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By E. DeGolyer

I. INTRODUCTION VOLCANIC origin. was among the first of the theories advanced to account for the occurrence of the salt domes of the Gulf coastal plain, northern Louisiana., and eastern Texas, and it is still being re-stated in various forms by the most recent contributors to our knowledge of the geology of such deposits. Argument has been largely by analogy and attention has repeatedly been called to the Mexican oil fields, particularly those of the Tampico-Tuxpam region, because of the occurrence of oil in close proximity to volcanic plugs in those fields, an occurrence supposed to have some resemblance to the common occurrence of oil in the salt domes of the United States. The author, having spent several months of the past year in a general study of salt domes and in a detailed study of certain domes in the United States, and having been acquainted for some time with the exploration of similar domes in the Isthmus of Tehuantepec region, Mexico, and with the general geology of the Tampico-Tuxpam region, Mexico, has reviewed the various theories of volcanic origin for salt domes which have been advanced to the present time. The purpose of this paper is to present such review and to discuss the supposed Mexican analogy.

Jan 5, 1918

By C. McLean, Erickson, S. G. Kolb, S. C. Moore

The Grossschloppen vein-uranium deposit, Bavaria, West Germany, was examined with underground workings during 1980-82 by Esso Erz GmbH, an affiliate of Exxon Minerals Company (EMC). Geologic evaluation entailed dense drilling of a portion of the deposit from workings constructed specifically for the program. Discovered in 1977, the deposit was initially explored by surface diamond drillholes which allowed definition of a 30-60 m wide vein system discontinuously mineralized along a 1000 m strike length and to at least a 450 m depth. The underground program was conceives as a cost-effective procedure to answer quest ions on vein correlation, grade continuity and variability. A 1200 m decline allowed access for detailed sampling of approximately 10% of the known area of mineralization. Fanned drillholes, logged by gamma probe, were spaced to provide intersections of veins at 10 to 20 m intervals. Six cross-cuts also penetrate the pitchblende and uranophane mineralization which occurs in 0.1 to 2.5 m thick quartz veins. Detailed cross-sections and level plans were constructed for resource estimates of the intensively studied portion of the vein system. The program resulted in the discovery of local, high grade areas and an average grade in the evaluated area nearly double that expected from surface drilling.

Jan 1, 1984

By J. R. Dawson, J. A. Glunt

Vesta No. 4 and 5 mines supply most of the high volatile coal required for Jones & Laughlin's by-product coke plants. Until 1944 all coal produced in these mines was loaded by hand. Pressure to mechanize at Vesta was brought on by the manpower shortage in World War II, and in 1943 a decision was made to change to mechanical loading. It was the opinion of those concerned that by use of selective mining the coal would be clean enough to be processed by the existing preparation plants. At that time coal cleaning at Jones & Laughlin consisted of hand picking the larger sizes at the mine tipples and wet washing at plants located at the Pittsburgh and Aliquippa Works. A typical section of the Pittsburgh seam as it occurs at Vesta is shown in Fig. 1. The 14 to 16 in. of drawslate immediately over the coal is too soft to be used for roof and must be taken down, leaving the rooster coal just above for roof. In selective mining an attempt is made to mine the coal under the drawslate first and then load out the drawslate separately as refuse. In full seam mining slate and coal are shot down at the same time and loaded out.

Dec 1, 1956

By Paul L. Russell

Of the potential applications of nuclear explosives to mining, excavation is perhaps the most obvious and the best understood, and probably the most practical for use in the near future. Large quantities of rock and earth can be moved by proper emplacement of nuclear explosives, but economic and practical relationship must be determined between the known capabilities of nuclear explosives and the required excavating to remove overburden. On an energy yield basis, even the cheapest of the present commercial explosives cost more than the most expensive nuclear explosive. Comparing the energy yield of a megaton thermonuclear device with the yield of TNT shows that one energy yield per dollar is 400 times greater for the thermonuclear device. However, small-yield nuclear devices (a few 10's of kilotons yield) are less efficient blasting materials than chemical explosives, with the result that the heat of explosion is utilized less effectively. While only 1 lb of conventional explosive is required to excavate 1 cu yd of rock, or about 2 million cu yd per kiloton, nuclear devices excavate from 100,000 to 300,000 cu yd per kiloton. This changes the economic situation, and it is thus apparent that nuclear explosives are cheaper only for the large explosions.

Jan 6, 1964

By J. A. Snyder, W. L. Finlay

SEVERAL notable studies of the effects of sub- stitutional solutes have been reported. Outstanding among these for its elucidation of general principles, is the summarized work of Hume-Rothery and coworkers.1 For a systematic study of the effects of substitutional solutes on the mechanical properties of the solvent lattice, the work of Brick, Martin, and Angier² on copper; of Frye and coworkers³,4,5 on copper and silver; and of Lacy and Gensamer6 and of Austin7 on iron may be mentioned. Titanium is one of the few elements offering the possibility of a similar study of interstitial solutes since, unlike most metallic elements, it exhibits extended solid solubility for most of the interstitial solutes—hydrogen, boron, nitrogen, oxygen, and carbon. This paper reports a survey of the effects of dilute solutions of nitrogen, oxygen, and carbon on the mechanical properties of high-purity alpha titanium. Previous Work: Van Arkel and De Boer showed" that high purity titanium was quite ductile and De Boer, Burgers and Fast established".' that not only were oxygen and nitrogen very soluble in solid titanium but that, long before the limit of solid solubility of either had been reached, these interstitial solutes rendered the metal brittle. Their electrical resistance data as a function of

Jan 1, 1951

By G. M. Ritcey

Continuous contacting equipment for solvent extraction can be divided into two major areas, according to whether their mode of operation is stagewise or differential (Figure 1). Mixer settlers and the recent Kenics and Sulzer mixers typify the stagewise contactors. In these counter- current contactors, the aqueous and the organic phase are mixed and then separated in a large settling area before the next stage of mixing. Countercurrent differential contact- ors, such as centrifuges and various types of columns, are more compact in that they require less ground area than mixer settlers. [ ] Contactors, in addition to being either stagewise or differential, can be further subdivided into non-agitated and agitated depending on the method used for mixing the phases and producing the countercurrent flow. The simplest contactors such as spray, packed, or perforated plate columns achieve both the mixing and countercurrent flow by means of the gravity difference between the two phases. In agitated contactors such as the Scheibel, Reciprocating Plate, and Sieve-Plate Pulse, mechanical agitation is introduced but gravity differences still produce countercurrent flow. To conserve plant space, and for large throughput with short contact time, centrifugal contactors are used where possible. The reader can refer to reviews on the subject (1-11).

Jan 1, 1978

By John H. Schissler

INTRODUCTION AND SUMMARY Complex copper-lead-zinc ore is mined from underground workings high in the Western Cordillera of the Andes mountains about 100 km in a stralght line north of the city of Arequipa in southern Peru. The Madrigal mine is situated in a steep-walled canyon into which the six operating levels "daylight". Production is from cut-and-fill stopes currently producing approximately 740 dry metric tons per day. The Santa Rosa vein, the most important producer in the district, outcrops for a distance of about 4 km, bearing N 75º W and dipping about 70º NE. In places the vein splits into two or three branches; widths of each vary between 1 and 4 m and total mineralized widths of up to over 8 m occur. Principal ore minerals are chalcopyrite, galena and sphalerite. Ore reserve grades for the Madrigal mine average about 1.45% Cu, 2.6% Pb and 5.0% Zn, 2.9 ozAg per metric ton. [Compania] Minera del Madrigal is a California limited partnership; the general partner and operator is [Compania] Madrigal, a wholly-owned subsidiary of Homestake Mining Company. HISTORY Shallow workings found on the Santa Rosa vein were probably made by the Spaniards during colonial times in their search for

Jan 1, 1977

By H. Hanemann

THE application of other than mechanical methods to the study of the mechanical-physical properties of metals has become in the last few years a topic of investigation of ever-increasing interest, both from the theoretical standpoint and from that of the engineer and constructor. Besides the investigations which have been made of 'the magnetic properties of ferromagnetic metals, in their relation to the mechanical properties of these metals, which will be discussed more in detail below, there have been made studies of other phenomena in the same relation, and methods for the mechanical testing of metals have even been suggested, for example, the microscopic method of Tammann,1 and the thereto-electric, method of Turner2 for determining elastic limits. The application of all such methods, which are based upon the dependence of some physical, crystallographic, or possibly chemical property, upon the mechanical state of the metal, must be preceded by close and careful correlation of these various "test" properties with the known mechanical state of the different metals or materials. It is with this view that the present work, as well as that of many previous investigators of, what .may be termed in the interests of brevity, the mechanical-magnetic properties of ferromagnetic materials of construction, has been done.

Jan 12, 1915

By Stewart R. Wallace

Members of the Society, it is a very great honor for me to be here today and to have the opportunity of telling you about some things that have been accumulating in the back of my mind for some time. Before attempting to do so, I should acknowledge my debt to the many people who are responsible for my presence here this afternoon. To do this properly, however, would consume much of my allotted time and I will therefore mention only two men, both of whom were directly involved in the discovery of the Henderson ore body. The first of these was Robert Henderson, now dead, who at the time the work was going on was vice president of Western Operations of the Climax Molybdenum Co. Truly, he provided the environment that permitted the exploration program to function effectively, and the deposit appropriately bears his name. The second man I meant to mention was resident geologist at Urad at the time of the Henderson discovery. I think I should explain right here that the Urad ore body and the Henderson ore body, although entirely separate, are closely related deposits, and that both are located at Red Mountain in Clear Creek County, Colo.

Jan 6, 1975

By T. L. Joseph

IN connection with its investigations of the blast'-furnace process, the Bureau of Mines, in coöperation with the Minnesota School of Mines Experiment Station, developed a 6-ton experimental furnace. Such a furnace was needed to determine the feasibility of producing ferromanganese from Minnesota manganiferous iron ores, a problem of national importance because of the present need for manganese in the steel industry and our small reserves of ferro-grade ores. Furnace operators are reluctant to use new or untried raw materials or to make decided innovations in practice on account of the financial hazard of experimenting with full-scale equipment. A small furnace which can be operated at a relatively low cost is particularly adapted for testing new, raw materials and for determining the feasibility of decided innovations in practice. Laboratory experiments, plus whatever information may be available, are valuable but often do not indicate the net result of changes in an operation involving a large number of interrelated variables. From time to time the coöperation of the Bureau of Mines is solicited in connection with problems involving departures from normal procedure. Under these circumstances some sort of a practical demonstration is a desirable forerunner to full-scale operations which appear feasible after small-scale tests.

Jan 1, 1928

By J. F. Sepulveda, J. D. Miller

Tar sand deposits in the state of Utah contain more than 25 billion bbl of in-place bitumen. Although 30 times smaller than the well-known Athabasca tar sands, Utah tar sands do represent a significant domestic energy resource comparable to the national crude oil reserves (31.3 billion bbl). Based upon a detailed analysis of the physical and chemical properties of both the bitumen and the sand, a hot-water separation process for Utah tar sands is currently being developed in our laboratories at the University of Utah. This process involves intense agitation of the tar sand in a hot caustic solution and subsequent separation of the bitumen by a modified froth flotation technique. Experimental results with an Asphalt Ridge, Utah, tar sand sample indicated that percent solids and caustic concentration were the two most important variables controlling the performance of the digestion stage. These variables were identified by means of an experimental factorial design, in which coefficients of separation greater than 0.90 were realized. Although preliminary in nature, the experimental evidence gathered in this investigation seems to indicate that a hot-water separation process for Utah tar sands would allow for the efficient utilization of this important energy resource.

Jan 9, 1978

By A. B. Parsons

Not so many years ago the interest of the average mining engineer in money matters-aside from his pay check or his consulting fees-was confined to the per-ton cost of mining and beneficiating ore and to the amount of capital that would be required to erect the plant necessary to carry out such operations on a prescribed scale. The so-called "business men" assumed that questions of marketing the products, of profits, and of dividends were in their exclusive sphere-matters too intricate or, perhaps, too practical for the mere engineer! In the case of a new enterprise, the promoter shouldered the entire responsibility for raising the necessary funds, and incidentally he got the lion's share of profits. In fact, he frequently profited handsomely even though the mine earned little or nothing. Occasionally the engineer turned promoter or entrepreneur--conspicuous examples are Herbert Hoover, D. C. Jackling, William Braden and F. W. Bradley- but by and large he remained in a sphere of his own. To what extent this condition of affairs has changed is difficult to say. It might be argued that it were better that it be not changed; and yet I cannot help feeling that in mine promotion lies a distinct opportunity for the

Jan 1, 1932

By J. Charles Miller

THE expansion of facilities for rapid transportation of perishables by train, truck and airplane has necessitated consideration of refrigerants of a minimum weight and volume per pound of cooling and has stimulated the use of solid carbon dioxide commercially. The gas probably has not had wide application in the past in air-cooling equipment for mines, theaters or buildings, owing to its thermodynamic properties, as will be deduced from examination of Table 2. However, consumption of the liquid in carbonating beverages remains a dominant factor. In addition to these uses, carbon dioxide is employed to a limited degree as an explo-sive in the liquid form, as a freezing agent in plumbing, in laboratories for low-temperature work, and in the manufacture of golf balls. SOURCES The principal sources of the gas at present are coke ovens, lime kilns, breweries and other fermentation plants, all of which are within easy reach of markets. Natural sources, however, have not received the consideration they merit, mainly because of their isolation. It is asserted by some manufacturers that the carbon dioxide gas produced from wells is unsatisfactory because it often contains impurities that are difficult to remove, while that produced as a byproduct is much purer or contains impurities that are easier to remove.

Jan 1, 1936

By Philip McKenna

WHEN a new material becomes available to industry, it is useful to describe its properties as a guide to its most effective application; and when the new material may be produced in compositions having a series of graded properties, tests to select the combination of properties best adapted for various uses are helpful. The class of materials to be con-sidered in this paper are hard tool materials produced by processes of powder metallurgy from hard carbide constituents and various matrices of iron, nickel or cobalt, or alloys of them with tungsten, or tungsten and carbon. The customary use of carbide hard alloys is for metal-cutting tools; although wire-drawing dies, lathe centers, follow rests, grinding rests, burnishers, rolls, extrusion dies, measuring gauges and micrometers, and a number of other tools are also made with these hard alloys as the essen-tial wear-resisting parts. The properties and tests to be considered are those affecting these uses. In the development of tool, materials since the industrial revolution we have had carbon tool steels, Mushet steel, high-speed steels, stellites, and now cemented carbide compositions. For an understanding of the latter category of materials their properties and uses relative to the older and more familiar tool materials will be considered.

Jan 1, 1938

By T. S. Fuller

The tensile properties of steels at elevated temperatures have been studied by numerous investigatorsll primarily for the purpose of determining their suitability for structural uses. Tests with this objective have been confined largely to the temperature range of approximately 20" to 500' C., because of the rapidly decreasing tensile strength at the latter temperature. Tests have also been extended to higher temperatures2 for the purpose of determining the most suitable forging range. This temperature range is also of theoretical interest. The phenomenon if increased tensile strength and decreased ductility .in the so-called "blue-heat" range, approximately 200" to 300" C., is well known. It was suggested to the Bureau early in 1926 that a study of the properties of rail steels in this temperature range might prove of interest in relation to the studies of transverse-fissure failures in rails. There were available from another investigation3 several new rails from several different heats made to approximately the same specification requirements, the complete manufacturing histories of which were known. It was decided to determine, at least in the preliminary series of tests, only the ultimate tensile strength, elongation and reduction of area, because of the difficulty, time and cost involved in determining the proportional limit and yield point at elevated temperatures.

Jan 1, 1930

By Hugh D. Pallister, Richard W. Smith

The Alabama flake-graphite industry has flourished only in times of war when importations of foreign graphite for crucible use have been greatly curtailed or cut off. World War I was a boom period and in 1918 some 30 plants produced 7,795,475 lb. of flake graphite. The industry languished following the war and no graphite was produced from 1929 to 1939. The Federal Bureau of Mines began investigating the Alabama graphite deposits in 1940 and worked out modern recovery methods that were applied to production during part of World War II. A prospecting program disclosed reserves of over 25 million tons of graphitic schists. In 1942 the War Production Board authorized the enlargement of the only plant then producing flake graphite and the construction of two new plants. Production of flake graphite from these three plants in 1943 is estimated at 8,100,000 lb. Increased imports from Madagascar late in 1943 shut down one of the new plants and curtailed production at the other. Alabama flake graphite has not yet been able to compete with Madagascar graphite for use in the manufacture of any but small graphite crucibles. The future of the industry must depend on meeting the higher carbon content demanded for other uses.

Jan 1, 1945

By W. H. Basssett

THE amount of oxygen present in refined copper bears an important relation to the effects of various impurities on physical properties of copper, as well as the effects of reducing gases at higher temperatures. It seems fitting at this time, when the effects of reducing gases on copper are being discussed, to describe methods that have proved satisfactory for the determination of oxygen and sulfur, and to present some results obtained by investigation of these methods in the authors' laboratory. The procedure for the determination of sulfur is closely interrelated with that for oxygen and has, therefore, been included. It was first proposed by Hamper that oxides in copper could be accurately determined by the loss in weight sustained by finely divided copper when reduced at red heat in pure hydrogen, or by the weight of water produced. Hampe's method was later modified by Archbutt,2 who established the accuracy of the method and demonstrated that equally accurate results were obtained by noting the loss in weight or by weighing the water formed. The determination of oxygen by heating in carbon monoxide has been proposed by West.3 In our hands this method has given slightly lower results than obtained by heating in hydrogen.

Jan 2, 1926

By R. L. Doan

WHEN the Plutonium Project was started in the spring of 1942 there was no technology to produce uranium metal of the required purity. Not only was there no such metal available; no one knew how to make it or fabricate it after it was made. Since this time vast technical effort has been ex-pended in the atomic energy field. A short 15 years later the metallurgy of uranium is probably better known than that of any other metal, with the possible exception of steel. At the beginning of the 1942 drive to obtain pure uranium metal the most available raw material was black uranium oxide (U3O8) of about 92 pct purity from the Great Bear Lake region of Canada. It took only three months for the project chemists to develop a process for bringing the purity of this oxide up to 99+ pct and another three months for Mallinckrodt Chemical Co. of St. Louis to build the purification plant and get it into operation. In early summer of 1942 the purified brown oxide (UO2) started moving to the Metal Hydrides Co. in Beverly, Mass., and to the Westinghouse Research Laboratory in Bloomfield, N. J., both of which had been granted Government contracts to try to make pure uranium metal.

Jan 9, 1957

By D. A. Elgillani, M. C. Fuerstenau, M. C. Kuhn

The species responsible for flotation when xanthate is added as collector for pyrite is dixanthogen. Measured oxidation potentials of these systems show that xanthate should be oxidized to dixanthogen, and the presence of dixanthogen on the pyrite surface is confirmed by infrared absorption. Zeta potential measurements are presented and related to collector adsorption. In spite of the normal presence of pyrite in most sulfide ore deposits, only a modest amount of study has been devoted to the xanthate-pyrite flotation system in the absence of activators and depressant~.'-~ As a result, little is known about the mechanism of xanthate adsorption on pyrite. From the few studies that have been made, however, a number of significant observations have been forthcoming. For example, the dependence of flotation response on the state of oxidation of the surface was noted in two studies — one conducted by Plante and Sutherland4 and a later one by plaksin.~ In another study, Gaudin and wilkinson3 found that ferric xanthate was not present on a pyrite surface. In a later investigation, however, Gaudin' and his colleagues did extract a small amount of ferric xanthate into benzene when pyrite was ground in an evacuated mill with water, benzene, and xanthate. This quantity was apparently

Jan 1, 1969

By D. D. Pollock, D. I. Finch

Relationships between the compositions of specially prepared manganin-type alloys and some of their electrical properties have been established. Empirical equations, based upon the electronic configurations of the alloying elements, are given which describe the resistivity, temperature coefficient, peak temperature, and thermoelectric power of Cu-Mn-Ni-Fe alloys at approximately room temperature. Calculations based upon these relationships are correlated with experimental data. SECURING suitable alloys for the construction of stable resistors, for use in precise electrical measuring devices, has been important ever since the art of electrical measurement was begun. German silver, Pt-Ag, and Platinoid are examples of some of the alloys in early use. These early alloys were un- satisfactory for one or more of the following reasons: l—insufficient stability of electrical properties with time, 2—poor reproducibility of electrical characteristics from melt to melt, 3—excessive temperature coefficients of resistance, and 4—excessive cost. Weston introduced the Cu-Mn-Fe and Cu-Mn-Ni-Fe alloys of the type now generally known as manganins. His patents are believed to represent the first disclosure of any alloy with a negative temperature coefficient of resistance. After this work, the German company, Isabellenhutte, in conjunction with Feussner and St. Lindeck, produced alloys of

Jan 1, 1957