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By Albert W. Deurbrouck

This report describes preparation characteristics of significant coalbeds in Tazewell County , Va . In 1961 Tazewell County produced 933,110 tons of clean coal from six coalbeds ; the Lower Banner , Raven , Jawbone , Upper Seaboard , and Pocahontas No. 3 and No. 5. Samples from all of these beds , except the Lower Banner , were included in this study plus a sample from the Pocahontas No. 4 bed . Of the samples collected , only one would require upgrading to be of metallurgical quality . The coals ranged in rank from high- volatile -A to low- volatile bituminous .

Jan 1, 1963

By B. P. Martinez

A process for regenerating spent pickle liquor is proposed in which some of the water is evaporated at atmospheric pressure and ferrous sulfate is precipitated as monohydrate crystals..Equilibrium conditions are set for a slurry of crystals in a mother liquor containing 5 percent FeS04 and 45 percent E2S04, by weight, and boiling at about 235° F. The slurry is pumped continuously to a filter, and the mother liquor from the filter is pumped back for reuse in the pickling tanks. The net result of the process is to remove ferrous sulfate in the regeneration plant at the same rate ac it is produced in the pickling tanks. This process is integrated with the steel-pickling operation and controlled by the pickling requirements for particular steels. Spent pickle liquor is removed for regeneration continuously from both batch and continuous picklers at higher acid concentrations than would be dumped to waste because no acid is neutralized or discarded. However, the process is not designed to keep a sulfuric acid concentration stronger than 25 percent in any pickling tank. To retain flexibility in the pickling operation, all acid makeup is added to the pickling tanks. Rinse waters are used as water makeup for the pickling tanks. To further minimize waste of acid in the rinse waters, improvements of rinsing practices are outlined.

Jan 1, 1953

By R. H. Lien

The Bureau of Mines investigated a roast-leach process for recovering a marketable lithium product from a montmorillonite-type clay deposit located on the Nevada-Oregon border. The clay sample treated in the investigation contained 0.6 wt pct Li. The lithium recovery process consisted of several unit operations. The lithium silicate compounds in the clay were converted to Li2SO4 by roasting a pelletized mixture of clay, limestone, and gypsum at 900° C in a direct-gas-fired rotary roaster. Water--leaching the calcine at 40 pct solids extracted the Li2SO4. Lithium recovery from the leach solution involved concentrating the solution by evaporation, adding Na2CO3 to the concentrated solution to precipitate Li2CO3 , and filtering the slurry to obtain the product. The product filtrate was recycled to the evaporator following a crystallization step. About 80 pct of the lithium in the clay was recovered as 99-pct-pure Li2CO3. Process operating costs were estimated at $2.12/lb Li2CO3 produced; the current Li2CO3 selling price is $1.48/lb. Raw materials. accounted for 30 pct of the total operating cost.

Jan 1, 1985

By R. C. Anderberg, F. J. Caervenyak, F. J. Frattali, H. J. Kandiner, R. A. Brown

"INTRODUCTION Considerable interest was shown .prior to and during World War II in the winning of metallurgical-grade alumina from anorthosite, kaolin, siliceous bauxites, diasporic clays, and other aluminum-bearing ores. Laboratory and pilot-plant investigations were made on many of these ores by the Bureau of Mines, and a series of reports on them is being prepared. This report covers the tests made on the application of the lime-soda-sinter process to anorthosite, which is a mixture of albite, NaAlS1308, and anorthite, CaAl2Si208. Extensive deposits of anorthosite occur in the Laramie Range in Wyoming and extend into Colorado; other deposits are found in New York, with outcroppings appearing in Vermont, Maine, and Labrador.Anorthosito can not be treated by the Bayer process for the production of metallurgical-grade alumina, because excessive losses of soda and alumina occur from the formation of sodium-aluminum silicate due to the large amount (50 percent) of silica in the ore.RESULTS OF INVESTIGATIONSSmall-scale laboratory tests supplemented by pilot-plant runs have demonstrated that the alunina and soda occurring in the Wyoming anorthosite from the Laramie Range can be extracted and recovered satisfactorily by the lime-soda process. It has been shown that liquors containing approximately 95 gram of A1203 per liter can be consistently produced at Na20:A1203 ratios from 1.75 to 2.27, and that these liquors can readily be desilicated and carbonated to yield high-grade alumina trihydrate of quality comparable to that essential for cell-grade alumina. The optimum results were obtained with Na20:A1203 mol ratio of 1.03 and Ca0:Si02 ratio of 2.14 in the sinter when calcined at an average temperature of 2,444ºF. for 25 minutes."

Nov 1, 1947

By C. M. McCulloch

The methane content of virgin bituminous coalbed can now be measured accurately in the field with exploration core samples from vertical boreholes. The gas content of the coal per unit weight can be used either to design a mine ventilation system or to determine if degasification of the coalbed will be necessary before mining, and to determine the gas resources in the coalbed. The equipment necessary to conduct the test costs less than $50. The gas con-tent of the coal in place in the ground is determined by summing the gas lost from coring, gas measured during desorption, and the residual gas in the coal. Upon removal from the borehole, the core sample is placed in an airtight container and des orbed for several weeks until the desorption rate is below 0.05 cm3/g for 5 consecutive days. The gas lost from the core while it was being cored and the residual gas are estimated by a new graphical method. The amount of gas remaining depends upon whether the coal is friable or blocky. Friability appears to relate to the depth of the sample below the surface, fixed carbon percentage, Hardgrove grindability index, and proximity to tectonic disturbance. Friable coals emit nearly 96 pct of the total gas during desorption whereas a blocky coal emits only 60 pct of its total gas. Coalbeds that are ill defined as to their blocky or friable nature must be tested in the laboratory for unambiguous analysis.

Jan 1, 1975

By Kenneth M. Earl

This report describes the results of a field study conducted by the Bureau of Mines during 1956 and 1957 on manganese-and iron-bearing mineral deposits in the southern district of Aroostook County, Maine. The work was undertaken to determine the extent of deposits largely concealed under glacial drift and to obtain subsurface samples for manganese mineral identification and research in ore dressing and extractive metallurgy. The investigation was confined to the Westford Hill-Daggett Hill area in Hodgdon Township and to the Stewart prospects and vicinity in Linneus Township. Over 50 magnetic anomalies were mapped by magnetometric surveys in the Westford Hill-Daggett Hill area, Hodgdon Township. The largest anomaly, as outlined by the 1,000-gamma contour, indicates a deposit 3,200 feet long with a maximum width of 350 feet. The smallest anomaly measures about 10 feet wide by 25 feet long.

Jan 1, 1962

By E. P. Youngman

The basic mining law of French Morocco is the Edict of 1914, "Danir of Jamary 19, 1914, for the Regulation of Mineral Prospecting and Exploitation in the Zone of the French Protectorate of the Cherifien Empire," which, as the preamble states, was promulgated at the instance of the Director General of Public Works, in consideration of the fact that mines constitute one of the sources of wealth of the Empire. According to a consular report, dated May 18, 1923, by Bradford, men- tioned above, the mining industry of that country, aside from the exploitation of the extensive phosphate deposits, can scarcely be said to exist, but the potential field for mining is promising. However, no large-scale exploitation of the mineral wealth of French Morocco can be hoped for until there is complete pacification of large areas that are still in an unsubdued state or until adequate transportation facilities, scientific prospecting, and large investments of cap- ital are assured. An edict in 1920 (Dahir of January 27, 1920) modified the law mentioned above by declaring the prospecting for and the exploitation of phosphates to be exclusively reserved to the Government. The Dahir o. August 7, 1920, announced the creation of the Cherifien Phosphate Office (Office. Cherifien des Phosphates), a State monopoly charged with the exploration, management, and exploitation of the phosphates of Morocco.

May 1, 1930

By Edward D. Thimons

As U.S. mines go to greater depths, the high temperatures and humidities characteristic of such depths make it difficult to maintain a comfortable environment in working areas. Better techniques for cooling these deep working areas are needed. At the Homestake gold mine in South Dakota the Bureau of Mines has tested a water spray cooler inserted into the fresh air vent tube entering a warm stope. The cooler supplied more than 6 tons of refrigeration to the stope air, which dropped from an inlet temperature of 83° F dry bulb and 75° F wet bulb to 73.5° F dry bulb and 71.5° F wet bulb. These preliminary results show the water spray cooler to be a feasible concept. However, there is a need for substantial refinement and further testing, and work on the concept will be continued under contract to the Bureau.

Jan 1, 1979

By Charles Seitz

The Bureau of Mines has modified its parts-per-billion helium-4 analyzer to improve the analytical capabilities of the instrument. The modifications resulted in the following improvements: (1) The analytical precision of the instrument for 10 consecutive analyses was improved to ±1 ppb at the 5,000-ppb helium-4 level, (2) the helium-4 sensitivity was increased almost tenfold, and (3) the minimum detectable limit for helium-4 was improved to 0.5 ppb. The modifications made to improve the instrument included replacing the ion-source control circuit with a direct-current solid-state design, controlling the temperature of the ion source, stabilizing and reducing the pumping rate of the vacuum system, and optimizing peak integration.

Jan 1, 1986

By H. M. Smith

The production of oil during the early development of new oil fields is usually accompanied by large quantities of natural gas. Since in most fields gas under pressure is the main source of the energy causing the oil to move through the sands into the wells and thence to the surface, coincident production of natural gas will continue as long as present-day producing methods are used. Generally the use of this gas is restricted, since markets are not readily available. Consequently, a large portion of the gas produced is often wasted by being blown into the air. The magnitude of gas waste is well brought out in the following statement by Miller:5 Only a few outstanding examples need be cited to show the enormous production of gas that accompanies the discovery of new sources. In April, 1927, the Ventura field produced approximately 210,000,000 cubic feet of gas a day; and during the summer of 1927 Alamitos Heights reached a peak gas production of 102,000,000 cubic feet a day; on December 1, 1928, as a result of the summer's deeper drilling in the Long Beach field, surplus gas production amounted to 125,000,000 cubic feet a day. It is estimated that in January, 1929, the Santa Fe Springs field will have a daily gas production of 387,000,000 cubic feet from the recently discovered Buckbee oil zone. Of this amount 274,000,000 cubic feet a day will be the surplus above the amount required for field and plant fuel, taken out by utility corporations, and that used in repressuring the Meyer sand which lies above the Buckbee zone.

Jan 1, 1931

Provide an instrument for continuous remote monitoring of carbon monoxide concentration in underground mines. Approach A carbon monoxide fixed? point continuous monitor consists of two modules. A line-powered control module is designed to power a remote transducer module; provide continuous readouts, visual and audible alarms, operational checks; and activate fans and equipment shutdown circuits if preset CO concentration levels are exceeded. How It Works The control module must be used in conjunction with a single transducer module. Developed under contract. the control module is a wall-mounted Instrument which contains a readout and alarm capability and power supply

Jan 1, 1981

By Frank C. Andreuzzi

The Division of Environmental Activities, U.S. Bureau of Mines, conducted a solid waste demonstration project on a burning coal refuse bank. The primary objective of this project was to develop and evaluate an efficient method of extinguishing burning coal refuse and moving it. A series of tests were performed using water monitors and related apparatus to quench the burning material and, at the same time, using earth-moving equipment to transport, spread, and compact the extinguished material. The method found to be most effective consisted of water-quenching the surface material to a workable depth, ripping, and removing the quenched material with a bulldozer and tractor-scraper. The total cost was estimated to be $0.44 per cubic yard.

Jan 1, 1970

By A. G. Smelley

As part of research conducted in its mission to effect pollution abatement, the Bureau of Mines, U. S. Department of the Interior, is developing a dewatering technique that allows for disposal of phosphatic clay wastes, for reuse of water now lost with clays, and for reclamation of mined land. The technique utilizes a high-molecular-weightnonionic polyethylene oxide polymer (PEO) that has the ability to flocculate and dewater phosphatic clay wastes. A synergistic flocculation study was made to determine whether a portion of PEO could be replaced by other reagents. Several groups of reagents were tested: (1) those that increased the zeta potential of the phosphatic clay wastes; (2) those capable of hydrogen bonding; and (3) those which flocculated the phosphatic clay waste. Reduction in PEO consumption occurred only with addition of those reagents able to flocculate the slime. The use of natural guar gums resulted in a lower PEO requirement and also yielded a dewatered product of higher solids content, 43 to 45 percent, versus 33 to 35 percent obtained with PEO alone.

Jan 1, 1980

By L. A. Stewart

"SUMMARYThis paper describes most of the chrysotile-asbestos deposits of Arizona. Mining methods are discussed briefly and asbestos-mill flowsheets are incorporated. Arizona asbestos mines are the only sources on the American continents of naturally iron-free chrysotile spinning fiber that is so urgently needed for electric-cable coverings, especially on warships.Asbestos was first recorded and recognized in Arizona in 1872, and a minor amount was produced from a deposit in the Grand Canyon in 1900. The discovery of a deposit in the Salt River district in 1912 initiated intensive prospecting, and deposits soon were developed. The total Arizona production of all grades of asbestos through 1953 is estimated at 30,000 to 35,000 tons.The deposits of the Central Arizona region, which are discussed in this paper, are scattered over nearly 2,000 square miles. The annual output is relatively small, because the asbestos occurs in thin, discontinuous veins and only in areas where intrusions of diabase are adjacent to or crosscut certain favorable units of the pre-Cambrian Mescal limestone. This stratigraphic limitation, combined with other essential geologic conditions, tends to restrict the size of the deposits.Virtually all of the deposits are in rugged, mountainous country, and many of the mines are on steep canyon walls. In the average mine, production of 1 ton of commercial asbestos requires removal of 30 to 40 tons of waste rock. Mining and transportation costs consequently are high.Several deposits of chrysotile that is somewhat harsh and of moderate tensile strength have been known for years but were not worked because of the former exacting demands of industry for high-strength, soft asbestos. However, improve¬ments in asbestos fiberization and spinning technique, combined with the urgent need for asbestos, have made this so-called semisoft fiber desirable, and deposits of this type now are being exploited."

Jan 1, 1955

By M. M. Tilman

The objectives of this research were to determine the practicability of using cobalt as a means of controlling the amount of ferrite in the micro-structures of semiaustenitic stainless steels, and to determine the effects of reduced ferrite content on mechanical properties of these steels. Cobalt additions of up to 3 weight-percent were made to type 17-7 PH2 (AISI 631) stainless steel. Ferrite contents were determined for alloys in the aged condition, and for alloys quenched from the hot working temperature. Ferrite can be completely eliminated from the microstructure of 17-7 PH stainless steel by additions of cobalt, but complete elimination of the ferrite phase results in lower tensile strength, yield strength, and hardness. Tensile properties, hardness, and impact strength were determined for aged material. A subzero temperature treatment before heattreating was necessary to obtain maximum strength in the alloys containing cobalt. Addition of 2 weight-percent cobalt enhances mechanical properties of 17-7 PH stainless steel.

Jan 1, 1968

By Jerry T. McLendon

The proper disposition of phosphatic clays has been the subject of research and debated for years by phosphate producers, State and Federal research agencies, regulatory authorities, and environmentalists. To date, no "universal" solution exists for the ultimate disposl of phosphatic clays. This Bureau of Mines report examines the state of conventional clay disposal technology and reviews the technical progress of innovative alternatives. Twenty impoundment sites were investigated by the Bureau of Mines using geotechnical methods and laboratory analysis of cored samples. In addition, quasi-static cone penetrometer soundings were conducted to define clay and/or sand-clay interfaces en masse. Samples of the top, middle, and bottom hole segments were obtained at each station for laboratory studies of clay densities, pore fluids, plasticity, and mineralogical properties. The results of this study support the continued use of initial clay settling impoundments but emphasize the need for "in-line" systems to reduce the initial volumes of plant-generated phosphatic clays. The effective use of sand tailings is also encouraged to promote further consolidation of clays via self-weight stressing, sand-clay admixtures, and/or surcharging sand caps.

Jan 1, 1984

By J. C. Edwards

To have the capability to predict the development of localized spontaneous heating within a porous coalbed that is subjected to forced air ventilation or in an otherwise quiescent environment in which buoyancy develops, the Bureau of Mines developed three time-dependent mathematical models, which were used to calculate the temperature increase associated with chemisorption of oxygen by the coal. In each model, spontaneous heating is driven by an Arrhenius first-order reaction between the oxygen and coal. Two models are two-dimensional, and one is one-dimensional. In the first two-dimensional model, a constant-velocity forced convection airflow is specified; and in the other, buoyant flow is allowed to develop in the absence of forced convection. The third model evaluates the airflow from Darcy's law and a specification of the pressure at the surface of a one-dimensional porous coalbed. Numerical computations demonstrated how each model could be used to predict the onset of spontaneous heating when the porous coalbed was subjected to constraints of an imposed internal heat source or a high temperature airflow. The effects of particle size and coalbed compaction upon spontaneous heating were examined with the third model.

Jan 1, 1990

By R. E. Cerullo

Many computer programs have been written which are capable of performing a least squares fit, both linear and nonlinear, to data gathered by the petroleum researcher. However, when the petroleum engineer tries to program methods of analysis he has used manually in the past, such as forecasting production by decline-curve analysis, more than a knowledge of the use of existing least squares programs becomes necessary. It is the intent of the authors to report the techniques used in the development of such a decline-curve program.

Jan 1, 1970

By J. S. Browning

The purpose of this Bureau of Mines project was to develop a method for recovering kyanite and sillimanite from the present zircon-mill tailing of the Jacksonville and Starke, Fla., plants of Humphreys Gold Corp. The kyanite and sillimanite in the ore are not being exploited at present, but procedures for recovering the two minerals were worked out by the Bureau in the interest of conserving natural resources. The current zircon-mill tailing of the Starke plant contains up to 20 percent of a mixture of kyanite and sillimanite. A similar product of the Jacksonville plant contains up to 15 percent kyanite and sillimanite. The average annual production of the tailing now being stockpiled contains several thousand tons of the two minerals. Laboratory batch-flotation tests were made on the materials to determine the feasibility of flotation methods for recovering high-grade concentrates. Various reagents were employed under different conditions to determine the optimum conditions for flotation of kyanite and sillimanite and retardation of the gangue materials. The results of the preliminary flotation tests were encouraging enough to warrant more comprehensive testing of a larger sample of the ore in the laboratory pilot plant.

Jan 1, 1956

By William D. Monaghan

The U.S. Bureau of Mines evaluated a teleoperated continuous mining machine for deep mining in thin-seam applications as low as 1 m. Teleoperation increases the safety of mining machine operators because it removes the operator from the face, an area of immediate hazards to safer outby locations. By using teleoperation, the miner can avoid many including unexpected roof falls that can maim or kill miners instantly, methane and coal dust explosions that can be ignited with just a small spark or flame, adverse health effects from miners breathing coal and silica dust, adverse long-term inner ear damage from loud noise pollution, and other hazards related to heavy mining equipment moving about in confined underground roadways. This report presents the surface evaluation results of a teleoperated control system.

Jan 1, 1994