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By Joseph M. Pugliese

The Bureau of Mines through its contract research program recently analyzed the mining and environmental requirements in the premining stage for copper mining in the northern highland of Wisconsin. The Critical-Path-Method (CPM) was used in this research. However, a step-by-step derivation of the CPM Diagram was beyond the scope of this effort. The Bureau of Mines objective now is to show, step by step, how the original hand-computed CPM Diagram was constructed. The streamlining (restructuring) of this diagram from the original effort is also summarized. The critical path time (longest time) through the original CPM Diagram was 25.12 yr, excluding public liaison effort. This diagram showed the involvement of the regulatory agency, mining applicant and public in the premining stage. Analysis of this diagram produced a streamlined version which reduced the critical path time by nearly 7 yr. The CPM construction methodology offered here may be applied to mine planning for any mining operation.

Jan 1, 1983

By Charles S. Allbright

This report describes hydrogenation of petroleum distillate fuels in bench scale equipment and the effects of hydrogenation on the storage stability and the composition of the fuels. Two distillate fuels were hydrogenated in laboratory equipment using a commercially available cobalt molybdate catalyst. Reactor temperatures were varied from 600° to 850° F and pressures from 100 to 600 psig. Product fuels were analyzed by ASTM, Bureau of Mines, mass, and infrared methods. Hydrogenation of a catalytically cracked fuel from Oklahoma crude oil significantly improved the storage stability, reducing insoluble gum formed during 9 months of storage at 110° F from 19.0 to 1.3 mg per 100 ml fuel, average. Conversion of the olefins to other hydrocarbon types varied with the temperature of hydrogenation--at 700° to 850° F the conversion was mainly to aromatics, at 650° F about 50:50 to saturates and aromatics, at 600° F principally to saturates. Processing a fuel composed of a mixture of virgin distillate and catalytically cracked stock, both from Illinois crude, at 700° F and 200 psig effected marked improvement in stability; the buildup of insoluble gum in storage was lowered from 18.3 to less than 1 mg per 100 ml fuel.

Jan 1, 1967

By William Y. Mo

This Information Circular provides a detailed background documentation of how the Bureau of Mines projects U.S. mineral demand to the year 2000. These statistical projections serve as a quantitative basis for contingency forecasting of the low, high, and probable U.S. demand for nonfuel minerals by end-use categories and are published in the Bureau of Mines Mineral Commodity Profiles and Mineral Farts and Problems series. Aluminum is used as an example in this study.

Jan 1, 1980

By J. D. Brown

The electron optics, vacuum system, and sample stage assembly for the Bureau of Mines? electron probe X-ray spectrograph were purchased. Four scanning curved-crystal spectrometers, two reflection- and two transmission-type, were designed and constructed by the authors. The reflection spectrometers are placed in a vacuum chamber for measurement of long-wave-length X-radiation. Detection, pulse-amplitude discrimination, and recording circuits are provided for the simultaneous measurement of four X-ray spectral lines. Minimum spot size is approximately 2 microns in diameter at 30 kilovolts and a sample-to-ground current of 5 x 10-8 ampere. At this voltage and current the limit of detection with reflection spectrometers is less than 0.05 weight-percent for most elements. The limit of detection for elements determined by transmission-type spectrometers, evaluated at 35 kilovolts and 5 x 10-8 ampere, is approximately 0.1 weight--percent for all elements having excitation voltages below 20 kilovolts. In general, reflection spectrometers exhibited satisfactory but poorer resolution than the transmission type, resolution of the spectrometers being limited primarily by crystal imperfections, with greater mosaic structure being introduced by the grinding process for the reflection crystals. Several applications of the electron probe X-ray spectrograph are described. Analysis of a uranium-steel is discussed in detail to illustrate calculation of composition from measured X-ray intensities.

Jan 1, 1962

By R. H. Sprute

This report describes a feasibility study to consolidate coal waste sludge in a 100-acre pond by applying direct current between floating and buried electrodes. The study was conducted by the Bureau of Mines under a cooperative agreement with Washington Irrigation and Development Co., located near Centralia, Wash. Part 1 covers results of laboratory tests at the Bureau's Spokane Research Center and a small-scale field test at the cooperator's coal preparation plant in western Washington. The process is efficient and cost-effective when power is applied at low current density. A proposed system, fully described in part 2, has electrodes covering 21 acres of pond surface radially arranged around a central power platform. Densification of pond contents would require 2 to 3 years of treatment. Total cost of equipment, labor, and material is approximately $500,000.

Jan 1, 1982

By R. E. Siemens, Gary L. Hundley

The Bureau of Mines has devised and demonstrated a process for recovering Ni and Co from low-grade domestic laterites . The process consists of four mmaajjoorr steps : ( 1 ) reduction roast , ( 2 ) ammoniacal leach , ( 3 ) solvent extraction , and ( 4 ) electrowinning . Several solid - liquid separation steps are required that affect the economics of the overall process . In this study , two techniques for solid - liquid separation , centrifugation and thickening , were investigated . This report presents the results of ( 1 ) laboratory and pilot plant studies to determine parameters for sizing centrifuges and thickeners and ( 2 ) an economic study of the two techniques , based on the requirements of a commercial - size ( 5,000 - tpd ) laterite processing plant . Sizing and other equipment - related recommendations , based on data from the Bureau's studies , were obtained from commercial manufacturers . The costs of thickening and centrifugation , including all the unit operations affected , were determined by the Bureau's process evaluation group . The total operating costs for separation using the two techniques ( including depreciation on the capital cost of equipment ) were found to be quite close : $ 17.26 per ton of laterite for centrifugation and $ 18.15 per ton of laterite for thickening . For centrifugal separation , the greatest cost was found to be the initial capital cost for the separation equipment ; using thickeners , the greatest cost was for reagent recovery .

Jan 1, 1983

By Raymond W. Hiteshue, Sam Friedman, Martin D. Schlesinger

The Bureau of Mines in cooperation with the El Paso Natural Gas Co. investigated the effect of high temperature and pressure at short residence times on the hydrogenation of a New Mexico coal to gaseous and liquid hydrocarbons . The study was made in a bench - scale semicontinuous unit at pressures of 500 to 6,000 psig , 480 ° to 1,000 ° C , and residence times of less than 1 minute to 15 minutes . Ammonium heptamolybdate was impregnated on the coal to furnish 1 percent molybdenum based on maf coal . Coal could be rapidly hydrogenated at elevated temperatures and pressures to yield large quantities of gaseous hydrocarbons and small quantities of lowboiling oils , high in single - ring aromatics . At 800 ° C and 6,000 psig and a residence time of 1 minute , the yield of hydrocarbon gas was 43 percent and of liquid hydrocarbons 9 percent , based on maf coal . With a 15 - minute residence time , the yield of gaseous hydrocarbons increased to 68 percent with a decrease in yield of oil to 6 percent . At higher hydrogen velocities , the yields of oil were much greater but contained large quantities of asphaltene . Low concentrations of molybdenum (0.01 and 0.1 percent ) or a high concentration of iron ( 1 percent ) were ineffective at 800 ° C , 6,000 psig , and short residence time .

Jan 1, 1964

By E. V. Cilento, K. A. DiGregorio, R. C. Lantz

"DIGREGORIO, K. A., E. V. CILENTO, AND R. C. LANTZ. A kinetic model of superoxide production from single pulmonary alueolar macrophages. Am. J. Physiol. 256 (Cell Physiol. 25): C405-C412, 1989.-A kinetic model was developed to describe the production of superoxide (02) by single pulmonary alveolar macrophages (PAM). Model predictions were compared with experimental results obtained from single rat PAM. The 02 was quantified by measuring the reduction of nitro blue tetrazolium (NBT) to a diformazan precipitate (NBTH,) from video-recorded images of individual cells. The kinetic model considered three reactions: 1 ) the production of extracellular 02 from the reduction of oxygen by NADPH oxidase using intracellular NADPH as the substrate, 2) the subsequent dismutation of 02 to form H,O,, and 3) the reaction of 02 and NBT to form diformazan. NBT specificity for 02 was analyzed by comparing results in the presence and absence of superoxide dismutase (SOD) that catalyzes the dismutation of 02 to H,O,. Measured PAM heterogeneity was accounted for by varying the concentration of intracellular NADPH, its rate of depletion, and the concentration of intracellular NADPH oxidase in the kinetic model. Model predictions compared favorably with experimental results except when SOD was present. This discrepancy may be due to diffusional limitations because NBT is a relatively small molecule (818 mo! wt) compared with SOD (34,000 mol wt). In addition, the cell surface is both ruffled and negatively charged, which may introduce steric hindrances and/ or electrostatic effects, since SOD is also negatively charged, whereas NBT is positively charged.PULMONARY ALVEOLAR MACROPHAGES (PAM) protect the lungs by phagocytizing foreign debris and bacteria. This process is accompanied by the production of superoxide anion (02) at the surface of the plasma membrane (3, 31). Superoxide readily dismutates to form H20 2 and subsequently, other oxygen metabolites which have been shown to be both antibacterial and cytotoxic (21, 25, 35).Superoxide is produced from the reduction of extracellular O, at the surface of the cell membrane by NADPH oxidase by the following reaction (3, 4)"

Jan 1, 1989

By F. E. Joyce

The Bureau of Mines studied copper-nickel minerals (mainly sulfides) of the Duluth Gabbro Complex in north-eastern Minnesota to determine their response to selective high-temperature sulfatization techniques. The gabbro, containing 0.44 percent copper and 0.13 percent nickel, was ground to minus 325 mesh and sulfatized in a heated, rotating, stainless steel bench-scale retort. Tests demonstrated that over 95 percent of the copper and 80 percent of the nickel can be converted to water-soluble sulfates, depending upon the roasting conditions employed. Yield equations were developed using regression analysis for predicting the extraction of copper and nickel between the temperature limits of 520° to 670° C, the roasting time limits of 3 to 7 hours, and S02 limits of 10 to 40 percent in S02-air mixtures.

Jan 1, 1971

By R. E. Heithecker

The principle of determining volumes of liquid by alternately drawing in and discharging given quantities of the fluid from a confined space or compartment of known volume and mechanically counting the number of displacements is well established. This is true particularly in water measurement. For several years, oil meters employing the same basic principle have beer used for gaging oil production from individual wells, groups of wells, and in some areas for metering the entire production from a property. Especially in areas where there is town-lot drilling and space for tankage is at a premium, oil meters have been used successfully to gale the oil. This facility has obviated the necessity of installing gage tanks. Oil meters also have been used in pipe-line and refinery operations and in loading tankers. Present knowledge e of the subject shows that positive-displacement oil meters can be used for measuring crude oil in the field and elsewhere, provided the meter-counter mechanism is in proper adjustment and the oil has been studied sufficiently to determine the pro-per factor to be applied to the volume as registered by tae meter, possible the adjustment for the shrinkage of the oil caused by liberation of gas from solution.

Jan 1, 1938

By Benjamin W. Haynes

This research was conducted as part of the U.S. Department of the Interior, Bureau of Mines program to recover metals, glass, and a combustible fraction from municipal solid waste (MSW). The objective of this analytical study was to determine the concentration of antimony, arsenic, and mercury in samples taken from various sampling areas in the Bureau of Mines raw refuse recycling plant and to compare these values with those for coals used in the generation of electricity. To provide the necessary analytical data, sensitive reproducible ashing-chemical digestion-atomic absorption procedures were adapted from published procedures. It was determined that antimony and mercury concentrations in the combustible fraction of MSW are approximately an order of magnitude higher than those found in coals presently used for power generation;' the arsenic concentration is similar in both fuels.

Jan 1, 1978

By Walter Murphy

For a number of years the Bureau of Mines has been studying the properties of crude petroleums produced in the United States and the Western Hemisphere. A number of reports have been published giving the analyses of crudes from the different fields and regions as made by the Bureau of Mines Hempel method of analysis.4 Several of these reports include analyses of crude oils from the Rocky Mountain region.5/ The search for new fields and new producing horizons in old fields in the Rocky Mountain region has been quite intensive during the last few years, and a number of discoveries have been made.

Jan 1, 1937

By Carl F. Wingquist

In support of Bureau of Mines studies of thermal fragmentation of rock, the elastic moduli of four types of rock were measured at temperatures ranging from room temperature up to 1,500° F (1,089° K). The sonic method was employed to determine the resonant frequencies of the rock specimens and from these frequencies, the elastic moduli were calculated. Data for Young's modulus, shear modulus, and Poisson's ratio are given as a function of temperature for Dresser basalt, Reserve taconite, Jasper quartzite, and Charcoal granite. Young's modulus and the shear modulus decreased with increasing temperature up to about 1,200° F and then became relatively insensitive to temperatures from 1,200° to 1,500° F.

Jan 1, 1969

By Felix duBreuil

The present sampling procedure for evaluating the rock dusting conditions in a coal mine is time consuming. This study considers means by which this procedure could be simplified. Surveys were conducted in six coal mines in Pennsylvania to determine the in¬combustible content of the deposited dust. Some 2,000 samples were analyzed and statistically evaluated. It is suggested that the mean incombustible content could be obtained with fewer samples and smaller samples without greatly increasing the sampling error.

Jan 1, 1972

By Alton B. Cook

A material balance equation was derived for calculating (1) the initial oil volume and (2) the relationship of average reservoir pressure to net gas in storage in reservoirs used for natural gas storage operations. The equation is also applicable to secondary-recovery operations where reservoirs are completely repressured and gas cycled. Using this equation minimized two probable sources of appreciable error in conventional material balance calculations: inaccurate measuring of and accounting for produced gas, and differences between true reservoir pressure and average reservoir pressures as derived from bottom-hole pressure measurements. A new procedure is presented for calculating water encroachment. By solving the conventional material balance equation and the derived equation for gas storage simultaneously, the values for initial oil in place and net water encroachment can both be determined.

Jan 1, 1966

By Ludwig Schmidt

The consumption of gasoline in the United States varies materially with the seasons; during some of the summer months it exceeds the rate of production and in the other seasons the production of gasoline exceeds the consumption, The usual practice of the larger refiners is to store surplus stocks during the winter season in order to meet the heavy demands during the summer months. The following table shows the stocks of gasoline at refineries on the last day of April for the past five years: 1919 593,616,170 gallons 1920 643,5526644 " 1921 747,222,900 " 1922 892,567,766 " 1923 1,336,417.871 "

Jan 1, 1923

By C. M. McCulloch

The natural vertical fracture system in bituminous coalbeds is called cleat. Cleat orientation commonly controls the direction of mining with major development paralleling the face cleat. Previous researchers have categorized the origin of cleat as endogenetic, relating the origin of cleat to compaction and coalification, and exogenetic, relating the origin of cleat to tectonic forces. In the coalbeds studied for this report it was found that tectonic forces were the controlling factor of cleat formation. Face cleats were formed as extension fractures during structural deformation, and butt cleats, as release fractures during erosion and uplift. The face cleat of the Pittsburgh coalbed rotates from N 80° W in north-western West Virginia to N 57° W in southwestern Pennsylvania; the face cleat maintains a perpendicular orientation to the shifting axial trend of local structures. Cleat orientation in other bituminous coalbeds in Virginia, Utah, Oklahoma, and Central Pennsylvania showed a similar relationship to local structure. Directional permeability of coal is directly related to cleat. Holes drilled perpendicular to the face cleat yield from 2.5 to 10 times the amount of gas released as compared with holes drilled perpendicular to the butt cleat.

Jan 1, 1974

By Jr. Fish

As a part of a study of iron are resources in the Appalachians, 9 diamond drill holes aggregating 1,580.7 feet were drilled in a portion of the Butt Mountain area of northeastern Giles County, Virginia. Three hematitic sand-stone beds were intersected in the Clinton formation but only one was consistent in thickness and grade in all 9 drill holes. This bed averages 18.9 percent iron over an average thickness of 24 feet. The drill cores were logged and chemical analyses were made on 161 individual samples and 22 composite samples. Beneficiation studies were made of three composite hematitic sandstone samples each representing a separate bed containing 14.6, 19.8 and 20.0 per-cent iron. Major mineral constituents of the samples were hematite, quartz, and sericite.

Jan 1, 1967

By Robert R. Perron

The U. S. Bureau of Mines is engaged in many diverse programs for improving mine safety. Of particular interest to the Bureau are new and improved means for minimizing the hazard of fire which can be initiated by prolonged low energy electrical faults on trolley line systems. When a high energy fault occurs on a trolley line, wherein the current exceeds the magnitude normally drawn by legitimate loads, such as locomotives, then the circuit breakers at close-by power rectifier sets trip. Tripping of the breakers not only protects the equipment at the rectifier sets, but also disconnects the energy source from the fault and thereby minimizes the fire risk. However, the fault current is frequently of a level substantially below that required to trip the overload breakers. When the fault is a substantial percentage of the set level of the breakers, the energy dissipated by the fault is frequently sufficient to clear the system by rapidly burning itself clear. Such a fault is often short-lived and does not present as serious a fire risk hazard as a prolonged, much lower energy fault, wherein the energy level is too low to clear the system. The breakdown of a trolley line insulator, in which there was a 15 to 30 ampere fault to ground, would represent such a fault or illegitimate load and a substantial fire risk.

Jan 1, 1975

By V. E. Edlund

As part of its efforts to devise new and improved methods for recovering lithium from unconventional resources , the Bureau of Mines investigated a lime -gypsum- roast , water- leach technique for processing lithiumenriched ( 0.01-0.68 pct Li ) clays . This report presents the results of a study of the technical feasibility of extracting lithium from raw material representative of clay beds associated with the McDermitt Caldera complex in Nevada and Oregon . prepared from water used Pellets suitable for bench-scale roasting studies were mixtures of minus 200 -mesh clay , limestone , and gypsum , with as the pelletizing agent . Roasting pelletized charges at 900 ° to 1,000° C temperatures for 1- to 4-h periods produced calcines that leached readily , yielding water - soluble lithium sulfate ( Li₂SO4 ) . A 5-3-3 ( weight ratio ) mix of clay , limestone , and gypsum produced calcines with the best leaching characteristics . More than 91 pct of the contained lithium was extracted from pelletized mix batches roasted in covered refractory boats . Lithium recovery decreased to about 87 pct when the mix was roasted under dynamic conditions in a gas - fired rotary furnace . A reaction mechanism was postulated which indicated that dilution and loss of SO2 and oxygen in the combustion exhaust adversely affected the leachability of the dynamically roasted calcine .

Jan 1, 1983