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The Institute conducts jointly with the American Society of Civil Engineers, American Society of Mechanical Engineers and American Institute of Electrical Engineers, certain activities as listed below, and is joint owner with them of certain properties. United Engineering Trustees, Inc. When Mr. Carnegie made his gift which made possible a home for the engineering societies, a separate corporation was organized to act as a holding company and to manage the common property. This was long known as the United Engineering Society, but the name has now been changed. to one which more nearly reflects the real function of the corporation. It holds title to the Engineering Societies Building and to various funds placed in its charge and is managed by a Board of Trustees, of which three are chosen by each of the four societies, American Institute of Mining and Metallurgical Engineers, American Society of Mechanical Engineers, American Institute of Electrical Engineers and American Society of Civil Engineers, which have equal and undivided interests in the property. The land and building cost two million dollars. During the gear 1934, the constitution and By-laws of The United Engineering Trustees, Inc., were thoroughly revised and a better organization of its functions was affected: The Engineering Foundation and the Engineering Societies Library were made "departments? of the United

Jan 1, 1936

By Adrian Brown

INTRODUCTION The primary tool which is available to improve the stability of an open pit mine at a given slope angle is control of groundwater pressure. This paper sets out the methods by which water pressure control can be achieved in large mines in different materials. The emphasis of this paper is on large mine slopes because. these slopes exhibit the greatest need for groundwater control, the greatest economic benefit from groundwater control, and the greatest technical challenge in achieving groundwater control. STABILIZATION USING MTER PRESSURE CONTROL Groundwater pressures reduce the stability of slopes in two fundamental ways, as shown schematically in Figure 1. In the example, a horizontal failure surface intersects a vertical joint or weak zone. Water pressure acts: o On the base plane to reduce the normal force on the sliding surface and hence reduce frictional resistance to sliding, and o On the vertical back plane, to create a driving force for the system.

Jan 1, 1983

A severely technical article, however well written, can not be an agreeable form of literature. It suffers from the defects of its qualities. One defect is a congestion of language, due to a multiplicity of adjectival nouns. The sentences are packed with words of unpleasing sound, charged with complex ideas, crowding one another so closely that the phraseology moves like an ice-pack in Bering Sea or a log-drive in a river; the undercurrent of meaning may continue to move, but the surface is obstructed. This verbal congestion is made evident by ugly compoundings, many of which are adopted by the technical writer in the mistaken belief that they give directness to his statements. For example: A unanimously approved scheme "A scheme unanimously approved " The continuous temperature record "The continuous record of temperature " To stimulate interest in synthetic plant construction "To stimulate interest in the construction of synthetic plants " In smelters reverberatory-furnace firing with powdered coal has been practised for a decade. "In smelting, the firing of reverberatory furnaces with powdered coal has been practised for a decade." A tar consumption of one pound per ton "A consumption of tar at the rate of one pound per ton " A mechanical ventilating system

Jan 1, 1931

By Robert Mehl

IT is generally understood by workers in the field of the crystal struce ture of metallic alloys that terminal solid solutions are of two types, the substitutional and the interstitial. In reviewing the literature, the work of Weiss1 on the crystal structure of the alpha copper-tin alloys wa-encountered, in which a new type of terminal solid solution was proposed. In brief, Weiss' findings showed that the density of the alloys calculated from the side of the unit face-centered cube on the assumption of simple substitution-that is, with four atoms to the unit face-centered cell-was much higher than the density measured directly. It was suggested that the assumption of four atoms to the unit cube is not valid for these alloys, and that each unit cube contained less than four atoms; in other words, that one tin atom replaces more than one copper atom, leaving some atomic positions unoccupied. Such a structure, if verified, would have far-reaching significance in the study of the crystal structure of metallic alloys. It would indicate a complexity in terminal solid solutions not hitherto suspected and might encourage work leading to the discovery of other alloys of the same type, and perhaps to types intermediate between it and the two recognized types. It is of importance, therefore, to reinvestigate these alloys with respect to the type of solid-solution structure obtaining therein.

Jan 1, 1929

By John D. Kalasky

Continuous mining has revolutionized the coal industry but intensified the problems of earlier mechanization. From the installation of the first miner, it was recognized that face ventilation would be one of these problems. To establish an efficient work cycle for the equipment being used, conventional mechanized mining provides four or more development faces. Continuous mining, relying on a single machine, requires only one face, although more than one can be driven alternately by the same machine. In gaseous areas mined by the older methods, the intermittent rate of exposure allows time for the face to bleed off or be cleared, and the width obtained with conventional units makes it possible to hang a brattice line almost to the face. Continuous mining increases the ventilation hazards; there is no margin of time, and very limited space.

Jan 9, 1959

By D. M. Wyslouzil

Standard testing methods are described that are presently used for the selection of grinding equipment. Correlation between laboratory batch grinding tests and pilot plant continuous tests are established by means of particle size distributions and flotation results. Conventional and autogenous grinding circuits are discussed showing the relationships of the controllable circuit parameters.

Jan 1, 1982

By R. L. Loofbourow

The objectives of this report are (1) to indicate what is known of natural rock temperatures as deep as 5000 ft below the surface, (2) to indicate methods for estimating such temperatures in localities where directly measured temperatures are un- available, and (3) to outline as far as possible, areas in the 48 states within which rock temperatures are likely to be low and high. The usual object of temperature measurements in deep mines and wells is to learn the temperature of air or another circulating medium. This usually differs significantly from the undisturbed rock temperature. The subject is complicated further by the variety of the thermal properties and structures of rock masses, the migration of fluids within them, the diversity of the history of rock masses and of the processes which have been at work on them during that history.

Jan 1, 1966

By Thomas E. Howard

Recipient of the 1975 D. C. Jackling Award - "For his vision and initiative in defining, planning, directing, and accomplishing mining research programs; for his leadership in focusing worldwide attention on the need for research to improve underground excavation for mining and civil applications; and for his lecture. . ."

Jan 1, 1976

By Earl Greiner

THE constitution of the iron-silicon alloys containing from 14 to 33.4 weight per cent silicon has been studied by a number of investigators, whose results have been reviewed in a monograph published by the Engineering Foundation1. In these previous researches, the solubility of silicon in iron was determined by thermal, microscopic or magnetic methods and the compound Fe3Si2 was reported to be stable at tempera-tures from 0 to approximately 1030° C. This paper describes the results of an X-ray investigation of the solubility of silicon in iron and gives data which prove that the Fe3Si2 phase is unstable below 825° C. In order to obtain the present results on the solubility of silicon in iron, the authors have utilized the lattice constants of the alpha-phase iron-silicon alloys given in a previous publication2, and also some addi-tional data which will subsequently be described.

Jan 1, 1936

By A. F. Crawley

THIS paper describes part of a series of density measurements on low melting point metals being undertaken at the Mines Branch, Department of Energy, Mines and Resources, Ottawa, Canada. This program has received support from the Canadian Zinc and Lead Research Committee and the International Lead and Zinc Research Organization. Examples of the type of work being done have already been given in earlier papers' , which deal with the densities of lead, tin, and some of their alloys. Densities were measured using a graphite pyc-nometer by a technique which has already been described." The cadmium and indium, supplied by the Consolidated Mining and Smelting Co. of Canada were of 99.999 pct purity. Density determinations on indium, as for lead and tin,1,2 were made under a vacuum of about 5 x 10-6 torr because the oxidation and vaporization characteristics of the metal do not create experimental difficulties. This contrasts markedly with cadmium which, even at the relatively low temperatures of our experiments, has a high vapor pressure and a strong oxidation potential. To suppress the harmful effects of these properties, determinations on cadmium were made with success under an atmosphere of argon, the technique having been previously established in this laboratory for measurements on zinc.3 The densities of cadmium and indium are listed in Table I and plotted in Figs. 1 and 2. From the graphs, it is readily observed that the densities of both metals vary linearly with temperature. This relationship expressed mathematically is of the form:

Jan 1, 1969

By William B. Potter

We have come together on this occasion, as so often before the members of the Institute have met in friendly council, to hear and discuss whatever investigation, observation, and experience during the past months may have developed of value or interest to the many departments of knowledge and practice represented in this association. The member, possessed of the true scientific spirit which this Institute is especially intended to foster, brings here the results of his experience and study unrestrained by fear of giving undue advantage to competitor or rival. He appreciates, moreover, the responsibilities of membership and his duty to the cause, and how much is to be gained by himself from the keen but friendly criticism of his fellow-workers and even by the suggestions that may come of shrewd question or chance remark from those who labor in other but related fields.

Jan 1, 1889

By G. Adel, J. Richard Lucas, C. Haycocks

This paper describes over sixteen computer programs developed at Virginia Polytechnic Institute and State University during the past twenty years to assist in the design of coal operations. Overall development concepts in the construction of the programs are outlined, commencing with those used in the exploration phase of mining and extending through economic analysis and into the design of specific engineering systems such as belt, rail and power networks, scheduling, rock mechanics problems and simulation of face systems. Summarized information is given for the use of the major programs including user restrictions, input data, typical output and industrial applications and case studies. Analysis has been made of the programs' applications by industry throughout the world. Such analysis is facilitating development of new programs as well as a refinement of existing ones. To date programs have been constructed in four categories: exploration, ground control, economic and simulation. Face production simulations are stochastic in nature and require the use of time study data obtained at sites underground. Future programming efforts currently under development are aimed at interactive programs for use with minicomputers and, where advantageous, with graphical displays.

Jan 1, 1983

By S. K. Kawatra, R. A. Seitz

Various mathematical models and expressions to describe the behavior of a hydrocyclone have been presented in the literature (Lynch and Rao, 1977; Plitt, 1976; Plitt and Kawatra, 1977). Two of these models, by Lynch (1977) and by Plitt (1976), have been extensively used for process control studies (Kawatra and Thayer, 1879; Seitz and Kawatra, 1984). However, neither of these models relates the fineness of grind in a hydrocyclone overflow to the corrected efficiency curve of a hydrocyclone. If such a relationship were available, then one could relate fineness of grind to the operating variables using equation (1) or (2). A plant metallurgist is interested in knowing the fineness of grind rather than the dso(c) of a hydro- cyclone. As a consequence, several empirical relation- ships between fineness of grind and hydrocyclone operating variables are available. These relationships (Fewings, Wickham, and Wiseman, 1979; Manning, 1978; Watson, Cropton, and Brookes, 1970; Watts, Thompson, and White, 1978; Wiegal, 1973) have only a limited relationship with each other and have met with varying degrees of success. The object of this paper is to develop a fundamental relationship between fineness of grind and the efficiency curve of a hydro- cyclone

Jan 1, 1986

By Robert I. Kingman

SUFFICIENT testing has been performed with the Dutch State Mines Cyclone for thickening and desliming flotation feed at the concentrator of the National Lead Co., Tahawus, N. Y., to prove its application for this work. It is the purpose of this article to present some of the test results, operational details and advantages of cyclone thickening and classification. The metallurgy of the mill operation was described by Frank R. Milliken, assistant manager of the titanium division.l The present flowsheet for the recovery of ilmenite consists in grinding the crushing plant product in four open-end rod mills in closed circuit with mechanically vibrating screens to approximately -20 mesh. The screen undersize is treated in Crockett magnetic separators which produce three products: magnetic concentrate, nonmagnetic tailing containing ilmenite and gangue, and a Crockett slime overflow. The non- magnetic tailing is classified into eight sizer spigots products and a classifier overflow. The spigot sand products are tabled separately to produce a rough ilmenite concentrate, a middling product and a tailing. The table middlings are returned to Crockett feed. The table concentrate is dewatered and dried and further concentrated on Wetherill magnetic separators to produce the finished ilmenite concentrate.

Jan 8, 1950

By James R. Evans

Forecasting demand is an art as well as a science, and much personal judgment is required. National forecasts made for sand and gravel, crushed stone, and/or aggregate may be misleading or unhelpful locally. This is because of significant variation in demand within different geographic and/or political areas in the US, and/or the use of an inadequate data base and forecasting methodology. The best forecasts may be made for local or regional market areas, irrespective of geographic or political boundaries, provided a proper data base is available.1 The Bureau of Mines compiles detailed statistics on commodities sold or used in the construction industries and, therefore, is in an advantageous position to make national aggregate demand forecasts. Definitions of some terms used in this presentation are necessary before proceeding.

Jan 1, 1980

By W. N. Marchant, P. T. Brooks, P. B. Altringer, R. O. Dannenberg

The US Department of the Interior, Bureau of Mines conducted laboratory tests to devise a process for recovering a marketable grade of tungsten from the brine of Searles Lake, Calif. The brine contains only 56 ppm W (70ppm WO3). Using ion exchange resins synthesized by USBM chemists, 98% of the tungsten was extracted from the brine and 92% of the tungsten was recovered as a marketable iron-tungsten concentrate containing 44% tungsten as tungsten trioxide. Although major technical problems have largely been resolved, research is progressing to escalate testing in a process research unit to provide more reliable data for an economic appraisal

Jan 1, 1980

By A. L. Holley

The three principal mines from which the celebrated Salisbury iron ores are obtained are called respectively the "Old Hill," "Davis," and "Chatfield" ore beds, and are situated in the town of Salisbury, Litchfield County, Conn., on the eastern slope of the Tocconuc range of hills.* The Old Hill Ore Bed is a tract of land of 100 acres, originally granted by the General Court in October, 1731, to be laid out by Daniel Bissell of Windsor. It mas Boon after surveyed and located by Ezekiel Ashley and John Pell. The descendants of Ashley are still proprietors in the mine. The supply of ore has been very abundant, and for many years was easily obtained, but latterly the cost of raising has been greatly increased. Up to about 1840 the average yield was estimated to be about 4500 tons per annum. The production has gradually increased until the average yield at present is estimated at 15,000 tons annually. The largest production in any one ymr was about 20,000 tons. The proprietors of this mine were incorporated many years ago under the style of " The Salisbury Ore Bed Proprietors." The Davis Ore Bed, named after an early owner, was originally called Hendricks Ore Bed, and was owned before the organization of the town of Salisbury by Thomas Lamb, one of the first settlers

Jan 1, 1879

By R. R. Van Valkenburch

IT has always seemed to me that mining methods are inventions that follow necessity. I have yet, to be connected with a property where the consultant who has been engaged has laid out a mining method that has been strictly adhered to through the life of the mine. Possibly there are exceptions. As a general rule, perhaps, the method becomes the result of sad experience. I suppose if a person were to attempt to measure the tendency to get away from shrinkage stoping, he would need to send out a questionnaire and expect to receive truthful answers, and, having compiled the results, I think we would find that throughout the country there would be but few cases where present value of product permits the old original so-called shrinkage method to be followed. The method that I had hoped to hear Mr. Fozard expound is strictly an adaptation of shrinkage. Cav-ings do not enter. It was developed by Mr. Fozard and his staff at the Beatson mine of the Kennecott Copper Corp., at, Latouche, Alaska. Stephen Birch, in the TRANSACTIONS in 1923, submitted a brief paper on the mining at Beatson. He stated that a new adaptation of shrinkage was being tried because, although at sur-face the copper .content had been relatively high, at lower levels, in the mine it had decreased.

Jan 5, 1927

By C. H. Li, R. J. Stokes, T. L. Johnston

Sodium chloride crystals are brittle in the presence of surface microcracks. Water immersion leads to an enhancement of ductility which is retained indefinitely in dry air providing the crystal is dried without leaving a surface precipitate. Storage in a damp atmosphere results in a surface reaction and consequent rembrittlement. Although elimination of surface flaws in ionic solids does not necessarily enhance ductility, there is always a change in the location of the fracture origin. EVER since the original experiments of Joffel there has been controversy over their interpretation and no satisfactory generalized explanation has yet been given. It is generally admitted that when sodium

Jan 1, 1961

By Richard R. Klimpel

This paper takes the liberation model recently developed by Klimpel and Austin for liberation from a binary system and reduces the over-all model form to a number of useful limiting cases. General use of the complete model form, while quite broad in utility, requires a numerical integration computer program for prediction of liberation given a specified minor component grain size distribution coupled with an optimization algorithm such as linear programming in order to back- calculate the associated grain size distribution from experimental data. In this paper, analytical solutions to the model are achieved for various assumed distributions of the minor component. These solutions are algebraic equations capable of predictive use with a hand calculator and back-calculation with very simple trial and error search procedures. The use of these special model solutions is illustrated on several sets of experimental liberation data, and the approach is shown to have practical utility.

Jan 1, 1984