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By D. H. Platt

Gypsum and gypsite, used in the manufacture of plaster and plaster products, have been mined from deposits near Acme, Hardeman County, Tex., for more than 30 years. The Certain-toed Products Corp., 120 East Lancaster St., Ardmore, Pa., operates the Acme, Tex., mine. Underground hauling was done with storage-battery and Diesel-electric-powered shuttle cars. Many mining companies and individuals have manifested interest in all types of equipment powered by Diesel or Diesel-electric units, as attested by the recent increase in use of Diesel-powered equipment in underground metal and nonmetal mines. The purpose of this paper is to describe the manner in which a storage battery-powered Joy Model 60D2 shuttle car was converted to Diesel-electric power. The conversion was made, at the instance of the operating company, by Stewart & Stevens on Services, 4801 Lemon Ave., Dallas, Tex. This is believed to be the only such converted shuttle car in use.

Jan 1, 1950

By J. A. Herdlick

Under authority of the Strategic Materials Act of June 1939, the Federal Bureau of Mines, in cooperation with the Geological Survey, began a broad program of investigation of the strategically important chromite deposits in Sweetgrass, Stillwater, and Carbon Counties, Mont. Extensive occurrences of chromite along the Stillwater Complex in Stillwater County were investigated. The two principal deposits, The Mouat-Sampson and Benbow mines, ultimately were developed and placed in production by the Federal Government. As a part of this general development program, the Carbon County chromite deposits near Red Lodge were examined by Bureau of Mines engineers in 1940, and by the Geological Survey .1-1 1942. The district was examined earlier by Schafer, and the Four Chromes area is mentioned briefly by Westgate. Although the Red Ledge deposits were considered to be of minor importance as compared to those of the Stillwater Complex, several of the ore bodies were adaptable to open-pit mining' methods, and one large deposit on Line Creek Plateau was readily accessible to the Red Lodge-Cooke highway. In 1941, the U. 3. Vanadium Corp. began mining crude lump-chrome ore from the deposit on Line Creek Plateau to supplement national stockpiles, which were being depleted by the rearmament program and the disruption of chrome-ore imports by the European war. Access roads gore constricted to Hellroaring Plateau, and the mining operations were extended to that area. A gravity concentrator with a capacity of 200 tons per day was built and operated at Red Lodge to beneficiate lower-grade ore from the district.

Jan 1, 1948

By Arthur V. Petty

The Bureau of Mines has investigated the effect of refractory oxide additions, introduced in soluble form, on the refractory properties of 42-, 58-, and 70-pct-A1203 brick. Brick having porosities ranging from 12 to 16 pct were impregnated with solutions containing chrome, chrome-iron, zirconium, calcium, magnesium, cobalt, nickel, tin, and manganese ions. Additions of some of these ions provided dramatic improvements to such properties as hot modulus of rupture, hot load, and particularly slag resistance. These improvements can be related to reduction of porosity, amorphous grain boundary phases, formation of more refractory bond phases, and reduction of the wettability of Al203-containing refractories by metallurgical slags. Fifty-eight-percent-AI203 brick, impregnated with chrome, showed hot modulus of rupture, hot load, and slag resistance two to five times better than those of untreated 70-pct-AI203 brick. This could result in reducing the Nation's dependence on imported refractory-grade bauxite generally required for high-A1203 brick, as domestic alumina resouces could be used to produce the improved refractories.

Jan 1, 1984

The Bureau of Mines, in an effort to improve resource conservation, mine planning and development, is currently investigating the loading behavior of pillars in multiple-seam developments. The simultaneous mining of two or more coalbeds may cause instability between room-and-pillar operations resulting in an interaction known as pillar load transfer. Although pillars may be adequately designed for single-seam mining, the development of a second seam may complicate loading conditions in both operations. If pillars are not adequately designed to contend with this load transfer, failure of the mine structure may result. To improve multiple-seam development and pillar design, the Bureau studied the loading characteristics of pillars in three separate multiple-seam operations. In all three cases, instrumented pillars recorded increasing pressure after development of the second seam. Increases in the average pillar pressure ranged from 7 to 110 pct over predicted overburden loads. An analysis of pillar loading before and after second-seam mining indicates that the ratio of overburden to innerburden thickness is a critical factor influencing load transfer. Based on this relationship, safety factors for case study pillars are calculated and alternative design considerations are discussed.

Jan 1, 1988

By William H. King

The property of the Cupric Mines Co. is situated in the San Francisco mining district, Beaver County, Utah, 21 miles westerly from Milford (fig. 1), the rail and supply center for the area. Scheelite mineralization was not discovered until 1941, although the occurrence of lead and copper minerals had been known previously. S. VI. Hobbs, of the Federal Geological Survey, examined the Cupric property in November 1941 and prepared topographic and geologic maps of the area. This work was supplemented by additional investigations in January 1943 and March 1944 (fig. 2).

Jan 1, 1949

By D. Harrington

Fire is always a serious-menace, whether in a residential or in an industrial region; in wartime it is particularly damaging in an industrial plant. The mining industry is especially vulnerable, as its plants are generally more or less isolated front centers of population and do not have access to modern fire-fighting equipment; moreover, owing to the transitory rapture of most mines, their surface structures; are often relatively flimsy and flammable.. Trained firemen seldom are available at or near mining plants to teach the fundamentals of fire-fighting to local fire brigades, with the result that efficiency in combating actual fires is lacking. Often the attitude "it can't happen here" is held by the management of a mining property, unless the plant has suffered a serious fire; even then lapse of time is very likely to induce forgetfulness as to the possible hazards. The necessity for producing metals for the prosecution of this war has increased management's responsibility. Whereas heretofore the loss of a plant or mill by fire meant merely monetary less to the stockholder of the company, now the national interest is affected, in that the nation suffers from loss of production of minerals indispensable for war purposes.

Jan 1, 1943

By R. R. Sayers

Carbon monoxide poisoning, as usually encountered, is an acute condition resulting from breathing atmospheres containing that gas. It is characterized clinically by headache, dizziness, weakness in the legs, increased respiration at first which later becomes irregular and depressed, collapse, unconciousness, and death; anatomically it is characterized by temporary changes in the red blood cells due to the combination of carbon monoxide with hemoglobin, and, in prolonged severe exposures, degenerative changes in various tissues of the body, especially those of the central nervous system. No race or nationality is immune or has a, special tolerance for carbon monoxide. From data at hand, it is known that both sexes are about equally susceptible. All ages are affected, but small percentages seem to have a more deleterious effect upon young animals and this is possibly true of children. Exercise, high temperature and humidity, and low oxygen content of en atmosphere increase the degree of poisoning for a certain concentration of carbon monoxide. Anything that lowers the physical fitness of a man, such as illness, overwork, or excesses of any kind, exaggerates the effects. More cases of poisoning from carbon monoxide occur in coal mines in the cold months of the year, because explosions take place more frequently during that period, also in homes where gas is used for beating purposes, and in garages from accumulation of automobile exhaust gases due to poor ventilation.

Jan 1, 1923

By H. P. Greenwald

For some years past the Safety in Mines Research Board of Great Britain has been making an intensive search for. materials that would be more efficient than rock dust and that could replace it wholly or in part as a moans of preventing the prorogation of coal-dust explosions in mines5/ In the course of this work several rock ducts and numerous inorganic compounds were tested. The results place incombustible substances in two main groups; (1) Those whose effect in suppressing the combustion of coal dust is proportional to their capacity for absorbing heat, and (2) those that shoo much higher effectiveness than would be expected from their heat capacity. The first group includes several inorganic compounds and materials commonly ground for use as rock dust, such as shale, gypsum, and limestone. Outstanding examples of the second group are compounds of the halogens6/ with the alkali metals,7/ especially potasium and sodium8/. British investigators term those salts "inhibitors" because it is assumed that their presence has a hindering or inhibiting effect on one or more of the chemical reactions that together constitute combustion. In other words, the action of an inhibitor is postulated as chemical rather than physical; theoretically, the effect is to prevent liberation of energy instead of to absorb energy already liberated.

Jan 1, 1940

By Robert W. Smith

The Bureau of Mines is engaged in a systematic evaluation of the thermodynamic properties of combustion gases. These studies are designed to provide basic thermodynamic information of high accuracy, facilitating the theoretical study of flame and combustion phenomena. This report is the fourth of a series4/ presenting results of the study for particular fuel-oxidant systems. These calculations have as their objective the evaluation of the constant pressure flame temperatures of methane-air, propane-air, and ethylene-air mixtures for a range of pressures.

Jan 1, 1953

By James Noll

Total carbon (TC) is sometimes used to measure or characterize diesel particulate matter (DPM) in occupational settings such as underground mines. DPM samples are collected on quartz fiber filters. When using quartz fiber ?lters, adsorption of gas phase organic carbon (OC) has been reported, causing a positive bias in the particulate TC results (adsorption artifact). Most of the data on the sampling artifacts and corrections apply to environmental air sampling, where samples are collected at a much higher filter face velocity and the OC concentrations are generally much lower relative to occupational sampling. In this study, we investigated the effects of adsorption artifact on samples from occupational settings. Samples were collected with and without denuders to determine the amount of gas phase OC collected and the accuracy of certain corrections. In underground stone mines, the adsorption artifact was found to positively bias the particulate TC by greater than 20% for filter loadings below 25 µg/cm2 TC (8-h time weighted average) 262 µg/m3). The tandem ?lter correction reduced the effect of the artifact, as high as 60% of the TC value, to less than 11% for laboratory data. It also significantly reduced the effect of the artifact obtained for field samples.

Jan 1, 2008

By Charles Prasky

This report describes fluidized bed techniques employed by the Bureau of Mines at Minneapolis to differentially sulfatize the manganese in two samples of low-grade manganiferous ferruginous carbonate slates from the Cuyuna Range district, Minn. Suitable mechanics of operation were established. A space rate of 1.25 to 1.5 fps, a retention time of 3 to 3.5 hours, a temperature of 700° C, and a 10 percent sulfur dioxide gas in air were adequate for sulfatizing the slates by fluidization. Under these conditions the overflow product removal rate from the 4-inch-diameter reactor was 4 to 5 pounds per hour. The sulfur dioxide was used more efficiently in the two-stage treatment than in the single-stage treatment. However, approximately 80 percent of the manganese was converted to sulfate by either treatment.

Jan 1, 1963

By Frank E. Cash

The data in this circular were compiled so that individual phosphate companies might have the benefit of the experience of other phosphate companies, and that industries in general might compare experiences (taking into consideration relative hazards), thereby promoting accident preven¬tion. ACKNOWLEDGMENTS The descriptive matter is taken in part from a. paper by Cash and von Bernewitz.4/ Production figures ore from Mineral Resources of the United States;5/ accident data were furnished by each of the operating companies in the pebble-phosphate district, and their assistance in making this report possible is gratefully acknowledged.

Jan 1, 1936

By W. W. Agey

As a result of a field examination made during the Bureau of Mines intensive manganese program, three lots of ore were procured from the famous old Paymaster District, 7 miles from Midway Wells, Imperial County, Calif. This district is an old producer and shipped approximately 10,000 tons of 45-percent manganese ore during World War I. A 2-ton lot of ore was taken of a Bureau engineer from the exposure of a small fissure vein in conglomerate on the Turtle Group of claims; 1 mile east of the Pacific Coast Manganese Corp. claims. The vein material consisted of manganese oxides, calcite, and quartz in fairly coarse association.

Jan 1, 1949

By W. L. Dare

This information circular is one of a series, published by the Federal Bureau of Mines, on methods and costs of mining uranium ore on the Colorado Plateau. This report describes the relatively small-scale operations of the Salt Wash miner: The mining method followed, the equipment used, and the production costs. It describes 10 lease-operated mines of Union Carbide: Nuclear Co. that are typical of Salt Wash operations on the plateau. These mines lie within the Uravan mineral belt3/ and arc in the Gateway, Bull Canyon, and Uravan mining districts. (See fig. 1.) Generally the ore bodies occur as irregular, discontinuous layers of ore minerals within sandstone beds in the Salt Wash member of the Jurassic Morrison formation. The ore bodies sometimes occur as rolls, pod associat with carbonaceous trash, or tabular masses. Their size and erratic distribution preclude the use of a prearranged and uniform stoping system. The mining method is simply to follow the ore and leave open scopes behind.

Jan 1, 1959

By W. E. Robinson

A laboratory study wan made to determine whether drying and preheating Colorado oil shale with waste retort gases has any appreciable effect on its oil yield. Samples of crushed oil shale were heated at subretorting temperatures in a specially constructed electric furnace by gases similar in composition to waste gases from oil-shale retorts. The results of this study showed that preheating oil shale with nitrogen or a reducing mixture had no effect upon the oil or water yield. However, oxygen in the preheating gas caused a decrease of oil and an increase of water. In general, the oil yield decreased with (1) increase in oxygen content of the heating gases, (2) increase in temperature of the heating gas, (3) increase in heating time, and (4) decrease in the particle size of tho shale. The decrease in oil and the increase in water resulting from preheating were due to oxidation of the benzene-insoluble organic material (kerogen) rather than to oxidation of the benzene-soluble organic material (natural bitumen) in the shale, A small amount of oil was volatilized during preheating, which would constitute an additional loss if prober precautions were not taken to recover it. The results obtained in this laboratory study indicate that oil shale can be preheated without appreciable decrease in oil yield by proper selection of preheating conditions.

Jan 1, 1951

By A. T. Coumbe

The first national survey covering sales of fuel oil by States and principal uses was made in 1926 by E. B. Swanson of the Bureau of Mines (then under the U. S. Department of Commerce) under a cooperative agreement with the American Petroleum Institute. This annual study, covering the market for fuel oil, was made through 1930 with the financial help of the institute bat has since been continued by the Bureau up to the present time. The scope and coverage of the survey have gradually changed over the years as new uses for fuel oil have been found and new products have come into importance resulting in market expansion. Range oil (No. 1 fuel oil or kerosine) came into use for cooking and space-heating daring the depression era in New England, and it was first reported as a total in the 1931 survey. In 1934 the sales were compiled on a State basis. State totals for distillate fuel oil, Diesel fuel, and residual fuel-oil sales were first shown for 1934 and by principal uses and States in 1937. Kerosine deliveries by States and main uses were also released for the first time in 1937.

Jan 1, 1952

By Helen E. Edwards

The Bureau of Mines is engaged in a systematic evaluation of the thermodynamic properties of combustion gases. These studies are designed to provide basic thermodynamic information of high accuracy facilitating the theoretical study of flame and combustion phenomena. This report is the third of a series3/ presenting results of the study for particular fuel-oxidant systems. The equilibrium composition of the products of combustion and the adiabatic flame temperatures of specified oxyacetylene systems have been computed.

Jan 1, 1953

By Jacob Schoder

This is one of a series of papers published by the Bureau of Mines on mining and milling methods and costs. The Tennessee-Schuylkill Corporation, Chloride, Ariz., mines and mills a lead-zinc ore containing gold, silver, and a small amount of copper. The mill products are lead and zinc concentrates that are shipped to smelters. The company was the second largest producer of lead and zinc in Arizona in 1937 and was seventh in gold production. Operations discussed are those being conducted at the mine in October 1938 and are representative of the complete operating period from 1936 to date.

Jan 1, 1939

By Scott Turner

We are here today to witness the graduation of 63 young men as Engineers in the mineral industries . It is an important occasion and one in which the public takes a keen interest , since this school has long been famous for the educational facilities it affords young men, and for the high professional standing of its graduates . : : : It is fitting that once each year we should pause to review the path the student has traveled , and to reflect upon the perspective opening before him as an engineer . I was invited to come from Washington to take part in this ceremony and to say something to these young graduates . In searching for a theme ," it occurred to me. that perhaps my best contribution would be to duscuss certain beliefs as to college training , deal with the situation in which the young engineer finds himself on graduation , touch on the new ideas of the social and political responsibilities of the engineer , and point out what he may expect to find in practice , and , above all , what he must do to orient himself properly in the mining profession and maintain the best traditions of our brotherhood . Let us first review your college days and see what they have done for you . I am told there are still many temptations in college . I know there used to be . Rest assured the same holds true in the professional life ahead of you. The main difference is , perhaps , that your greatest temptations in college were those offered by your teachers , who tried to entice you into realms of harder work, closer application , increased concentration , clearer thinking and better understanding , by animating your curiosity and increasing your powers of reasoning and of observation . In other words , here you have carefully and systematically been decoyed toward finer and loftier things . Do not expect that similar helpful influences will greet you on every side in your professional life . Often quite the contrary is the case .

Oct 1, 1930

By Robert N. Roby

The Hornsilver lead-zinc property was examined by the Bureau in 1942 and again in 1944. A project was started on the property in April 1946 and completed in January 1947. Silver was first discovered in this district in 1883, and while complete production records are not available, it is known that a substantial tonnage of high-grade silver ore was shipped before 1887. All of the ore was mined from surface or near-surface workings. When the high-grade oxidized ore was exhausted, the district became inactive and remained so until the 1920's. In 1928 and 1929 some activity was shown in the district, but the Hornsilver mine was not reopened until November 1937. Between 1939 and 1946, the mine produced about 16,000 tons of ore of 531 ounces of gold, 283 ounces of silver, over a million pounds of load, and nerdy 2 million pounds of zinc. The property is now controlled by the Era Mining & Development Co., which has acquired the Last Chance and Ella groups of claims, in addition to the Hornsilver mine.

Jan 1, 1948