testing and predictive procedures used to obtain relevant chemical hazard properties. The decision to issue a standard rests solely with the membership, which consists of representatives from industry, testing laboratories, consulting firms, government, academia, and instrument suppliers. Consequently, the procedures are automatically relevant, timely, and widely applicable. The purpose of this paper is to highlight some of the widely used standards, complemented with hypothetical but relevant examples describing the testing strategy, interpretation, and application of the results. A further goal of this paper is to encourage participation in the consensus standards development process. The paper is published in two parts. The first part (in the preceding issue of Process Safety Progress) dealt with the E27 standards pertaining to thermodynamics, thermal stability, and chemical compatibility. The second part, published here, focuses on the flammability, ignitability, and explosibility of fuel and air mixtures. © 2005 American Institute of Chemical Engineers Process Saf Prog 24: 12?28, 2005

Jan 1, 2005

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