Search Documents

By Ronald M. Lewis

Quadratic functions, Q(hkl), are given to six places in increments of 0.01° for 2? from 00 to 90° for FeKa and from 25° to 180° for FeKa1. The wavelengths used for Fe in the computation are those agreed upon by the Editorial Commission of the International Tables for X-ray Crystallography (1950): FeKa1 1.93597 A.; Feka2 1.93991 A. INTRODUCTION At the Federal Bureau of Mines laboratory, Norris, Tenn. X-ray diffraction crystallography using tubes with iron targets revealed a need for a handy reference for the quadratic functions of iron radiation. The tables presented here were prepared to satisfy that need. The quadratic form Q(hkl) may be expressed in terms of the Bragg diffraction angle 2? and of the wavelength ? as

Jan 1, 1961

By L. Cheng

This report presents the results of a Bureau of Mines laboratory investigation of the effect of water sprays in reducing respirable dust that escaped the face area of a full-scale wooden model of a mine en-try containing a wooden model of a ripper-type continuous mining machine and exhaust brattice. Areas examined were (a) the general effectiveness of a low-pressure water spray system mounted on top of the mining machine boom, a high-pressure spray system mounted under the boom, and the combined top-and bottom-spray systems, and (b) the effect of these three spray systems on the capture of coal dust particles of different sizes. Dust was injected into a sump cavity at the face. Airborne respirable dust concentration was mea-sured behind the brattice with a personal sampler and cyclone, and particle size distribution was mea-sured with a cascade impactor. When used alone, the top-spray system captured about 55 pct of the respirable dust in the face area and the bottom-spray system captured 60 pct; the capture efficiency of each system is decreased when they are used simultaneously. From a mass-concentration viewpoint, each spray system preferentially captures larger dust particles.

Jan 1, 1988

By Paul C. Hyndman

Three properties in the Tuolumne River RARE II area, the Eagle Bluff Mine (lode) and the Indian Creek Bar and Bossy Bar Prospects (placer), have identified subeconomic gold resources (table 1). Nineteen other properties have potential for gold resources. Adjacent to the study area, five properties have identified mineral resources, and nine others have potential for resources. Properties having high-grade zones (shoots), but licking enough tonnage to be classified as resources, are listed in table 2. Gold, in lode and placer deposits, is the principal mineral commodity in the Toluene River study area. Ten properties within the RARE II boundary have gold-rich zones or shoots; they range in size from 12 to 2,500 tons and in average grade from 0.09 to 0.97 oz gold per ton.

Jan 1, 1983

By James W. Miller

An investigation was begun by the Bureau of Mines in 1948 to determine the preparation characteristics of American coals. Results of the investigation were planned to be reported on a county basis and from the data developed, to determine: (a) Which coals either as mined or after beneficiation by conventional preparation are chemically suitable under present standards for producing metallurgical coke; (b) Which coals require special and more intensive treatment in preparation than is now practiced; and (c) Which coals cannot be considered potential sources of metallurgical coke, regardless of preparation. This report is one in this county series that describes the preparation characteristics of the coals of Perry County, Ky.

Jan 1, 1956

By Lloyd A. Morley, Robert Stefanko

This report was prepared by The Pennsylvania State University, College of Earth and Mineral Sciences, ' Department of Mineral Engineering, University Park, Pennsylvania, under USBM Grant No. GO-133077. The grant was initiated under the Coal Mine Health and Safety Research Program. It was administered under the technical direction of the Pittsburgh Mining and Safety Research Center with Mr. G. J. Conroy acting as the technical project officer. Mr. J. A. Herickes was the grant administrator for the Bureau of Mines. This report is a summary of the work recently completed as part of this grant during the period 19 June, 1973 to 17 June, 1975. This report was submitted by the authors on 18 July, 1974. This technical report has been reviewed and approved.

Jan 1, 1974

By Frank C. Townsend

Centrifugal model embankments with varying geometries and materials were constructed of- coal waste material, accelerated From 100 to 120 times earth's gravity, and subjected to various throughflow rates until failure occurred. Complementary laboratory tests were performed on the waste materials to obtain strength and permeability parameters for analytical calculations to predict observed centrifugal model behavior. Failures in the form of deep.-seated failure, or erosion and sediment transport or a combination of both, occurred in model embankments with 1V:1-1/2H and 1V:2H slopes when the phreatic surface due to seepage exited on the downstream slope: Positive seepage control, i.e., a toe drain successfully prevented sloughing and failures. Slope stability analyses agreed well, albeit conservatively, with observed model performance. Factors of safety ranged from 0.7 to 1.02 at the instant of failure for models with retrogressing slips as compared with 1.05 to 1.7 for stable embankments, These models verified existing criteria of a minimum safety factor of 1 3 and the necessity of positive seepage control.

Jan 1, 1980

By Allan E. Martin

As part of a comprehensive investigation of tie mechanism of desufurization of iron and steel by slags, the Blast Furnace Studies Section, Metallurgical Division, Bureau of Mines, in cooperation with the Institute of Technology-, University of Minnesota, has made a study of the forms in which sulfur occurs in blast-furnace slag. This report presents data on the three sulfides most important in iron smelting, namely, ferrous sulfide, manganous sulfide, and calcium sulfide. The tendency of these sulfides to form colloids in the molten slag was determined by an examination of quenched samples with an ultramicroscope. Vogt5/ conducted experiments on sulfide silicate melts and examined synthetic blast-furnace slags in a partly crystallized condition. His conclusions were that FeS, CaS, and bins, or isomorphous compounds, such as (FexCay)S and (MnxCy)S, were precipitated Prom the melt, depending on the composition of the slag. In all specimens sulfides were visible and were spherical.

Jan 1, 1941

By B. W. Gandrud, G. T. Bator

The recent introduction of small coal jigs in Alabama to meet the needs of truck - mine operators for cheap and economical cleaning equipment marks another step in Alabama's pioneering record in the mechanical cleaning and preparation of coal . During the past 4 or 5 years a number of these small jigs , with capacity of 5 to 10 tons per hour , have been installed at Alabama truck mines and at a few truck mines in Illinois , Tennessee , and Pennsylvania . Most of the installations have been at mines that specialize in the production of domestic , stoker coal . This report describes three models of small jigs and includes performance data obtained recently on one of the models by the Bureau of Mines, United States Department of the Interior , in cooperation with the University of Alabama, Tuscaloosa , Ala . , for the purpose of comparing it with fullsize jigs on a performance basis . With literally hundreds of truck mines now in operation throughout the country , it has been assumed in preparing this report that there is widespread interest in the availability of small - scale inexpensive preparation equipment for use at such mines in the production of steam and domestic coal and in some instances coal for manufacture of coke . Practically none of the coal from Alabama truck mines is scld to coke - oven plants ; but in some sections of the country truck mines supply a considerable amount of coking coal, and the use of small, inexpensive washers at some of them might be very advantageous during the present war emergency from the standpoint of increasing pig - iron production through improvements in coke quality .

Aug 1, 1943

[Thin roport. C"WAW; I Ac rvq"I LN 01 a tvchniv&ll nnd oco I in j ;- I iv It i on c)l roncc p Ln,I I Lc!iin I OV Lhe undprnro"nd vNing, ruh h! i zn(kn, And 1" viiii rutoriin- of Opp &L :;halo drponi1q. Study L-I 10 1 1:; ..vi c I i rst d it cc tvd L ""Ards "vA I "it Wit "I the ippLWAhle q(t)¬logy, .in:;"(OLud ;hintvirak, r"ck muchnnics, ii; Olu rolturving, acum; mining, votitiInthn, iiiHtl I' it inn, vaFrry, :ind nn': iru"muniAl iNpiet InvI ors ConroptuAl mv:Lvmn wore nv"tWqjW rind Wen ovALUOILed agalnSt I lIt"n I it' 1 ttCS I runt ho I I I ;I I cc!ii i (.:I I A I I( I ocon "mi t?. vivwpn Lnt . Thu I CS" ICS 01 Lhunv vv&"Mions wpru thun ;lira ly-Ptl ind, KNqwd upon this analls is , hit foll"wkg two syntvmn writ' 5VIecLind lor furLhpu study in Phaso Ll: 4 -Ili I I : kcoiii nid Pi I lair -Art ica L DrL I I and Blasr SyKyw 1V: THOW Hori"g-Horiz"nuaL Ring Drill anti BI-ast Thiq rvpnrL is nahmillrd in fulAllarrit or We Phzni, J parLion ul (Arnt KICL Oinhou SON LO/ 1 by Nni x & Kc Won , I nc. Co thp D. nvor Rostnrch Cvntpr, Uni-LPd AL"tpn DWPAUxiont of the InLerilor, QUrCJlH of Mines. Ark wns tonpirrind as of March, 1979.]

Jan 1, 1975

By N. N. Moebs

The atmosphere in part of an air-sealed coal mine was monitored continuously through a drill hole for oxygen content to determine the effectiveness of sealing a mine against the entrance of air and the major force that caused the phenomenon of mine breathing through the overburden. The differential pressure across the seal and the barometric pressure on the outside also were recorded. A general correlation, obtained between the oxygen level, differential pressure, and barometric pressure, indicates that changes in air pressure are the cause for periodic replenishment of the oxygen in the mine. Mine effluent quality was determined by conditions in many sections of the mine and could not be related to the oxygen level at the drill hole.

Jan 1, 1972

By Larman J. Heath

Wellbore enlargement was tested using hydrazine hydrate in a gas-storage well in Ohio to increase the well productivity. The wellbore was to be enlarged by chemical disaggregation of the sandstone adjacent to the wellbore. Productivity immediately declined 49.1 percent and gradually declined to zero in 7 months. A down-hole camera survey showed a white-to-gray precipitate covering the entire wellbore surface. The precipitate was chemically analyzed and identified as mostly carbazic acid, a hydrazine derivative of carbonic acid. Formation of this precipitate was not anticipated; this viscous sub-stance caused the gradual loss in productivity of the well. The wellbore was not enlarged. Laboratory tests were run to determine what clay stabilization measures could be taken in sandstone cores to prevent clay swelling and particle migration caused by hydrazine hydrate. Normal clay stabilization methods did not prevent the virtually complete loss in permeability to hydrazine hydrate. Other laboratory tests using natural gas diluted with small amounts of carbon dioxide confirmed the ease with which carbazic acid could be formed in a hydrazine hydrate-saturated environment within and adjacent to the wellbore.

Jan 1, 1970

By R. Karl Zipf, David Newman

The objective of this is paper is to review the current state of knowledge and practice in highwall mining (HWM). HWM has become a widely-applied method in surface mining, commonly used alone or in conjunction with contour or slot mining. It provides 800-feet to 1,200-feet of additional recovery when the economic stripping ratio is reached in contour mining or in slot mining when surface access to a reserve is limited. A significant attribute of the highwall miner is its versatility. HWM has been used successfully to mine abandoned pre-reclamation law highwalls, points or ridges uneconomic to mine by underground or other surface methods, outcrop barriers left adjacent to underground mines, separate benches of the same seam where the parting thickness or quality differences between benches render complete extraction uneconomic, previously augered areas containing otherwise inaccessible additional reserves and close or widely spaced multiple seams. The theory and design methods to assess roof, pillar, and floor stability are presented followed by three case histories. Simple design charts for sizing HWM web and barrier pillars are also presented. A recommended web pillar width may be obtained from the design charts given the overburden depth, the HWM cut width, and the mining height. Given the depth and panel width for a set of HWM cuts, another set of charts gives a suggested barrier pillar width. The case histories, from Northern and Southern Appalachia are used to illustrate the application of rock mechanics to quantify the stability of the highwall, roof, web pillars, and floor. The case histories involve 1) mining through a previously augered highwall, 2) mining under back-stacked spoil and 3) selective mining of closely spaced benches of the same seam. Because each site is unique, the appropriate pre-mining geotechnical analyses range from the calculation of roof, web pillar, and floor bearing capacity stability factors to detailed numerical modeling of the auger and underground mine workings. When operating in the vicinity of existing underground mine or auger workings, the determination of ground deformation and strains resulting from highwall mining is a necessary facet of a ground control investigation.

By T. E. Gray

This report describes the preparation characteristics of the more significant coalbeds in Monongalia County, W. Va. It is one of a Bureau of Mines series planned to determine coals suitable for producing metallurgical coke, either as mined or after beneficiation. Over 9.5 million tons of coal was produced in Monongalia County in 1957, of which more than 7 million tons was cleaned mechanically in 8 cleaning plants. On January I, 1954 the Bureau of Mines estimated that 1,576 million tons of recoverable coal remained in the county in beds 28 inches or more thick.

Jan 1, 1960

By J. L. Holman

The Bureau of Mines is conducting research to improve technology for the recovery of strategic and critical metals, such as cobalt, nickel, and chromium, that are lost in bulk and particulate superalloy-type scrap because it has not been possible to process mixed contaminated scrap efficiently. The research approach involves melting and casting mixed superalloy scrap into soluble anodes for electrodeposition of Ni-Co alloys by controlled-potential electrolysis. The initial experimental results described in this report are from electrolytic tests us-ing alloy anodes cast from elemental nickel, cobalt, and chromium, the main constituent metals of superalloys. Baseline data and operating parameters are necessary for Ni-Co and Ni-Co-Cr alloys before detailed experiments can be conducted on the more complex superalloy scrap. This basic research assessed the effects of cathode potential, S04:CI electrolyte ratio, electrolyte pH, stirring rate, deposition time, cathode current density, and chromium concentration on cathode current efficiency, alloy deposit composition, and deposition potential at a cell temperature of 55° C.

Jan 1, 1985

By T. H. Jeffers

The Bureau of Mines conducted a laboratory investigation of copper electrowinning from electrolytes produced by solvent extraction. The purpose of the research was to gain a better understanding of the fundamental relationship between copper electrowinning conditions, anode corrosion, and cathode purity. Processing variables were evaluated in a cyclic semicontinuous system in which the depleted electrolyte was used to strip copper from loaded organic extractant. For the production of high quality copper cathodes, the electrolyte was dosed with cobalt and stripped of organic solvent extraction reagent. An optimum cobalt addition of 60 ppm, and removal of the entrained extractant with activated carbon provided the best conditions for electrowinning copper containing the least amount of lead and controlling anode corrosion. As little as 13 ppm of the entrained organic extractant, LIX 64-N, significantly accelerated anode corro-sion. However, the addition of 1,000 ppm of organic diluent kerosine did not affect anode corrosion. After cobalt dosing and removing the entrained extractant, cathodes containing less than 2 ppm lead were consistently electrowon at widely varied current densities, electrolyte copper and acid concentrations, and temperatures. Dosing of the electrolyte with selected impurities including magnesium, aluminum, manganese, and iron did not affect the cathode purity. However, 0.05 giL of chloride ions markedly increased anode corrosion and the sub-sequent transfer of lead to the cathode copper.

Jan 1, 1985

By Charles Prasky

The objective of this investigation by the Bureau of Mines was to determine the response to sulfatization of diverse low-grade manganiferous materials in the iron formation of the Cuyuna district. In line with this objective a bench-scale sulfatizing procedure was developed that was less expensive and more rapid than pilot-plant methods. Samples from the central and south- western parts of the North range were tested. Results of evaluating a total of 46 pelletized samples, originating in areas with an estimated potential resource of 94 million long tons with a manganese content of 7 percent, indicates that approximately 87 percent of the manganese may be recovered as a synthetic manganese ore. This is equivalent to more than 12 million long tons of a metallurgical-grade ore, containing 46 percent manganese. It is anticipated that a premium product, containing over 50 percent manganese, may be obtained by sulfatizing procedures. This report is part of a continuing investigation5 6 of Cuyuna iron range manganese deposits in Crow Wing County, Minn. Lewis and coworkers describe the manganiferous iron formation in the bedrock of the Cuyuna district and include a description of a high-temperature differential sulfatizing process for recovering a ferrograde manganese product. The low-grade manganiferous

Jan 1, 1961

By C. J. Walker, Ray V. Huff

The feasibility of inert - gas cushions in underground gas storages was studied by the Bureau of Mines in accordance with a continuing program of cooperative research between the natural gas industry -- through the American Gas Association . As mixing of the inert - gas cushion with the stored natural gas is undesirable , the various mechanisms tending to bring about such mixing were the subjects of both theoretical and experimental studies . These studies indicated the practicability of such cushions is dependent upon both reservoir and operating conditions . Equations and tables of illustrative data relating the various reservoir and operating conditions to the expected time required for undesired mixing to occur in ideal reservoirs are presented . This information permits estimating the relationship of such factors in actual storage operations .

Jan 1, 1964

By Lowell B. Moon

The Stange and Byrnes Heirs manganese mines, adjoining properties in Bland and Giles Counties, Va., have produced at least 20,000 long tons of concentrates containing 8,000 long tons of manganese. They were selected as the site for a strategic-mineral development project because of the existence of geologic possibilities for extensions of the known ore body. In plan, the long dimension of the ore body parallels the axis of a major anticline. Localization apparently is due to longitudinal and transverse fracturing incident to two-way folding. That the manganese oxides were deposited by downward-moving solutions is suggested by the fact that mineable concentrations are confined to a coarse, porous sandstone under-lain by impervious silt and clay. Bureau of Mines project work began on January 15, 1941, and was completed on April 23. The work sampling the faces of the pit, bulldozer trenching, and churn drilling. Pit sampling consisted of 132 channel samples usually 5 feet long and taken at 20-foot intervals. Seventeen trenches aggregating some 4,500 feet in length were dug by the bulldozer. Trenches averaged 12.6 feet in width and 5 feet in depth. A total of 1,978 feet of churn drilling was done in 33 holes. In preparation for churn drilling it was necessary to construct roads to 21 of the 33 sites. A total of 2,867 linear feet of road averaging 13 feet in width was built.

Jan 1, 1950

By Erle C. Donaldson

A study of subsurface waste disposal in the United States shows that in eight States a wide variety of industrial wastes are being injected into formations ranging in age from Precambrian to Recent. More than 30 wells ranging in depth from 300 to 12,000 feet are used for waste disposal into subsurface formations which include unconsolidated sand, sandstone, vugular limestone, and fractured gneiss.

Jan 1, 1964

By E. K. Stanek

The field tests involved ten coal mines in which transients were initiated on the dc system from which the parameters of the dc mine electrical power system could be determined. The data processing involved the use of a Fourier Analyzer to filter noise and fit an exponential curve to the field waveforms. From this data analysis it was possible to find the dc system resistance, inductance and time constant. The survey of nationally recognized laboratories was conducted to establish that the recommended test criteria were practical. The development of test criteria for dc fuses used in mines was based on the measurement of parameters in the field, the survey of testing laboratories, literature searches, laboratory test, etc. A computer program was written to analytically predict the parameters measured in the field. This approach has limitations but reasonable agreement with field results was obtained. A brief laboratory testing program was carried out to verify the practicality of the recommended criteria and establish the accuracy of the conclusions concerning dc fuse performance.

Jan 1, 1984