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By Jacqueline V. Rich

The relationship between surface and ground water quality and copper mining in the Globe-Miami area is investigated in this three-year study. Methods to prevent, minimize, mitigate, or treat polluted waters are identified and evaluated. Best Management Practices are incorporated in a recommended plan to manage the area's water quality.

Jan 1, 1983

By Frank Cook

In this two-year study, an evaluation of mining and reclamation practices at 159 randomly sampled surface coal mines in the United States was conducted. It is concluded that reclamation practices in most of the 22 coal-producing states were adequate during 1975, but that improvement in reclamation performance was desirable in the acid area of the central U. S. and in mountainous southwestern Virginia. Productivity improvements should result from research to determine efficient or optimal operating procedures for dragline stripping of single and multiple seams, surface mining of lignite, multicut and multiseam haulback mining on steep slopes, mountaintop removal, and surface mining in swampy or deeply glaciated areas. Specific candidate research projects are discussed in this report.

Jan 1, 1976

By E. M. Tignor

A research program to aid development of improved methods for increased production of petroleum from partly depleted reservoirs is a vital part of the Bureau of Mines effort to effect true conservation of that mineral resource. This report presents results of an investigation to identify the clay minerals within some Appalachian petroleum-reservoir sands, the effect of clay content on the fluid-flow behavior of those sands, and the use of brines in water-flooding operations. Permeability measurements using kerosine, calcium chloride brine, simulated oilfield brine, potassium chloride brine, sodium chloride brine, and distilled water were made on reservoir-rock cores. Clay fractions were separated from sand grains of disaggregated portions of each core sample, and the clay minerals were identified by the differential thermal analysis method. Relations of the permeability to various fluids were developed.

Jan 1, 1957

By D. R. Tesarik

Displacement and stress changes in cemented backfill and ore pillars at the Buick Mine, near Boss, MO, were monitored by engineers from the U.S. Bureau of Mines and The Doe Run Co., St Louis, MO. A test area in this room-and-pillar mine was backfilled to provide support when remnant ore pillars were mined. Objectives of this research were to evaluate the effect of backfill on mine stability, observe backfill conditions during pillar removal, and calibrate a numeric model to be used to design other areas of the mine. Relative vertical displacements in the backfill were measured with embedment strain gauges and vertical extensometers. Other types of instruments used were earth pressure cells (to identify loading trends in the backfill), borehole extensometers (to measure relative displacement changes in the mine roof and support pillars), and biaxial stressmeters (to measure stress changes in several support pillars and abutments). Two-and three-dimensional numeric codes were used to model the study area. With information from these codes and the installed instruments, two failed pillars were identified and rock mass properties were estimated.

Jan 1, 2010

By Donald F. Smith

This report describes the construction and calibration of two ice calorimeters and includes results of high-temperature heat-content measurements, made by the Federal Bureau of Mines, on rubidium fluoride, hafnium tetrafluoride, cesium chloride, and cesium iodide. The heats and entropies of fusion of rubidium fluoride, cesium chloride, and cesium iodide have been calculated at their respective melting points using equations derived from the experimental heat-content data. Hafnium tetrafluoride did not melt within the range of temperatures investigated. Heat and entropy of transition of cesium chloride from the alpha to the beta form were also determined. INTRODUCTION Free-energy data usually afford the cheapest and quickest means of determining the feasibility of experimentally untested reactions. For known reactions, free-energy data show the variation of the equilibrium constant with temperature and make it possible to calculate, without experiment, the maximum ratio of product to raw material for a given chemical process.

Jan 1, 1961

By D. S. Colby

The productive capacity of natural-gasoline and cycle plants in the United States as of January 1, 1952 was 811,596 barrels per day, an increase of 163,691 barrels per day since the last survey on January 1, 1950. The rate of growth during these 2 years has been 12 percent per year s only slightly below the maximum rate, recorded from 1948-50. This survey, for the first time, presents capacity data on a barrel rather than a gallon basis. Also, for the first time, a break-down of capacity by products has been obtained. The combined LP-gas producing capacity of plants and fractionators equaled 382,790 barrels per day, 47 percent of the total industry capacity tor all products. During January 1952, LP-gas and natural gasoline and other products were each produced at the rate of 76 percent of the January 1 capacity.

Jan 1, 1952

By R. E. Mussier

This investigation was made to study new methods to prepare high-purity yttrium metal, Various methods were used to prepare pure intermediate compounds, primarily chlorides, bromides, and iodides, which were subsequently reduced to metal. The process found most suitable for the preparation of pure anhydrous yttrium chloride involved thermal dehydration of a mixture of hydrated yttrium chloride and ammonium chloride while under vacuum. Yttrium bromide and iodide were prepared most effectively by the direct halogenation of yttrim carbide. Yttrim carbide was obtained by reacting and melting yttrium oxide-carbon mixtures in a carbon-arc furnace. Yttrium halides were purified by vacuum distillation and reduced by alkali or alkaline-earth metals. Lithium and sodium proved to be the best reductants from the standpoint of yield (>95 pct) and purity (>99.8 pct) of the yttrium. The product of the reduction step was sponge metal, which was consolidated readily by conventional cold-mold, arc-melting procedure. The purest yttrium obtained in laboratory scale work was prepared by sodium reduction of yttrium chloride and contained only 125 pp oxygen; other impurities did not exceed 1,000 ppm. In larger scale tests yttrium containing only 800 to 1,000 ppm total impurities was obtained by lithium reduction of yttrium chloride. The tensile properties of high-purity yttrium were determined. Mechanical tests showed that yttrium can be forged, extruded, rolled, spot welded, and deep drawn.

Jan 1, 1963

By John Paul Gries

During World War II, when the curtailment of imports led to an unprecedented demand for domestically produced mica, beryl, and other pegmatitic minerals, the Bureau of Mines and the Geological Survey entered upon a program designed to expedite the production of these minerals from the Black Hills area of South Dakota. The program involved mapping, sampling and drilling many pegmatite dikes found in the southern portion of the area and beneficiation tests in the field and in the Bureau of Mines laboratories at Rapid. City, S. Dak., Rolla, Mo., Salt Lake City, Utah, and College Park, Md. This paper describes the mode of occurrence and the sampling and beneficiation tests on one dike, the Helen Beryl pegmatite, which was investigated as part of the general pegmatite study in South Dakota. Investigation of the Helen Beryl Pegmatite by the Bureau began in August 1943 and was terminated in April 1944. During this period the Bureau took a series of bulk samples from pits for beneficiation tests, drove an adit through the center of the dike to obtain feed for a bulk-sampling plant operation, and finally drilled a series of long holes to sample the deposit further. Geologists of the Federal Geological Survey mapped the deposit and the faces of all excavations and logged drill holes from sludge samples recovered from long-hole drilling.

Jan 1, 1949

By Jack L. Henry

The Bureau of Mines conducted seven pioneering experiments in a 12-inch-diameter Kroll reduction reactor to examine the feasibility of coreducing the chlorides of Ti, AI, and V to produce a homogeneous titanium alloy sponge. The coreduction studies proceeded in a normal manner, and the yields of sponge were comparable with those of pure titanium sponge made in the same reactor. Vanadium concentration was very uniform throughout the sponge cake when VC14 in solution in TiCl4 was fed into the molten magnesium. More difficulty was encountered in feeding solid VCl2 and AIC13. Vanadium and aluminum concentration in the sponge was not uniform, and mechanical difficulties were experienced with the small-scale screw feeder. Although the sponge varied in composition from region to region, the ingots prepared from it were uniform in composition.

Jan 1, 1974

By E. E. Maust

The literature on the activation of sphalerite for flotation by short¬chain xanthates leaves unanswered the question of whether a compact surface film of activator sulfide is necessary or merely sufficient for high flotation recoveries. Studies by Guarnaschelli and Plaksin indicate that xanthate adsorption and flotation of sphalerite are increased with increasing hole/ electron ratio. These results, and the known acceptorlike behavior of many heavy-metal impurities in zinc sulfide, suggest that activation may result from a traditional semiconductor doping effect at the surface. Using the theory of chemisorption states on ionic crystals as developed by Levine and Mark, the Bureau of Mines has carried out A calculation to estimate the surface-state energies of various metals when they are substituted at zinc sites on (110) sphalerite surfaces. Based on a simple Madelung-Born treatment of ionic solids, the calculation indicates that many of the metals known to activate sphalerite for subsequent flotation have lower surface-state energies than nonactivators. The results of these calculations are discussed from the standpoint of consistency with the proposed activation mechanism and observed flotation results. The satisfactory agreement obtained is taken to be support for the proposed mechanism, and further elaboration of a surface-doping model is attempted.

Jan 1, 1976

By John T. Metcalf

The assembly procedures for nine different wire rope terminations used in the mining industry are presented in a format and manner to facilitate training and to provide points where inspection of the termination should be performed. The nine terminations addressed are: Flemish Loop with Steel Sleeve & Thimble, Flemish Loop with Steel Sleeve, Wedge Socket, Swaged Socket, Turn Back Loop with Sleeve & Thimble, Thimble Splice with Four Tucks, U-Bolt Clip & Thimble, Zinc Poured Socket, and Epoxy Resin Poured Socket. The manual was prepared to be used primarily for field type mining operations or training where high capacity machinery is quite limited. It is nut the intent of this manual to suggest that the procedures presented are those to be used by manufacturers or other commercial enterprizes. A different set of procedures may be more appropriate where ideal space and equipment resources are available. The assembly procedures were derived from standard industrial practice, manufacturer's recommendations, and the open literature on the subject. These same procedures were used to prapare test specimens for an extensive series of pull and axial fatigue tests. The results of these tests indicate that these procedures are satisfactory in all respects. This manual is to be used as part of a complete training program. Although a brief glossary is included, there has been no attempt to make this a primer on wire rope. The selection of wire rope termination hardware, like the selection of the wire rope, is a subject not covered by this manual. The reader is cautioned that there are various sources for such hardware and this selection must be done carefully.

Jan 1, 1978

By Clarence O. Babcock

This report describes the results of Bureau of Mines laboratory and preliminary field tests on a rock bolt of helical shape. The flexible construction allows the bolt to maintain a more stable load level than is possible with a straight bolt. Bolt load changes resulting from anchor slippage, blasting shock, or changes in mine geometry with mining advance are minimized. Preliminary field tests were performed at the Kaiser Steel York Canyon mine where the load changes of straight and helical bolts were measured using a vibrating-wire load gage. The field tests were performed to establish the viability of the concept of a helical bolt. The practical usefulness in terms of performance and economics remains to be shown. The change in bolt load for the flexible bolts was one-third that for the straight bolts. There were no malfunctions of the gage, and the bolts maintained a more uniform load than the straight bolts used as controls.

Jan 1, 1978

By Raja V. Ramani, Wilson Miola

"The potential health effects of quartz-bearing airborne dust in mine and mill atmospheres point to the need for the quantification of quartz content in the source material for determining the source-sink relationships and for choosing applicable control measures. While a standard method exists from a regulatory point of view for the sampling of coal mine atmospheres for determining (i) respirable dust concentrations and (ii) the amount of quartz in the samples, there is no generally accepted standard method for quartz analysis in bulk samples of coal and host rocks. Generally, the bulk sample is reduced to a powder for producing quartz analysis samples. Extensive controls arc necessary to ensure representativeness of the analysis samples when these are very minute fractions of the bulk samples. Since the amount of analysis sample is not limited, alternative methods for quartz analysis may also be tried. It is, however, necessary to adopt a procedure which will satisfy several statistical requirements to guarantee representativeness of the quartz analysis samples.In this paper, the important factors in the preparation of quartz analysis samples from the host rocks and bulk samples are discussed. The method developed to prepare the analysis samples is outlined. The results of application of the procedures are presented. The procedure developed for quartz analysis sample preparation is based on sound statistical foundations. The procedure has been validated for reproducibility and homogeneity.The current methods used for quartz analysis in powders are the P-7 infrared spectrometry and quantitative X-Ray Diffraction (XRD). Both have similar restrictions concerning the sample characteristics and operational problems, which arc intrinsic to radiation beams, device geometry, mechanics and controls of the radiation behavior. Although improvements can be made in the spectrometers and diffractometers, some of the most important steps are the procedures for analysis sample preparation from bulk samples and for calibration of the instruments. The sample preparation process is often referred to as one of grinding and sizing the bulk sample to generate the powder for the scanning devices. The particle sizes are referred to and their influence emphasized but the representativeness of the sample is assumed. Assuring sample representativeness during the sample preparation procedures is critical.For the sampling of airborne respirable dust in coal mines, the collection devices, the collection procedures and the analysis procedures are defined. This is not true for bulk samples where weights must be reduced thousands of times to generate the analysis samples for the scanning devices. The specifications to be developed may include bulk sample amount, sample reduction procedures, sample particle size distribution and sample amounts. However, the common problem of insufficient sample amount which is often encountered with mine airborne dust samples need not exist for bulk samples. Further, the same bulk sample can yield analysis samples for several experiments. The latter, of course, requires sample homogeneity.Three concepts are important in the selection of any procedure for sample preparation and analysis. These arc accuracy, reproducibility and representativeness. The adopted procedure has to guarantee a homogeneous sample representative of the population, a defined level of accuracy and reproducibility. Important statistical concepts are embedded in these requirements, particularly with respect to estimation and dispersion errors. Accuracy and reproducibility are totally different though not independent concepts. Estimation is related to accuracy and the true value. Dispersion is related to reproducibility and is measured by the classical statistical standard deviation of the distribution of a series of measurements or analysis performed over the same lot or analysis sample. The dispersion variance (or dispersion error) does not tell a"

Mar 1, 1992

By Donald W. Mitchell

Certification tests for urethane-foam systems and techniques for apply-ing foam safely in mines are described. Fire hazard from foam exists if flame propagates beyond the ignition source or penetrates the foam. Foam that passes the certification tests can be applied on stoppings, continuous sections of ribs of relatively wide passageways (with no foam on the roof), short sections of roof such as overcasts, roof cavities, and intersections (with no foam on the ribs), and between buntons on one wall of a shaft. Foam on the ribs and adjoining roof presents a fire hazard. Stoppings covered with foam passing the certification tests are resistant to penetration of heat, flame, and smoke than similar stopping without foam. Flame propagation can be arrested by water sprays. Spontaneous ignition of foam can be prevented.

Jan 1, 1966

By James P. Bennett

The U.S. Bureau of Mines investigated the role of imported natural flake graphites in dolomite-carbon refractories used in steelmaking processes and evaluated carbon fibers as a potential substitute. Varying quantities (1.5-30 pct) of natural flake graphite and carbon fibers were added to test samples. The effect of the additions on modulus of rupture (75°-2,750° F), deformation under load (2,750° F), and air-slag-metal resistance (3,000° F) was studied. Carbon purity of natural flake graphite additions did not influence hot strength, deformation under load, or air-slag-metal resistance. When the quantity of 90-pct-carbon graphite addition varied between o and 30 wt pct, hot strength was highest, deformation under load lowest, and air-slag-metal wear the least at 10 wt pct. As test temperature increased from 500° to 2,750° F, the hot strength difference became less. Carbon fiber additions were limited to 1.5 pct in dolomite-carbon brick. At this level, physical properties were generally comparable to those obtained with natural flake graphite, but were below values obtained with 10-pet-f1ake graphite additions. Carbon fibers are not considered a satisfactory substitute for natural flake graphite.

Jan 1, 1989

By Gerald W. Elger

To determine the feasibility of removing nonferrous metal impurities from automobile scrap by thermal treatment in a rotary kiln, the Bureau of Mines conducted four series of tests with synthetic scrap mixtures heated at various temperatures under oxidizing and reducing conditions. The treated scrap mixtures were melted in an electric-arc furnace and cast into small ingots for impurity evaluation. Analyses showed that the ingots were essentially free of residual metal impurities except for copper. Test data indicated that in an oxidizing atmosphere the percentage of copper removed increased with treatment temperature. Percent of copper removed in a reducing atmosphere was found not to be temperature dependent. A significant finding was that copper was embrittled under some of the operating conditions and was mechanically removed by fragmentation.

Jan 1, 1968

By T. H. Miller

This piper is a continuation of a series of yearly review articles started in 1925 by Thomas Varley. The development of flotation has been rapid, and better understanding of the functions o' flotation reagents has resulted in many changes in the kinds and quantities o reagents used. It is the purpose of this report to present the information in such a manner as to be of value to the milling industry as well as to the manufacturer of flotation reagents. These data have been compiled from a. survey of approximately 250 flotation plants of all classes within the United States. Many of these plants made complete reports of their operations, out others were apparently unable to supply this information in sufficient detail to meet the requirements of this investigation. Although it is realized that the data obtained in this survey are not as full as they should be to render the greatest service possible to the milling industry, it is hoped that succeeding articles will include complete information regarding milling; conditions and recoveries. As in the past, every effort has been made to conceal individual plant operations. RESULTS OF INVESTIGATION Table 1 gives the tons of ore treated by gravity and flotation methods and the concentrates produced as reported by 208 plants. The totals of 77,043,535 tons of ore and 4, 596,640 tons of concentrates from this table compare with totals of 78,973,012 tons and 4,683,972 tons respectively (furnished by the Bureau of Mines, Division of Mineral Statistics), indicating that the milling survey is about 98 per cant complete.

Jan 1, 1930

By Gary L. Hundley

The Bureau of Mines has devised a procedure to recover chromium chemicals from low-grade domestic chromites, which contain silicon and aluminum impurity levels that are too high to permit processing by present industrial processes. The Bureau procedure consists of reacting chromite with molten sodium hydroxide (NaOH) under oxidizing conditions to form sodium chromate (Na2Cr04). The reaction product is leached with methanol to remove the majority of the unreacted sodium hydroxide, then with water to remove the sodium chromate and the remainder of the sodium hydroxide. The sodium chromate product is recovered by evaporative crystallization from the aqueous solution. This report presents results of laboratory tests to determine the optimum fusion conditions and the chromium extractions obtained from several domestic chrotdte concentrates. These concentrates are from a variety of sources, including the Stillwater Complex in Montana, Kanuti River-Caribou Mountain, Red Bluff Bay, Kenai Peninsula, and Kodiak Island areas in Alaska, deposits in northern California, and a nickel-cobalt laterite from southern Oregon. All of these concentrates were successfully treated by the Bureau procedure. The best chromium extrac-tions obtained for each of these materials ranged from 69.5 to 98.9 pet.

Jan 1, 1985

By William J. Campbell

The columbite-tantalite mineral series was studied by various instrumental techniques to establish the relationship of density to composition. The samples used were carefully selected to obtain a mineralogical purity of at least 98 percent. Impurities were determined by optical microscopy, X-ray diffraction, and optical and X-ray spectroscopy. Each sample was analyzed by fluorescent X-ray spectroscopy for iron, manganese, columbium (niobium), and tantalum. The existence of a unique relationship in this isomorphous series permits a simple correlation of the intensity of a spectral line with the concentration of the analytical element.

Jan 1, 1955

By J. H. Bilbrey

A recording thermobalance ,vas used to determine the rates of oxidation of mol-ten tin over the temperature range 550°-900° C. Oxidation rates were found to vary widely for a given temperature, as previously reported by other investigators. 1 X-ray diffraction data indicated that the probable cause of these variations was the development of preferred orientations in the crystals forming the oxide film. No reasons for the differences in degree of preferred orientation were discovered. For relating the weight of the oxide formed (w) to the time of oxidation (t) an equation of the form wn = kt was found to best represent the experimental data. INTRODUCTION In the course of conducting investigations on the feasibility of using selective oxidation techniques for the purification of various metals in the molten state it was soon discovered that data on the oxidation of molten metals and alloys were very scarce. In contrast to the many hundreds of publications on the oxidation of metals in the solid state there are relatively few articles on the rates of molten-metal oxidation. In view of this scarcity of data, it was decided to institute a series of investigations into the oxidation processes of molten nonferrous metals and alloys with the expectation that the information derived could be put to practical use in developing and improving refining processes based on selective oxidation. This report is the first of a series in which oxidation data for molten nonferrous metals and alloys are presented.

Jan 1, 1955