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By D. C. Dahlin

The Bureau of Mines conducted laboratory batch beneficiation tests on samples from four potential platinum resources in southeastern Alaska to concentrate platinum and other precious metals. Thin Investigation was done as part of the mission of the Bureau to insure an adequate supply of minerals to meet the Nation's needs. Petrographic studies and beneficiation methods including gravity concentration, froth flotation, and magnetic separation were used to determine mineral association and to attempt to concentrate the platinum values with a primary mineral value such as chromite, copper sulfide, or magnetite. A high-graded sample from the Salt Chuck copper sulfide deposit yielded the platinum-group metal concentrate; the maximum grade attained was 0.04 oz Pt and 1.5 oz Pd per ton of high-grade copper sulfide concentrate. The other samples yielded low-grade primary mineral concentrates with low platinum-group values, and/or the platinum-group metals did not concentrate with the primary mineral value.

Jan 1, 1981

By K. J. Miller

A laboratory electrophoresis column was designed to separate pyrite from fine coal by utilizing an observed difference in the electrophoretic mobilities of the two materials in water. The apparatus worked well when tested with synthetic mixtures of coal and pyrite, but some modifications in design and procedure were necessary to provide a sharper separation. After these changes were made, the column was tested with a high-pyritic-sulfur raw coal sample. The column successfully fractionated the sample, removing not only the pyritic refuse, but a siliceous refuse as well. The invest ion demonstrated on a laboratory scale that pyrite and other impurities can be separated from fine coal by electrophoresis.

Jan 1, 1970

By V. R. Spironello

The Bureau of Mines is conducting studies of the slags related to ferrous technology to evaluate acceptable substitutes for the auxiliary flux, mineral fluorspar, in foundry operations. This work is directed toward the Bureau's goal of minimizing the Nation's dependence on scarce and critical minerals Comparative basic practice cupola (18-inch-ID) trials were made to evaluate a waste material called "used potlining," which contains significant levels of fluorine, sodium, and aluminum in various compounds. Used potlining is recovered from alumina reduction cells after its useful life, and was supplied by the Aluminum Co. of America (Alcoa) to the Bureau for evaluation. The material in the lump and pelletized form (with limestone) provided extremely fluid slags based on visual observation during cupola operation. No adverse effects were found on cupola performance, metal and slag chemistry, the environment, or mechanical properties of the castings produced. Fluorine recovery in the slag was equal to, or higher than, that of fluorspar; fluorine losses to the scrubber water and solids were lower. The acidity of the scrubber Hater was somewhat neutralized. No difference was observed in furnace-refractory attack, as determined by the level of magnesia in the slag and visual inspection. The recovery of sodium in the slag, presumably as the oxide, significantly increased slag fluidity, suggesting that less than equivalent fluorine may be required. There was no contamination of the gray iron by the aluminum from the used potlining. Used potlining was completely satisfactory as a substitute for fluorspar in cupola ironmelting.

Jan 1, 1981

By L. M. Adams

Experiments in reclaiming acidic surface-mined coal lands with raw fly ash from bituminous-coal-fired powerplants were conducted by the Bureau of Mines at two sites in northern West Virginia. Plots at both sites were treated with varying tonnages of fly ash from three area powerplants and were planted with a variety of grasses, legumes, trees, and shrubs. Eight grasses and seven legumes were investigated. Greatest promise for growth under harsh soil conditions was shown by Kentucky 31 fescue, rye and red top grasses, and birdsfoot trefoil, a legume. Survival of trees and shrubs was negligible. Addition of fly ash to the spoil increased the pH to a range tolerable to some types of plant growth, improved the texture of the soil, and increased the available water of the resulting mixture.

Jan 1, 1971

By E. Morrice

This report of the Federal Bureau of Mines presents a laboratory procedure, with the requisite equipment, for electrowinning ingot (liquid) cerium metal from a fused-fluoride bath, the metal purity being about 99.9 percent. Physicochemical studies, including bath properties and electrochemistry, are included, with a speculative model of the mechanisms involved. An historical review of the methods used for electrowinning misch metals and yttrim-group metals, as well as individual rare-earth metals, is presented. The electrolytic preparation of metal from fused salt and nonaqueous media is summarized, along with the unsuccessful attempts at depositing the metals from aqueous solutions.

Jan 1, 1961

By William J. Campbell

This analytical method development and evaluation was undertaken by the Bureau of Mines to provide accurate determinations of eight minor elements in low-alloy steels prepared from ferrous scrap. Fluorescent X-ray spectrography was the principal method investigated. Confirming analyses were made by conventional instrumental and chemical methods. All X-ray data were processed by a timesharing computer. No corrections were found necessary for inter-element effects or overlapping spectral lines. Concentrations were calculated from the least-square fit of a linear calibration equation derived from measurements on three sets of standard steels. These studies show that X-ray spectrographic analysis of lathe-finished surfaces provides accurate determinations of aluminum, copper, chromium, manganese, nickel, phosphorus, silicon, and tin.

Jan 1, 1973

By Jerry W. Ramsey

The Bureau of Mines examined a low-, a medium-, and a high-volatile Pennsylvania anthracite by densimetric methods using four mesh si.s of each anthracite. Using high-pressure mercury the macropore volumes and distributions of these pore volumes determined, densities in mercury were calculated, and specific pore vo1.r. ware obtained from these mercury densities in conjunction with helium densities. The helium densities were also used with the ultimate analyses of these anthracites in calculating structural parameters by statistical densimetric methods. The effect of 106 or 108 rads of gamma irradiation in the presence of air and in vacuum upon the properties studied with two mesh sizes of each anthracite. Results of the statistical densimetric method seem to show some breakdown of condensed ring structural units at the lower irradiation level, with subsequent polymerization at the longer period of gamma irradiation. The structural parameters obtained also indicated that in going from high- to low-volatile anthracite, either the number of condensed rings per structural unit increased, or the degree of polymerization increased.

Jan 1, 1965

By P. L. Swanson

Over a recent 20-month observation period, the U.S. Bureau of Mines obtained seismogram records from a single vertical-component, short-period seismometer installed at the surface of a metal mine in northern Idaho. The seismic events were analyzed for local (Richter) magnitude (M), time of occurrence, location, and relation to rock bursting and production blasting. Approximately 150 seismic events with -0.5 = M = 2.9 were located within the mine, yielding a b value (slope of the logarithm of the number of events with magnitude greater than M versus M) of 0.5. Event locations were constrained using a dense underground array of high-frequency accelerometers. Twenty of the surface-recorded events, with 0.5 = M = 2.9, were associated with rock bursts that produced damage requiring at least 1/2 day of cleanup and/or repair. Other possibly hazardous rock bursts, with magnitudes as small as -1.1, were numerous but were not associated with significant structural damage. Approximately 60 pct of the seismic events with M > -0.5 and 75 pct of damaging rock bursts occurred within 45 min of blasting. Estimates of characteristic rupture dimensions for rock bursts with -1.1 = M = 2.9, based on a conventional dislocation shear-slip model of failure, range from 3 to 300 m.

Jan 1, 2010

By H. C. Ko

Calorimetric determinations of low-temperature heat capacities and standard enthalpy of formation were made by the Federal Bureau of Mines for basic aluminum sulfite, A1203?2.0S02?5.3H20. The standard values of entropy (S°), enthalpy of formation (?Hf°), and calculated Gibbs energy of formation (?Gf°) at 298.15 K are 85.2±0.1 cal/deg-mole, -943.1±1.2 kcal/mole, and -820.7±1.2 kcal/mole, respectively.

Jan 1, 1976

This report discusses the nonfuel critical minerals position of the United States-both current and future (to the year 2000). We have assumed that there will be no major global disturbances-military, political, or economic-during the rest of this century. However, international relationships, strategies, and conditions that affect the supply of minerals are very tenuous, normal trading patterns can be easily upset, and national and ideological objectives can and do interfere with "normal" free market conditions. For example, the Department of Defense has reported that the Soviet Union is engaged in a strategy designed to reduce the availability of strategic minerals, through either physical disruption, market manipulation, or domination of producing or neighboring states. Although such a strategy poses serious concerns for the United States and the free world, the impacts of disruptions are not covered in this publication. Historical Perspective The modern industrial economy of the United States is founded on the production and use of minerals.* Two hundred years ago our forebears began taming a raw continent, developing a base for agriculture and a rudimentary minerals producing system. In the 19th century, with the aid of imported labor and capital, the development of America's vast natural resources was undertaken, and the transition from an agricultural to industrial society was underway. By the century's close, the United States had emerged as a great industrial power, partly through the development of such mineral resources as iron in Minnesota and coal in Pennsylvania.

Jan 1, 1983

By E. J. Gleim

In keeping with past custom, it is the purpose of this publication to bring up to date previously published lists of equipment that meets safety standards of the bureau of Mines so that the mining industry may be informed as to the development and availability of equipment that can be used safely. The present lists supplement those in Bulletin 543. Permissible Mine Equipment Approved to January 1, 1953; Information Circular 7722, Permissible Equipment Approved During the Calendar Years 1953-54; and Information Circular [40], Permissible Equipment Approved During the Calendar Years 1955-56. These [ew] lists also contain equipment meeting those standards revised since the last listing. A revision of Schedule 16C (now Schedule 16D4/) was officially approved on September 28. 1958. Schedule 29 was another standard revised in 1958. The revision was officially approved on September 8. 1958, and is known as Schedule 29A5/ .

Jan 1, 1960

By Levent Ozdemir

The results of a laboratory research program aimed at the development of a water jet assisted drag bit cutting system for coal mine applications are presented. Two types of drag bits, a conical and a plow bit, were tested in a hard sandstone rock with jet pressures of up to 20,000 psi. Jet locations investigated were in-front and behind the bit. For each jet mounting location, three jet impingement distances with respect to bit tip were tested. The closest jet impingement location to bit tip was found most effective, providing the greatest force reductions on the bit. Overall, significant bit force reductions up to 50 percent were obtained with jet assist. Also observed was a drastic reduction in airborne dust when jets were employed.

Jan 1, 1986

By Otto Ruhl

"INTRODUCTION With the conclusion of the war and the ensuing readjustment of industry to peacetime conditions, the Bureau of Mines recognized that definite and complete figures on the reserves of zinc and lead ores in the Tri-State District would be needed for an evaluation of the problem of reconversion. In October 1945 its engineers began examination of all the mines and pros¬pects in the Tri-State area and assembling of the basic data for a complete detailed estimate of the reserves of the field. Six to twelve months will be required to complete the report with the personnel available; therefore, it has been deemed advisable to provide as much data as possible for imme¬diate use. Accordingly, a confidential report prepared in January 1944 for the use of and in cooperation with the War Production Board has been brought up to date to form the basis of this preliminary estimate of reserves.The 1944 report has been revised by first subtracting from the reserves then set up for each mill group the amounts mined and milled by those properties for 1944 and 10 months of 1945, with November and December estimated. These production statistics were taken from the monthly reports of the Metal Economics Division of the Bureau of Mines. The remaining reserves were then adjusted by additions of tonnages of new reserves disclosed by developments during the years 1944 and 1945. Such additions were based upon the data furnished by various operators, upon estimates supplied by the Federal Geological Survey District Office at Miami, Okla., and upon estimates of the engineers of the Bureau of Mines Joplin field office.It is apparent from the work so far accomplished in the detailed exami¬nations now under way that the final estimate of reserves will probably be somewhat greater and will differ to a certain degree from these preliminary totals, not only as to the tonnages of ere but also as to grades and distribution by areas. This is due to the fact that all the factors of development, exploration, and geology are being considered in the present examination and report for each individual mine and prospect, whereas the previous reports covered only the immediate development factors surrounding each mill group then in active operation or projected for operation at some early date in accordance with the possible needs for war production."

Aug 1, 1946

By Ernest L. Corp

Seepage forces computed by a finite-element flow program are combined with gravity forces in an elastic-plastic stress-analysis program to determine the stability of mine-waste slopes. Computer output provides a cross-sectional plot of the dam or embankment showing the safety factors for each element. The combined finite-element program called SEEP-SLOPE was used to analyze several trial embankments and the 1972 Buffalo Creek Dam failure Safety factors computed by the finite-element method (FEM) were compared with those computed by Bishop limiting-equilibrium method. For individual slip circles, there was little correlation between the factors of safety computed by the two methods. Both predict failure, but FEM shows a different mode of failure plus development of potential failure zones not indicated by conventional methods. Besides having a better theoretical basis than the Bishop method, FEM requires no assumptions regarding the location or geometry of the failure surface. As a result, the program will show progressive development of a failure zone, and areas can be pinpointed where remedial measures should be taken. In addition, nonhomogeneous cross sections can be analyzed, and zones of potential piping can be defined.

Jan 1, 1975

By F. F. Aplan

"The material known as coal has a highly variable composition. As a consequence, coals show a great variation in their physical and chemical properties as a function of coal rank. The situation is further complicated because the preparation engineer must deal with raw coal, as mined. This is an assemblage of coal, upwards of 30% mineral matter and, typically, several percent pyrite. The kind and amount of the mineral constituents is also highly variable from source to source. A knowledge of coal rank and source location, and the kind and amount of associated impurities, is the first step in evaluating the response of a raw coal to preparation procedures. The raw coal must first be characterized before information from one source can be extrapolated to that of another.INTRODUCTIONCoal is a black or brownish-black combustible solid, derived from a heterogeneous mixture of plant remains and associated mineral matter that have undergone chemical and physical metamorphic changes by biological and geological processes without free access to air. It is composed principally of carbon, hydrogen and oxygen with lesser amounts of nitrogen and sulfur. 'Its exact chemical and physical nature has remained poorly defined, because the term 'coal' refers to a broad range of coalified solids ranging in rank from anthracite to a variety of bituminous coals of differing volatile matter content, sub-bituminous coals, and ending with lignite and brown coals. The variation in chemical and physical properties through these ranks is massive. In summary, Luckie's (1988) assertion is apropos: ""There is no such thing as coal; there are coals"". The coal preparation engineer, and, most especially, those scientists and engineers from other disciplines wishing to work with coal, must constantly keep this admonition in mind because what is true for one coal seam is often not directly applicable to another."

Jan 1, 1989

By T. E. Green, E. F. Spano, W. J. Campbell

A combined ion exchange X- ray spectrographic method was evaluated for the determination of 11 metallic elements in high - purity tungsten : Aluminum , calcium , chromium , cobalt , copper , iron , magnesium , manganese , nickel , titanium , and zinc . Copper , nickel , and manganese in the 5- to 100 - microgram range ( 1 to 20 parts per million based on 5 - gram samples of tungsten ) , calcium in the 10- to 100 - microgram range , and cobalt in the 5- to 20 - microgram range can be determined within an accuracy of ± 10 percent of the amount present . Limits of detection of these elements are 0.05 to 0.14 microgram . The overall method was unsatisfactory for the determination of aluminum , chromium , iron , magnesium , titanium and zinc in tungsten .

Jan 1, 1964

By A. C. Fieldner, S. H. Katz

"Introduction.Recent experiments (Fieldner, A.C., Katz, S.H., Kinney, S.P., and Longfellow, E.S., Poisonous gas from carbon tetrachloride fire extinguishers, Jour. Franklin Institute, October, 1920, pp. 543-565), by the Bureau of Mines have shown that carbon tetrachloride extinguisher liquids when applied to fires produce small quantities of irritating and poisonous gases which may be dangerous in very closely confined spaces where conditions are such that the user can not escape without breathing the fumes. The results of the experiments have been confirmed in an independent investigation by the Underwriters Laboratories (Nuckalls, A.H., Corrosive action and products formed when carbon tetrachloride extinguisher liquids are applied to fires, Nat. Fire Protection Assoc. Quarterly, vol. 14, January, 1921, pp. 221-236) who conducted similar experiments for the purpose of determining the corrosive action of these fumes on metals. Both investigations showed that carbon tetrachloride vapor, hydrochloric acid gas, and phosgene were produced in addition to the ordinary products of combustion, such as smoke, carbon monoxide and carbon dioxide. The Bureau of Mines' tests were made by applying a one-quart extinguisher to a wood fire of excelsior in a gas-tight room of 1000 cubic foot capacity. The glass and metal construction of this chamber limited the experimental fire to very small dimensions. It was, therefore, deemed desirable to make a test on a larger scale in the entry of the Bureau's experimental mine in order to similate more nearly the practical use of carbon tetrachloride and other types of extinguishers in mines.Description of extinguishers.Two series of tests were made under identical conditions on different days. Commercial carbon tetrachloride extinguishers were used in the first series of tests and ""foamite firefoam"" extinguishers in the second series of tests."

Jun 1, 1921

By Eric B. Sansone

The Federal Coal Mine Health and Safety Act of 1969 requires coal mine operators to sample accurately the amount of respirable dust in the mine atmosphere. A technique approved for such sampling employs a 10 mm nylon cyclone followed by a membrane filter (nominal pore size ????= 5 µm) and a pump. The pump is required to provide a flow rate of 2.0 ± 0.1 liters per minute. Calibrations have yielded a range of flow rates (1.4 to 2.8 1pm) at which the cyclone should be operated to remove the non-respirable portion of the dust. The purpose of this project was to evaluate the performance of the 10 mm nylon cyclone at flow rates of 1.8 and 2.0 1pm using a polydisperse coal dust aerosol. The penetration characteristics of the cyclone were to be compared to the United States Atomic Energy Commission's respirable dust standard. The effect of relative humidity on cyclone penetration characteristics was also to be observed.

Jan 1, 1973

By G. R. Hopkins, A. B. Coons

A survey of the petroleum pipe lines by the Bureau of Mines as of May 1, 1923, shows that on that date there was a total of slightly more than 90,000 miles of pipe lines in the United States, having a capacity of approximately 15,750,000 barrels, which is equivalent to one-fourth of the nation's average production for one month. These lines varied in diameter from 2 to 16 inches, the weighted average being 6 inches. The total pipe-line milenge was about equally divided between trunk lines and gathering lines, though the capacity of the former was about four times that of the latter. This was due, of course, to the difference in average diameter, that for the former being 7.4 inches as compared with 3.7 inches for the latter. The common size for trunk lines was 8 inches, and for gathering lines 2 inches. Oklahora, with 19,180 miles of pipe lines, is the leading State in total mileage, with Texas second and Pennsylvania third. From point of trunk lines alone Texas is considerably ahead of any of the other States, a position which it owes to its size and to the growth in the rovement to its Gulf ports. Cali- fornia, though the leading State from point of production, ranks only seventh in pipe-line mileage. This is due to the fortunate location of the Los Angeles Basin fields, some of which are within sight of the refineries to which their oil is delivered or of the port of San Pedro through which their oil is shipped. The last survey of this nature, made in the spring of 1924 by the U. S. Geological Survey, recorded a total mileage of nearly 83,000 with a capacity of approximately 14,450,000 barrels. This indicates an increase of 9 per cent in both mileage and capacity during the two years.

Jan 1, 1927

By J. W. Eckerd

The crushing of chestnut-size (1-5/8 by 13/16 inch) Pennsylvania anthracite in four commercial crushers (impact) jaw) hammer-mill) and gyratory types) was studied by the Bureau of Mines to determine which could produce the largest proportions of buckwheat Nos. 1 and 2 sizes (9/16 by 3/16 inch). Single pass dry and wet crushing techniques and the effect of stage crushing were evaluated. Calculations were made to show the effect of closed-circuit reduction on production rates and yield of the various sizes. The data show that the gyratory crushers produced the greatest percentage of the desired sizes. A ring-type hammer mill produced the greatest tonnage of buckwheat No.1 and rice (14.9 tons per hr.) during dry grinding tests) but the yield of these sizes was only about 55 percent) as compared with 62 to 70 percent for the gyratory crushers. The impact and jaw crushers produced the smallest amount of buckwheat and rice and the largest quantity of oversize material.

Jan 1, 1960