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By D. F. Toner

THE decomposition of the ß phase in the copper-aluminum system has recently been subjected to considerable investigation1-4 As a result of this work, principally by Haynes, much additional interest has been aroused concerning the various transitional or metastable phases in the Cu-A1 system. No attempt has been made to resolve the question of whether the PI and ß" phases of Klier and Grymko5 are the same as the rosette-shaped phase first observed by Smith and Lindlief6 in 1933 during an isothermal transformation study of an eutectoid alloy. It is the purpose of this study, however, to obtain

Jan 1, 1960

Ask any mineral industry executive what he considers one of the most expensive aspects of getting a product to the ultimate consumer and invariably the answer will be transportation. Some company officials say that transportation charges alone account for over half of the total cost of most products. If these judgments are correct and a recent invention turns out to be the long-awaited breakthrough that shippers have been looking for, then many producers can look forward to slashing their delivery costs by 90%.

Jan 9, 1969

By G. C. Mudd, E. J. Myers

Within the last 15 years David Brown Gear Industries has manufactured approximately 200 large mill gears over 6m diam., 58 of them over 9 m and up to 12 m diam. The experience has not been without problems, due to a lack of clear understanding of the loads and stresses imposed on large gear wheels. American Gear Manufacturers Association (AGMA) practices suggest that a service factor be used for mill gears. But what is meant by "service factor"? The layman might be forgiven for believing that the term is synonymous with "safety factor," but this is certainly not true. The service factor is an aggregate of the following in some proportion: -An application factor, i.e., an allowance for the fact that systems do not run smoothly with uniform torque. -An ignorance factor covering the imperfections in the basic gear calculation. -Possibly a safety factor. In the following sections some of the ways in which the limits of applicability can be overstepped are discussed.

Jan 1, 1983

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Jan 1, 1938

An appropriate change in Art. I, Sec. 9, of the bylaws was voted by the Board on April 16 whereby, in the case of Student Associates applying for change of status to Junior Member, only two endorsers are needed instead of three, provided one of them is the same member who endorsed his original application for Student Associateship.

Jan 1, 1952

By Milton C. Neul

As recently as the mid-1930's, steam and rail haulage were still the primary means of moving large quantities of rock. However, 2- to 5-ton standard on-highway trucks were beginning to be used in the mining industry's efforts to lower haulage costs. It was quickly obvious that rubber-tired equipment was more flexible, faster and more maneuverable. The trend towards haulage trucks had begun. Now while savings were being realized, the severe operating conditions encountered in open pit operations proved too much for the lightly constructed frames, gasoline engines and highly inflated tires. As a result, a few years later, the first 10 to 15-ton, two-axle heavy duty trucks were designed specifically to operate under off-highway conditions.

Jan 3, 1966

By Walter C. Labys, Fereidoon Shahrokh

This paper presents an application of computer simulation methods to the modeling and forecasting of the United States coal market. The computer methods employed as well as the model constructed are based on economic and econometric theory. The contents of the paper include a description of the coal market, the corresponding computer model, tests of model validation, computer generated scenarios for the period 1980-1985, and comparisons of the scenarios generated with that of other major coal forecasts.

Jan 1, 1983

By J. Chupak, D. J. Salley, G. L. Simard

Radiotracers were demonstrated to be of considerable value in a study of the interaction of dithiophosphate with galena. The interaction had characteristics of both chemisorption and chemical reaction, being complex because of the nature of the galena surface. Sorption was rapid and markedly reversible, and flotation occurred at relatively small amounts of dithiophosphate sorbed.

Jan 3, 1950

By L. C. Brown, E. B. Hawbolt

If a single-phase alloy is rapidly cooled such that insufficient time is available for an equilibrium transformation to occur, the high-temperature phase may be retained to room temperature or may undergo a massive or martensitic reaction. The massive or martensitic product develops without a composition change and usually has a crystal structure approximating an adjacent equilibrium phase. The characteristics of a massive transformation are intermediate between the equilibrium reaction in which long-

Jan 1, 1969

[ALBERTA, UNIV. OF AZIZ, Khalid FLOCK, Gerald L HART, Richard T NAOER, Walter SCHEIDEGGER, Adrian E SHIELS, David Alexander ALUMINUM CO. OF AMER. GAYLE, Douglas Z MINTER, John L MOORE, Thomas C NEUSTAEDTER, J A REISS, Royal W SPEYRER, Henry R AMARILLO OIL CO. BEST, John B Jr COX, Arthur F GRAY, Stanley F Jr KEENS, Roy J MORRIS, Edward S TIPTON, J A WHITIS, Thurman S]

Jan 1, 1961

By James W. Clark, William C. Dixon, Kevin L. Wiley, Thomas R. Couzens

This paper is a description of certain geologic aspects of the Inspiration mining operation. It is not a geologic description of the Inspiration deposit nor an exposition of all the geologic work. Involved in the development and exploitation of the deposit. A few specific examples of the application of geology and geostatistics to the mining process are given to illustrate the progress that has been made in making the Inspiration Mine more efficient and cost effective, and a statement of the philosophy of geologic applications is offered.

Jan 1, 1985

By R. M. Board

This paper will focus on measurement and control of four main aspects of crushing, namely horsepower, bowl level, mantle position and feed rate, and will discuss related sensors and control techniques, some of them designed specifically for crusher control, that have proven successful and reliable in many installations.

Jan 1, 1982

By E. A. Khopunov, V. I. Revnivtsev

The process of triboelectric separation from the point of view of its potential for selective separation of various mineral particles can be described as "dry flotation." Large scale practical applications of this technique are limited because suitable models which can describe contact charging of mineral particles have not been developed. Among the various concepts a promising one is an attempt to change development in dielectric minerals within the limits of contact phenomenon in semiconductors. Experimental investigations reported in this paper indicate that the charge development is mainly a result of contact electrification of dielectric minerals characterized by "donor" and "acceptor" type energy spectra due to lattice defects.

Jan 1, 1980

By K. V. S. Sastry, S. C. Panigraphy, D. W. Fuerstenau

The batch balling behavior of hematite, magnetite and limestone was found to depend markedly on the grinding method used for feed preparation. Wet ground materials require higher moisture for balling than do dry ground materials. Further, as the fineness of the wet-ground material is increased, the overall rate of agglomeration decreases, whereas the opposite is true for dry-ground materials. In contrast, the resulting pellet size distributions are not affected by the nature of the feed material preparation. These differences and similarities in the agglomeration behavior between wet and dry ground materials may result from the hydrophilic/hydrophobic nature of the surfaces, the formation of pre-agglomerates during dry comminution, and possible variations in the packing density of particles in the agglomerates.

Jan 1, 1978

By I. C. White

Only two factors appear to be directly responsible for the geographic distribution of sulfur in the coal fields of West Virginia: these are the stratigraphic position of the coals in question, and the eastward or westward location of the deposits. There appears to be a progressive increase in the sulfur content of West Virginia coals from the oldest Peqnsylvanian deposits in the Pocahontas, New River, and Kanawha Groups of the Pottsville Series up through the Allegheny, Conemaugh, and

Jan 1, 1920

By Charles S. Barrett, Robert F. Mehl

The system cadmium-mercury has attracted much attention, chiefly because of its importance in the study of electrochemical standard cells. The constitutional diagram, as it is accepted today, is essentially that developed by Bijl l (Fig. 1), though there has been a great amount of work done on the system by other workers.2 A year ago the senior author published a paper on the crystal structure of the system, in which were described determinations of crystal structure

Jan 1, 1930

By Erkki Laurila

INVESTIGATION of the methods of analyses for magnetite and ilmenite in the Otanmäki iron-titanium ore and respective mill products has resulted in certain improvements in the methods conventionally employed. The outcome of the investigations is summarized as follows: 1-Development of a diamond-drill core analyser for the determination of magnetic susceptibility of drill cores containing magnetic minerals. 2-Development of a magnetite-ilmenite analyser for pulverized products. 3-Development of a potentiometric method of chemical analysis for the determination of iron, vanadium, and titanium in succeeding steps from one test sample. 4-Proposal for a continuous and automatic magnetite assay method.

Jan 9, 1951

By H. A. Kuhn

The Pittsburgh coal field in Western Pennsylvania is conceded to be the most important in the world.

Jan 1, 1915

By E. H. Ahrens

This paper deals with the responsibilities of an operating geologists and the relationship of operations to exploration. It should be of interest to those soon to enter the profession, those new to mining geology and as a review to more experienced geologists. Subjects discussed include detailed geologic mapping, sampling, core logging, assaying, selection of proper map scale, posting geological and assay data, section preparation, identification of ore controls, delineation of development drill targets and geologic hazards, models and the very important topic of salesmanship. Methods and ideas, proven valid in vein, pyrometasomatic replacement and porphyry copper deposits are presented. Hopefully, these will smooth the path for new members of our profession.

Jan 1, 1984

By Reynold Q. Shotts

Data are presented which show that fractions of varying densities from the same coals are oxidized at different rates by nitric acid. From oxidation data, the approximate quantity of "bright" and "dull" components may be calculated. Definite relationships between oxidation rate and rank are shown for density fractions from at least two bituminous coals.

Jan 8, 1950