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By F. M. Goodwin, John Campbell, G. W. Jones

"INTRODUCTION In previous reports 5 results were given of a manhole investigation carried out over a period from June 1929 to July 193C in cooperation with the Edison Electric Illuminating Co. of Boston. Mass., and during 1931 in cooperation with the Edison Electric Illuminating Co. of Boston and the Boston Consolidated Gas Co., to determine the general hazards of combustible gases and vapors in manholes and other underground openings owned by the Edison Electric Illuminating Co. and to develop methods of eliminating these hazards. These investigations have demonstrated that the detection, control, and elimination of combustible hazards in manholes can best be obtained by a close cooperation of the interested parties through a systematic and continuous inspection of manholes, under proper supervision.The investigation carried out during 1932 has been along lines similar to those conducted during 1929, 1930, and 1931 test crew consisting of two men, one an employee of the Consolidated Gas Co. and the other an employee of the Edison Electric Illuminating Co., was continuously employed during the year in the testing of gases in manholes served by the Edison system. The test crew was under the direct supervision of John Campbell, superintendent of the special service department of the Edison Electric Illuminating Co., and F. M. Goodwin, vice president of the Consolidated Gas Co.As in the previous investigations, all tests were numbered. The test-data sheets, on which the information regarding the tests was recorded, were prepared in triplicate, ono copy going to the Edison Co., one to the gas company, and the third to the Bureau of Mines at Pittsburgh, Pa. These test-data sheets were then filed (1) according to the town, (2) the street location, and (3) the manhole number; in this way a complete record of each manhole tested was immediately available. A typical test-data sheet was given in the 1931 report. These data sheets were found to entirely satisfactory and no changes were made during the 1932 investigation. The procedure of sampling manhole atmospheres, shipment of the samples to Pittsburgh, and method of analysis has been the same as that described in the 1931 report and need not be repeated here. Likewise, there has been no change in the method of calculation of explosibility of the samples analyzed or the use of charcoal filter tests given in appendix A."

Jun 1, 1933

By T. J. Ballard

The Tallapoosa Copper mine in Haralson County, Ga., has been operated, or under development at various times since before the Civil War. The geology of the deposit is similar to that of many of the pyrite deposits occurring in the belt of ancient crystalline and metamorphic rocks that extends diagonally northeast-southwest across the State. The Bureau of Mines, in its program of investigation of, strategic mineral deposits, diamond-drilled four holes totaling 1,570.3 feet at the deposit during the period June to September 1947 to verify the old drill records and the continuation of the deposit at depth.

Jan 1, 1948

By Charles Prasky

This report describes bench-scale studies and pilot-plant development of the Bureau of Mines process for roasting iron ores with a ferrous scrap reductant, such as discarded automobile hulks, to yield artificial magnetite. Quality magnetic concentrates containing about 66 percent iron and 6 percent silica with iron recoveries of over 90 percent were obtained after roasting fine-grained oxidized or nonmagnetic taconite with unburned, sheared automobile hulks in a rotary kiln. The relatively complete oxidation of the lighter gage metal in the automobile during roasting resulted in a metallic byproduct consisting of the unconsumed heavier gage metal scrap. This residual or tailored scrap is potentially useful as heavy melting stock and has more value than the original automobile hulk.

Jan 1, 1970

By G. L. Oldright, Virgil Miller

"INTRODUCTION The first ten papers of the series on smelting in the lead blast furnace described the operation at the custom smelter of the International Smelting Co., Tooele, Utah, and at the plant of the Bunker Hill Smelting Co., Kellogg, Idaho, which handled a very rich lead concentrate. These previous papers may be considered a picture of the traditional lead smelter treating custom ores and of the smelter that will treat the type of product likely to be made in the future - lead concentrates of an increasingly rich grade.The great plant at Trail is of special interest to those smelting lead products containing much zinc and faced with the necessity of transforming all of their byproducts into commodities which may be sold profitably. The plant is equipped to produce electrolytic zinc, lead, copper, silver, bismuth, and cadmium. Part of the sulphur evolved from treating the ores is converted into sulphuric acid. Complete fertilizers for agricultural purposes are also produced.The smelter of lead ores has long considered that zinc is one of the most difficult ingredients that he has to handle. Even with the gretat improvement in flotation practice today, the residues from electrolytic zinc plants leaching zinc concentrates must still be smelted for their lead content. Of the total gangue material not separated from the lead concentrate sent to the smelter, zinc is still one of the most notable in percentage. The most successful way of coordinating the over-all operations of a concentrator, an electrolytic zinc plant, and a smelter provided with a plant for re-treating the blast-furnace slag for its lead and zinc content must be of interest to many treating complex ores.ACKNOWLEDGMENTThe data in this paper were collected in cooperation with the Consolidated Mining & Smelting Co. of Canada, Limited, and its entire technical staff. Detailed acknowledgments of assistance received are given in the papers from which this one is briefed."

Sep 1, 1934

By Donald O. Capstick

In 1481, U.S. Bureau of Mines personnel conducted a survey of mines, prospects, and mineral resources in the Table Mountain RARE II area. There are no mines or active prospects in the study area. One prospect in the study area, the Waterfall Prospect, is estimated to contain 480 tons (440 t) of indicated subeconomic tungsten resources averaging about 0.18 percent tungsten trioxide (W03). Other tungsten occurrences are at the Stevens Prospect, just northwest of the area. Stone and sand and gravel deposits in the area are not considered to be resources because equal or better quality material is available closer to major markets. INTRODUCTION The 4,400-acre Table Mountain study area is 13 mi (21 km) southwest of Bishop, California, on the eastern flank of the Sierra Nevada range. The John Muir wilderness adjoins the study area on the southwest (fig. 1).

Jan 1, 1982

By David E. Siskind

The Bureau of Mines has studied the fracturing produced in the vicinity of large-diameter blastholes in Lithonia granite. Cores were taken from the vicinity of AN-FO production blasts and examined using a total of seven laboratory and field measurement techniques to delineate zones of damage and evaluate the effectiveness of the seven diagnostic tests for fracture-state determination. Laboratory measurements of acoustic pulse velocity, porosity, permeability, compressive strength, and Young's modulus indicated the extent of fracturing with the acoustic techniques providing the best means of distinguishing between fractured and unfractured core. A severely fractured zone was found to extend approximately 25 inches (64 cm) from the center of the 6-l/2-inch blastholes, equivalent to 8 blast-hole radii. A second zone, characterized by a lesser degree of fracturing extended from 25 to 45 inches (64 to 114 cm) or 8-to l4-blasthole radii. Beyond 45 inches (114 cm) the rock was undamaged.

Jan 1, 1974

By Mark S. Sanders

The purpose of this work was to develop and field test improved knee protection for underground coal miners working in low seam mines. In a previous phase of this contract (Sanders, 1982), experimental knee pads were developed and field tested. The field test revealed several design deficiencies with the knee pads, and suggestions for improving the design were made. The work summarized in this report, therefore, consists of modifying the design and method of fabrication of the knee pads originally describes by Sanders (1982), and of field testing the improved design. The new prototype was shorter and wider than the original design, and used a neoprene pass-through strap design rather than a cloth strap molded into the pad itself. The new prototype was constructed by slush molding a hollow bladder that was then filled with foam. Initial reactions to the pads in the field test were very positive. However, after two months, the opinions about the new prototype became less positive. They were judged, generally, to be no better or worse than the pads usually worn by the field-test participants. Problems were encountered in the field with respect to durability. Water seeped into the inner cavity of many of the pads and caused the foam to deteriorate. It was concluded that it would not be cost-effective or feasible to significantly improve upon current commercially available knee pad designs.

Jan 1, 1986

By Kenneth H. Johnston

Information and data necessary for research on improving methods of oil recovery from low-permeability reservoirs and for comparison and evaluation of performance of such reservoirs with those producing from more permeable sands were obtained. Core analyses, well logs, production tests, well stimulation techniques, primary and secondary production records, and data on two water-flood projects were examined for wells producing from the Bartlesville sand, West Avant field, Osage County, Okla. Overall recovery from the study area was generally poor with only 9.0 percent of the pore volume recovered to January 1, 1968. Larger fracture treatments (8,000 to 12,000 gal) could have resulted in an increase in primary oil recovery. Secondary recovery by water-flooding accounted for only 1.9 percent of the pore volume because of the inability to control the large volume of injection fluid that escaped from the flood patterns and the excessive volumes of water produced with the oil. Future waterflood development in other low-permeability reservoirs should include the drilling of new input wells, use of injectivity surveys to locate possible natural fracture systems, or zones of high permeability, and control of injection fluids by altering flood patterns and/or plugging of the more permeable zones.

Jan 1, 1968

By d&apos, Kathleen J. Amico

THIS summary appears in Minerals Yearbook volumes I and III, which cover mineral production in the United States, its island possessions, the Canal Zone, and the Commonwealth of Puerto Rico, as well as the principal minerals imported into and exported from the United States. The several commodity and area chapters contain further details on production. A summary table comparing world and U.S mineral production also is included.

Jan 1, 1964

By James W. Jensen, Aarne Visnapuu

Experimental modifications have been made by the Bureau of Mines on standard pneumatic rock drills to reduce the noise of the air exhaust, drill steel resonance noise, and noise radiated by the drill body. A close-fitting case and muffler around the drill body, consisting of a metallic honeycomb skeleton filled with viscoelastic absorber on the inside and a durable outer shell, provide both exhaust and drill body noise muff ling and absorption. Drill steel resonance noise is reduced by a constrained-layer treatment consisting of a tubular metal cover bonded to the ouside of the sod by a viscoelastic filler. Damping alloy components have been developed to reduce metallic resonance noise. Combined, these modifications have reduced the drilling noise level in granite from 115 dbA to 97 dbA. Data are presented on the individual and combined effects of these modifications on drilling noise and performance.

Jan 1, 1975

By G. E. Rennick, F. E. Armstrong, J. Pasini, J. R. Abrams

An oil well penetrating the Pittsburgh bituminous coalbed in northern West Virginia was plugged and safely mined through 3 months later. A sensitive chemical tracer, introduced into the oil reservoir before the test, was not detected in the mine air following the plugging and during mining of the pillar and penetration of the well. Effectiveness of the plugging in preventing reservoir gas from entering the mine through the well hole was verified by continuous monitoring of the mine air for indications of sulfur hexafluoride, an inert gas detectable in amounts as minute as 112 part per billion. Expand- able cement and fly ash-gel-water slurry were utilized to seal the well above and below the coal seam. Three other wells were also plugged using various techniques.

Jul 1, 1972

By d&apos, Kathleen J. Amico

THIS SUMMARY is shown in volumes I and III of this series on mineral production in the United States (including Alaska and Hawaii), its island possessions, the Canal Zone, and the Commonwealth of Puerto Rico, and on the principal minerals imported into and exported from the United States. For further details on production, see the several commodity and area chapters. A summary table comparing world and U.S. mineral production also is included. [ ]

Jan 1, 1960

By T. F. Anstett

The Bureau of Mines investigated the availability of platinum from known major deposits in market economy countries. Fifteen of these deposits contain demonstrated resources totaling 302 million troy ounces of platinum. Detailed geologic, engineering, and cost evaluations were performed on each deposit to determine its potential for platinum production. There are large amounts of demonstrated platinum potentially available from market economy deposits that were not analyzed owing to lack of adequate data or to technological limitations. These include 297 million troy ounces contained in the UG2 and Platreef of the Bushveld Complex, South Africa. This analysis indicates that about 11 0 million troy ounces (2.3 million ounces annually) of platinum are potentially available at the January 1980 producer price of $420 per troy ounce, nearly all from South Africa. An additional 85 million troy ounces occurring in Zimbabwean deposits would become available only through more than a quadrupling of that price. In order to meet projected world demand of 3.5 million troy ounces in 1990, platinum price may have to increase. Only one domestic deposit, the Salmon River in Alaska, is capable of producing platinum at $420 per troy ounce. Regardless of price, at assumed production capacities, domestic deposits could supply less than 10 percent of annual U.S. requirements.

Jan 1, 1982

By Nicholas P. Kripakov

The U.S. Bureau of Mines examined the applicability of existing material models to solve practical geotechnical mining-related problems by solving a yielding pillar stability problem considering confining effects on strength. Numerical difficulties normally encountered with modeling strain softening behavior were eased with a simplified computational procedure using a quasi-elastic approach to account for residual strength after initial failure. Although in agreement with a confined-core pillar design method using actual mine conditions that include mine layout geometry, overburden geology, and rock properties of the deposit and surrounding structure, the results cannot be verified because measured field data are not available at this writing.

Jan 1, 1981

By Donald N. H. Chi

The unsteady, one-dimensional, compressible-flow equations have been solved numerically for a deflagration propagating through a gallery of finite length closed at the ignition end and open at the opposite end. These equations were solved for two situations wherein (1) the propagating flame was extinguished after 0.1 sec or before the return of aerodynamic disturbances reflected from the open end, and (2) the flame was allowed to propagate a full 0.8 sec until it was extinguished. It was found that the process of sudden flame extinguishment creates rarefaction waves that, upon entering the burned zone, produce resonance within the burned cavity. For the relatively small value of the product of the expansion ratio (8.5) and the effective burning velocities of 7.4 m sec-1 for the first experiment and 4.9 m sec-1 for the second experiment, it was found that the acoustic approximation provides an adequate estimate of the pressures developed ahead of the flame during the system's early history.

Jan 1, 1974

By M. Howard Berliner

During the spring of 1944, the Bureau of Mines investigated the Crescent mine area near the village of Rewey, Iowa County, Wis., as part of a general investigation of the zinc-producing area of southwestern Wisconsin. The work was done when every effort was being made to increase the production of metals important to the Nation's war program. The Bureau of Mines completed 24 churn-drill holes in an area immediately to the west of a mineralized section which had been mined through shallow workings for lead and zinc more than 40 years earlier.

Jan 1, 1948

By W. T. Millar

Magnetite mines in the Sterling tract, Orange County, N. Y., were operated almost continuously from pre-Revolutionary days until 1923. The Red-Back mine, one of several in this tract, was discovered in 1780; operated briefly in 1880; and abandoned, presumably because the iron ore contained considerable sulfur. The mine is in rough, mountainous country, with altitudes ranging from 500 to 1,100 feet. The magnetite deposit occurs in complex metamorphosed pre-Cambrian formation and is thought to be a replacement of limestone by magnetite. A dip-needle survey, completed in 1916, traced magnetic anomalies for a mile along the outcrop. A preliminary examination of the Red-Back mine was made by W. T. Millar, Bureau of Mines engineer, in December 1942. The Bureau of Mines bored seven diamond-drill holes aggregating 2,727.6 feet during the winter of 1943-44. A zone of magnetite mineralization was intersected in each of the holes.

Jan 1, 1949

By C. Stephan, E. Weiss, J. Trackemas, M. Sapko

The National Institute for Occupational Safety and Health (NIOSH), Pittsburgh Research Laboratory (PRL), in collaboration with the Mine Safety and Health Administration (MSHA), the mining industry, and seal manufacturers recently conducted a series of full-scale experiments within the underground experimental mine at PRL’s Lake Lynn Laboratory. The purpose of the experiments was toe valuate the explosion-resistant characteristics of several new seal designs for rapid deployment during mine emergencies. These seals can be deployed in 6 to 10 hr and are capable of with standing explosion overpressures in excess of 140 kPa (20 psi). These novel seal designs use available mine materials, do not require conventional rib hitching, and, most importantly, can substantially reduce exposure time for coal miners during sealing and mine recovery operations.

By J. H. Perry, D. W. Houseknecth, C. A. Kertis, A. T. Iannacchione

Major problems facing the development of coal and gas resources of the Hartshorne Coalbeds include the complex distribution of minable and unminable coal, high methane content and bed pressure, faulting, variations in degree of dip, presence of natural gas fields in associated sandstones, and legal problems, caused by local geologic characteris- tics, in identifying gas origin. This Bureau of Mines study provides pertinent geologic information for long-range planning of subsurface coal and gas production from the Hartshorne Coalbeds. Pittsburg, Coal, Hughes, and Atoka Counties, OK, have approximately 1 billion metric tons (1.1 billion short tons) of Hartshorne coal in place. The methane resource of Hartshorne Coalbeds is estimated at 9.2 billion m3 (325 billion ft3) and varies with overburden and rank, These estimates were compiled from gas well density logs, coal-core data, out- crop measurements, abandoned mine maps, and the literature. The Hartshorne Coalbeds represent a valuable coal and gas resource which at present is contributing nothing to coal and gas production. This report discusses potential problems and serves as a reference for future exploration and development work. Recognition of these potential geologically related problems prior to development of this basin will reduce hazards and allow for an economic recovery of these resources.

Jan 1, 1983

By Stephen C. Brown

THE expansion of the world economy which has been in process since 1958 continued in 1963 and both production and consumption of minerals rose. Gross national product (GNP) rose sharply in the United Kingdom and Japan, continued to expand in the United States and Canada, and maintained a high though slightly declining rate of growth in the European Economic Community (EEC) despite the appearance of excess capacity in certain lines and inflationary pressures in Italy and France. The steel and motor vehicle industries both increased output in North America, Western Europe, and Japan. The less developed areas benefited substantially from an improvement in their terms of trade, and their export earnings increased some 8 percent in 1963; although estimates of GNP for the majority of them are 110t yet available, it is probable that this increase was partly reflected in a substantial rise of GNP.2 In the United States the expansion was steady and extended through all sectors of the economy producing no distortions likely to disturb its continuing growth; at yearend with unemployment still at about 5.5 percent of the labor force and operating rates of industry estimated at about 87 percent of capacity, there was a substantial margin for further expansion. Though the balance of payments was still in heavy deficit for the year, in the last half it was moving rapidly toward equalibrium as net exports rose and capital outflows declined; prices were relatively stable, inventories increased only slightly and the activity of mineral-consuming industries remained high, steel output rising by 11 percent to highest level since 1957 and the auto industry output equalling the 1955 record.3

Jan 1, 1964