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By Joseph Moses Botbol

This study was designed to demonstrate the viability of using high-frequency radio transmission as a means of communications between a remote field camp and a time- sharing computer system. A field camp near Johnstown, Pa., was linked by high- frequency radio to a base station 160 miles to the southeast in Vienna, Va. The base station was in turn linked by telephone to a time-sharing computer system near Los Angeles, Cal. Error-free data transmission utilized highly stable receivers and transmitters, forward error correction, and dual-frequency diversity. Three geologic applications programs resident in the Los Angeles computer were executed from a graphics cathode ray tube terminal in the field. Bulk data equivalent in volume to 4 days of typical spectrographic analytical work generated by one spectrograph and one spectrophotometer were transmitted from the field to the base station. All programs, were executed successfully, and all data were transmitted error free.

Jan 1, 1976

By F. W. Robinson

THE temperature coefficient of electrical resistance of pure metals is high and therefore the resistance increases rapidly with rising temperature. In 1871, Siemens suggested the use of this property as an accurate means of temperature determination. Owing to practical difficulties, particularly the contamination of the metal and consequent permanent change in its resistance and its resistance-temperature relation, this method fell into disrepute as a practical standard until revived later by Callendar and Griffiths, and subsequently by Holborn and Wien, all of whom showed that the earlier difficulties were not inherent in the method but incident to the mode of protection of the resistance coils. Following .the work of these investigators, the problem of temperature measurement by this means has been the subject of careful study and has now assumed an importance second only in practical adoption to the thermo-electric method. It is generally recognized, both here and in Europe, that the standard temperature scale should be the thermodynamic as it permits the evaluation of high temperatures on the basis of the radiation laws of Stefan and Bolzmann, of Rayleigh, and of Wien and Planck, on a scale consistent with that obtained by means of the gas thermometer at low temperatures. Lord Kelvin showed that only. a very small correction, amounting to about +0.7° at 1000° C.-almost within the limits of experimental errors-is necessary to adjust the constant-volume nitrogen thermometer to the ideal thermodynamic scale.

Jan 9, 1919

By S. F. Ravitz

IN his excellent book on the Principles of Flotation, Wark1 makes the following sig-nificant statement concerning the theory of flotation: Two questions of first-rate importance must be considered . . . First, it must be decided whether the sulfide minerals require a collector in order that they may float, or whether as has been claimed, they possess an inherent float-ability and need no collector. Second, it must be decided whether the xanthate type of col-lector can react with or be adsorbed by the unchanged sulfide minerals themselves, or whether, as many claim, reaction with the collector is dependent upon initial oxidation of the mineral surface. In the theory of flotation there are no two questions of greater impor-tance than these. Ravitz and Porter2 presented evidence that galena can be floated without a col-lector, and even without any reagent, pro-vided oxidation products are thoroughly removed from its surface. They found also that thoroughly cleaned galena floated faster when xanthate was used than when a frother alone or no reagent was used, and that, without a collector, the recovery decreased gradually upon exposure of the mineral to air. Their work, however, has met with considerable criticism. 1(127),3-6 This paper is presented to answer the objections that have been raised, and to present additional data that confirm their results.

Jan 1, 1940

By R. P. Rothwell

A Reference to the geological map of Alabama shows the Goalmeasures of that State to form three distinct fields. The Coosu, or most easterly, contains about one hundred square miles ; the Cahaba, or middle field, which is also the most southern true coal in the United States, contains about 230 square miles ; and the Warrior field, which contains in the State of Alabama some 5000 square miles, is the southern extremity of the great carboniferous deposit, which extends through Pennsylvania, West Virginia, Kentucky, Tennessee, and Georgia. But very little has yet been done towards developing those coalfields, partly owing to the absence of all commercial manufacturing enterprise in the South under slavery, and partly owing to the want of capital and the disturbed condition of the South since the war. During the past three or four years I have devoted a large part of my time to the examination of the coal and iron ores of this range,

By I. Plaskin

Interaction of sulfide minerals and native metals I with reagents in flotation is largely determined by particle-surface changes resulting from action of the medium and dissolved gases. A number of early studies were devoted to the selective action of various gases on minerals.' Mc-Lachlan' paid attention to oxygen as the most active gas affecting flotation properties of sulfide minerals. Opposing views were expressed concerning the influence of sulfide oxidation on xanthate flotation: Taggart3 recognized the positive influence of oxygen, and I. W. Wark4 rejected it. Shvedovh ffered the hypothesis of partial oxidation. As to the influence of such gases as hydrogen" and carbon dioxide on mineral floatability, opinions also differed. Effect of Oxygen on Sulfide Mineral Flotation: Research on the influence of oxygen and other gases on the floatability of sulfide minerals and native metals has been carried out at the Institute of Mining of the USSR Academy of Sciences in

Jan 1, 1960

By Donald L. Everhart

Beginning in 1906, data has been compiled on the distribution of uranium in phosphate de- posits. Particular emphasis has been placed on uranium in phosphate by a number of geologists and geochemists in the US Geological Survey in research sponsored by the US Atomic Energy Commission (now Nuclear Regulatory Commission) and the US Department of Energy (DOE) during the 30-year period from 1951 to 1981. A comprehensive study of uraniferous phosphate resources the United States and the Free World was completed, under the auspices of DOE, in 1979. Apatite is the main carrier of uranium in phosphate. Uranium generally replaces calcium in the mineral lattice. In marine phosphorite throughout the world, the uranium content is characteristically in the range of 0.005 to 0.02% by weight. Phosphorite takes in uranium by structural substitution in apatite or other mineral phases, by absorption, or by the formation of independent mineral phases. Apatite derived from the interaction of ground water, guano and limestone is typically relatively low in uranium content-in the 0.001 to 0.005% range. In primary accessory apatite of igneous rocks, as well as magmatic and metasomatic apatite segregations of alkalic rocks and carbonatite, uranium content is generally between 0.001 and 0.01%. In all these phosphate deposit types, secondary enrichment of uranium through

Jan 1, 1983

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Jan 1, 1938

By C. E. Birchenall, J. R. Stubbles

ThE equilibrium between lead, lead sulfide (PbS), and atmospheres of H2 and H2S has been determined previously by Jellinek and Deubel,' and SudO.' Blbem and Kroger3,4 used Jellinek's data to calculate the sulfur dissociation pressures of PbS crystals (of

Jan 1, 1960

Jan 1, 1953

W. G. MATTESON,* Fort Worth, Tex. (written discussion?).-Dr. Brokaw has evidently given a great deal of time and study to this phenomenon and his conclusions seem sound and logical. .Mr. Lee Hager was probably the first geologist of repute to attach any great importance to the occurrence of paraffin dirt in connection with the Gulf Coast oil-producing salt domes. The writer has been reliably informed that through his discussion, the idea was promulgated that the presence of this so-called paraffin dirt was one of the most important and reliable indications of the presence of an oil-producing salt dome. Despite very strong evidence to the contrary, Hager evidently still has considerable confidence in this theory, as brought forth in his discussion1 of Dr. Brokaw's paper. Halter here gives all the paraffin dirt occurrences known to him, and adds, "Fifteen of these localities, including practically all of the greatest fields, have produced oil in some quantity." . The acceptance of the list of occurrences as submitted by Hager depends upon what material we are justified in including under the term "paraffin dirt." If we agree to a broad classification, whereby paraffin dirt is. to include all spongy, earthy, decomposed, vegetable material, or spongy soil impregnated with the same, then Haggler's list will have to be not only accepted but perhaps enlarged. On the other hand, if we confine ourselves to a strict interpretation of the substance known as paraffin dirt, based .upon typical occurrences, general understanding, and application, several of Hager's occurrences will be seriously questioned by many geologists. The typical material is excellently described by Hager as a dirt or soil-like substance "resilient to the step, like rubber, which falls apart in small squares when dug. Intimately mixed with the soil itself and between the cracks and joint planes is a yellow, jelly-like

Jan 11, 1918

By P. F. Richardson, J. L. Perisho, W. J. Roe

Handling and transport of coal during the winter months can be a severe problem. The inability to unload frozen coal from rail cars produces serious economic and logistic problems due to transportation delays, rail car shortages, and demurrage on the rail cars. One method of dealing with the problem of unloading frozen coal has been to spray freeze conditioning agents onto the coal before it is loaded into rail cars. Both water soluble and oil based formulations have been used as freeze conditioning agents. The water soluble treatments generally contain a polyhydroxy alcohol, such as ethylene glycol, or salts of alkaline earth metals, such as magnesium chloride and calcium chloride, as freeze point depressants. The oil based treatments consist principally of hydrocarbons, such as No. 2 oil or diesel fuel. The authors' tests have shown significant differences in the effectiveness of these freeze conditioning agents, depending on the particular coal substrate being treated. These differences correlate with the coal porosity and inherent moisture of the substrate. In general, the greater the porosity of the coal, the smaller the effect of the freeze conditioning agents. Coal porosity has a greater impact on water soluble freeze conditioning agents than oil based products. The authors investigated the pore structure of a variety of coals using mercury intrusion. Findings were related to the effectiveness of different freeze conditioning agents as measured by unconfined compression strength tests. In general, coals with a large number of very small pores (between 0.05 µm and 0.03 µm) do not respond as well to freeze conditioning chemicals.

Jan 1, 1986

By F. P. Dewey

The most serious problem that confronts the lead-smelter is the waste caused during smelting by the volatilization of both lead and silver, which are consequently lost in the form of fume. It is not difficult to collect a portion of the solid materials passing out of the

Jan 1, 1890

US 4,181,588 - Direct extraction of lead from lead sulflde ore. Ore is leached with a solution of ferric chloride and sodium chloride. The leach liquor is filtered to remove sulfur and gangue, then cooled in a crystallizer to precipitate lead chloride The slurry from the crystallizer is subjected to electrolysis to deposit lead chloride on the cathode plate. Solution from the electrolysis cell is used in the leaching step. M.M. Wong and F.P. Haver, assigned to US Secretary of the Interior Jan 1, 1980. 6 pp. (204-115). Filed: 1-4-79 (1,026).

Jan 1, 1982

By D. Krammer, E. S. Machlin

The effect of a brior high-temperature creep strain on the low-temperature ductility of commercially pure nickel has been evaluated. The low-temperature (-196°C) ductility decreases linearly with an increase in prior high-temperature (920°C) creep strain. The effect is experimentally correlated to the formation of inter crystalline cracks and voids during the prior high-temperature creep strain. The magnitude of the effect is also believed to be a function of the notch sensitivity of the material. SEVERAL mechanisms have been presented to explain the process of inter crystalline cracking in metals undergoing high-temperature creep. zenerl has suggested that grain boundary relaxation of shear stresses could build up high stresses at ob- stacles to grain boundary shear and thereby nucleate a crack. Chang and rant' have experimentally demonstrated that cracks do form at obstacles to grain boundary shear such as lines where three grains meet. The role of vacancies in the mechanism of high-temperature inter crystalline cracking has been explored by Machlt with the conclusion that the nu-cleation of voids by vacancy condensation is almost

Jan 1, 1960

By C. H. Jr. Herty

THE removal of sulfur from steel has been studied by many investigators, but the quantitative relationships between the factors involved have not been determined. This is undoubtedly due to the number of variables encountered in practice, an attempt to study any one reaction or relation being affected by other reactions the relative importance of which cannot be estimated. The factors that affect the extent of removal of sulfur in the basic open-hearth process are generally considered to be: 1. Basicity of the slag: (a) Iron oxides in the slag; (b) carbon in the metal, or carbide in the slag; (c) temperature. These factors affect the reactions: FeS + CaO = CaS + FeO FeS + CaO + C = CaS + CO + Fe. 2. Amount of sulfur in the gas. 3. Amount of manganese in the metal. The factors which affect the rate of removal of sulfur include, in addition to these 4. Fluidity of the slag: (a) Normal changes in fluidity with temperature; (b) changes in fluidity because of the addition of special reagents such as fluorspar. 5. Agitation of the bath.

Jan 3, 1925

By T. H. Courtney, G. W. Pearsall, J. Wulff

The mechanism, of the decrease in transition temperature of Nb3Sn was studied. Presintered Nb3Sn powder compacts were heated in a dynamic vacuum at elevated temperatures. Loss of tin resulted from these heat treatments and transition temperature as a function of tin loss was discontinuous at a critical value of tin loss. In general, decreases in transition temperature were correlated with deviations from AS a class, the A15 structure-type (also known as Cr3O or ß W) compounds have the highest superconducting transition temperatures.' In this class are stoichiometry and presence of vacancies in niobium sites. The effect of vacancy distribution on the physical properties of Nh3Sn is considered. It is concluded that the close-packed atomic A chain in the A3B A15 structure must be preserved both in coutinuity and direction if good superconducting properties are to he obtained. tempting to associate these high transition temperatures with the most unique crystallographic feature of the A3B structure: the three close-packed, orthogonal chains of A atoms.'0"' There are at least three principal mechanisms by which the perfection of these "A-atom chains" could be interrupted: changing stoichiometry, inducing disorder, or introducing vacancies. Departures from stoichiometry in either direction in V3Ga lower the transition temperature.7'8 In niobium-

Jan 1, 1965

Jan 1, 1887

By Frederick Laist

The ores received at the Washoe Smelter come almost entirely from the mines in Butte and contain the following minerals : Chalcocite, Cu2S; covellite, CuS; chalcopyrite, CuFeS2, (trace); bornite, Cu3FeS3; enargite, Cu3AsS4; malachite, Cu2CO4 + H2O (trace); pyrite, FeS2; sphalerite, ZnS; rhodo-chrosite, MnCO3, (less than 1 per cent.); rhodonite, MnSiO3, (less than I per cent.). The country-rock of Butte is of the granite family and is a quartz-monzonite containing a little less silica than typical granite. It is made up of the following rock-minerals in approximately the proportions indicated: Minerals. Composition. Per Cent. Quartz SiO2 20 Andesine 1/2 NaAlSi3O8; 4 CaAI2Si2O8 42 Orthoclase KA1Si308 23 Hornblende 1/2 Ca(MgFe)3Si4O12; & (MgFe)2(AlFe)4Si2O12 6 Biotite (HK)2(MgFe)2A12Si3O12 9 Titanite CaTiSiO5 0.1 Apatite (CaF)Ca4(PO4)3 0.05 Magnetite (FeO)(Fe2O3 0.15 Pyrite FeS2 0.02 99.32 The main country-rock (quartz-monzonite) is cut by dikes of aplite, a granite having the following composition: Quartz, 30; andesine, 20; orthoclase, 45; ferro-rnagnesian minerals, 3; pyrite, 0.1; total, 98.1 per cent. Closely associated with the copper-deposits are dikes and bodies of " Modoe" porphyry, technically known as quartz-

Jan 1, 1913

By H. K. Martin

IN September 1954 the Lavender pit concentrator at Lowell, Ariz., began treating low grade porphyry copper ore from the nearby Lavender mine. Nominal capacity of the mill is 12,000 tpd, but production now averages 16,226 tpd. Plant design was somewhat affected by the re-use of old equipment and the substantial re-use of old buildings. A breaking-in period between June 24 and Sept. 1, 1954, was devoted to training operators and making minor changes in launders, chutes, and piping. From Sept. 1, 1954, to July 1, 1956, the mill treated 8,598,105 dry tons of ore, from which 556,541 tons of concentrate were produced, containing an indicated 144,055,185 lb of copper.

Jan 11, 1957

By Herman Poole

When finely divided ferrous sulphide, FeS, is roasted at a moderate, carefully-regulated temperature, the iron and sulphur are oxidized, the first products being probably ferrous oxide and sulphurous acid. In the presence of oxygen of the air the ferrous oxide soon becomes ferric oxide, and, in the presence of oxygen and the ferric oxide, the sulphurous acid oxidizes to sulphuric acid. These facts are well known, having been established by Plattner many years ago. As a further reaction, some of the sulphuric acid parts with a portion of its oxygen to oxidize more ferrous oxide to ferric oxide, and a portion of it escapes uncombined, or else unites with the iron oxides to form sulphates. Ferrous sulphate is usually soon oxidized to ferric sulphate, and if the heat becomes sufficient, this is then decomposed into sulphuric acid and ferric oxide. As a result of these reactions a mass of more or less pure ferric oxide is formed which is generally made porous by the escaping gases and, if rabbled properly, practically all the sulphur is expelled. If ferric sulphide or ordinary pyrites, FeS2, is roasted, a portion of the sulphur sublimes and usually burns to form sulphurous or sulphuric acid, although at times and under favorable conditions, some of the sulphur is driven off uncombined, and can be collected as such. Under ordinary methods of roasting, however, only a small portion escapes combustion. By the combustion of the sulphur an increase of heat is developed and, as a consequence, the reactions mentioned take place more rapidly and actively,—more sulphuric acid is formed and the oxidation is more complete—nearly all the iron being left as ferric oxide with practically no sulphate or ferrous oxide. When the iron sulphide is in lumps the roasting proceeds generally as with fines, but with some changes due to mass. The

Jan 1, 1906