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By J. W. Paul

[A study of mining methods and underground practices as they influence injury from falls of roof or coal reveals data as to the location in the mine where such injuries occur with the greatest frequency and as to some of the methods and practices which are in use for the prevention of injury. This paper, which presents statistics bearing on the frequency and place of occurrence of accidents and, discusses regulations and practices which have resulted in a low frequency rate from falls of roof and coal in a few representative mines takes its information from mine-accident reports and from the results of studies conducted in a group of 80 mines in the bituminous coal fields of western Pennsylvania, Ohio, and West Virginia. The statistics from this group of mines cover periods of one to four years but average 2 years and 7 months. During this time these mines produced over 110,400,000 tons of coal, equivalent to one-fifth of the annual production of all bituminous mines in the United States. The coal beds of the mines in the group studied are mostly flat, with local pitches of moderate degree. A number of mining plans are in use, each of which follows a general system of multiple entries, cross entries, and rooms. Room and pillar in panels either advancing, retreating, or half advance and half retreat and the block systems are employed. The methods of pillar extraction are by splitting, slabbing, pocket-and-stump, and open end. It is hoped that in presenting some of the details of the methods and practices at particular mines of this group which have commendable records in the prevention of injury some good may accrue to many other bituminous mines which 'nave similar natural conditions.]

Jan 1, 1933

By J. S. Webb

This is one of a series of papers dealing with mining methods, practice, and costs be¬ing published by the United States Bureau of Mires. In this paper a description of the mining practice in vogue at the Braden unit of the Kennecott Copper Corporation is undertaken. PRODUCTION At present (1931) the entire production of ore is being obtained from the Teniente mine. The miring method in use is an adaptation of block undercutting which has been a development of the stoping and pillar caving experience obtained at this property. Improvements in mining practice are constantly being made.

Jan 1, 1932

To develop a business case that promotes adoption of noise controls by reducing barriers to industry acceptance and enhancing drivers that foster their implementation. Background Over 75% of the U.S. mining workforce is exposed to hazardous noise, putting them at risk of noise-induced hearing loss (NIHL). Consequently, coal miners suffer high rates of hearing impairment that increase to 70%-90% by retirement age. To address the noise problem for coal miners, researchers from the National Institute for Occupational Safety and Health (NIOSH) first determined that the continuous mining machine (CMM) ranked first among machines associated with reported coal noise overexposures. Further studies found that most CMM noise is generated by three component systems on the machine: dust collection, cutting, and conveying. Of these systems, the on-board chain conveyor was found to be a dominant noise source. Noise generated by the conveying system was addressed through the development of a urethane-coated flight bar chain. The coated chain, shown in Figure 1, has demonstrated an 8-hour time-weighted average (TWA) reduction of operator exposure by 3 dB(A). It has since been accepted by the Mine Safety and Health Administration (MSHA) as a "technologically achievable" noise control for CMM operators who are exposed to noise that exceeds the MSHA permissible exposure level. Having demonstrated the noise reduction performance of the coated chain, NIOSH has assembled information into a business case that can be used by operations considering adopting the chain at their worksite.

Dec 1, 2009

By R. V. Lundquist

The Bureau of Mines made a laboratory study of the amenability of anorthosite rock ( from the San Gabriel Mountains , Los Angeles County , Calif . ) to treatment by the lime soda sinter process for the extraction of alumina . The study was done under a cooperative agreement with the California Division of Mines and Geology . This report presents the results of the investigation , and it includes a review of the geology of the deposit ( 7 ) by Dr. Gordon B. Oakeshott . Interest in the recovery of alumina from submarginal aluminum silicate ores is stimulated by the fact that the domestic aluminum industry depends on imports of bauxite for its alumina requirements . Of the 8.0 million long dry tons of high - grade bauxite consumed in 1961 for producing metallurgicalgrade alumina , only 0.9 million long tons , or 11 percent , was mined in this country . During past years many organizations have carried out research programs to determine if alumina could be extracted economically from such domestic ores as clays ( 3 , 4 ) , anorthosite ( 8 ) , and other silicate sources . Successful alumina extraction is the ultimate objective of the Bureau of Mines program.

Jan 1, 1963

In 2006, a total of 280 metal mining operations reported employment to the Mine Safety and Health Administration (MSHA).1 Metal mines were the smallest mining commodity sector, comprising 1.9% of all mining operations. ? Gold mines comprised 46.8% (n=131) of all metal mining operations. Other common types of metal mines were copper ore (n=34; 12.1%), and iron ore (n=33; 11.8%). Nevada had the largest number of metal mines (n=53; 18.9%), followed by Alaska (n=31; 11.1%).

Sep 1, 2008

By D. A. Stanley

The Bureau of Mines has developed a simple titration technique for determining the points of zero charge (PZC) on minerals. The technique consists of titrating a mineral slurry with the potassium salt of polyvinyl sulfuric acid (PVSK) in the presence of an indicatory dye and a positively charged polymer. Values obtained by this simple method are in good agreement with values found in the literature.

Jan 1, 1982

By C. F. McCarroll

[Laboratory research and, control in the u?odnction an; utilization of petroleum and its product s have eqLmde& greatly during the past decade, rind much of the routine control and experimental equipment noirr requires the con-stant daily use of liquid nercury. In spite of this greater use, very little consideration has becn given to the hazard that might be occasioned by the toxic vapors of mercury unavoicl.a~l.p spilled or otherwise exposed to the atmosphere during the normcl 2rgced1u.e of ln30r~tor;~r operations. A sfmple visual exami~stion gf' sone of the laborztories reveals the prescnce of a considerable quantity of mercury in the craclcs of floors, on work tebles, ad on and mo7md eql~ipmeilt st.ads. Usually this yercurj ie contaminated with oily and dirt BO th~t it remint; in R finely divided state and a srnarl amount presents a relativell- lag? surface for evaporation. Since mercury shows meas~rable vo!-atility st a tempero.turc as lor^ 2s 8.5O F., mercury vapor will bo present in the atnosphere of anjr laboratory wbr.e mercury is exposed. promiscuously]

Jan 1, 1939

By D. Harrington

In recent years over 100,000 persons have been killed annually in the United. States by accidents; about one-fifth of these have been workers in some of our industries; about one-third have been killed by motor vehicles; about another third have mot death in home accidents, chiefly falls, burns, scalds, explosions, poisons, asphyxiations, suffocations, cuts, scratches, and so forth; and the rest have been killed in public accidents, excluding those caused by vehicles but including accidents on railroads or electric cars, drowning, and deaths by firearms and. other means. Definite statistics on nonfatal accidents are not readily available, but at least 10,000,000 fairly serious accidents probably occur in the United States annually. The latest industrial-accident statistics are obtainable from 1935 National Safety Council publications, in which annual industrial fatalities are divided about as follows (in round numbers): Agriculture, 4,500; trade and service, 4,500; construction, 3,100; transportation and public utilities, 2,900; manufacturing, 2,600; mining, quarrying, petroleum, etc., 1,900.

Jan 1, 1938

By I. S. Solet

This study, of the liquidus temperatures and densities of molten alloys of zinc and aluminum was made as part of a broader investigation on refining of scrap aluminum. One of the methods of refining involves the separation of liquid and solid phases by gravity segregation and by filtration. More accurate data were required on the liquidus temperatures and the densities of molten' mixtures of the metals than were available in the technical literature. New data on the liquidus curve were obtained by thermal analysis. The new temperatures are, for the most part) somewhat higher than those reported previously by other investigators. The density of molten mixtures of zinc and aluminum were found to be less than would be calculated by assuming that the two metals occupy the same respective molal volumes in solution as they do as pure metals.

Jan 1, 1949

This is an audience, I know, that shares my interest in a subject that is currently getting a lot of attention -the tendency of our Nation to draw increasingly on overseas supplies of certain mineral commodities, and proportionately less on domestic sources for these minerals. That we do obtain substantial quantities of some essential minerals from abroad is easy to demonstrate. That we will continue to do so in the foreseeable future is not in doubt. Uncertainty begins, however, when we try to interpret the significance of these facts. As with many phenomena, their meaning is open to a variety of interpretations.

Jan 1, 1980

By Rita D. Sylvester

"IntroductionThe Bureau of Mines was established in the public interest to conduct inquiries and scientific and technologic investigations concerning mining and the preparation, treatment, and utilization of mineral substances; to promote health and safety in the mineral industries; to conserve material resources and prevent their waste; to further economic development; to increase efficiency in the mining, metallurgical, quarrying, and other mineral industries; and to inquire into the economic conditions affecting these industries. The organic act of the Bureau, as amended by Congress and approved February 25, 1913, made it the province and duty of the Bureau to ""disseminate information concerning these subjects in such manner as will best carry out the purposes of this Act.""In accordance with this directive, the Bureau reports the findings of its research and investigations in its own series of publications and also in articles that appear in scientific, technical, and trade journals; in proceedings of conventions and seminars; in reference books; and in other non-Bureau publications. The number of these reports, the wide range of subjects they cover, and the variety of mediums in which they appear make the kind of list and index presented in this special publication both necessary and valuable. This issue describes reports and articles published during the period January I, 1965, to December 31, 1969. It supplements the 50-year list of Bureau publications issued from July 1, 1910, to January I, 1960;' the 50-year list of articles by Bureau authors published outside the Bureau from July 1, 1910, to January I, 1960;3 the 5-year list of Bureau publications and articles from January I, 1960, to December 31, 1964.' It includes all the material in the four annual lists of Bureau publications and articles from January 1, 1965, to December 31, 1968, as well as the Bureau publications and articles for 1969."

Jan 1, 1970

By R. O. Dannenberg

Applicability of the fluosilicate sintering process to recovering beryllium from beryl-spodumene concentrate analyzing 1.4 to 3.7 percent BeO (10 to 30 percent beryl) was investigated. The work was one phase of a Bureau of Mines research program undertaken to assess applicability of conventional processes and to devise new procedures for treating various potential beryllium feed materials. Beryllium recovery of about 70 percent in a product of 99-percent BeO grade was achieved in treating 3D-percent beryl concentrate. The process consisted of (1) sintering a briquetted charge of concentrate, soda ash, and sodium fluosilicate for 3 hours at 750° C.; (2) extracting the soluble beryllium by multiple stages of water leaching; (3) adding caustic to the leach solution and boiling to hydrolyze and precipitate crude beryllium hydroxide; (4) dissolving the crude beryllium hydroxide in sulfuric acid and separating the solution from undissolved silica; (5) sulfidizing the acid beryllium solution to precipitate heavy metal impurities; (6) adding ammonia to the clarified sulfate solution to precipitate beryllium hydroxide; and (7) converting the hydroxide to beryllium oxide (beryllia) by calcining at 900° C. About 60 percent more sodium fluoSilicate was required per unit of beryl than is used industrially in treating 10-to 12-percent BeO concentrate (80 to 90 percent beryl). Recovery decreased, and flux requirements increased, when treating concentrates containing less beryl.

Jan 1, 1963

By R. J. Gajan

As part of its research program on secondary metal refining, the Federal Bureau of Mines has developed a fast method for determining aluminum, iron, copper, cadmium, and lead in zinc-base alloys. The new method is intended for use by trained technicians in laboratories with inexpensive equipment. It can be used either in the analytical laboratories of the many small plants that are characteristic of the secondary metals industry or in laboratories engaged in basic research to improve refining processes. A complete analysis for the foregoing elements can be made in less than 3 hours from a single sample in solution. The method is especially helpful when a small amount of sample is available. Aluminum and iron are determined spectrophotometrically and the other elements polarographically. The new method is now being used for control analysis in metallurgical research, and the results compare favorably with previously used spectrographic methods. Luke and Braun4/ described a photometric method for the determination of aluminum in zinc diecasting alloys in which the aluminum was complexed with Aluminon reagent (ammonium salt of aurintricarboxylic acid), forming a red lake. An adaptation of this method was used for determining aluminum. Beers law is obeyed between 0.01 and 0.06 milligram of aluminum.

Jan 1, 1961

By J. Wade Watkins

One potential peaceful application of nuclear explosives is stimulating the production of liquid or gaseous hydrocarbons from essentially nonproductive deposits of petroleum, natural gas, oil shale, and tar sands. Within the United States the appreciable difference between producible proved reserves and ultimate reserves and resources of hydrocarbon deposits is of such magnitude that much petroleum, natural gas, shale oil, and bitumen will not be produced unless significant technological progress is made in production techniques. The shattering effect of contained nuclear explosives and, to a lesser extent, the heat produced, have been considered as stimulative forces when the thickness, depth, and nature of such deposits permit considering the use of nuclear devices. Mechanical production problems would be less in an oil or gas reservoir than in an oil-shale or tar-sands deposit. Also, tar-sands resources in the United States may not be adequate to warrant serious consideration of applying nuclear-explosives stimulation. Gas reservoirs should present the least-radioactive-contamination problem. The technical feasibility of using nuclear explosives cannot be evaluated fully at present. Additional information is needed on the effects of pressure, heat, and radioactivity on the solids and fluids of hydrocarbon deposits, the nature and extent of induced fractures in different rock media, and the possibility of isolating and confining or removing radioactive contaminants. Final technical feasibility can only be determined by a field test. If technical feasibility is established, economic feasibility will depend upon the comparative cost of producing hydrocarbons by nuclear explosives and by conventional means. It is probable that an economic comparison would favor nuclear stimulation only where devices of relatively high yield could be used practicably and safely.

Jan 1, 1964

By George A. Morgan

The 53 countries that constituted Africa in 1989 accounted for a significant portion of total world output of a number of mineral commodities. Among the most significant minerals to be produced in Africa were andalusite, antimony, asbestos, bauxite, chromite, coal, cobalt, copper, diamond, fluorspar, gold, lithium minerals, manganese, phosphate, platinum-group metals, and the titanium minerals-ilmenite and rutile, vanadium, vermiculite, and zircon. Despite the underdevelopment of much of Africa, mineral raw materials played a very important part of the national economies of many of its countries. In terms of percent-age of export earnings, minerals accounted for more than 90% in some cases. In several countries with agrarian economies and little economic diversification such as Angola and Guinea, a single mining operation could represent an important source of foreign exchange. These latter operations tended to be the more easily mined surface deposits of diamond, gem stones, and precious metals. Mineral commodities for which Africa had a high percentage of world output were bauxite, 16%; chromite, 44.5%; cobalt, 76.5%; copper, 13.9%; diamond, 50.7%; gold, 32.9%; manganese, 27.1 %; phosphate, 22.1 %; platinum-group metals, 48%; uranium, 29.2%; vanadium, 54%; and vermiculite, 41 %. Several of these, chromite, cobalt, diamond, and manganese, were not produced in the United States.

Jan 1, 1992

By J. Kruttschnitt

This paper, describing milling practice at Mount Ira Minis, is one of a series covering milling methods and cost that is being published by the Bureau of Mines, United States Department of the Interior. The Mount Isa concentrator began operations in day 1931 by treating a mixture of oxidized and sulfide ores. Since March 1935 only sulfide ores have been milled; this change involved major alterations to the flow sheet. The maximum capacity on mixed oxide and sulfide ores was 2,650 tons per day; the present capacity is approximately 1,880 tons of sulfide ore per day. The installation of additional crushing, grinding, and flotation equipment when completed early in 1939 will increase the maximum capacity of the concentrator to 2,240 tons of sulfide ore daily.

Jan 1, 1939

By John D. Foulkes

A study to categorize and characterize underground metal/non-metal mining operations from the viewpoint of telecommunication requirements and practices. The objectives were to: ? Gather and analyze data; ? Identify communication requirements; and ? Recommend systems for operational emergency and post-disaster telecommunications.

Jan 1, 1979

Hang ventilating air curtains so that they can be installed, moved, opened and closed more easily than curtains that are spadded or nailed in place. Approach Low-leakage plastic curtains fitted with grommets along the top were threaded onto a steel cable which is suspended from roof bolt plates. The system was tested in two mines. How It Works The curtains are threaded onto a steel cable which is suspended from roof bolt plates by S-shaped hooks. See Figure 1. The outby end of the cable is reeled off a hand operated winch; the inby end of the cable is anchored to a roof bolt plate by means of a cable grip and an S-shaped hook. To install the curtains the following procedure is used. First, the winch is located at least 5 feet outby the last open cross-cut. The base of the winch can be secured to the mine roof with short roof bolts, only about a foot long.

Jan 1, 1978

By C. J. Thompson

Two sulfur compounds--the 2,2,5-trimethyl- and the 2,2,5,5-tetramethyl derivatives of thiacyclopentane--were identified in Wilmington, Calif., crude oil, using microdesulfurization and gas-liquid chromtography techniques.

Jan 1, 1963

By George T. Faust, S. R. B. Cooke

"The Southern Experiment Station of the Bureau of Mines, United States Department of the Interior, in cooperation with the University of Alabama, is investigating the preparation of pulverized coal for fuel. In this study the relative amount of surface in various products and samples had to be assessed. Because of the familiarity with screens and because of the simplicity of using the inverse ratio of the opening for ascertaining the amount of relative surface in the respective sizes, screens down to and including 270-mesh were used. This choice was made in full cognizance of the irregularity of screens, but it seemed that if the same screens were used throughout all the tests the relative values would be satisfactory.In dealing with the subsieve sizes, pneumatic elutriation was used to make several fractions to extend the sizing analysis into the range of hypothetical screens. This kind of a sizing analysis was thought necessary because it is familiar to all operators, and, furthermore, it is amenable to several ways of plotting curves that bring out the characteristics of various coals and various methods of grinding.The method of obtaining the data from which to set up the hypothetical screen scale is the subject of this paper. It consists in determining the average projected area of the particles in the respective elutriated products. By extending the ""area method"" to sieve sizes, a factor is found that may be applied to the subsieve sizes, and thus the scale is projected in a regular manner. This method avoids contentions about specific surface and steers clear of ""average diameter"" except as material sized on screens may be said to have an average diameter."

Aug 1, 1939