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By J. W. Miller

One of the major problems confronting coal producers in this highly competitive era is whether or not the potential profit to be made from the products of coal flotation would warrant the capital investment required for the necessary equipment. The author supplies two theoretical cases to illustrate methods for computing such costs.

Jan 3, 1961

By Bennett Bates

A PAPER presented in South Africa' during 1925 by H. A. White gave a formula to express the efficiency of classification. The formula was originally developed by H. W. Newton of The Dorr Co. The derivation of this formula is as follows: Where E = Over-all efficiency of classifier Eu = Efficiency with respect to sand discharge Eo = Efficiency with respect to overflow I = Tons feed to classifier (input) 0 = Tons overflow U = Tons sands (underflow) i = Fraction of oversize in classifier feed o = Fraction of oversize in overflow u = Fraction of oversize in sands

Jan 5, 1927

After a three-year period characterized by inflation, recession, depressed metal prices, lack of demand, enormous world inventories, and rapidly escalating costs, the Canadian mining industry is showing welcome signs of recovery. A rise in world metal prices and particularly strong demand for gold, uranium, and coal have stimulated the industry in early 1979. In this atmosphere of growing optimism, over 3000 mineral industry executives, economists, geologists, and mining and metallurgical engineers convened in Montreal, April 26-29, for Canada's largest mining convention, the Annual General Meeting of the Canadian Institute of Mining and Metallurgy.

Jan 6, 1979

By B. C. Burgess

IN the first edition of this volume,44 feldspar was introduced as "the I commonest mineral of the crystalline rocks," usually in small grains associated with other minerals and commercially produced only from pegrnatites. Now other crystalline rocks, such as alaskites and granites, have become present or potential sources of feldspar. In addition, feldspar has encountered very vigorous competition from such substitutes as nepheline syenite and aplite. COMPOSITION AND PROPERTIES The feldspars form a group of which the principal species are orthoclase, microcline, albite, and anorthite. These are aluminum silicates of potassium, sodium and calcium. There are also a barium feldspar, celsian, and barium orthoclase feldspar, hyalophane, rarely found and of no commercial importance. None of the minerals in the feldspar group are found pure or nearly pure. The potash feldspars, orthoclase and microcline, nearly always contain some albite (soda microcline, an- orthoclase); the soda feldspars usually contain some anorthite (lime feldspar). There is a series of soda-lime feldspars known as plagioclase in which the albite and anorthite molecules replace each other in varying proportions from albite through oligoclase, andesine, labradorite, and bytownite to anorthite. Theoretical chemical composition of the principal feldspars is given in Table 1. The Whiteware Division of the American Ceramic Society sub- mitted a list of definitions of ceramic terms, in April 1947, for use in technical literature. For feldspar it gives: "A group of igneous minerals consisting chiefly of the aluminum silicates of potash, soda and lime, in which one base generally predominates." Commercial feldspars are intergrowths of at least two species of feldspar, which occur associated with one or more accessory minerals such as quartz, muscovite, biotite, garnet and tourmaline as well as with small but varying proportions of the decomposition product, kaolinite. An intergrowth of quartz and feldspar frequently contains

Jan 1, 1949

By John A. Wolfe, James A. Niederjohn

Applications of mathematical statistics to the field of exploration are still relatively new. There are two primary reasons why little has been published in this field. First, if one discovers an effective technique for exploration, he does not like to disclose it. Second, the geologist needs to work closely with a mathematical statistician, and the communications barrier between the disciplines is formidable. The authors, one a geologist and the other a statistician, were interested in the economic benefit which appeared to be possible in the inter-disciplinary area they call "geostatistics."

Jan 11, 1962

By Charles Fettke

The deposits described occur in a belt starting 1 ½ miles east of Juncos and extending 6 miles in a southeasterly direction. They are of the contact metamorphic type, being associated with a limestone and calcareous tuff that is interbedded with andesite tuffs and andesites which have been invaded by a quartz diorite intrusion. Of the fire occurrences examined, the largest can be traced for a horizontal distance of 2000 ft. No mining has, been done, but some of the outcrops lead to the belief that deposits of commercial size are present. IN CONNECTION with the gathering of data for a report on the geology of the Humacao district of southeastern Porto Rico during the summer of 1916, under the auspices of the Scientific Survey of Porto Rico and the Virgin Islands, conducted by the New York Academy of Sciences, the writer had an opportunity to make a brief examination of the magnetite deposits of the eastern portion of the island. Inasmuch as these deposits have attracted some attention as possible future sources of iron ore, and as there is only scanty reference made to them in literature,1 a short description based on this reconnaissance survey was deemed to be worthy of record. The magnetite deposits of eastern Porto Rico occur in association with a belt of limestone, trending approximately S 53° E, which begins 1 ½ miles east of Juncos and can be traced for about 6 miles toward the coast. Four outcrops of magnetite were observed, which are designated

Jan 2, 1924

By Walter E. Heinrichs

Before covering the separate methods used in mining geophysics, it may be well to mention some current basic geophysical prospecting concepts. As in most fields, a better understanding and means of studying these fundamentals usually provides the more common improvements, rather than new principles being discovered. The relative detail and complexity of most mining geology often results in the use of geophysics in problems it cannot solve. On the other hand, suitable applications are often ignored or left unrecognized. To minimize this, it is important to consider geophysics as a phase, or additional tool, in geological or exploration engineering.

Aug 1, 1956

By Arthur B. Cummins, Henry Mulryan

DIATOMITE is a hydrous or opaline form of silica, commonly known as diatomaceous earth, diatomaceous silica or kieselguhr. The term "infusorial earth" has lost its original meaning and today is incorrect in view of the distinctions between diatoms and infusoria. Various locality and variety names are obsolete but some retain local significance. Moler and Celite are trade names that have become associated with diatomite products from certain deposits in Denmark and near Lompoc, California. COMPOSITION Diatomite is essentially silica with some combined water (2 to 10 pct). Frequently it contains organic matter (from traces up to over 30 pct) and varying amounts of inorganic impurities such as sand, cryptocrystalline silica, clay, volcanic ash, calcium carbonate, magnesia and soluble salts. In the natural or crude state, diatomite contains from 10 to 65 pct or more of free water. Table I gives analyses of several diatomites from deposits of different types. PROPERTIES Pure varieties, either massive or stratified, are friable and porous, of low apparent density, and somewhat chalklike in appearance. Varieties containing organic matter vary from sedimentary oozes to peatlike materials. Impure varieties may be more or less claylike, sandy, calcareous or cherty. Compacted types approach porcellanite and silicified shales. COLOR-white, cream, gray, tan, brown, greenish to nearly black. HARDNES-light-weight varieties appear 1 to 1.5 because of porosity, but microscopic particles are 4.5 to 6.5. SPECIFIC GRAVITY-1.9 to 2.35. APPARENT DENSITY---dry block form, 20 to 40 lb per cu ft; dry powder, 5 to 16 lb per cu ft. CRYSTAL SYSTEM-generally amorphous (isotropic by X-ray diffraction) but frequently showing faint cristobalite pattern.67.68,70 MELTING POINT-1400° to 1650°C. STREAK-white. LUSTER

Jan 1, 1949

By N. A. Ziegler

THE present publication is a continuation of the work on gas analysis, described in a paper presented before the Institute of Metals Division a year ago.1 While that paper was largely descriptive in character, dealing with the various parts of the apparatus and method of operations, the present one gives numerical data obtained as a result of a series of experiments with iron-carbon alloys. The apparatus and the methods applied are essentially the same as previously described, changes being only in minor details. Attention should be called to the fact that in the present work we are dealing with the gaseous mixtures obtained as a result of vacuum melting of various ferrous alloys. It should be understood that when the terms "degasified sample" and "products of degasification" are used, they refer to the sample remaining after the vacuum fusion of the alloy and the gaseous products removed therefrom, respectively. The writer does not wish to create the impression that the metallic products of this process are absolutely free from any gaseous elements, nor that the gases obtained are present as such in the original sample. These two points are not yet definitely known and are subjects for future investigation. The point, however, which has been established beyond doubt, is that all the gases dealt with come from the metallic charge and are present either in the charge as such, or are produced as a result of chemical reactions going on within the charge.. The suggestion that the gases are due to the reactions between the metallic charge and the refractory materials has no valid basis.

Jan 1, 1929

By N. A. Ziegler

THE present publication is a continuation of the work on gas analysis, described in a paper presented before the Institute of Metals Division a year ago.1 While that paper was largely descriptive in character, dealing with the various parts of the apparatus and method of operations, the present one gives numerical data obtained as a result of a series of experiments with iron-carbon alloys. The apparatus and the methods applied are essentially the same as previously described, changes being only in minor details. Attention should be called to the fact that in the present work we are dealing with the gaseous mixtures obtained as a result of vacuum melting of various ferrous alloys. It should be understood that when the terms "degasified sample" and "products of degasification" are used, they refer to the sample remaining after the vacuum fusion of the alloy and the gaseous products removed therefrom, respectively. The writer does not wish to create the impression that the metallic products of this process are absolutely free from any gaseous elements, nor that the gases obtained are present as such in the original sample. These two points are not yet definitely known and are subjects for future investigation. The point, however, which has been established beyond doubt, is that all the gases dealt with come from the metallic charge and are present either in the charge as such, or are produced as a result of chemical reactions going on within the charge. The suggestion that the gases are due to the reactions between the metallic charge and the refractory materials has no valid basis.

Jan 1, 1929

By D. R. Weir, R. M. G. S. Berezowsky

Pressure oxidation of gold containing concentrates and ores is an effective pretreatment for liberating refractory gold. This is particularly true when an appreciable portion of the gold is associated with sulfides and is not amenable to conventional cyanidation. A brief review of the literature on pressure oxidation of refractory gold materials is presented. The chemistry of the aqueous oxidation of arsenopyrite and pyrite is discussed. Data obtained on pressure oxidation and subsequent cyanidation of concentrates and ores tested at the Sherritt Research Centre are also presented.

Jan 1, 1985

At the Kidd Creek mine operated by Ecstall Mining, Ltd. near Timmins, Ontario, Honeywell has installed a sophisticated new quick- thinking computer system that keeps tabs on conditions along three separate processing streams at once and relays continuous 60-second data to the mill operator. Believed to be the first of its kind, the system picks up data from two independent x-ray spectrometers simultaneously. A digital computer from Honeywell's Computer Control Division receives and interprets real-time information gathered by online x-ray analyzers, and the system then advises control room operators of the relative amount of each of five elements at five points in each of the three process streams. The system is reported to provide a quantitative analysis of the five elements at a given point in the process within one minute-which is about 120 times as fast as a chemical laboratory assay could be performed. With this instant data at his command, the mill operator can make timely process adjustments to correct any deviation from optimum flotation results, thus salvaging valuable minerals that would inevitably be lost with slower detection methods. The minerals recovered at Kidd creek are copper, lead, iron, silver and zinc.

Jan 8, 1968

The early records of coal in Kentucky by Walker and Gist have already been mentioned. Thomas Hutchins was aware of it in 1778, or perhaps several years earlier, as in writing of the Buffaloe, now Green, River, he said, "several persons who have ascended this River, say, that Salt Springs, Coal, Lime and Free Stone etc. are to be found in a variety of places."1 The next record found is an entry to Ellis and Marshall, of 878 acres on Coal Bank Creek, in the, then Fayette County on July 14, 1784.2 The settlement might have been made, or the name given, some time before. Hermeline, in 1783, mentioned iron ore and coal on the Green River,' although he had not been west of the Susquehanna River; his knowledge of coal might have come from Hutchins, although the latter made no mention of iron in that locality. In November 1790, coal was mined on Sturgeon's Creek in Lee County and floated in three barges down the Kentucky River to Cleveland's Ferry, where it was hauled to Lexington. The results were not equal to the expectations, and it was 1793 before the experiment was. repeated 4 In 1791, the estate of Samuel Wharton advertised for sale 31,000 acres "in the county of Jefferson, on the North Side of the Green or Buffaloe river, in the State of Virginia."5 In November 1795 three patents were issued for land in the then Lee County, aggregating 130,000 acres. These patents cover much of Harlan County. The descriptions of these surveys mention passing stone coal. on Rough Branch of Martin's Fork, a "great deal of stone coal" on Blacksnake Branch of Pucketts Creek, and "a quantity of stone coal" probably on Crummies Creek.6 Jedediah Morse, in The American Gazetteer, 1798, said that in Kentucky "in many places there are appearances of potter's clay, and coal in abundance." It is possible that shipments may have been made from near

Jan 1, 1942

By J. F. Myers, S. D. Michaelson, F. C. Bond

THIS work was undertaken with the object of collecting plant data on rod milling, making laboratory tests on representative samples of the various ores, and arriving at a basis for comparing the relative efficiencies of different mills operating on widely different materials and under varying conditions. These efficiencies consider only power consumption and do not include the other elements of operating costs. The over-all economic efficiency may be quite different from the consumption efficiencies with which this paper is concerned. It is hoped that these collected data will be of value in indicating the most favorable conditions of rod-mill operation. Operating-plant data on 14 different installations from 11 plants throughout the United States and Canada were collected, and laboratory tests were made on samples of these ores. The plant rod mills were all operated wet, and either in open circuit or with circulating loads so small as to be negligible. Data were obtained on one roll-crushing operation at the Utah Copper Co., for comparison. The rolls were operated wet in closed circuit with 10-mesh vibrating screens, and with a high circulating load averaging about 600 pct. This particular roll operation can be considered as a model of efficiency. The collected plant data are necessarily incomplete in some instances. Each ore was assigned a code number, and the name and location corresponding to the code number are listed in Table I when permitted. [ ] The power data in every instance refer to motor input. Net power was reported by the operator for samples I-39 and I-45, and this was increased by 20 pct to compensate for motor losses and power factor. The plant rod-mill data are listed in Tables 2 and 3. In Table 2 the speeds are calculated on the basis of partly worn rod-mill liners 2 in. thick. Where D

Jan 1, 1947

By J. F. Myers, S. D. Michaelson, F. C. Bond

This work was undertaken with the object of collecting plant data on rod milling, making laboratory tests on representative samples of the various ores, and arriving at a basis for comparing the relative efficiencies of different mills operating on widely different materials and under varying conditions. These efficiencies consider only power consumption and do not include the other elements of operating costs. The over-all economic efficiency may be quite different from the consumption efficiencies with which this paper is concerned. It is hoped that these collected data will be of value in indicating the most favorable conditions of rod-mill operation. Operating-plant data on 14 different installations from II plants throughout the United States and Canada were collected, and laboratory tests were made on samples of these ores. The plant rod mills were all operated wet, and either in open circuit or with circulating loads so small as to be negligible. Data were obtained on one roll-crushing operation at the Utah Copper Co., for comparison. The rolls were operated wet in closed circuit with 10-mesh vibrating screens, and with a high circulating load averaging about 600 pct. This particular roll operation can be considered as a model of efficiency. The collected plant data are necessarily incomplete in some instances. Each ore was assigned a code number, and the name and location corresponding to the code number are listed in Table I when permitted. The power data in every instance refer to motor input. Net power was reported by the operator for samples 1-30 and 1-45, and this was increased by 20 pct to compensate for motor losses and power factor. The plant rod-mill data are listed in Tables 2 and 3. In Table 2 the speeds are calculated on the basis of partly worn rod-mill liners 2 in. thick. Where D

Jan 1, 1949

Climax Molybdenum Co. has contracted with the Government to operate its property at Climax, Colo. at maximum capacity for five years. Substitution of synthetic lubricants, polyalkylene glycols and their derivatives, for petroleum products in certain industrial applications is yielding substantial savings in production costs and improved operation of mechanical equipment.

Jan 1, 1951

By T. Y. Yan, W. F. Espewheid

The various ion exchange reactions occurring during restoration of formations contaminated with ammonia during in situ uranium leaching are reviewed. Data are presented on the restoration of a previously leached laboratory packed column wing lime saturated brine. Although this restoration fluid selectively and effectively removed the ammonia, 24.5 pore volumes are required to reduce the ammonia concentration from 500-3 mg/L (29- 0.18 gr per gal). The essence of NaCl in the restoration fluid at levels in formation water is beneficial in improving the selectivity of the system for NH4+ removal and reducing Ca + + ion consumption

Jan 1, 1984

Manganese nodules are essentially a surficial resource-there are four times as many nodules on the surface of the deep ocean floor as in the next 3 ft of underlying sediment. Target mine sites in the North Pacific occur in water 12,000 to 18,000 ft deep. The mining technique is comprised of four major factors: the mining device, lifting method, surface vessel, and ore transport. Certain deep-ocean mining proposals are revolutionary in character. Current research has tended to construct simple but flexible devices to work at the great depths and corrosive environments of the deep-ocean floor

Jan 4, 1975

By C. D. Dolman

SINCE the outbreak of the war we have discovered in the United States minerals of which there was no general knowledge, and which compared very favorably with anything that could be found in any foreign country. One of these was magnesite, or the carbonate of magnesium as it occurs in nature. This mineral crystallizes in the rhombohedral form, has a specific gravity of 3.00, molecular weight of 84 4, molecular volume of 28.1, and a hardness of 3.5 to 4.5.1 Had it not been for the development of the California deposits of this mineral and the discovery of immense new deposits in Stevens County, Wash., the production of steel during the war would have been more seriously handicapped than it was. Now, that the war is over, we face the possibility of competition' with the cheap Austro-Hungarian magnesite; and while that may not he so cheap as it was before the war, adequate protection should be given the producers in this country to insure the full development of our own resources. The consumption of magnesite in the United States in 1913, the year preceding the war, was 172,591 tons of calcined and 22,872 tons of crude magnesite. Less than 3 per cent. of this amount was produced at home. At the present time, practically all of the magnesite used in the United States is produced at home. Expensive plants have been constructed, extensive exploration work done, and production pushed to the utmost to supply the necessary requirements of the war. Thus a considerable industry has been built up within our borders. Some magnesite has been imported from Canada and Mexico, but the Canadian ore was of an inferior grade and could not be used satisfactorily. During the year 1918, production decreased in both the United States and Canada; the production in the United States was 225,000 tons in 1918 as against 315,000 in 1917, and in Canada 39,365 tons in 1918 as against 58,090 in 1917.

Jan 8, 1919

RECENTLY seven Boy Scouts were chosen from all the troops in the United States for their all-around ability, excellence in' scouting, and special ability as writers. Two of the members of this selected group were sons of In-stitute members. In the accompanying illustration, Ber-nard Queneau, son of A. L. J. Queneau, of the U. S. Steel. Corp., can be seen at the extreme left, just behind Theo-dore Roosevelt, who is shaking hands with the boy next to. Carl Zapffe (standing in the middle with his hands behind him), the son of Carl Zapffe, manager of the iron ore prop-erties of the Northern Pacific Railroad.

Jan 6, 1928