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By J. L. Hoffman, F. W. Wood, R. A. Beall, W. E. Anable

For melting and purifying reactive and refractory metals , two electronbeam furnaces have been constructed and operated on the principle of highpowered vacuum diodes . It was necessary to design the vacuum and electrical systems , mechanical features , and operating procedures to cope with dynamic conditions . Vacuums of 10-5 torr , tens of kilowatts of power at 5 to 10 kilovolts , and the evolution of impurities at thousands of liters per minute constitute a challenging combination . The furnaces have been used to melt either button specimens weighing several hundred grams or , by feeding material as a consumable electrode , small ingots weighing several kilograms . Hafnium is among the metals that can be purified . For example , hafnium starting material with Rhn 94B was softened to Rhn 70B after 2 hours of melting under a 25 - kw electron beam , and impurity levels were reduced as follows : Oxygen , from 700 to 350 ppm ; nitrogen , from 71 to 20 ppm ; hydrogen , from 6 to 1 ppm ; aluminum from 75 to < 20 ppm ; chromium , from 80 to < 10 ppm ; iron , from 100 to 40 ppm ; and silicon , from 40 to < 20 ppm .

Jan 1, 1963

By August J. Kwitowski

This Bureau of Mines report summarizes the development of a protective operator compartment for a new generation thin-seam mobile bridge carrier. The developed compartment is commercially available and is currently employed on approximately 15 bridge carriers used in the mining industry. The design of the compartment, which employed human factors engineering and small- and full-scale mockup models, is fully described. Details of the compartment&apos;s fabrication, evaluation, and demonstration in a commercial low-seam coal mine are also provided.

Jan 1, 1986

By A. D. McMahon

Changes in world mine and smelter supply sources of zinc have led to changes in zinc supply patterns in the United States during the past 3 years, 1970-72. The result has been a growing reliance on foreign sources of zinc metal to furnish an ever-increasing portion of expending domestic requirements. This review of fundamentals and historical developments is intended to provide background in order to place the future of the U.S. zinc industry fn perspective. The properties and uses of zinc are described. A new study on U.S. reserves is presented with description by geographical region and comparisons with older reserve data. The technology of the zinc industry from prospecting through refining is described with emphasis on the metallurgy involved in the various methods of smelting. Production, consumption, and imports are discussed and illustrated with graphs and tables to review the past and present patterns. Government actions affecting the industry are shown.

Jan 1, 1974

By T. F. Anstett

The Bureau of Mines evaluated the potential availability of chrysotile, amosite, and crocidolite asbestos from 42 properties in market economy countries. This resulted in the development of tonnage-cost relationships indicating the quantity of grades 3 through 7 asbestos at various average total costs of production at 0% and 15% rates of return on invested capital. The availability of grades 2 and 8 was also evaluated, but since each is produced at only one property, no analytical results were given. Total demonstrated recoverable chrysotile fiber potentially available of grades 3 through 7 from the 42 properties evaluated follow: 1.59 million t, 21.00 million t, 16.74 million t, 15.54 million t, and 19.27 million t, respectively. The total amount of crocidolite is 1.69 million t. Owing to the good potential for discovery and development of new deposits, long- term availability of fiber of all three types is not in jeopardy. However, many of the crocidolite properties evaluated in the northern Cape crocidolite field of South Africa have relatively small demonstrated resources, and new deposits will have to be exploited by the late 1990&apos;s to sustain projected levels of production.

Jan 1, 1985

By Robert D. Saltsman

Two modes of seal application were identified, and promising state-of-the-art seals of both types -shaft and drum -were selected for initial rating by non-destructive testing. Only one shaft seal survived the initial test, and a search was made for other candidate seals including new seals. One new type of seal was found that gave promising enough operation, as both a shaft and drum seal, to be recommended for installation in prototype wet-head machines.

Jan 1, 1975

By A. R. Mumford

During the course of an investigation conducted by the fuel section of the Bureau of Mines , on a hand- fired return- tubular boiler plant , it was found that the average cost of fuel to produce 1,000 lb. of steam was $ 0.5287 . Tests conducted after some simple changes had been made in the furnaces , and in the control of the boilers , showed the previous high cost of fuel per 1,000 lb. of steam could be reduced to the reasonable figure of $0.3540 , or the equivalent of over 30 per cent saving in fuel cost .

Mar 1, 1923

By A. N. Fried

With the growing importance of fluid injection in recent years, the petroleum industry has been investigating and field- testing a variety of new methods designed to modify the physical properties of reservoir oil to improve the efficiency of gas and water injection. These procedures include condensing-gas drive, LPG (liquefied petroleum gas) injection, alcohol-slug process, high-pressure-gas displacement, detergent-solution flooding, and in situ combustion (30, 37).3 A new and different method to increase the effectiveness of gas and water injection has been tested by the Bureau of Mines, Consideration of both fundamental and practical factors that operate to limit the oil recovery attain- able by conventional oil-displacement mechanisms led to the concept of a displacement mechanism called the foam-drive method. This report describes the experimental study that tested this concept in the laboratory.

Jan 1, 1961

The first metal-mine accident-prevention course was prepared and published in 1942-45 as a series of seven miners&apos; circulars (Nos. 51-57). The scope of the course has been broadened, revised, and brought up to date, and it is being published as a similar series of seven miners&apos; circulars on accident prevention in metal and nonmetallic mines. These circulars are: 1. Accident Statistics (Miners&apos; Circular 51), dealing with general statistics on accidents and injuries at metal and nonmetallic mines, including causes, costs, and the uses of investigations and reports of all accidents.

Jan 1, 1957

By W. L. Dare

This information circular is one of a series published by the Federal Bureau of Mines in which the methods and costs of producing uranium ore on the Colorado Plateau are discussed. This report describes the three largest company-operated uranium mines of Climax Uranium Co. - the G-1, the Mineral Joe, and the Frank No. 1. Climax Uranium Co., a subsidiary of American Metal Climax, Inc., was [corporated] May 11, 1950, just 2 years after establishment of the domestic uranium program by the Atomic Energy Commission. Twenty-five years earlier Arthur H. Bunker, now chairman of the board, American Metal Climax, Inc., organized and operated the U. S. Vanadium Co. at Rifle, Colo.3/ Soon after Climax Uranium Co. was organized, it entered into a contract with the Federal Government to build a uranium-vanadium processing mill in Grand Junction, Colo. Under the contract Climax leased from the Federal Government certain uranium-bearing lands that had been withdrawn from public entry in 1948. From Minerals, Engineering Co. on June 12, 1950, Climax acquired other uranium-vanadium properties on Calamity, Outlaw, and Monogram Mesas in Colorado and on Polar Mesa and in the Yellow Cat area of Utah. To house the milling equipment, Climax leased the old Grand Junction sugarmill building of the Holly Sugar Co. Milling facilities, based on a then new process developed for treating both uranium and vanadium, were completed, and the plant went into production in 1951.

Jan 1, 1959

The Bureau of Mines recognized the need for a demonstration program to distribute and apply existing information regarding the illumination of working places in mines. This report details the performance of illumination systems which were installed on several different types of mining machinery.

Jan 1, 1978

By S. J. Aresco

The Bureau of Mines has been active in promoting the purchase of coal for Government use under specificetiona that define the requirements in terms of heating value of the coal, expressed in British thermal units, and the composition as shown by proximate analyses. To these, when required, are added the fusing temperature of ash and the free-swelling index. Under most of these specification contracts the bidders guarantee the quality of the coal, end that guaranteed by the successful bidder becomes the standard of his contract. The deliveries are sampled in accordance with instructions3/ issued by the Bureau; the samples are analyzed in the Bureau&apos;s laboratory to determine whether the coal is of the quality guaranteed by the contractor and, if it is not, a price adjustment is made. Analyses of the delivered coal and "tipple" samples (samples collected at mine tipples as coal is being loaded into railroad cars or trucks) provide valuable data for use in evaluating future bids. In addition, the continuous sampling of coal as delivered 1s a check on the practical results obtained in burning the coal.

Jan 1, 1953

By J. Frederick Stampfer

Current certification testing of self-contained breathing apparatus includes tests with human subjects wearing the apparatus while exercising. During these tests, certain apparatus variables are measured during rest periods. Because of concerns that the present tests may not accurately simulate the stresses to which an apparatus is subjected in the field, the Bureau of Mines proposed new human subject tests. It was also felt that different measurement techniques would supply more reliable data on the apparatus response to these stresses. The Los Alamos National Laboratory was asked by the Bureau to evaluate the proposed tests and monitoring techniques. The major conclusions derived during this study are these: (1) The proposed tests are not too physically demanding. (2) As long as human test subjects are used, a minimum subject weight should be required for certification tests. (3) Important apparatus variables are the breathing resistance, temperature, and carbon dioxide and oxygen concentrations of the inhaled gas. (4) Continuous monitoring should be used, rather than monitoring only during rest periods. (5) New pass/fail criteria based on realistic estimates of the user&apos;s physiological requirements, as tempered by present and future engineering limitations, are needed. (6) When available, breathing machines, rather than human subjects, should be used for most certification testing. (7) A more realistic ergonomics test than that proposed is needed. (8) A gas leak test for the system and a facepiece leakage test are also needed.

Jan 1, 1983

By G. J. Slavens

The U.S. Bureau of Mines conducted research on preparing submicrometer titanium nitride (TiN) powder as a substitute for tungsten carbide (WC) in cutting tools and wear-resistant parts. Earlier research on a small scale was expanded to include a larger reactor. The TiN powder was produced by contacting titanium tetrachloride (TiCI4) with anhydrous ammonia (NH3) in the presence of Mg at 1,100° C. The powder was collected in an electrostatic precipitator (ESP) filled with ultra-high-purity (UHP) Ar. All collected powder was thermal vacuum distilled to remove Mg and magnesium chloride (MgCl2), leaving the purified TiN. Powder handling and purification procedures were conducted to assure low oxygen content in the powder product. Oxygen content in the distilled TiN powder product was as low as 0.40 wt pct. Nitrogen averaged near 22.0 wt pet with a high of 22.4 wt pct. The purified powder product had an average median particle diameter of 0.14 µm with a standard deviation of 0.09 µm.

Jan 1, 2010

By Joseph Coffman

There are 14 operations that supply 97% of the Market Economy Country (MEC) manganese and contain nearly all of its resources. Six mines account for about 70% of the production and 85% of the resources; there are no known resources that are economically close to those that are currently being mined. Costs (January 1989 dollars) of producing manganese concentrates from the operations evaluated are estimated to range from $ 0.96 to $ 1.86 per long ton unit (ltu or 22.4 lb) of contained manganese. Total MEC demonstrated resources evaluated amount to about 1.2 billion tons of in situ ore containing 474 million tons of manganese. Identified resources amount to about 1.8 billion tons of in situ material. Key results of the study indicate the following: 1. The MEC supply of manganese will be from the currently mined resources well into the next century. 2. Centrally Planned Economy Countries (CPEC&apos;s) will be increasingly dependent on MEC manganese ore and concentrate in the future. 3. At the 1976 to 1987 demand increase rate, total MEC resource needed through the year 2000 would be about 282 million tons of in situ material. 4. Transportation and infrastructure support will continue to be major elements of production costs.

Jan 1, 1992

By A. C. Fieldner

In the course of its investigations on the properties of coal and in rendering fuel-inspection service to other agencies of the Government, the Bureau of Mines has accumulated a comprehensive file of coal analyses that includes data on virtually every coal field of commercial importance in the United States. As knowledge of the composition of coal is potentially valuable to every user of coal, the Bureau publishes its analytical records. Before 1921 such publications contained analyses of coal from all parts of the United States; individual analyses or average analyses of a series of shipments of coal were given with the name and location of the mine producing the coal. Beginning in 1921 the analyses were published by separate States because the quantity of data had become so great. The separate papers published to date, with Bureau of Mines Technical Paper numbers, are as follows: Alabama, 347; Arkansas, 416; Colorado, 574; Illinois, 634 and 641; Indiana, 417; Iowa, 269; Kansas, 455; Kentucky, 30S; Maryland, 465; Missouri, 366; Montana, 529; New Mexico, 569; Ohio, 344; Oklahoma, 411 ; Pennsylvania (bituminous), 590; Tennessee, 356; Utah, 345; Virginia, 365; Washington, 491 and 618 (618, published in 1941, supplements 491); West Virginia, 405 and 626; and Wyoming, 484. From time to time the various papers will be revised to include later analyses and other data. The Bureau of Mines annually receives many inquiries as to the composition of coals obtained from specific localities or, conversely, as to the localities from which a given kind of coal may be obtained. This paper presents a summary, in tabular form, of the composition of commercial coal resources of the country. Specimen analyses are given exemplifying the analysis of coal mined in each coal-producing county, or, where it was feasible, coal from each bed in each county; also, ranges of analyses, within which the composition of most of the coal represented will fall, are given where there were enough analyses to permit satisfactory determination of the ranges. In addition, the degree of metamorphism from lignite toward anthracite of much of the coal is indicated by the classification by rank. This classification reveals to more experienced users of coal some of the general properties of coal, that is, whether the flame will be long or short, whether the coal will cake in the fire, and how it is likely to behave on exposure and in storage.

Jan 1, 1942

By Norma Golumbic

The primary purpose of the Bergius (hydrogenation of coal) and Fischer-Tropsch (hydrogenation of carbon monoxide) processes is the production of synthetic liquid fuels. This objective is of importance in insuring an adequate supply of motor fuels and lubricating oils in the United States. In the urgency of the basic research and process development work on synthetic liquid fuels, the possibilities for the production of synthetic chemicals inherent in these processes have hitherto received little attention in this country. However, the by-products, as well as the primary products, from the Bergius and Fischer-Tropsch processes are rich source materials for organic chemicals. The overhead oil from liquid-phase hydrogenation of coal, for example, contains benzene, toluene, xylene, cyclohexane, methylcyclohexane, aromatic solvents, about 20 percent tar acids (largely phenol, cresols, and xylenols), and 3 percent nitrogen bases. Wax, alcohols, and acids are by--products of the Fischer-Tropsch synthesis. In addition, techniques have been developed which make possible the production of aliphatic hydrocarbons, alcohols, acids, aldehydes, and other oxygenated organic compounds. These chemicals are more valuable on a unit basis than gasoline. Because of continued rapid expansion of the plastic, resin, lacquer, and solvent industries, larger amounts of many of these chemicals will be needed in the near future.

Jan 1, 1949

By C. Thomas Hillman

The practical concern of economic minability of large, high-grade manganese nodule deposits in the northeast Pacific Ocean is addressed in this Bureau of Mines report. Principal objectives are to (1) estimate tonnage and grade of deposits with significant potential and (2) describe and estimate profitability of operations designed to mine and process deposits with greatest apparent potential. Analysis of data from over 800 ship stations identified three areas for detailed study. Average metal contents of these areas range from 1.30 to 1.45 wt pet nickel, 1.00 to 1.24 wt pct copper, 0.21 to 0.26 wt pct cobalt, and 26.8 to 27.8 wt pct manganese. Estimated recoverable nodule resources are 67.0, 66.9, and 148.8 million dry metric tons (t). A system to mine, transport, and process nodules from the three sites is described and costed. Although hypothetical, the system utilizes hydraulic mining and Cuprion (Kennecott) processing, which have been successfully tested at pilot scale. Nickel, copper, and cobalt are the three primary products, but ferromanganese is a considered option. Estimated capital requirements are approximately $1.5 to $1.7 billion for three-metal production. If ferromanganese were recovered, an additional investment of about $130 million would be required. Operating costs range from $71 to $83 per dry metric ton of nodules without manganese, and from $103 to $123 per dry metric ton with ferromanganese. Discounted cash flow analyses predict low returns, ranging from 2.7 to 5.2 pct with ferromanganese and from 4.1 to 6.0 pct without.

Jan 1, 1983

By Pedro Lilienfeld

This Final Report describes a program whose objective was to design, develop, fabricate, and test an airborne mass monitor for unattended and recording measurements of the concentration of dust in mining environments. Sensing collection are performed by beta-radiation attenuation and inertial implementation respectively. The instrument is portable, battery or line operated provides a digital printout of the mass concentration during each selection sampling period, as well as the accumulated mass of dust, and the elapsed sampling time.

Jan 1, 1974

By FREDERICK L. WARD

This paper , describing the operation of the Ward Sand and Gravel Co.'s plant at Oxford , Mich . , is one of a series being prepared for and published by the United States Bureau of Mines on methods and costs of mining and preparing sand and gravel throughout the United States . These papers are designed to disseminate technical information regarding the methods used . The cost tabulations represent local operating expenditures only and not total production costs . It is recognized that publication of total costs might in some instances cause embarrassment to individual producers as well as to the industry as a whole . On the other hand , operating costs are essential to the technical discussion and study of the methods employed . The attention of the reader is specifically called to this differentiation in order that no misunderstanding of the scope of the cost tabulations shall ensue . The plant described is a dredging operation with many unique features ; especially noteworthy are the mining of the sand and gravel with hydraulic jets operating on the principle of a water ejector , the unusual construction of the dredge and the self- unloading barges that tend it , the transportation of the sand and gravel to shore in barges instead of in pipe lines , the large storage capacity of the plant , and the fact that all material goes into storage before being shipped .

Jan 1, 1932

By Robert L. Lagace

A prototype adaptive volume control for the loudspeaker output of mine trolley carrier phones was designed, built, and tested in the laboratory and in a mine. This volume control senses, and adapts to, the ambient acoustic noise environment in such a way as to produce a loud sound output under noisy conditions, and a quieter output under quiet conditions, thereby producing an understandable and unstartling volume level under all noise conditions. The design approach, prototype hardware, and test results are described, and the device is shown to be feasible for in-mine operations. The circuit design principles are easily applicable to currently available mina trolley carrier phones. Recommendations for practical improvements are included. An in-mine experiment to assess the practical feasibility and utility of the dedicated wire technique for overcoming poor trolley carrier phone system performance was designed, performed, and evaluated. The technique involves the use of a single, low-loss, properly terminated auxiliary wire, placed in the rail haulageway, which allows signals to naturally couple to and from the trolley wire/rail transmission line, and thereby significantly decrease the overall signal attenuation rate on the trolley wire/rail line. The in-mine dedicated wire experiment, results, and conclusions are described, and the technique is shown to be a valid and practical one for significantly Improving carrier phone system performance in mines. Guidelines for the installation and use of the dedicated wire are provided. Recommendations are made for obtaining further practical information on its performance and utility. A second in-mine experiment to assess the feasibility and utility of the low-impedance (low-Z) line technique for overcoming poor carrier phone signal transmission in mines was designed, performed and evaluated. The low-Z line technique involves the periodic connection of shunt capacitors between the trolley wire and the rail to artificially lower the line characteristic impedance. This causes the low impedance shunt loads encountered across the trolley wire/rail line to be less mismatched to the line, thereby reducing the overall attenuation of carrier phone signals. The results of in-mine experiments performed along unenergized and fully operational sections of trolley wire/rail line are described. The experiments were designed to measure line parameter such as inductance and capacitance per unit length, characteristic impedance, and propagation phase velocity, in addition to signal strength versus distance behavior under normal and low-Z line conditions. The low-Z line technique is shown to be valid, but not as practical as the dedicated wire technique which is recommended as the most favorable for most coal mine applications.

Jan 1, 1979