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Jan 1, 1938

By D. W. Peaceman

In previous papers by this author on numerical calculations of multidimensional miscible displacement, some simplifying assumptions were made in writing the dispersion term of the differential equation. It was assumed that the flow vectors were essentially parallel to the x-axis. However, in most multidimensional miscible displacements, the flow vectors are not so simply oriented with respect to the coordinate axes. This paper derives the correct dispersion term /or the more general case; gives a difference approximation /or the dispersion tern; and derives the stability criterion for the corresponding explicit difference eguation.

Jan 1, 1967

By AIME AIME

WILLIS McGERALD PEIRCE-"Jerry" to his host of friends, and on that account a hit of a puzzle to those who have known him only as "W. 14."-a native of Buffalo, educated at Penn State College, Illinois: and Yale universities, has bee11 associated throughout all of his professional career with the New Jersey Zinc Company. Jerry has served successively as investigator, section chief, and division chief in the research department of the company and has just been promoted to chief of research.

Jan 1, 1937

By Vi-Duong Dang

Lithium requirements in the next few decades for batteries and controlled thermonuclear fusion reactors (CTR) may exceed the availability of the current mineral and brine reserves. It is thus prudent to search for new reserves and resources to satisfy these and future lithium applications. The lithium content of the waters from the Smackover oil field. located in the Gulf Coast region of the United States, ranges from 100 to 500 mp/l and could represent a substantial new reserve. Experimental evidence described in the literature indicates that a specific chelating agent dipivaloylmethane (DPM), of the diketone type, has a specific selectivity toward lithium in the presence of other metal ions in aqueous solutions. Based in part on this unique property of dipivaloylmethane, a conceptual design of a full-size plant to extract lithium from the Smackover brine is presented in this paper. This study includes alternate flow-sheet development, design information on the major units of the process, energy requirements, and an economic analysis of a facility capable of producing 106 kg of lithium per year. The economics of three different process concepts depend primarily on the amount of water needing to be evaporated from the initial oil-field feed waters in concentrating the brine. The results, as a function of production rates, are indicated only in a general manner.

Jan 1, 1978

By G. W. Tracy, R. D. Carter

A method based on an approach by Hurst' is developed for calculating water influx behavior. Using this method, superposition calculations may be eliminated. The principal diflerence between this method and that of Hurst is that, over finite intervals of time, constant oil-productton rates are assumed by Hurst whereas constant water influx rates are assumed in the presently described method. By adopting the assumption of constant water influx rate for finite time periods, a method is developed for calculating water influx behavior which lends itself to convenient combination with the material balance equation in the Schilthuis form. Above the bubble point, an equation is given for the explicit step-wise calculation of pressure history for a prescribed oil-production history. Use of this method of calculating water influx behavior should result in a considerable saving of time as compared to superposition calculations when the calculations must be made without using a digital computer. The connection is shown between the method described herein and the method developed by van Ever-dingen and Hursr2 (which requires superposition cal-culations). Also, results obtained using the two methods are compared.

By AIME AIME

MIING Engineer. Metallurgist, Economist-in any of those three capacities Paul Tyler should be able to make a living. Further- more, he has proved his ability as an operating man teacher, researcher. and prolific writer. For the last three years he has been chief engineer of the non-metal Economics Division of the. U. S. Bureau of Mines.

Jan 1, 1941

Copper cyanide is a common component of cyanide-treatable precious metal ores. The copper concentration in production heaps can be predicted from laboratory column tests, but the exact correlation is not necessarily intuitive. Generally, heap leach operators like to keep copper concentrations in solution below 300?500 ppm and may note problems with gold recovery and cyanide consumption when copper concentrations exceed this amount. There are several methods of copper removal from cyanide solutions including ion exchange; direct electrowinning; acidification, volatilization, and recovery (AVR); and sulphide precipitation such as the sulphidization, acidification, recycling, and thickening (SART) process. SART involves acidification with addition of soluble sulphide, separation of the resulting copper sulphide precipitate, and addition of lime to re-establish alkalinity prior to returning the solution to the leaching process, recovering both copper and cyanide as valuable products. In principle SART is very simple. Yet some SART plants that have been built may have been unnecessarily complex. This paper explores the basics of SART and makes the case for a simple plant design as applied to the heap leaching circuit.

Jan 1, 2012

By Y. Wang, M. M. Singh, H. L. Hartman

Knowledge of the state of stress at the bottom of a drillhole is of practical importance in rock drilling, since the induced stresses must exceed the strength of the rock in order to cause fracture. This note reports on a numerical method to determine the stress distribution at the bottom of a borehole induced by a static bit load and overburden and fluid pressures. The procedure adopted is similar to that for the plane-strain, discrete model employed by Harper and Ang.1,2 The rock medium is considered to be homogeneous, isotropic, and elastic-perfectly-plastic. METHOD OF ANALYSIS AND PROGRAMMING The discrete model adopted consists of two types of points: mass points and stress points. The configuration and numbering notation are depicted in

Jan 1, 1967

By AIME AIME

HENRY YONGE WALKER is one of Canada's numerous gifts to the American mining and metallurgical industry, having been born it1 New Brunswick 59 years ago. At eighteen he came to the United States and has since been continuously identified with what are known as the Guggenheim interests. His first position was in the capacity of clerk at the Philadelphia Smelting & Refining Co. plant of M. Guggenheim Sons at Pueblo, Colo. In 1905 he was transferred to the plant of the American Smelting & Refining Co. at Everett, Wash., as assistant manager, two years later going to the Tacoma plant in the same capacity though with added

Jan 1, 1938

By Lawrence Y. Marks

During the mineral survey of the Bob Marshall Wilderness and study areas by the author in 1971, 1973, 1974, and 1976 (Marks, 1978), the area designated Reservoir-North (RARE II No. H1-485) in January, 1979, (U.S. Forest Service, 1979) was examined, along with other lands adjacent to the earlier study areas. However, the 1978 open-file report covered only areas originally designated for study. The present report on Reservoir-North is based on earlier work. No work has been done in the area since 1976. Mineral Appraisal Reservoir-North RARE II area (No. H1-485) is in the Northern Disturbed Belt which has been identified as having high potential for natural gas accumulations and lesser potential for oil accumulations (Mudge, 1978). Oil and gas lease applications in the area, indicate interest by oil companies.

Jan 1, 1981

By AIME AIME

THE career of Erie V. Daveler, reelected director of the Institute last February, illustrates, among other things, the value of technical schooling and experience as a mining engineer as preparation for executive and administrative work. For twenty years after graduating in the mining course at the University of California, in 1907, he was actively engaged in operating mines and mills in the West. After two years cyaniding silver ores at Tonopah, Nev., he joined the staff of the Utah Copper Co. at Bingham, his first assignment being research in ore dressing. Since that time he has been associated continuously with companies allied with Utah Copper, through D. C. tackling who dominated the affairs of the

Jan 1, 1937

By G. P. Dyke

The MRMR classification system was developed specifically for mining applications, namely caving operations, and is one of three rock mass classification systems used in the South African mining industry today. Increased usage of the MRMR classification system has raised concerns that it does not adequately address the role played by discontinuities, veins and cemented joints in a jointed rock mass. To address these concerns, Laubscher and Jakubec introduced the In-Situ Rock Mass Classification System (IRMR) in the year 2000. Although the IRMR system is more applicable to a jointed rock mass than the MRMR system, a quantitative comparison of the MRMR and IRMR classification systems indicates that there is not a significant difference between the resultant rock mass rating values derived from the two classification systems.

Jan 1, 2008

By R. C. Ku, A. J. McEvily, T. L. Johnson

AS reported in a recent paper,' we attempted to measure the response to stress of as-quenched Fe-Ni-C martensites (Ms of -35°C) in both the micro-and macrostrain regions. To avoid effects associated with the diffusion of carbon, tensile specimens were quenched from room temperature at 78°K and tested after 15 min in situ. It was assumed that the transformation had terminated and that the retained austenite was essentially stable. In the tensile tests microplastic strains of the order of 10"* were measured at stresses below 20 ksi. It was concluded that the observed strains were due to the motion of dislocations in the martensite, the dislocations having been introduced during transformation. It was argued that transformation or plastic deformation of the retained austenite did not contribute to the non-elastic deformation measured in the microstrain region. In contradiction to the above argument, Magee and paxton2 have more recently shown that the strain due to isothermal transformation of retained austenite to martensite can contribute to plastic deformation at low stresses even at 78°K. Moreover we were unaware (nost)-a culpa) of a paper by Machlin and cohen3 in which it was clearly shown by resistance measurements that isothermal transformation at 78°K leads to the formation of an additional 1 pct or so of martensite after the initial athermal transformation, even in the absence of external stress. We have verified Machlin and Cohen's results in the following manner. A capacitance microstrain gage was placed on a tensile specimen before immersion in liquid nitrogen. After 15 min at 78°K detectable burst phenomena had ceased and it was then possible to obtain a continuous record of the additional extensional strain due to spontaneous isotherma1 transformation. The results for the Fe-Ni-C series studied are shown in Fig. 1, and are similar to those of Machlin and Cohen who investigated a low-

Jan 1, 1968

By H. Helmstaedt, P. Thurston, R. Harrap

"Evolution of the continental lithosphere over Earth’s 4.6 billion year history is one of the fundamental questions of geoscience. Much of the Earth’s present-day continental crust formed during the first 2 billion years, the Archean eon, of the planet’s lifetime and thus, Archean processes of lithospheric formation must be studied in order to address this question. Until recently, the processes of Archean lithospheric evolution were thought to be fundamentally different from present-day plate tectonic processes. However, subsequent evidence suggests that the growth of Archean continents may be explained in terms of modern tectonic accretionary tectonics similar to those presently operating in the southwest Pacific region. The evidence supporting this hypothesis was compiled largely by Canadian geoscientists working in the Superior Province of the Canadian Shield in northwestern Ontario, over the past 15 years. Study of Archean rocks is also economically important because the Archean rocks of the world, although comprising only a relatively small fraction of the exposed continental crust, contain much of the world’s mineral wealth, including more than half of the world’s gold, as well as significant base metal reserves. Furthermore, the vast majority of primary economic diamond deposits are derived from the lithospheric roots beneath Archean cratons.The LITHOPROBE Western Superior Transect is located within the western part of the Superior Province in northwestern Ontario (Fig. 1). The Superior Province is the largest and best exposed Archean crustal block in the world and forms the nucleus of the North American continent. The internal structure of the Superior Province records a history of the processes that formed the earliest lithospheric elements of the Earth into cratons, thus providing an ideal laboratory for investigating early crustal evolution. The Western Superior Province is characterized by a regional pattern of alternating, 100 km to 200 km wide geological belts (Fig. 2). The observed geologic relationships between and within these subprovinces have been explained in terms of a modern tectonic model of terrane accretion. Oceanic floor, volcanic island arcs, oceanic sediments and continental fragments were accreted successively from north to south against the southern margin of a cratonic nucleus (North Caribou terrane, Fig. 2) which grew steadily in size with the arrival of new terranes through geologic time. If this model is correct, it suggests that the tectonic processes operating today have been active without major variation over the past 3 billion years."

Jan 1, 1998

By T. M. Daulton, Chester F. Lee

The Atlin Mining District is in the northwest corner of the Province of British Columbia. Ruby Creek, where the operation to be described is situated, is 17 miles east of the town of Atlin and about 18 miles south of the south line of Yukon Territory (Fig. 1). Gold was discovered in the district in January, 1898, and the production to date from placer mines has been $4,518,000, according to the reports of the Minister of Mines for the province. Geology The essential points in the regional geology are given in the following paragraphs. Long erosion produced a plane-like surface slightly above sea level with a few peaks and ridges.' A gradual uplift followed and erosion increased, the streams cut deeper, the cuts so made being afterward increased by glaciation. The ice straightened and planed the slopes of the main valleys and widened and lowered their floors, in some cases flooring the valleys with silt, sand, gravel, and clay. As the glaciers rapidly retreated, lakes were formed. As to the origin of the gold, J. C. Gwillim says? "The Surprise granite has been carried northward toward Gladys Lake and Teslin, and the granite of the great plateau on the Taku trail was found in blocks on the opposite range across Hurricane River 10 miles north of its original position. Otherwise there is little evidence of far removed material, the boulders of the lake shore and creek beds being of local appearance. This appears to strengthen the opinion that the placer gold had its origin within the drainage basins where it is now found." In the gold-bearing creeks of the Atlin district there are two "runs"

Jan 1, 1917

By J. R. Cahoon, W. V. Youdelis

In a previous communication by one of us,1 a theory of inverse segregation was presented by which the maximum segregation and segregation distribution throughout a unidirectionally solidified, binary-alloy ingot could be calculated. The theory, which is based on the mechanism of volume contraction and interdendritic flow, quantitatively accounts for the observed maximum segregation in the A1 (rich)-CU' and Al-Zn2 alloy systems, and for the segregation distribution along the ingot lengths for the A1-Cu system.''4 One of the drawbacks to a more extensive use of the segregation equations is their complexity, particularly for the calculation of the segregation distribution throughout the length of the ingot, involving long tedious numerical calculations to obtain the segregation. Computer pro- grams, written in Fortran II for use on an IBM 1620 computer, have been developed by the authors (and are available from them), providing quick and accurate methods for the determination of the theoretical maximum segregation in any binary-alloy system, and also for the segregation distribution in any unidirectionally solidified binary-alloy ingot. The segregation distribution is controlled by the lengths of the various solidification zones'74 which are in turn controlled by the cooling rate, and are determined from temperature-distribution curves obtained during solidification. The theoretical segregation distributions shown in Fig. 1 illustrate the effect of the zone lengths on the distribution Curve 1, indicative of a slowly cooled ingot, represents an ingot having long solidification zones, while Curve 2, indicative of a rapidly cooled ingot, represents an ingot having relatively short zones. Although these distributions are calculated for an A1-10 pct Cu ingot, the shape of the distribution would be similar for any binary-alloy ingot. These curves show clearly why early workers obtained results which indicated that the maximum (chill-face) segregation approached zero at very fast cooling rates.3 Actually, the maximum segregation is independent of cooling rate,' but even at short distances from the chill face the amount of segregation drops considerably, particularly in a rapidly cooled ingot, making it very difficult to establish the amount of segregation occurring at the chill-face. The authors would like to thank Dr. J. A. Goldak for his assistance in the preparation of the programs. The financial assistance of the Steel Co. of Canada and of the National Research Council of Canada in the form of Scholarships to one of us (J. R. Cahoon) is gratefully acknowledged.

Jan 1, 1964

By AIME AIME

EVER since his college days at the University of Iowa, the professional interest of Morris Morgan Leighton has centered on geology, and he now heads the State Geological Survey of Illinois. Just 52 years ago--on Aug. 4, 1887-he was born at Wellman, Iowa. He remained at the State university for his Master's degree, awarded in 1913. A two-year fellowship at the University of Chicago led to a Ph. D. degree, after which Dr. Leighton went out to Seattle as instructor in geology at the University of Washington during 1915-'16. He returned to Iowa as assistant professor of geology at Iowa State Teachers' College for a year, followed by another year at Seattle, after which he returned permanently to the Middle West, first as acting professor of geology at Ohio State and then, from 1919 to 1923, as assistant professor of geology at the University of Illinois and geologist for the Illinois Geological Survey. Of the latter organization he has been chief since 1923, with no present teaching duties. As a result of the successful work of the Survey, notably in non-metallics and in the initiation and stimulation of the recent oil activities in the southern part of the State, it is soon to have a new building with modern laboratory facilities.

Jan 1, 1939

President MRS. ROBERT HURSH River Road, Silvermine Norwalk, Conn. First Vice -President MRS. WILLIAM C. SCHNEIDER 45 Wayne Ave. White Plains, N. Y. Second Vice-President MRS. ERNEST H. WOLFES 180 Riverside Drive New York, N. Y. Third Vice-President MRS. JOHN C. BURTON 271 Fox Meadow Road Scarsdale, N. Y. Fourth Vice-President MRS. S. A. IONIDES 379 Marion Street Denver, Colo.

Jan 1, 1941

By G. A. Bole, F. W. Davis

The purpose of this paper is not to report, to the Institute, the results so far obtained in the survey, by the Bureau of Mines, of the metallurgical requirements for open-hearth refractories, but to present an outline that we hope will serve as a basis for discussion. The systematic survey that the Bureau proposes to make has not been outlined, although considerable preliminary work has been done in the way of interviewing open-hearth superintendents in several of the larger steel plants from the Chicago district eastward. At the several conferences so many of the opinions were diametrically oppoeite, when considering the same point, that it was thought that such an opportunity as the Institute offers in the way of a clearing house for moot metallurgical topics should not be overlooked. For this reason, the paper has been prepared as a basis for a discussion which, it is believed, will be of value in outlining the program of the Bureau. D. A. LYoN, Assistant Director. The importance of securing suitable refractories for metallurgical operations is daily becoming more universally recognized; particularly in the manufacture of open-hearth steel, where the life and earning power of the furnace depends largely on the judgment and care exercised in the selection of the correct quality of refractory for each of the parts. Any innovation that would make available to the steel manufacturers refractories with longer life or better suited to their needs than those now employed, and at a cost that would permit of their use, would be of enormous value to the industry at large. It is quite probable that revolutionary changes would not be necessary. Material now used in some parts of the furnace might, by more suitable preparation, be made of much greater service; in other parts, possibly entirely different material would be necessary in order to effect much improvement. Inasmuch as different parts of the furnace structure perform different functions and are subjected to different service conditions, a refractory suitable for one part will be entirely unsuited for another. For this reason, to make a comprehensive study of the refractory requirements of the processes, we should consider the furnace as built up of a number

Jan 1, 1924

By Leonard B. Gulbransen, John R. Lewis, W. Martin Fassell, J. Hugh Hamilton

A simple reproducible method was developed for determining the ignition temperatures of magnesium and magnesium alloys and by this method magnesium and over 100 magnesium alloys were measured. The ignition temperature of magnesium was determined in O2-SO2, O2-N2 mixtures and in O2 from 0.166 to 10 atm pressure. The ignition temperature of magnesium is generally lowered by alloying and increased by an increase in oxygen pressure. WITH the expanded use of magnesium alloys in industry, ignition temperatures are of considerable importance, especially in heat treating and for service at elevated temperatures. Magnesium alloys exhibit a relatively slow linear oxidation rate up to temperatures near the melting point.' At some critical temperature the rate of oxidation becomes extremely rapid. This high rate of oxidation is accompanied by the emission of light and additional characteristics suggesting a flame. The literature concerning the ignition temperatures of magnesium and magnesium alloys is relatively incomplete and the values reported by various authors are not in agreement. The most probable reasons for this are: 1—The absence of a suitable definition of ignition, and 2—the need of a standardized method of determining the ignition temperatures of inflammable metals and alloys. The exact date of the discovery of the fact that magnesium will ignite and burn is unknown. It is likely that H. Davey encountered this property of the metal during its preparation in 1808. The first reference in the literature specifically on ignition of magnesium is by Lenze, Metz, and Rubens.' They investigated the inflammability of certain magnesium alloys. Brown3-' reported that magnesium ribbon will ignite in air at 507 °C by what was called the rising temperature method. Hartman, Nagy, and Brown" reported that magnesium powder ignites from 475" to 560°C depending on particle size. According to Guise, Mars, and Wilson prolonged heating in air at 427°C of common casting magnesium alloy causes it to ignite. Samples of magnesium alloys were placed directly in the flame of a torch by Carapella and Shaw.' These investigators obtained some evidence of melting prior to ignition. For commercial magnesium, they reported an ignition temperature of 650°C. Their values varied from 450" to 800°C for magnesium alloys. Willmore and Peterson" studied the effect of air velocity, humidity, rate of heating, and foreign metal contact on the ignition temperature of magnesium. They conclude that melting is not a prerequisite for ignition and that the conditions which influence ignition are complex and difficult to analyze. The only quantitative theoretical treatment of the ignition temperatures of magnesium and magnesium

Jan 1, 1952