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By E. P. Youngman

Tantalum is a rare element ; estimates indicate that there is less tantalum than gold in the earth's crust . After remaining a laboratory curiosity for many years , it was used to a limited extent and for relatively few years (1903- 1911) for incandescent electric-light -bulb filaments . Another wave of interest in tantalum appeared when its electrolytic-valve action was taken advantage of in charging storage batteries , especially for radio work . Tantalum chargers were eventually displaced by other types of chargers , but for a time they were manufac tured in sufficiently large numbers to create a demand for the metal and to bring about its production on a commercial scale in the United States . As tantalum became available in larger quantities and at substantially lower prices , and as high prices for platinum encouraged the employment of tantalum as a substitute , the metal was put to many new uses . Ferrotantalum was made and sold before the World War , and patents have been taken out for a number of special alloys for industrial purposes , but probably the largest use for the metal to-day is in vacuum tubes .

Aug 1, 1930

By M. A. Hammer

In this study by the Federal Bureau of Mines Pennsylvania anthracite from the Eastern Middle field was oxidized by concentrated nitric acid at steam-bath temperature for 24 to 1,000 hours. The quantitative data obtained include yields of nitric-acid soluble and insoluble products and the distribution of carbon and ash in each. The acid-insoluble residues were examined for solubility in aqueous sodium hydroxide. With a sodium hydroxide concentration of at least 1 normal, a portion of the residue could be extracted in the form of a true solution. With lower alkali concentrations, peptization occurred. Alkali solubility of the residue increased with length of oxidation. However, when expressed in percentages of original coal weight, the alkali solubility remained essentially constant after 192 hours of oxidation. This suggests that the alkali-soluble products are converted to acid-soluble products at the same rate as the original coal substance is converted to alkali-soluble material. Microscopic observations of the peptization of the acid-insoluble residues revealed a gross micellar physical structure. The action of nitric acid is apparently not restricted to the surface of a coal particle. The acid penetrates the particle through the pore structure, dissolving some of the ash and altering the bonds between the coal micelles. The bond alteration, as indicated by ultimate analyses, involves the physical and chemical adsorption of the components of nitric acid. Some of the altered bonds are not thermally stable; this instability is shown by the complete loss of peptizing ability when the acid-insoluble products are heated above 200° C. This loss is accompanied by the evolution of water, oxides of nitrogen, and hydrocyanic acid.

Jan 1, 1961

By Emery Chilton, Charles Taylor, Mark Senk, Linda McWilliams

Three-axis ultrasonic anemometers are used to study airflow in the NIOSH ventilation gallery where ventilation in an underground mine is simulated. In this study, performance characteristics of this anemometer are evaluated and the effects of sensor orientation and sampler location on flow readings are examined. The study results provide guidelines for more effective use of the ultrasonic anemometers in the ventilation gallery.

By John R. Reigart

The Tri-State district, as its name indicates, is composed of portions of three States, the southeastern corner of Kansas, the northeastern corner of Oklahoma, and an adjacent strip of Missouri east of these portions of Kansas and Oklahoma. An area approximately 40 miles long in a northeasterly-southwesterly direction, and 30 miles wide at right angles thereto, containing minable occurrences of ore at widely scattered locations, comprises the district. However, what has been and is the main productive area, is a strip about 35 miles long and 10 miles wide, which begins at Miami, Okla., as its southern extremity and runs in a northeasterly direction through Commerce, Picher, and Hockerville, Okla., Baxter Springs and Galena, Kans., and Joplin, Webb City-Carterville and Carthage, Mo. Almost the entire present production comes from the area between Commerce and Baxter Springs.

Jan 1, 1932

By J. S. McNabb

"A search for manganese ore by core-drill exploration was carried out by the Bureau of Mines in the Philipsburg mining district in Granite County, Mont., in 1939 and 1940. This work was based on detailed studies of the manganese ore bodies of the district previously made by the Geological Survey.In 1949 further search for manganese in the district was deemed advisable. Diamond drilling was begun the following year as a joint program by the Geological Survey and the Bureau of Mines with the primary purposes of probing ore-leasing structures and extending the limits of known ore bodies. A secondary objective was to test a geologic theory based on a new conception of manganese-ore localization. The exploration targets were designated and the drilling results interpreted by the Geological Survey, and the Bureau of Mines was responsible for the drilling, sampling, and core handling. Improved drilling equipment and methods were utilized in an effort to obtain better core recoveries than resulted from the earlier drilling campaign.The Philipsburg mining district, Granite County, Mont., is 27 miles south of Drurrnnond, about 45 miles airline northwest of Butte, and 1 mile east of Philipsburg. During the course of the investigation patented lode-mining claims owned by the American Machine & Metals, Inc., the Contact Mines, Inc., and the Moorlight Mining Co. were diamond drilled.The district has been an important source of domestic manganese dioxide ore since local recognition of the mineral's importance during World War I. Peak annual output in 1918 of about 127,000 tons of manganese ore was utilized principally by the steel industry. A small but relatively steady output has persisted to the present to satisfy demands by battery manufacturers for battery-grade manganese dioxide.The known manganese deposits of the district are in sedimentary rocks of Paleozoic age. These rocks lie along a north-trending anticline traversed by a series of east-west tension veins. The east flank of the anticline terminates at a steep-dipping fault contact against a small granodiorite batholith.Replacement deposits of manganese oxides and carbonates occur locally in or closely associated with tension veins cutting calcareous rocks, or adjacent to the intrusive. Rhodochrosite has been a common accessory mineral in deposits valuable chiefly for lead, zinc, and silver. Some of the replacement deposits characteristically are irr2gular in outline, whereas others have fairly regular walls marking the limits of favorable beds."

Dec 1, 1955

By William Cochran

The mineral waste disposal system at the Grace Mine, Morgantown, Pa., was designed to minimize environmental effects while allowing much of the waste from the iron mine, mill, and concentrator to be utilized. Standard cost estimating procedures were used by the Bureau of Mines to determine waste disposal costs. Mill tailings and rock waste disposal costs were estimated at $0.151 and $0.276 per ton, respectively, for the 1965-67 production period. Total waste disposal cost was reduced about $0.015 per ton by utilizing part of the waste as aggregate. The net average cost for disposal of all mineral waste was $0.189 per ton.

Jan 1, 1969

By Franklin H. Persse

The Bureau of Mines estimated reclamation costs for 13 surface coal mines in nine States west of the Missisisppi River. With the exception of the Pacific Coast coal province, at least one mine in each of the western coal provinces was studied. Cost estimates were, made using standard estimating procedures from data obtained from company records, interviews with industry personnel, and onsite observations. Estimated costs are presented in four categories which represent the four phases of mined-land reclamation: (1) Design, engineering, and overhead; (2) bond and permit fees; (3) backfilling and grading; and (4) revegetation. Estimated costs as of the first quarter of 1976 are expressed as averages and ranges in terms of per acre, per ton of coal produced, and per million Btu. Total reclamation costs ranged from $860 to $7,200 per acre, from 6 to 84 cents per ton, and from 4 to 35.3 mills per million Btu. A mine in the Northern Great Plains coal province (Region D) showed the highest per acre cost whereas mines in part of the western region of the Interior coal province (Region A) experienced the greatest per ton and per million Btu cost. The high cost of reclamation in the Western United States is reflected in the backfill in and grading category, particularly in the cost of topsoil removal and subsequent replacement as required by individual State reclamation regulations.

Jan 1, 1977

By E. G. King

The literature contains little thermodynamic information regarding inter-oxidic compounds of the ferroalloy elements and, as a result, thermodynamic considerations of extractive and utilization processes involving these elements have been hampered. As part of a Bureau of Mines program to improve this situation, this paper reports the heats of formation of three calcium vanadates and two magnesium vanadates. There were no previous similar data for any of these compounds. The experimental method was hydrochloric acid solution calorimetry, using calorimetric reaction schemes involving the vanadates and their component oxides. The results were expressed as heats of formation from the component oxides and from the elements. Corresponding free energy of formation values were calculated. The data show that the calcium and magnesium vanadates are stable with respect to all possible decompositions in which vanadium remains pentavalent. This conclusion is similar to the one drawn by Koehler6 for three sodium vanadates.

Jan 1, 1962

By S. M. Shelton, A. L. Engel

"This report presents the results of investigations of ore-testing projects assigned to the Ore-Dressing Section, Metallurgical Division, Bureau of Mines, at the Mississippi Valley Experiment Station, Rolla Mo. During the fiscal year ended June 30, 1941.The manner of approving ore-testing projects has been explained in a previous reports. 4/ The testing procedures likewise have been described. 5/The treatment methods described are based upon laboratory experiments with small amounts of sample and naturally are subject to the inherent, normal, limiting conditions of such procedure. It is not intended to describe treatments in detail, but rather to indicate applicable methods. Local operating conditions, when the laboratory results are applied to plant operations, may require further study. Large-scale pilot-plant tests should be made before commercial operations are begun, so that translation from the experimental stage will yield satisfactory results."

Mar 1, 1942

By A. R. Kirchner

This paper describing the practice at the concentrator of the Minas de Matahambre, S. A., is one of a series being; prepared by the Bureau f Mines on milling methods and costs. The Minas de Matahambre, S. A., concentrator treats the production of the Matahambre mine and has a capacity of 1,300 tons of copper ore per day by selective flotation. During the year 1930 the heads averaged 4.55 per cent copper, the concentrates 29.20 per cent copper and the recovery was 95.96 per cent.

Jan 1, 1931

By E. J. Lintner

This paper is one of a series being prepared by the United States Bureau of Mines describing clay mining, crushing, and grinding methods and costs at various operations throughout the United States. These papers are designed to disseminate technical information regarding methods used. The cost tabulations represent local operating expenditures only and not total production costs. It is recognized that in many instances publication of total production costs may cause embarrassment to the individual operator as well as to the industry as a whole. On the other hand, operating costs are essential to a technical discussion and study of the methods employed. The attention of the reader is called specifically to this differentiation in order that no misunderstanding of the scope of the cost tabulations shall ensue. The following report deals with the methods employed by the Malvern Clay Co., Malvern, Carroll County, Ohio. The author wishes to acknowledge the assistance of the following persons: H. C. Ross, vice-president and general manager, and H. C. Dormer, secretary and treasurer.

Jan 1, 1937

By Daniel R. Babich, Jeffrey R. Vipperman, Eric R. Bauer

Prolonged exposure to loud noise can cause permanent damage to the auditory nerve and/or its sensory components. Despite regulations and efforts by government and industry to reduce noise-induced hearing loss (NIHL), it is still a problem in the U.S. coal mining industry. The Mine Safety and Health Administration noise standard (30 CFR3 62), which was enacted in September 2000, is aimed at reducing NIHL in the mining industry. To address NIHL in various aspects of coal mining and provide the necessary information to effectively implement control technologies, the National Institute for Occupational Safety and Health conducted a cross-sectional survey of noise sources and worker noise exposures. Noise surveys consisting of full-shift worker noise exposure (dose) determination, time-motion studies (task observations), and equipment and/or area noise profiling were completed in 8 underground coal mines, 10 surface coal mines, and 8 coal preparation plants. The studies revealed that more than 40% of all workers monitored were subject to noise exposures above 90 dBA TWA8. A summary of these studies is presented, their application to administrative and engineering controls is discussed, and exposure reduction methods are reviewed.

Jan 12, 2006

The Bureau of Mines is operated to assist in promoting economic development through increased efficiency in the mining, preparation, treatment, and utilization of mineral substances; to aid in conserving mineral resources through preventing waste; and to help the mining industry improve health conditions and increase safety. Accomplishment of those ends is sought through investigation of scientific, technologic, and economic problems of the, mineral industries and dissemination of resulting information. Building materials of mineral origin constitute an important product of mining, and the Bureau makes studies of these in the various fields mentioned. The following commodities come within this classification: Asbestos, anhydrite, asphalt, cement, clay and clay products, diatomite, dolomite, glass and mineral wool, granite, greenstone, gypsum, lightweight building materials, lime, limestone, magnesite, marble, sand, sand and gravel, sandstone, sand-lime brick, slate, soapstone, and trap rock.

Jan 1, 1937

By E. P. Youngman

Great Britain has never had a basic raining law such as is in force in most foreign countries. This lack may be due to the fact that, with the exception of gold and silver, all metals or minerals belong to the owner of the surface land. Even with respect to the precious metals, gold and silver, which are not abundant in Great Britain, the right of the Crown, though still technically acknowledged, is not always insisted unon. All other metals and minerals are vested in the ground landlord, who may sell, lease, or other¬ wise convey them. The State has little to do with the mining industry except in. regulatory and judicial matters. The Government must settle controversies and provide for easements, rights of way for railroads, roads, and canals, or, in general, effect the same control that it exercises over other industries. As mining was carried on in very early times in England, of necessity a certain legal procedure came into existence, which in effect was little more than a private contract between the owner of the mineral (whether an individual or the State) and the miner. The nature of such contracts, of course, has changed radically with the changed relations between classes, as England lias developed from the feudal into the modern State. From the medley of ancient procedure and custom, a concession system of mining in^its simplest form lias evolved. Of the earlier conditions. Van Wagenen says

Oct 1, 1931

By D. G. Kesterkel

Low-melting thoriurnrbase binary alloys or metal solutions were prepared by two different techniques involving the electrolysis of ThO2 dissolved in fluoride melts. Experiments were performed at 950° to 1,250° C using electrolytes containing ThF4 and various alkali and alkaline earth fluorides. In the first method, electroreduction of ThO2 and deposition of thorium on a nickel or iron cathode formed a molten alloy that dripped off and collected on the bottom of the cell, or in a tungsten cup. An electrocodeposition technique was used to prepare thorium-base alloys or solutions containing nickel, iron, chromium, or manganese. Electrolytic reduction of the component metal oxides and simultaneous deposition of the two metals on a tungsten cathode yielded a liquid alloy product. Complementary experiments were performed on the fused fluoride electrowinning of dendritic thorium from Th02 at 1,075° to 1,200° C in which thorium crystals were recovered and arc-melted into buttons. Major contaminants were aluminum, carbon, copper, iron, oxygen, and silicon, totaling 0.2 percent.

Jan 1, 1966

By W. E. Young

This study was made to present the mining methods and costs of a uranium mine typical of other mines in the highly productive Westwater Canyon member of the Morrison formation in New Mexico. Four mining methods have been used at the Section 23 mine: the retreat- room-and-pillar method, a sublevel-slicing method (also called top-slicing), the horizontal-cut-and-fill method, and a modification of the ring-drill method. The application of the methods at this mine and at other mines in the area should be of benefit to operators with similar problems. Ore bodies in the Section 23 mine are irregularly shaped and vary in size, in rock strength, in moisture content, and in uranium concentrations; different mining methods are required and mining costs are not constant. A 6-month period of operation at the Section 23 mine was analyzed and mining costs, not including amortization, depreciation, or Federal taxes, averaged about $6.80 per ton.

Jan 1, 1965

By D. H. Platt

Data obtained from on-the-site observations have been compiled to describe the equipment and installation methods used for satisfactory suspension roof support in a large-diameter tunnel. Experimental roof bolting was undertaken from June 1950 until May 8, 1951, in the East Delaware tunnel, which is part of the Delaware aqueduct in Delaware and Sullivan Counties, N. Y. Revised suspension-roof-support plans and specifications were prepared during the spring of 1951 by the City of New York Board of Water Supply; these were approved by the State of New York Department of Labor April 13, 1951, and adopted by the City of New York Board of Water Supply on May 8, 1951.

Jan 1, 1952

By James P. McGee

Use of nuclear reactors to furnish high-temperature heat is a field that has not received as much attention as propulsion and electric power production. Investigations are being conducted under a joint Atomic Energy Commission (AEC)--Bureau of Mines research program to determine the feasibility of using nuclear heat for chemical processing. A part of this process-heat-reactor program is the study of a system in [hich] helium transfers heat from 8 nuclear reactor to a chemical processing [essel]. This requires construction of (1) a nuclear reactor to operate with helium exit temperature of 2,500° F. and with pressures in the range of 250 to 500 p.s.i.g. and (2) a processing vessel (heat exchanger) to convert the enthalpy of the helium into chemical process reaction heat. Neither component exists at present, and development of each promises to be a formidable task. To aid in the study of such a system, the Bureau of Mines has designed and constructed a vessel heated by electrical induction to simulate a source of nuclear fission heat. This vessel is undergoing preliminary testing. Gasification of coal and reforming of hydrocarbons are promising uses for nuclear heat. It appears that a higher price per unit of nuclear heat can be tolerated for chemical processing than that allowable for power generation.

Jan 1, 1960

By W. E. Young

This study was made to present the mining methods and costs of a uranium mine typical of other mines in the highly productive Westwater Canyon member of the Morrison formation in New Mexico. Four mining methods have been used at the Section 23 mine: the retreat-room-and-pillar method, a sublevel-slicing method (also called top-slicing), the horizontal-cut-and-fill method, and a modification of the ring-drill method. The application of the methods at this mine and at other mines in the area should be of benefit to operators with similar problems. Ore bodies in the Section 23 mine are irregularly shaped and vary in size, in rock strength, in moisture content, and in uranium concentrations; different mining methods are required and mining costs are not constant. A 6-month period of operation at the Section 23 mine was analyzed and mining costs, not including amortization, depreciation, or Federal taxes, averaged about $6.80 per ton.

Jan 1, 1965

By Robert E. Barieau

In the design of plants to separate helium from natural gas , it is necessary to estimate the enthalpies of the various streams at various positions in the process . This Bureau of Mines report surveys the various methods that have been used to determine enthalpies and gives information on the organizations with such capabilities . The minimum information required for developing an enthalpy diagram is presented , and the relative merits of the various methods are discussed . It is concluded that methods that require no mass flow rate or energy measurements are to be preferred .

Jan 1, 1965