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By Wm. O. Vanderburg

This report on the mining and milling of tungsten ores is the second part of a general study of the domestic tungsten industry. The first part, comprising general information on tungsten, has been printed as Bureau of Mines Information Circular 6821. The purpose of these papers is to increase efficiency in the mining, preparation, and utilization of the tungsten resources of the United States. The tungsten industry forms so small a part of the vast mining and metallurgical operations of the illation that private metallurgists have not had enough inducement to give special attention to the recovery of tungsten minerals from the ores, and many of the small companies are financially unable to undertake research work. A study of the milling of tungsten ores reveals that further improvement is possible, especially in the treatment of slimes. Recent experimental work by the Bureau shows that the flotation process is applicable to certain tungsten ores. The future of the tungsten industry it the United States depends to a great extent on utilization of the low-grade deposits of the contact-metamorphic type.

Jan 1, 1935

By S. Lim, G. Walsh, V. Romero

The cable television show, Mythbusters, contacted the New Mexico Institute of Mining and Technology requesting a pressure gauge to be used in underwater testing. The requirements for the gauge were: it must be passive (i.e. require no power to function), it must indicate when a certain, pre-determined pressure was reached, and that indication was to be visual. A pressure gauge was developed, using standard, commercially available rupture discs, set to burst at 500 psi. Underwater testing was conducted using a 400 lb Pentolite charge. Test devices were set out at ranges from 50 to 200 feet from the seat of the blast. The rupture discs showed a lethal range up to 100 feet, but not at 150 feet. This result matched well with the behavior predicted through modeling and simple shock physics calculations. Additionally, the geometry between the incoming shock and the pressure gauge did not seem to have a strong effect on gauge performance.

Jan 1, 2009

By Raymond W. Hiteshue, Sam Friedman, Paul Dobransky, Robert Madden

A hvab coal was carbonized in a closed system at 600 ° C and 40 to 1 , 200 psig to produce a high- Btu gas and char . By retaining the volatiles within the system, it was possible to virtually eliminate production of tars and oils . Depending on pressure and residence time , yields of combustible gases (72 to 92 percent methane ) amounted to 4,000 to 6,000 cubic feet per ton of maf coal and gross heating values of these gases varied from 830 to 960 Btu per cubic foot . Yields of char (maf ) were about 1,600 pounds per ton of maf coal . Increased residence time favored production of gases but reduced their heating values , whereas increase in pressure resulted in somewhat higher heating values and lower production . Similar effects were observed from the carbonization of a low- temperature tar . If these results could be translated to an economical carbonization process for producing high- Btu gas from coal , the demand for coal could be expanded by 40 to 50 million tons per year . Because of large yields of char , a process of this type would obviously have to be integrated with coal - fired power plants . Fortunately , operations could be conducted at essentially atmospheric pressure as product gas under this condition can be obtained in satisfactory yields and with good quality .

Jan 1, 1964

By M. Le Roux, Q. P. Campbell, N. Hughes

Water plays a significant role in minerals processing; this is especially true in coal preparation where water-based beneficiation is widely accepted and consistently delivering sharp separation efficiencies and high product yields. Although wet processing is favoured, the substantial process water requirement may prove this impractical and unsustainable in some parts of the world. Many coal-rich regions (including South Africa) have experienced severe water shortages. Coupled with the effects of drought, some countries experience freezing winters from which problems related to frozen process water and machinery may arise. Hence coal preparation practices will soon have to adapt, irrespective of the technical and economic feasibility offered by the currently employed water-based methods. As a result, extensive research into the development of dry methods for effectively beneficiating coal has progressed. This review paper intends to provide a collection of the relevant information pertaining to dry coal processing globally, and aid in understanding the applicability, performance, success or failure thereof. The methods available for dry materials preparation, with special regard to those applicable for coal beneficiation, are detailed in terms of principle, applicability, limitations and performance. Dry coal beneficiation has potential to aid the current wet-based methods with some considerations to possible limitations set forth by coal geology, application, product specification, particle size distribution, moisture, efficiency, capacity and cost. These methods may be established in future, especially in the arctic, arid and under-developed regions through new plant installations, expansions and small mines processing. Keywords: Dry coal processing, preparation, cleaning, beneficiation

Jan 1, 2020

By Bernard S. Covino

The Bureau of Mines is conducting a study of methods to improve the efficiency of the process used to pickle stainless steels. A review of the literature on pickling of stainless steels showed that the chemistry of several process operations involved in the pickling of stainless steels is not fully understood, and that further research could improve the pickling efficiency. The benefits of this research would be a reduction in the annual loss of several thousands of tons of critical minerals such as nickel and chromium, and a reduction in the amount of solids and spent acid solution that are currently discarded. The conclusion from this review is that further research is needed in four operations that either directly or indirectly influence the pickling process: hot working, annealing, conditioning, and the actual operation of pickling, Laboratory studies of the pickling operation are presently in progress.

Jan 1, 1984

By C. W. Owings

"PURPOSE OF REPORTMany bituminous coal-mine officials realize that coal dust presents an ever-present coal-mine explosion hazard, and that persons forced to breathe large quantities of it may be more subject to respiratory infection than persons working in less dusty atmospheres. As an outgrowth of the realization that coal dust should be allayed at its source, many mining companies have expressed the desire to install dust-allaying equipment, and in a number of mines, water or wetting solution is being applied on the cutter bars of mining machines, on mobile loaders, belts or conveyors underground, and tops of mine cars. Spraying equipment also has been installed on dumps to allay dust during dumping operations. Dust-allaying equipment has not been standardized, however, because manufacturers have found that many prospective purchasers of such equipment have different ideas. These manufacturers wish to standardize, so far as feasible, the types and placement of such equipment. Many mine officials, although interested, do not know the best or most effective methods for allaying dust.For a number of years the Bureau of Mines has advocated allaying dust by applying water or, more recently, water modified by a wetting agent on the cutter bar of mining machines and by applying water to loaded and empty mine cars in order to keep as much dust as possible from spilling onto the haulage roads. In recent years this Bureau has also advocated applying water with or without a wetting agent during mechanical loading of coal and during unloading of coal from trackless cars or buggies and from elevating conveyors. It has now become apparent that specific arrangement of pipes, hose, and nozzles should be standardized to at least some extent. It is the purpose of this report, therefore, to give in detail suggested arrangement of dust-allaying equipment in the hope that both manufacturers and mine officials will have available dust-allaying equipment with maximum efficiency to do the desired work."

Nov 1, 1945

By Albert E. Long

During the summer and fall of 1948 the Bureau of Mines, in cooperation with the U. S. Geological Survey, conducted 6xperiments in diamond core drilling in the Phosphoria formation in southeastern Idaho and southwestern Wyoming. Nearly all of the diamond core drilling in the Phosphoria formation has been done by mining companies interested in finding and developing phosphate-bearing beds amenable to stripping. The recovery of sludge; and enough core (usually 30 to 60 percent) to identify certain marker beds produced by current drilling practices meets both the primary requirement of mining companies in determining depth of overburden and their secondary need to determine the phosphate content of relatively thick minable units whose general composition and nature are already fairly well established.

Jan 1, 1949

By Charles B. Kenahan

The effects of ultrasonic radiation on the electrodeposition of copper-zinc, copper-cadmium, and copper-tin alloys from cyanide baths were investigated by the Bureau of Mines at frequencies of 18.5 and 38 kilocycles per second, and at acoustic intensities up to 0.5 watt per cm3. Significant changes occurred in the composition of the deposited alloys; some of these deposits were brighter, harder, more adherent, or of finer grain size than nonirradiated deposits. The irradiated deposits were also smoother and less porous, and they afforded better corrosion protection for the substrate metal in sodium chloride solution. The limiting current densities of the cyanide baths were increased by the application of ultrasonics. Anode and cathode current efficiencies also were increased, and cell voltages were lowered; the relationship of these effects to current density is discussed. Electrode potential measurements showed significant depolarization effects at both electrodes during ultrasonic irradiation. The resulting decrease in cell voltage was due chiefly to depolarization at the anode, and the anode became less passive.

Jan 1, 1967

By K. K. Kelley, W. W. Weller

Heat capacity measurements of lead molybdate and lead tungstate were conducted over the temperature range from 51 ° to 298 ° K. The entropies were found to be S298.15 = 39.7 ± 0.5 cal / deg mole for lead molybdate and S298.15 = 40.2 ± 0.5 cal / deg mole for lead tungstate . The entropy values were combined with other pertinent data to obtain the entropies of formation of the two compounds from their constituent elements and oxides .

Jan 1, 1964

By D. S. Burgess

A commercially available Halon 1301 extinguisher has been evaluated as part of an explosion-suppression system for use in coal mines. Studies were made both of the dispersion pattern of the Halon 1301 at an initial pressure of 280 psig, and of the efficacy of this suppressant against 9.5 percent methane-air flames. These flames were quenched successfully only when the suppressant was applied before the fireball diameter exceeded 18 inches.

Jan 1, 1971

By A. R. Chambers

Malagash received its name from the Indians many years ago on acco.unt of its turbid (milky) waters, although,' the red men did not appreciate the significance of this turbidity, and were, of course, entirely ignorant of the crystal beds of pure salt that lay beneath their feet. The salt lake of the Mississippian, or Lower Carboniferous period, in which these beds occur, was apparently a large one, for there is evidence of its existence at intervals all the way from Sydney, Cape Breton, to St. John, New Brunswick, 300 miles as the crow flies, and there is no knowing what its other dimensions may have been, as much of this horizon is now buried on the one side beneath the waters of the Gulf of St. Lawrence, and on the other underneath the Atlantic ocean. About midway of the area and underlying the counties of Colchester and Cumberland, there occurs a synclinal basin of which the Malagash salt outcrop forms only a small portion of its northern limit. This basin has been described very fully by A. C. Hayes. (1) The operations carried on at Malagash since Hayes wrote his report have brought to light very little in the way of new geological data, except to confirm his pre-dictions as to the probable faulting of the salt strata, and the effect which these faults would have on mining operations.

Jan 1, 1924

By H. W. Kilau

The U.S. Bureau of Mines is evaluating water spray additives for the purpose of improving respirable dust control during coal mining operations, with particular emphasis on the longwall shearer. Recent field tests of surfactant-polymer reagents at two production longwall operations have shown favorable respirable dust reductions compared with water sprays containing no additive. Gravimetric dust samples obtained by a technician downwind of the shearer while following or preceding the machine showed dust reductions in the range of about 40% to 60% for some of the reagent formulations compared with using water alone. Three polymers were tested: two polyethylene oxide compounds of different molecular weight and hydroxypropyl methylcellulose (HPMC). All were effective for dust reduction, and two were cost effective when used in combination with sodium di(2-ethylhexyl) sulfosuccinate surfactant. How-ever, the use of these reagents requires the longwall operator to be more aware of headgate dust control. Experimental evidence indicates that dust captured by reagent-treated sprays at the shearer can be reemitted in the headgate area if stagcloader-crusher sprays and other dust controls are inadequate.

Jan 1, 2010

By Jorge Luis Cáceres Córdova

Durante los procesos mineros, el comité ejecutivo gestiona decisiones -confiables y económicamente rentables- según la información requerida. En ese sentido, el presente texto señala una metodología que integra las herramientas de gestión donde se garantice la confiabilidad de los activos de forma sostenida que prevenga pérdidas de producción, se reduzca los costos operativos, se evita riesgos a la salud y medio ambiente y se establezca una política de sustento cuantitativo a pedidos, cambios, bajas, terciarizaciones, entre otros, en base al riesgo y beneficio.

Sep 1, 2015

By Frank K. McIntosh

The Hamme tungsten district is in Vance County, N. C., and Mecklenburg County, Va. Principal development has been in Vance County. The district is approximately 8 miles long by 1 mile wide and extends northeast-southwest. Its center is about 3 miles N. 65° W. of Townsville, N. C. The occurrence of tungsten in the district was first reported in 1901, but it was not until the Hamme brothers revived interest in the deposits in 1942 that commercial development began. The Bureau of Mines, as part of the war minerals program, began exploration and development of the district in June 1943 and completed it in December 1943. The Federal Geological Survey cooperated by mapping the topography and geology and logging the drill cores. The program included mapping, trenching, sampling, diamond drilling, and analyses and beneficiation of ore samples, The principal ore mineral is hubnerite, which occurs in quartz veins within the schist and granite. The veins are generally lenticular along the strike and dip. About 50 quartz veins have been noted in the area, but many are barren or slightly mineralized.

Jan 1, 1948

By Peter G. Chamberlain

Novel and innovative mining methods are attracting the attention of mining engineers at an unprecedented level. Historically, the US mining industry has responded rather conservatively to new technology. The financial difficulties affecting the domestic mining industry in the early 1980s changed attitudes toward new technology. The market contraction during that period, coupled with an expanding world mine capacity, created a serious oversupply of many raw mineral products. Many mining companies found that retaining a share of world markets while making a profit required drastic cost-cutting measures.

Jan 1, 2008

By G. E. Veins

A three-phase, continuously-operated, 250 kv.a. electric smelting furnace has been installed at the Mines Branch, Department of Mines and Technical Surveys, Ottawa, for the experimental treatment of ores and by-products of interest to the Canadian mining, metallurgical, and chemical industries. In the operation of this furnace particular emphasis is placed on the accumulation of quantitative data which will be useful in determining the most suitable smelting technique and the nature of the products, and in arriving at preliminary conclusions regarding the cast of power and electrodes. The results obtained in the experimental smelting of iron, manganese-iron, titanium- iron, nickel, and chromiumiron ores, and of a number of industrial by-products, clearly show the value of such treatment for materials of this type.

Jan 1, 1957

By Yury Kapelyushin

Formation of cementite in the reduction of hematite by CO–CO2 gas was studied in situ using high temperature XRD (HT XRD) analysis. Reduction of hematite was examined in the temperature range 873–1173 K by CO–CO2 gas mixture with high carbon activity. When carbon activity in the system was 1.5, cementite was formed only at 1023 K; it was not observed in experiments at 973, 1073 and 1123 K. Formation of cementite was observed at 923–1073 K when carbon activity increased to 3–5; and at 873 K when carbon activity was 10. Formation of cementite at 973–1073 K proceeded through metallic iron; however, in the reduction of hematite at 873 and 923 K, iron was not observed; cementite apparently was formed directly from wüstite. XRD spectra were used to estimate concentration of carbon in austenite in the process of cementite fromation.

By Arthur Zentner

THE essentials of the electrolytic zinc process, as now used in commercial plants, date back to work done by Letrange in 1881. He used sulfuric acid to leach roasted sulfide and ,oxide ores, purified his solution very much as we do now, and electrolyzed the purified zinc sulfate solution. Ten years later Hoepfner developed a process using chloride solutions, and built three plants. One in England operated until 1924 in one of the works now merged in the Imperial Chemical , Industries, Ltd. Ashcroft built a plant in 1898 in the Broken Hill district of Australia. He used both chloride and sulfate solutions.. While his work failed, the aid his published results have been to later workers has made him an outstanding contributor to the de- velopment of the electrolytic zinc process. A good deal of work was done in the following years, aiming to electrolyze zinc chloride solutions and fused zinc chloride. Quite a bit of work on sulfate solutions was also done in the last years before the war. With the outbreak of the war, metal demand and rise in metal prices provided the stimulus which resulted in the remarkably rapid commercial development of electrolytic zinc. In this last period of development, all the work brought to commercial fruition has been with sulfate solutions. The high-density process, or the Tainton process, is used, as you know, in the Sullivan electrolytic zinc plant at Kellogg, Idaho, and will be used in the Evans- Wallower plant now being built at East St. Louis. The low-density process is used by the other plants now operating in the United States and other countries. There are now in operation and under construction four electrolytic zinc plants in the United States, two in Canada, two in Italy and one each in Australia, Rhodesia, Poland, Norway and Germany.

Jan 1, 1929

By M. L. Clark

Advances in the recovery of gold from heap leaching are being made daily, but of all the systems vital to the maximum recovery of gold from a leach pile, none is more important than the methods used to construct the pile in preparation for the leaching operation. The technology described in this paper illustrates the latest systems developed to minimize compaction in the pile during its construction and reduce the cost of placement of ore on the pile. The Florida Canyon Mine of Pegasus is evaluated in detail to show reasons for its high degree of success to date.

Jan 1, 1988

By H. I. Smith

THE recently developed potash industry in southeastern New Mexico, though based on a relatively new discovery, marks the latest and perhaps culminating phase of the effort to obtain a domestic source of potash that began with the leaching of wood ashes more than 300 years ago. In the search for mineral potash in America, the Geological Survey has played a conspicuous part and has paved the way for much of the private activity that now bids fair to free the nation of foreign domina¬tion in supplying the nation's potash requirements. HISTORICAL REVIEW A pamphlet published by Thomas Stephen in 1758 pictures the industry in its early struggling condition.1 Just before the Civil War, a deposit of mineral potash had been found in Germany and its value as a fertilizer had been discovered. On this account and because the supply of wood ashes had decreased, the Ameri-can potash industry gradually lost its importance. During the next 50 years, with European potash available with little effort and with satisfactory substitutes on the market for the manufacture of soap, the interest of the American people in American potash declined. In 1910 this interest was suddenly revived by the abrogation of American potash contracts in Europe. Congress passed an act, approved by President Taft March 4, 1911, providing for "researches with a view to determining geological conditions favorable to the presence of deposits of potash salts." Appropriations were made to the Geological Survey and the Bureau of Soils to carry out the provisions of this act. The work of the Survey was directed toward the finding of commercial bodies of natural soluble potash salts; the Bureau of Soils was more concerned with the processes of extracting potash from industrial wastes and organic sources. Private agencies also became interested in the program. The Geological Survey has continued its search throughout the ensuing period of more than 20 years and has studied many types of deposits in many parts of the country.

Jan 1, 1933