Search Documents

By Richard S. Watt

The Bureau of Mines is often called upon to analyze the demand for various minerals and fuels and to make projections of the future demand. Because minerals and fuels are raw materials and because the demand for raw materials [pends] on the demand for finished goods, these projections are usually [conned] with derived demand rather than final demand. In order to obtain quick [d] reasonably accurate analyses of the demand for mineral commodities, the [reau] developed a method and has used it successfully (31).4 To illustrate the [thod], this report presents a full analysis of the demand for a mineral commodity with enough general theory to permit application of the method to any mineral. Sodium chloride (common table salt) was chosen as the subject of the analysis because the demand for it is less complicated5 and permits a simple application and clear presentation of the method.

Jan 1, 1962

By B. K. Shibler

During a research program to develop improved methods for recovering elemental sulfur and useful sulfur compounds from secondary source materials, the technical literature was searched for pertinent articles on processing methods. This report summarizes results of the literature survey and describes the more important processes that have been used or suggested for recovering sulfur and sulfur compounds from all non-Frasch sources. The bibliography presented represents a survey of the available English language literature on the subject through 1958, with particular attention focused on the period 1950 through 1958. Engineering Index and Industrial Arts Index were the principal guides used in the survey of this period. Chemical Abstracts was used to a limited extent to identify a few key foreign articles and patents. The Sulfur Symposium (4)4 published in November 1950 by Industrial and Engineering Chemistry includes a broadly representative selection of the literature up to 1949. Therefore, this reference was used extensively to locate and list pertinent articles on processing methods reported in the period prior to 1950.

Jan 1, 1962

By R. C. Corey

GERMANIUM is an element that has come into widespread use in the electronics industry in recent, years. So far this increasing demand has been, met by ample supply: however, the future balance is uncertain, and the need has been recognized to discover additional domestic sources of germanium. This investigation was conducted to study the possibility of obtaining a potential supply of germanium from coal or coal ash. It has been known for some time that coal contains germanium; the discovery that By ash from coal-fired boilers often contains appreciably more germanium than the original coal suggested the possibility that coal ash might be an abundant and economical source of this element. In this study the concentration of germanium was determined in numerous samples of coal and ash. A number of miscellaneous waste materials also were examined in the course of the investigation; the results are reported as a matter of general interest. The methods and equipment employed are discussed in detail. Sample-preparation and analytical techniques are described in the appendix. Spectrographic analyses were made on a total of 639 samples, including coal, coal ash, slap ash from lignite and peat, wood ash, and various inorganic materials. Qualitative analyses were run on all samples, and quantitative determinations were made on those samples that contained enough germanium to be measured by this method The lower limit at which germanium can be determined quantitatively by spectrographic analysis is 50 parts per million (p. p. m.), but concentrations of less than 20 p. p. m. can be detected qualitatively.

Jan 1, 1959

By E. S. Shedd

Amenability studies were conducted by the Federal Bureau of Mines on an electrooxidation technique for the extraction of mercury from cinnabar ores, particularly those that are too low in grade to be furnaced or retorted economically. Oxidation was accomplished by electrolysis of the ore while slurried with brine. Mercury was dissolved through the formation of the soluble tetrachloro mercury complex, HgC142-. Mercury extractions ranged from 90 to 98 percent in 4 to 6 hours of processing time when tests were made on eight different types of cinnabar ores containing from 0.7 to 18 pounds mercury per ton ore. Salt concentration was varied from 4 to 10 weight-percent depending on whether Pb02 anodes and iron cathodes were used or whether graphite was used for both electrodes. Power consumption ranged from 17 to 64 kilowatt-hours per ton of ore treated. Ninety-nine percent of the mercury was recovered from pregnant solutions by precipitation on an active metal such as zinc, followed by distillation of the resulting amalgam at 600° C.

Jan 1, 1975

By John C. Nigro

This Bureau of Mines report summarizes the performance characteristics of a 30-day around-the-clock gasification-pelletizing test conducted in October and November of 1980 with North Dakota Indianhead lignite. Gasification was conducted in a commercial-size, 6.5-it-diam, Single-stage, fixed-bed, atmospheric pressure producer with a rated capacity of about 30 million Btu/hr. Iron oxide pellets made from a commercial hematite concentrate were fired with the low-Btu gas in a 2.8-ft-diam by 35-ft-long pilot plant rotary kiln at a rate of 900 lb of pellets per hour. Gasifier operations at fuel feed rates up to 3 tons of lignite per hour and hematite pellet induration with raw 160-Btu/std ft3 lignite gas are described.

Jan 1, 1982

A system to continuously measure the concentration of radon in mine ventilating air has been developed and tested in a uranium mine. In use, the air/radon mixture to be monitored is pumped through filters into a scintillation cell where nuclear decay of the radon produces flashes of light. These are electronically counted, giving a quantitative measure of the radon present. Air is continuously drawn from the mine atmosphere into the radon sensor box. This air sample passes through two filters into the detector cell as shown in the schematic diagram. A portion of the radon in the detector cell will experience nuclear decay, producing polomium 218 and an alpha particle. The alpha particles from the fraction that decays strike a zinc-sulfide coating on the inside wall of the cell and produce flashes of light. These enter a photo-multiplier tube which records each flash as an electrical pulse. An amplifier increases the voltage of each pulse, allowing electronic screening to remove noise and other undesirable pulses. The remaining pulses are counted by a conventional data acquisition system.

Jan 1, 1978

By Hugh Haddow

This paper describing the methods of recovery and treatment of a sand and gravel deposit and the preparation of these materials for a number of special markets is one of a series being prepared by the U. S. Bureau of Mines. It is of particular interest to those sand and gravel operators who have a surplus of fine sand which must be sent to waste, both from the point of view of, equipment and the variety. of markets supplied, and in that it describes one of the few sand and gravel plants which have resorted to hydraulic classification for sizing fine sand. ACKNOWLEDGMENTS The author wishes to acknowledge the assistance of J. R. Thoenen, mining engineer of the Bureau of Mines, in the preparation of this paper.

Jan 1, 1931

By J. J. Demeter

Experiments were conducted in 2- and 4-inch-diameter standpipes to evaluate the effectiveness of standpipes as pressure seals. During the experiments, these standpipes conveyed Alan-Wood magnetite (60 to 230 U.S. standard sieve mesh) by gravity flow from one vessel to another of relatively higher pressure. The information obtained has been helpful in a Federal Bureau of Mines investigation of how to make either synthesis gas or hydrogen by a modified steam-iron process employing a continuous recycling stream of granular iron-iron oxide at temperatures of 600° to 900° C. In this process the mixture of granular material flows by gravity from a reduction vessel at low pressures to an oxidation vessel at higher pressures. Data from the 2- and 4-inch-diameter standpipes indicate that it would be practical to use a standpipe as a pressure seal between the reductor and oxidizer. Investigators found that, by gravity flow, the standpipe could convey the Alan-Wood magnetite against pressure gradients up to 1.07 pounds per square inch per foot of column height.

Jan 1, 1961

By Reynold Q. Shotts

A study was made of the coal resources of an area in Jackson County, Ala., forming a part of the Flat Rock, Henegar, and Stevenson quadrangles. The area studied is a portion of the Plateau coalfield on Sand Mountain and is near the Tennessee Valley Authority's Widows Creek steamplant. Since no detailed geological study of this area had been published, some reconnaissance work was done. The coalbeds and adjacent strata such as sandstones, conglomeratic sandstones, and conglomerates were studied. Available drill logs, together with the areal geology, provided sufficient information to permit correlation of the coalbeds and an estimation of coal reserves. For all categories of reserves, computed on a regional basis, a total of 72,920,000 tons of coal more than 14 inches thick is estimated for the areas studied in Stevenson, Flat Rock, and Henegar quadrangles. Of this tonnage, 40,001,000 tons is estimated to have less than 60 feet of overburden. The total measured coal reserves for the above three quadrangles are 16,359,000 tons, with 12,411,000 tons under less than 60 feet of cover.

Jan 1, 1966

[lllc purpabr at thla report Vd, Lu JeLermlnr the health ar1J sdfet?; Nene11Le a octatc?J ultll Lne oar L.t support Ydlll ..up.I,ated lu dltetllative cupPurt svsLem, larrellLty hcle.g uaeJ af the Len,::rat 1, UI.Jlng 11-al tl. .1 a d 1 c L V h S LIdl'. L dal. I -ten- lu L he tt I .. L'., etuJ I e. 11'? L_1,1'1,11 .Jtd.. it, ..urn,at'l core ,LuJICCill JhLdll, an.: ...,La -IL .utia_tel .an LI?r oar of -l: l,.!rl .a..a. Ma terI.I auJ ...11,mc[Ii -ldla,tutcle 11. LI.ac .uwIttIca Welt a, a.. V.alte,, L.. .:Ltail, ..,,L., uI. LuClu,alug) Lelll anci ur devel?puJ I.,r Cul r1 , all. ...~.,rLrI Vt,ILt 1.'ere ~e,1C L? .Lher Gentiaii m111cc t, UL.-rye a Variety o. a rL vyl I pp.1Ca:t..n:. 'a.la IrL ..,_wLeiti, Iapl,.III ,tall ~,..:. IL all, maLertdl c1,arait-erlstIcs, JIRICn,IUIIe. and laden ul1.1 ILc rrgatrelaeuls. ,1 r.? p.'rt .a pro-1Jd, labor rep altrlarnts Jdta and illtlitI ieS tie l,ealtll d?J ,atetV ISSUC ,u-1aled Wit su furl Wall a an, CJl,wttuctSOn, I'aLentiaI appll.at1ou:. Ior support Walt, ,a,. , a, sdV.u,L111 .., u.1 retreating lungval1, single -t r-, roar al,- pi r. [,-+ln, anJ SuhIU..,Ina, Sill] b1OpplllgL ale 1:111neated aid al? e.aIWRac AS Sddemcni LV pre,C'IIL..: .,f LI. Clabllhty r+t rlul,I.,y111I? ulg4,rt .I Le.l,lwlug,. Lr i,,,rCASC Lllc rtCVLLrS rat, u., retrc.+tlnp .unui.,11? ur L., elply, A d v Ctnp IuI-,wall in uer;-!y iy1ng seam, . 11111.a1L .a1,.'iI1.-I,.. nr S.IU1tIVlil a1 milItlI; Lust, La LIldnt;2S L.~ gey support Vait Id tdmcLera la dlaa presents,.]

Jan 1, 1980

By Aarne Visnapuu

Dissociation and vaporization of gold chlorides and bromides were investigated by a static pressure method and by Knudsen cell mass spectrometer. Two distinct chlorine and three distinct bromine pressure-temperature relation-ships were observed for the respective salts. The chlorine pressures are attributed to the dissociation of Au2Cl6 and Au2C12, and the bromine pressures to the dissociation of Au2Br6, Au2Br4, and AU2Br2, These pressure-temperature relationships were used to calculate dissociation pressure equations, enthalpies, and entropies of dissociation for each salt. Mass analysis of the vapors over AU2Cls between 83° and 152° C confirmed the existence of gaseous AU2C16. Ionization potential of this molecule is 11.0±0.1 ev and enthalpy of vaporization is 28.l±2.0 kcal/mole. Mass analysis of the vapors over the gold bromides detected only Bra in the temperature range 15°-150° C.

Jan 1, 1971

By Sean Gallagher

Bolting large sheets of wire mesh screen (WMS) to the roof of underground mines prevents injuries due to rock falls. However, WMS can be heavy and awkward to lift and transport, and may result in significant spinal loading. Accordingly, six male subjects (mean age =45.8 years + 7.5 SD) were recruited to lift WMS in a laboratory investigation of the biomechanical demands. Biomechanical modeling was used to estimate external moments about L5-S1 for sixteen lifting tasks, using two sizes of WMS. Full-size WMS involved a two-person lift, while half-size WMS involved a one-person lift. Lifts were performed under 168 cm and 213 cm vertical space. Restriction in vertical space increased the maximum L5-S1 extensor moment from 254 to 274 Nm and right lateral bending moment from 195 to 251 Nm. Lifting full sheets of screen (as opposed to half sheets) resulted in an average 33 Nm increase in L5-S1 extensor moment. The L5-S1 extensor moment was increased by an average of 44 Nm (18%) when lifting screens positioned flat on the floor compared to an upright position. Relevance to industry: Large flexible materials are commonly lifted in industrial work environments, and may involve the efforts of two or more workers. The current study examines the low back loading associated with lifting large flexible screens and presents recommendations to reduce spine loading.

Jan 1, 2009

By Robert W. Waytulonis

The Federal Bureau of Mines contacted 29 organizations--mine maintenance departments and equipment manufacturers--concerning service experience and construction of diesel exhaust-gas water scrubbers. Scrubbers are used primarily on mobile diesel-powered mining equipment subject to 30 CFR 36. Because the scrubbers cool exhaust gas and act as flame arresters, their failure would compromise safety in underground mines. Scrubber maintenance problems and frequency and modes of failure were identified, and construction materials and techniques were evaluated. Three failed scrubbers were randomly selected from two cooperating mines, and their modes of failure were determined. In conjunction with failure analyses, mine water and scrubber water solution samples were chemically analyzed to characterize corrosive properties. Sludge and mineral deposits and different types of corrosion and metal fatigue were identified as problems leading to scrubber failure. The corrosion process is explained; maintenance practices, construction materials, and manufacturing methods that could be used to reduce premature failures and allow longer effective scrubber life are identified; and basic changes in scrubber design are suggested. If type 304 stainless steel is used throughout the scrubber and regular maintenance is performed, long, dependable service can be expected. Other materials such as 304L, 316, or other more exotic steel alloys may be necessary under certain conditions.

Jan 1, 1982

By M. C. Irani

This study is a survey of supply and demand for minerals, metals, alloys, and compounds used by the chemical industries in the Ohio River Basin (ORB) area of Ohio, Pennsylvania, and West Virginia during 1967. Data for the study were obtained from completed questionnaires received from chemical manufacturers and from interviews with officials of chemical companies and mineral producers and distributors. The information includes kind, quality, quantity, values, sources, specifications, uses, and methods of transportation. Results of the study show that of the total value of mineral materials consumed by the chemical industry, manufacture of inorganic chemicals consumed 46 percent; fertilizers, 22 percent; and soaps and detergents, 19 percent. Fifteen commodities accounted for 91 percent of the total value of mineral materials consumed. Five of these--phosphates, potash, salt, sulfur, and titanium dioxide--accounted for 59 percent of the total.

Jan 1, 1970

By L. G. Marshall

This report describes dredging and processing of sand and gravel from a glacial-fluvial deposit in the Raccoon River valley near West Des Moines, Iowa. Preliminary cleaning and separation of the sand and gravel at the dredge site with subsequent transportation to separate plants and the production and disposal of the various grades of aggregate material are also described. The geology of the deposit is summarized. A tabulated summary of costs in units of labor, power, and supplies is included.

Jan 1, 1963

By Herbert Cremer

The United States,-the largest nickel consumer in the world, produces virtually no nickel from domestic ores. Dependence upon outside nickel - sources and increasing strategic, importance of nickel focused the attention of the United States on deposits within its boundries. The most likely domestic sources of nickel are low-grade oxide and silicate deposits, such as the Cle Clum deposit, Kittitas County, Wash., and the Riddle deposit, Douglas County, Oreg. The Federal Bureau of Mines, Northwest Electrodevelopment Laboratory, Albany, Oreg. has been investigating electric smelting of low-grade oxide and silicate nickel ores. These smelting studies have been on selective reduction to produce low-carbon ferronickel. Selective reduction is based upon the relative reducibility of: nickel, iron, and chromium, in the order named, when the charge contains insufficient carbon or other reductants to reduce the entire quantity of these metals present in the ore.

Jan 1, 1954

By C. W. Owings, J. J. Forbes

"Although coal-mine explosions rank third among causes of underground fatalities, they receive more wide-spread attention than any other accidents in mines because frequently many persons lose their lives in a single disaster. Each bituminous coal-mine explosion endangers the lives of approximately 100 persons--the average number employed underground in a commercial mine. A critical analysis of coal-mine explosions in a restricted district gives a cross-section of relative existing explosion hazards, of common causes of ignitions of gas and dust, and of effective prevention measures. The Safety Division of the United States Bureau of Mines is collecting data on coal-mine explosions in the various States, and this circular is one of a series analyzing the causes and recommending methods for thy prevention of similar occurrences,The data on this circular are based on records of the United States Bureau of Mines and the West Virginia Department of Mines. Unfortunately practically all of the early records were destroyed by fire in the State House at Charleston, W. Va.; the remaining records were made available to the authors by N. P. Rhinehart, chief of the Department of Mines, and his cooperation is gratefully acknowledged.The earliest available reference to coal in West Virginia is that made by John Peter Lally who in 1742 found ""a great plenty of coals"" near a river later called Coal River. In 1809, Nicholas Roosevelt found coal along the Ohio River and used it on the New Orleans, said to have been the first steamboat west of the Allegheny Mountains. In 1810, Conrad Cotts opened a mine near Wheeling and sold coal for domestic purpose in 1812, a mine was opened on the Ohio River opposite Mason City and produced 1,200 bushels of coal that year. In 1840 the total West Virginia coal production was 298,691 tons; in 1863, the production had increased to 444,468 tons, and in 1883, to 2,335,833 tons. During this period apparently most of the coal was extracted from coal outcropping on the hillsides; little danger of gas ignition existed at that time, but explosions from blown-out shots occurred frequently. On February 22, 1383 the West Virginia legislature enacted legislation providing for a mine inspector to inspect the mines of that State, to prevent mine accidents, and to insure properly ventilated mines.In a special report to the Governor on December 31, 1884 the Inspector of Mines reported:We have 5 shafts, in 4 of which there is more or less gas; and in 1 of our drift mines there was an explosion on the 27th day of March 1880, whereby 2 men were killed and a boy badly burned.Table 1 lists 287 explosions in West Virginia coal mines. Several early explosions were listed in the annual reports of the West Virginia Department of Mines as ""blown-out shots"" or ""powder explosions"". The injuries usually were described; explosives accidents have been eliminated from these and other available data, and only those in which dust or gas were involved have been included in this paper as explosions."

Sep 1, 1934

Mine waste and mine reclamation are topics of major interest to the mining industry, the government and the general public. This publication and its companion volume are the proceedings of a conference held in Pittsburgh, April 19-21, 1988. There were nine sessions (50 papers) that dealt with the geochemistry, hydrology and problems of mine waste and mine water, especially acid mine drainage. These comprise Volume 1. The nine sessions (43 papers) that dealt with reclamation and restoration of disturbed lands, as well as related policy issues, are included in volume 2. Volume 2 also contains the ten papers that pertained to control of subsidence and mine fires at abandoned mines. Poster session presentations are, in general, represented by abstracts; these have been placed in the back of both volumes.

Jan 1, 1988

By Pedro Lilienfeld

This report describes the development, design, fabrication and testing of a port-able, battery-operated, light scattering monitor (henceforth to be designated as ILSDM) for the rapid measurement of the concentration of respirable dust in mining environments. This instrument incorporates state-of-the-art design characteristics and makes use of advanced solid-state components both for light emission as well as for its detection. The use of a pulsed light source combined with synchronous signal detection minimizes drift problems and optimizes the sensitivity of the measurement. Simplicity of operation, reliability and ruggedness, light weight as well as improved performance were salient objectives of this instrument development program. Continuous clean-air flow screening of all critical optical surfaces, and optimized optical detection and electronic signal processing design resulted in about a hundred-fold decrease of noise and drift with respect to precursor instruments. Equivalent mass concentration measurements 88 low as 10 micrograms per cubic meter can be routinely performed with time constants of about 2 second.

Jan 1, 1979

Reduce the danger to personnel and destruction of equipment caused by fires on surface coal augers. Approach: A reasonably priced reliable system which automatically senses a fire and activates dry chemical extinguishers, has been built and field tested. How It Works: Heat sensors mounted in the engine compartment and hydraulic hose areas detect the fire, usually before the operator does. This causes the system to automatically discharge A-B-C class dry chemical extinguisher through a fixed piping system.

Jan 1, 1976