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By James R. Aggson

This Bureau of Mines report presents a finite element analysis of roof stresses associated with a 4-foot-high by 18-foot-wide underground coal mine entry. This analysis starts with known loading conditions determined in an underground coal mine in West Virginia and is extended to other possible underground loading conditions. The roof failures predicted by the finite element analysis under known loading conditions correlate well with the roof failures observed underground. The most probable failure modes are identified for the various loading conditions considered. Various failure preventive measures are discussed.

Jan 1, 1979

By R. V. Higgins, H. C. Miller

"INTRODUCTION The development of methods for determining the total quantity of crude oil that a given pool could be expected to produce in the future and the well-spacing and drilling programs most likely to result in the recovery of the maximum quantity of oil at the minimum cost became problems of acute concern to American oil producers and petroleum engineers during the second decade of the twentieth century, The United States faced what seemed at that time to be a serious shortage of petroleum, and it appeared that the constantly increasing demand for petroleum and its products could not be adequately supplied. Undrilled prospective acreage, which until then had been plentiful, seemed to be getting scarcer, competition was increasing, the margin of profit to the producer was shrinking, and the need for developing constructive policies of conservation appeared paramount. As a result of physical and economic changes then taking place within the petroleum industry prompted by the seemingly uncertain future, accurate knowledge pertaining to the probable future production of oil wells and of oil lands especially was needed and greatly desired. Furthermore, the need for obtaining the maximum quantity of oil from known fields caused technical information - which up to that time had not been deemed essential to the successful and profitable operation of oil lands - to be sought eagerly. The need for technical information, such as methods for determining future reserves of oil and the rate at which the oil could be obtained under a specific program of drilling, was emphasized further with the passage of the Revenue Act of 1918, and oil producers with enough income to place them in the taxable class were compelled, for the first time, to report their taxable income 4/ to the Treasury Department."

Nov 1, 1939

By Curtis D. Edgerton

Miami Oölite limestone is the only significant construction mineral in southeastern Florida. Its source area coincides with that of rapid urban expansion. Two-thirds of the existing resource is already unavailable because of development. Land-use conflicts place future availability of limestone in jeopardy. However, a sufficient limestone resource to meet demand for many years is present if its extraction is not restricted. Adverse environmental effects of quarrying Miami Oölite are not severe; land values often increase following quarrying. Future availability depends upon--(l) achieving uniformity of Federal, State, county, and municipality statutory requirements governing quarry operations; (2) setting aside specific land areas for future quarrying; and (3) cooperative planning to provide for land utilization upon completion of quarrying.

Jan 1, 1974

By Herbert H. Einstein

The thrust of research reported in Part I was to collect in-situ data from exploration programs and the published literature, and to empirically establish distributional patterns for these variables. Since discontinui¬ties in a rock mass govern to a large extent its engineering properties and thus the performance of any slope in the mass, work has been devoted to determining the appropriate distributional forms for attitude spacing and length of discontinuities and to distributional properties of resis¬tance and deformability parameters. The conclusion from these analyses is that trace lengths are logNormally distributed and that joint spacing is Exponentially distributed, regardless of orientation of the sampling line, and regardless of whether each joint set is considered separately or not. Joint orientation (attitude) data representing 22 individual joint sets from eight sites (a total or approximately 20,000 joints), do nor strongly support any of the commonly used distributions as broadly applicable in practice. The autocorrelation )f geometric joint properties is also examined. However, no significant spatial correlation could be found even after extensive data manipulation. The investigation of resistance and deformability parameters starts with a review of mechanisms and models that are used to represent them. Review and statistical evaluation of approxi¬mately 2,000 discontinuity shear tests has shown that good statistical estimates for use in reliability analyses can be obtained for friction angles.

Jan 1, 1979

By Charles D. Litton

This U.S. Bureau of Mines report describes the results of two large-scale tests conducted to evaluate a prototype nitric oxide (NO)-compensated carbon monoxide (CO) fire sensor, developed by Carnegie Mellon Research Institute (CMRI). In the tests, small coal fires were allowed to develop in the presence of diesel exhaust at relatively low ventilation airflows. These tests compared the response of the CMRI fire sensor with that of other fire sensors, including the Bureau's diesel-discriminating smoke detector. During the tests, CO, NO, and smoke levels were continuously monitored in order to determine the sensor alarm times and gas levels as the fire developed. The data indicated that the NO-compensated CO fire sensor was capable of suppressing the CO produced by a diesel engine and that the sensor responded reliably to the CO produced from the test fires. The tests also showed that the Bureau's diesel-discriminating smoke detector alarmed earlier than the prototype NO-compensated CO fire sensor.

Jan 1, 1993

By Steven A. Fechner

The U.S, Bureau of Mines is conducting a four-year (1987-1990) study to assess the mineral resources and mineral development potential of the Valdez Creek Mining District in southcentral Alaska. This study is part of the Bureau's ongoing statewide mining district evaluation program. This report summarizes the Bureau's site specific evaluations of two areas (Tyone and Peters Creek) of the district that were investigated to determine the bedrock sources of gold and PCM in the alluvial gravel of both areas. In the Tyone Creek area, grains of gold (up to 0.0212 oz/yd3) and platinum group minerals (PCM) were recovered from alluvium and weathered conglomerate of the Jurassic Naknek Formation and Tertiary age using placer sampling techniques, Platinum and palladium were detected in the heavy mineral concentrates recovered from placer sampling the alluvium, and Naknek Formation and Tertiary conglomerates. In the Peters Creek area, grains of gold (up to 0.014 oz/yd3) were recovered from the alluvium and Tertiary Sterling Formation conglomerate. The Bureau's evaluations indicated that drainage basins containing conglomerate are the most favorable targets for placer gold and PGM exploration; and Tertiary conglomerate represents a high volume, low grade gold resource.

Jan 1, 2011

By W. C. Smith

This Bureau of Mines report discusses how pull-test data can help establish polyester resin column length criteria for roof bolts in evaporite minerals. The study evaluates the effectiveness of partial to full columns of resin in anchoring 4-ft, No.6, grade 40 rebar roof bolts in potash, salt, trona, gypsum, and borate mine roofs. Pull tests were performed on over 600 roof bolts in 11 evaporite mines. Column lengths ranging from 6 to 48 in (fully grouted) were evaluated for each test site. In general, comparative results among all test sites indicate that pull-out loads in excess of 10 tons (force) were attained with resin-grouted bolts having 13 to 75 pet less than a full column of polyester resin. Ten tons (force) of load-carrying capability compared favorably, in terms of strength, with the calculated yield strength of the rebar used in the tests, which was 8.8 tons (force). The site-specific nature of each test site, due to the unique combinations of geology, mine-induced stresses, and other unknown parameters, prevented the establishment of valid generic column-length criteria. For these reasons, data to evaluate resin-column-length effectiveness are best obtained on a mine-specific basis.

Jan 1, 1987

By H. S. Caldwell

A magnesium-base incendiary alloy, containing about 20 percent cadmium, 4 percent aluminum, and 0.5 percent zinc, was investigated in a series of vacuum-distillation experiments to determine the feasibility of recovering magnesium and cadmium as refined metals. Alloys prepared in the laboratory and actual bomb-casing alloy were studied at temperatures of 550° to 750° C. and pressures of 100 to 150 microns. Simple distillation and fractional distillation methods were only partly effective in separating the cadmium and magnesium. They were separated satisfactorily, however, with a special vapor baffle designed to condense the metals selectively. Magnesium and cadmium products were 99 percent pure and together comprised 82 percent of the total condensate. About 17 percent of the condensate was intermediate-grade alloy that could be recycled with new charge and contained about 70 percent magnesium and 30 percent cadmium.

Jan 1, 1959

By T. E. Gray

This report describes the preparation characteristics of the significant coalbeds in Harrison County, W. Va. It is one in a series of Federal Bureau of Mines reports planned to determine coals suitable for the production of metallurgical coke, either as mined or after beneficiation. Over 6.5 million tons of coal was produced in Harrison County, W. Va., in 1958, of which over 3.7 million tons was cleaned mechanically in seven preparation plants. All of the coal cleaned was from the Pittsburgh bed. It has been estimated that more than 1,816 million tons of coal remains in the county in beds 12 inches or more thick. The Pittsburgh and Redstone beds were selected by the Bureau for a study based on current production rates and estimated minable reserves. Sample locations were selected following a study of the literature, conferences with mining engineers and mining company officials in the field, and examination of the available sites. Six samples were collected from the Pittsburgh bed, and three samples came from the Redstone bed, Float-and-sink tests of the samples collected from the Pittsburgh and Redstone beds showed that neither coal could be upgraded to a metallurgical fuel under the standards set up for this study, even after intensive preparation. Finer crushing of the samples moderately increased the yields and slightly reduced both the ash and the sulfur contents in the 1.30-specific-gravity float fractions. Finer crushing slightly decreased the yields in the 1.58-specific-gravity float fractions, whereas it reduced the sulfur content 0.11 percent for the Redstone sample and 0.46 for the Pittsburgh sample.

Jan 1, 1961

By Heine Kenworthy

"INTRODUCTION In 1930 the Shenandoah-Dives Mining Co. near Silverton, Colo., put into operation a newly erected, 300-ton selective flotation plant to mill complex ores from its nearby mine. The operation was a steady producer and was enlarged to treat 600 to 800 tons a day. In 1942 the company opened and started milling an area in the mine containing semioxidized ore. The valuable mineral content of this ore was considerably higher than in, the straight sulfide ore previously handled alone. The mixture of clean sulfide and semi-oxidized ore was difficult to treat; consequently, tailing losses, especially with respect to lead, were high. A few years later, in order to study the possibilities of obtaining higher recoveries by a modification of the mill flow sheet, a 1,200-pound sample of mill, feed, taken over a period of several days by the company, was submitted to the Mississippi Valley Experiment Sta¬tion for testing-. Although this sample proved to contain more than twice as much lead as the average yearly mill feed, the same problem of recovering the oxidized values was present.A résumé of the ore-dressing treatment used in the Shenandoah-Dives mill follows. After crushing, the ore passes through a ball mill, the minus 5-mesh discharge of which is distributed to three tables. A finished lead concentrate is made on the tables, and the table tailing goes to the classifier which is in closed circuit with the ball mill. The classifier overflow is treated -by flotation to obtain a bulk sulfide concentrate at a relatively coarse size. The bulk concentrate is thickened and reground to about 95 percent minus 325-mesh before flotation treatment to separate a lead-copper and a zinc concentrate. A typical monthly average showed that the table concentrate contained about 45 percent lead, 1 percent copper, 4 percent zinc, 12 ounces of gold, and 40 ounces of silver; that the lead flotation concentrate contained '35 percent load, 6 percent copper, 7 percent zinc, 3.5 ounces of gold, and 50 ounces of silver; and that the zinc flotation concentrate contained 2 percent lead, 0.5 percent copper, 60 percent zinc, 0.15 ounces of gold, and 4 ounces of silver. Recoveries in salable products were roughly b5 percent of the lead, 70 percent of the copper, 45 percent of the zinc, 85 percent of the gold, and b5 percent of the silver."

May 1, 1948

By Carl Belser

This report is the first of a series dealing with the oil-shale reserves of the Green River formation in the Rocky Mountain Region. The known oil-shale reserves of northwestern Colorado at present considered to have economic value apparently are confined to the Piceanco Creek basin between the Colorado and White Rivers. The number of sampled sections is small, but there can be little doubt that the Piceance Creek basin is a potential source of enormous quantities of liquid fuels and the related byproducts obtained from oil-shale processing. The partly blocked and inferred oil-shale reserves of 25-gallon-a-ton shale are estimated to have an oil yield of 125 billion barrels and the reserves of 15-gallon-a-ton shale are estimated to have an oil yield of 494 billion barrels. The number of available sampled sections is inadequate for making firm estimates.

Jan 1, 1951

By Charles E. Whieldon, C. I. Pierce

Data on the oilfields in Mahoning , Columbiana , Carroll , Jefferson , and Harrison Counties , Ohio , were collected from scattered sources and compiled to make the information readily available to operators who may be interested in conducting secondary - recovery operations in the area . General geology , oil production , oil - productive acreage , core data , reservoir calculations by townships , and miscellaneous data and reference material are presented .

Jan 1, 1965

By C. W. Dwiggins

This report describes the development, theory, and application of techniques and instruments for quantitatively determining nickel, vanadium, and iron in oils, using direct, X-ray emission spectrographic methods (5, 6).3 The methods developed apply to petroleum and other oils as well as some specific fractions of oils. The quantities of nickel, vanadium, and iron in various petroleums are of practical and theoretical interest. Even traces of nickel and vanadium may poison cracking catalysts, and X-ray methods have been used for determining nickel in such catalysts (7). At least parts of the nickel and vanadium occur as metal-porphyrin complexes, a fact which may have considerable bearing on knowledge of the origin of petroleum.

Jan 1, 1962

By G. L. Neumann

"INTRODUCTION Mining in this area is inactive. The entire region is now comprised of small farms. Because approximately 1,500,000 tons of magnetite ore had been shipped from this area between 1855 and 1915, it was deemed probable that geophysical surveying and core drilling might indicate other ore bodies or sizable extensions of the previously mined ore bodies.ACKNOWLEDGEMENTSIn its program of investigation of mineral deposits, the Bureau of Mines has, as its primary objective, the most effective utilization of our mineral resources, thus fortifying our national security and economy. It is the policy of the Bureau to publish the facts developed by each project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual investigative work and prepares the final report. The Metallurgical Branch, Oliver C. Ralston, chief, analyzes samples and performs beneficiatien tests.The chemical analyses and beneficiation tests included in this report were performed at the Eastern Experiment Station of the Bureau of Mines at College Park, Md., under the general supervision of J. B. Zadra, chief, College Park Division, Metallurgical Branch, and the immediate direction of Dr. Alton Gabriel, head of the laboratory service unit.The Mineral exploration Was under the general supervision successively of G. D. Jermain, district engineer, C. B. White, district engineer, and McHenry Mosier, chief, College Park Division, Mining Branch.The geophysical section of the exploration was performed by G. B. Botsford, engineer of the Bureau of Mines. Assistance was given by the Division of Geophysical Exploration of the Bureau of Mines, Dr. F. W. Leo, chief."

Dec 1, 1947

By G. H. West, R. L. Sebastian, W. A. Darror

"This bibliography was compiled in the course of research work by the Bureau of Mines on the utilization of magnesites in the West. The results of the research will appear as a bulletin of the Bureau.1. ANALYTICAL METHODS. 11 Knight, X. and Wheeler, W.H. Proc. Iowa Acad. Sci., 13, 1907, 167 (C.A.1, 1370). Describes experience in analysing calcite and dolomite. Reports great excess of oxalate unnecessary and separation of sulphates by alcohol is best.2 Meyerhofer, J. Zeit, Angew. Chem., 21, 1908, 592. Direct determination of Mg as phosphate after removal of SiC2, by keeping R203 in solution with ammonium citrate.3 Merckschen Guano Phosphat Werke. Chem. Ztg., 33, 1909, 545 (C.A. 3, 2281). volumetric analytical methods.4 Popel, M. Zeit. Angew. Chem., 21, 1908. 2082 (C.A, 6, 412). Determination of CaO in presence of CaC03.5 Blasdale, W.C. Jour. Am. Chem. Soc., 31, 1909, 91? (C.A. 3, 2658). Studies of separation of Ca from Mg.6 Hundeshrgen, F. Zeit. Offent. Chem., 15, 1909, 85 (C.A. 3, 1853). Valua¬tion of caustic magnesia by analysis. Volumetric methods.7 Frerichs, H. and Krosberg, W. Apoth. Zeit., 24, 1909. 679 (C.A. 3, 2996). Tecting magnesia alba for Fe.8 Schoorl, N. Zeit. Anal, Chem., 48, 1009, 593 (C.A. 4, 5E9). Microchemical tests for Mg, Li, K. and Na.9 Heyer. Chew. 2Ag., 33, 1009, 1157 (C.A. 4, 1588). Determination of CaO in presence of CaCO3. CaCO3 in soluble in cold neutral solution of NH3 salts. Solubility Is diminished by free NH4OH."

Oct 1, 1923

By John H. Soulé

"INTRODUCTION The Mining Branch of the Bureau of Mines has used the wagon drill to sample mineral deposits in New Mexico. This method of sampling was successful and con¬stituted an important phase of the work on five exploratory projects undertaken in 1943, 1944, and 1945. The deposits varied in topographic features, geology, mineral content, and in the physical characteristics of the rocks drilled. The altitudes ranged from 630 to 7,800 feet. Three hundred and seventeen holes totaling 6,852 feet were drilled. The deepest hole was 66 feet; the average depth was a little less than 22 feet.The results of the above-mentioned work form the basis of this report. Special attention is given to the later and more improved techniques used. This report was written with the expectation that the procedures might prove advantageous to others in the exploration and sampling of near-surface mineral de¬posits, and that a more extended use of the technique might result.AcknowledgmentsAcknowledgment is due Charles H. Johnson, chief of the Rolla Division, Mining Branch, for helpful suggestions in starting this work, and to J. H. Hedges, chief of the Tucson Division, Mining Branch, W. R. Storms, engineer-in-charge of the Silver City, N. Mex., Field Office, and Donald H. Mullen, mining engineer attached to that office, for assistance in preparing and editing this report."

May 1, 1947

By R. S. McClain

Continuous-circuit flotation and batch-scale precipitation tests were made by the Bureau of Nines to determine rejection of carbon and recovery of fluorine and aluminum compounds from aluminum reduction plant residues, About 40 to 60 pounds each of aluminum fluoride and cryolite are lost for each ton of aluminum produced. Gasoline and turpentine were satisfactory for floating carbon from both fresh water and saturated solution systems. Soluble fluorine and aluminum compounds were recovered by precipitation with sodium aluminate and carbon dioxide. Over 99 percent of the carbon was removed by flotation. Fluorine and aluminum recoveries up to 77 and 63 percent, respectively, were obtained in a combined precipitate and nonfloat product, In the fresh water system the combined product was mostly cryolite with some gibbsite. In the saturated solution system the product was mostly sodium fluoride, some cryolite, and minor amounts of gibbsite.

Jan 1, 1963

By N. S. Dalal, Xianglin Shi

"Electron spin resonance (ESR) spin trapping experiments have been carried out to investigate the mechanism of sulfite oxidation em¬ploying 5,5-dimethyl-l-pyrroline-1-oxide (DMPO) as a spin trap. The results show that sulfite autoxidation, catalyzed by Mn(II), involves not only the SO-3 radicals but also the •OH radicals. An addition of H2 02 to the sulfite aqueous medium significantly increases the •OH radical formation. This result provides new clues to the chemical mechanism of the sulfite oxidation and the sulfite toxicity.INTRODUCTIONStudies of the oxidation of the sulfite (SO 2-/3) ions under various conditions are of high current interest because excessive exposure to sulfite is toxic and the origin of this toxicity seems to involve sulfite oxidative pathways [1]. An important fact is that human exposure to sulfite is on the increase [1,2]. Some of the increase in the sulfite exposure is linked to the fact that SO2 is a major air pollutant [2] and in aqueous media SO2 exists in equilibrium with SO2-/3. In addition, beverages and foods are common sources of sulfite intake. For example, sulfite is used extensively in the wine industry as an inhibitor of yeasts and bacteria and is present in finished wines in concentrations up to 6 mM [1]. Sulfite is also often added to dehydrated fruits, vegetables and soups, as well as fruit juices and beer [1,3,4]. Because of these, the mean daily intake of sulfite from diet (in the United States) has been estimated to be between 0.0014 and 0.14 mM/kg body weight [1]. At such high levels, sulfite exposure can have toxic effects, such as the induction of an acute asthmatic state [5,6]. Sulfite also appears to have adverse genetic effects [7] and can act as a mutagen or comutagen [8] and a cocarcinogen [5,7-9]."

Jan 1, 1990

By Frank J. Weibelt

In accordance with provisions of the Strategic Minerals Act of 1939, the Bureau of Mines surveyed the chromite occurrences in California. The Seiad Creek deposit afforded excellent opportunity for developing reserves that could be used by the nation in case of critical shortages of the mineral. Subsequently an exploration and development program was undertaken in April 1941, which was concluded in October of the same year. Work included road construction, diamond drilling, drifting and crosscutting, surface trenching, and sampling.

Jan 1, 1949

By J. E. Schiller

The Bureau of Mines is investigating methods to treat waste water that contains cyanide. This report describes a new method that removes heavy metals and all forms of cyanide. In the first step, hydrogen peroxide and sodium thiosulfate are added at pH 7 to 9 in a 1:2 molar ratio to convert free and weakly complexed cyanide to nontoxic thiocyanate. Then steryldimethylbenzylammonium chloride is added to precipitate ferro-cyanide, and finally, ferric sulfate is added as a sweep floc and sequestrant for heavy metals. After the suspended solids settle, the water is polished by filtering. The water initially contained 1 to 5 mg/L Fe, 1 to 5 mg/L Cu, and 10 to 30 mg/L total cyanide; the level of each of these constituents was reduced to less than 0.02 mg/L.

Jan 1, 1983