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Three separate and unconfined aquifers occur in the Hilton area, named relative to position in relation to ore horizons: Footwall Aquifer in the east; Ore-Zone Aquifer within the ore-bearing Urquhart Shales; and the Hangingwall Aquifer in the west.It is the on-going strategy it Hilton to drain the Ore-Zone Aquifer which occupies structurally- and sulphide-controlled leached zones in the steeply west dipping strata. The aquifer affects considerable ore reserves to 480 m below the surface. Dewatering began in 1976, and is essentially completed to 4 level (240 m below surface). Dewatering efforts are now based on 8 level (480 m below surface).

Jan 1, 1993

By T. E. Gray

This report describes the preparation characteristics of the significant coalbeds in Harrison County, W. Va. It is one in a series of Federal Bureau of Mines reports planned to determine coals suitable for the production of metallurgical coke, either as mined or after beneficiation. Over 6.5 million tons of coal was produced in Harrison County, W. Va., in 1958, of which over 3.7 million tons was cleaned mechanically in seven preparation plants. All of the coal cleaned was from the Pittsburgh bed. It has been estimated that more than 1,816 million tons of coal remains in the county in beds 12 inches or more thick. The Pittsburgh and Redstone beds were selected by the Bureau for a study based on current production rates and estimated minable reserves. Sample locations were selected following a study of the literature, conferences with mining engineers and mining company officials in the field, and examination of the available sites. Six samples were collected from the Pittsburgh bed, and three samples came from the Redstone bed, Float-and-sink tests of the samples collected from the Pittsburgh and Redstone beds showed that neither coal could be upgraded to a metallurgical fuel under the standards set up for this study, even after intensive preparation. Finer crushing of the samples moderately increased the yields and slightly reduced both the ash and the sulfur contents in the 1.30-specific-gravity float fractions. Finer crushing slightly decreased the yields in the 1.58-specific-gravity float fractions, whereas it reduced the sulfur content 0.11 percent for the Redstone sample and 0.46 for the Pittsburgh sample.

Jan 1, 1961

By T. Fujita

The removal of phosphorus is essential 1n order to increase the recycling of steelmaking slags for their manganese, iron and lime contents. This study aims at establishing the phosphorus mineralogy and its distribution in steelmaking slags, the effect of slow cooling, and the methods of phosphorus removal. A series of steelmaking slag samples was prepared at different cooling rates, and the mineralogy, chemistry and grain size of the samples were investigated with SEM/EDS and x-ray diffraction. The test results using high gradient magnetic separation are discussed.

Jan 1, 1988

By R. J. Wysor

Since the outbreak of the European war, few problems of raw-material supply have commanded more nation-wide attention than potash. It is well known that before the war the domestic production of potash was an insignificant percentage of the imports. The average annual importation of raw potash salts for several years prior to 1914 was slightly over 300,000 net tons, and of other potash manure salts about 700,000 tons. The sudden and almost total cessation of these imports created a unique and stringent situation. Methods of recovering potash from feldspar and other native mineral sources, and reclamation from hitherto waste products, have received a marked impetus. Soaring prices have been a keen incentive to research and industrial development. Although several brief articles concerning the possibilities of potash recovery have appeared in recent trade journals, it still may be a matter of some surprise to the average technical mind that potash might be reclaimed as a profitable byproduct in the manufacture of pig iron. At the present time it may be of special interest to present some data, largely of a technical nature, on this subject. A fairly thorough search of the literature reveals a number of articles concerning salts of the alkali metals in the blast furnace. Many of them deal with the theoretical rôle of alkali cyanides in the furnace. Several discuss the probable effect of the alkalies on the furnace brickwork. Two or three ambitious patents have been granted for reclaiming potash or other products from blast-furnace gas. However, we have heard nothing further as to the practical application of these patents. Little literature of importance has appeared during the last 10 years concerning alkalies in blast-furnace practice, and I have discovered no record whatsoever as to the actual sale or commercial disposal of flue dust for its potash content until this was inaugurated in our plant at Bethlehem. A bibliography of the most important articles discovered is appended. About 4 years ago, in the course of investigating blast-furnace stove efficiencies, I analyzed the fine, yellowish fume of which a considerable

Jan 1, 1917

By I. J. Lin

The effect of various types of structural modification on the critical micelle concentrations (CMC) and hydrophile lipophile balances (HLB) of certain surfactants has been considered. Using the concept of effective chain length for the substituted species, an index of hydrophobicity (I) has been defined. It is hoped that such an index will allow one to choose surfactants for particular purposes in a less arbitrary fashion than heretofore.

Jan 1, 1973

By burgess F, Manlapig E. V, Franzidis J. P

Bubble surface area flux, a parameter which is determined by bubble size and superficial gas velocity, has been identified as a criterion for flotation scale-up from a metallurgical point of view. Investigations at Hellyer, Scuddles and Mt Isa

Jan 1, 1997

By A. Meléndez

El presente trabajo señala el proceso del entrenamiento para Ingenieros de minas en la corporación minera Cerro Verde a través del plan de perfeccionamiento profesional elaborado por la misma empresa privada. El objetivo del plan es darle al profesional egresado, la experiencia práctica adecuada que complemente la formación académica. Asimismo se busca la eficiencia de su profesión, desarrollar la competitividad y el estímulo de superación del egresado dentro de la empresa minera.

Nov 20, 1972

By K. Hanumantha Rao, A. Javadi

Our recent studies revealed that the sulfide minerals in contact with water during grinding produced hydrogen peroxide (H2O2) where the amount of H2O2 production by the minerals found to be in the order of pyrite > chalcopyrite > sphalerite > galena. The H2O2 effect on the oxidation of pulp components and its influence on the concentrate grade and recovery in flotation have been studied and the results have been presented and discussed in this paper. Studies have also been carried out to build correlation between percentage of pyrite in the concentrate, grinding conditions and concentration of OH•/H2O2 in the pulp and as well of controlling the formation of these species through known chemical means for depressing the generation of the oxidant. Flotation tests using a complex sulfide ore with the same reagent scheme that is being used at Boliden concentrator in Sweden but with the addition of i) collector and depressant, ii) Na2S reductant and iii) inorganic (EDTA) and organic (TETA) surface modifiers, during grinding stage have been performed to judge the beneficial or detrimental role of H2O2 on the selective flotation of sulfides. The results demonstrate that the selectivity of metal sulfides against pyrite increases with increasing generation of H2O2 in the pulp liquid. H2O2 is also found to be a better oxidant in chalcopyrite-galena flotation separation than the commonly used K2Cr2O7.

Jan 1, 2016

By William M. Kester

Finely sized Upper Freeport coals are beneficiated to reduce ash and sulfur using high-intensity magnetic separation to process both (1) raw, untreated coal as well as (2) raw coal which was pre-treated thermally with steam and air. Substantial, sulfur and ash reduction can be obtained using both approaches to magnetic beneficiation of coal fines, but evidence indicates that pre-treatment which would constitute a costly supplementary step is technically inferior to the direct beneficiation of raw, untreated coal. These bench-scale studies demonstrate that if high-intensity,; high capacity, dry, magnetic beneficiation equipment can be developed and' installed at coal burning power plants or at appropriate points in coal preparation plants substantial quantities of sulfur may be removable from coal after pulverization as a means' to reduce air pollution.

Jan 1, 1965

By Harmon E. Keyes

Many organizations, including the Bureau of Mines, have made intensive studies of the application of leaching methods to relatively small low-grade disseminated deposits of copper ores, containing both oxide and sulphide minerals. One of the principal difficulties has been to obtain a solvent that could be made at a low cost and would effectively dissolve the copper minerals. Another drawback has been the high initial cost of a plant and the refined type of mechanism ordinarily required by standard practice for carrying out the leaching cycle. The Bureau of Mines has attempted to develop a cheap and efficient solvent that would especially meet the requirements of smaller plants. (See Bibliography.) It has been known that dilute ferric sulphate-sulphuric acid solution is an excellent solvent for most copper minerals, such as chalcocite, bornite, and oxidized forms, but not for chalcopyrite and certain silicates. A method of producing this solution from sulphurous products and waste liquors was developed by the bureau and tried successfully on a test-plant scale at the Southwest Experiment Station in cooperation with the department of mining and metallurgy, University of Arizona, Tucson, Ariz. However, this work did not involve the actual leaching of ores with the solutions thus produced or the cyclic use of the iron solutions in the regenerator cell. Except for certain laboratory tests, in which known impurities were added, no data were available to show the effect on regeneration if accumulations of impurities were built up in the leaching circuit.

Jan 1, 1930

By W. W. Adams, T. D. Lawrence

"The National Safety Competition covering the calendar year 1934 was the tenth yearly safety contest conducted by the United States Bureau of Mines. Participating in the competition were 334 mines and quarries in 38 States. Five mining or quarrying companies, each the leader in its group for having established the best safety record during the year, were awarded the national safety trophies ""Sentinels of Safety.""Since these annual contests were begun 10 years ago by the United States Bureau of Mines the scope of the competition has been broadened materially, both as to the number of plants participating and as to the number of man-hours of exposure to accident hazards. Moreover, marked progress in the prevention of accidents has been achieved, as is indicated by an almost constant downward course in toe accident-frequency rates for the contest group as a whole during the past 10 years. On the other hand, the accident-severity rates for the group showed an upward trend during the first part of the decade and a downward trend during the latter part of the period except in 1930 and 1934; in each of those years a disastrous explosion with abnormally heavy loss of life occurred at the property of one of the participating companies.Because of the abnormal nature of the major disaster in a bituminous-coal mine in 1930 and 1934 the accident-severity rates for the bituminous group for those years are not strictly comparable with the rates for other years. The rates for bituminous mines for 1934 in the present report have therefore been computed on two bases; first, to exclude the record of the company that suffered the disastrous explosion and, second, to include the record of this company. The first rate represents the normal experience of the bituminous coal companies unaffected by the disaster and is therefore more indicative of the real trend of the accident rates for this class of mines from year to year. The latter rate shows the actual experience of all bituminous mines in 1934. The report of the competition of 1930 likewise showed the rates for the bituminous group as computed both with and without the disaster that occurred that year.The National Safety Competition is conducted by the United States Bureau of Mines in the interest of safety in the mining and quarrying industries. This object is accomplished directly through the efforts of the competing companies and their employees to win first place in the competition and thereupon receive well-merited and national recognition for their achievement. Indirectly the purpose of the contest is accomplished through studies by the Bureau of Mines of the facts contained in the accident reports which the competing companies furnish to the Bureau to enable the Bureau to compute the accident rates that are the basis for determining the winners of the contest."

Jun 1, 1935

Jan 1, 1947

Jan 1, 1947

By R. V. Higgins

This paper describes a method and a computer program for calculating shape factors and areas of channels that turn more than 90° and conduct fluids into the backs of wells. The program represents an improvement over a previous Bureau of Mines investigation by using a 4-point Lagrange interpolation equation instead of a 3-point and by summing areas of trapezoids with either x altitudes or y altitudes. Some of the techniques reported in this paper can also be used to compute the areas between contours and the lengths of lines that turn more than 90°.

Jan 1, 1968

By M. H. Chetrick

Since 1945, a commercial-scale pilot plant for the gasification of lignite has been operated by the Bureau of Mines at Grand Forks, N. Dak. The description, operation, and objectives of this pilot plant have already been described in previous reports (6, 7, 8). Although the experimental data obtained from the operation of the externally heated retort have been tabulated and summarized (1, 7), few studies have been made in the correlation of these data. The purpose of the present investigation was to review the data taken in tests of the lignite-gasification pilot plant and to correlate the gas-composition data in terms of their basic factors.

Jan 1, 1950

By R. E. Eyre, L. P. Landucci

C URRENT practice in the zinc concentrate roasting plant of The Consolidated Mining arid Smelting Company of Canada Limited, at Trail, B.C., involves passing the furnace effluent gases through an electrostatic precipitator for the recovery of dust. After removal of the dust the gas is treated for recovery of sulphur dioxide by conversion into sulphuric acid ( 1). However. as roasting techniques improved, and furnace productivity in-creased, the rated capacity of the precipitator was exceeded and it was necessary to consider various means of improving the dust recovery. A study of methods indicated that a baghouse using silicone-treated glass fabric, might be suitable for this particular application. Glass fabric was chosen because the temperature of the roaster effluent gases would range from 450°F to 500°F and tempering air was undesirable to avoid dilution of the sulphur dioxide gas.

Jan 1, 1962

By Scott W. Hazen

This report describes exploration for lead-zinc ores at the Madonna mine between 1945 and 1953 by the Utze Lode Co., the Bureau of Mines, and the company with Government financial aid under the Defense Production Act of 1950. The Madonna mine yielded silver, lead, and zinc with a net smelter value of over $5,000.000. from 1882 to 1924. The mine was inactive from 1924 to 1942 when the Utze Lode Co. acquired the property. Possibilities for finding ore in the mine, especially at depth, were considered favorable. The Utze Lode Co. began rehabilitating the Madonna mine in 1945. An exploration program, which consisted of winze sinking and drifting, failed to produce commercial are.

Jan 1, 1956

By Lassi Klemettinen

For better understanding and maximal value utilization of the WEEE smelting process, the behavior and distribution of different trace elements must be known. In this study, the behavior of nickel as a trace element was studied in an equilibrium system with metallic copper—spinel saturated iron silicate slag (with 3 wt-% K2O)—iron aluminous spinel—gas. The experiments were conducted in alumina crucibles at 1300 °C, in oxygen pressure range of 10−10–10−5 atm. A time series of 15–60 min experiments was also conducted for investigating the formation rate of the primary spinel phase in the system. The results show that the distribution coefficient of nickel between metallic copper and liquid slag changes from approximately 70 to 0.4 along the increasing oxygen pressure range. In addition, a significant part of the nickel deports into the spinel phase. The spinel formation was investigated based on composition analysis results and visual observations from SEM-images.

By M. J. Lempel

A theoretical study of the heat-transfer characteristics of a dilute gas-solids mixture in an externally heated tube is reported. Detailed equations are developed describing the system, and a numerical method is presented to solve the equations using a digital computer. The methods are applied to a system containing fine coal particles entrained in hydrogen, flowing through a hot tube. Heat-transfer coefficients and several other physical constants are evaluated in detail.

Jan 1, 1967

By Bill S. Taylor

Dutch State Mines [D.S.M] introduced the Heavy Medium Cyclone into the United States for cleaning fine coal about three decades ago. Since that time the general industry practice has been to deslime the raw coal at 28 Mesh (0. 59mm) size. The plus 28M material is fed to the Heavy Medium Cyclone for cleaning, and the 28M x 0 fraction is processed by other means (e. g. flotation or hydrocyclones). This approach recognized that 28M was the smallest size particle that could be easily rinsed on vibratory screens without excessive loss of magnetite, and without blinding of sieve bend and vibratory screen decks. Another reason for the 28M de-sliming was to avoid excessive contamination of the media with non-magnetic coal, shale, or clay fines. The most undesirable of these contaminants is the sub-micron size clay particles (2) that greatly increase the viscosity of the media and reduce the numerical maximum level that the media specific gravity can obtain due to the lower specific gravity of clay with respect to magnetite. The higher the fugitive clay content, the more severe the preceding problems become. During the last 30 years, many conventional Heavy Medium Cyclone Plants have been built throughout the world. In the United States, the initial cyclone plants were confined to the production of high quality metallurgical coal where lower gravities of separation were required than could be obtained from the conventional hydraulic or air separation processes. In recent years a large and ever-increasing number of preparation plants producing steam coal have started utilizing Heavy Medium Cyclone technology due to the environmental pressures being encountered to produce low sulphur coal. Due to the inherent characteristic of many coals of having a lower pyritic sulphur content at lower specific gravity fractions, many applications and markets are appearing for separating steam coals at much lower specific gravities than have been historically normal in the United States. Therefore. Heavy Medium Cyclones are being utilized to a much greater degree in this field, due to the flexibility of low separating gravity ability coupled with high efficiency when high percentage of near gravity material is present.

Jan 1, 1978