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By Stewart K. Griffiths

A general method-of-lines numerical approach for modeling gas driven fractures has been developed and tested. The numerical solutions agree very well with known similarity solutions for laminar and turbulent flow. Acceptable accuracy is obtained with a very few numerical grid points and with modest execution times. The model has also been checked against the results of several field tests, in which air was used to drive axisymmetric fractures into permeable tunnel-bed tuff.

Jan 1, 1984

By A. L. Holley

THE intention of this paper is not to discuss this important subject in all its bearings, but merely to point out why mechanical tests of steel, as ordinarily made, are not, alone, of any special value to engineers-certainly not to general mechanical engineers. The agents of the Barrow Hematite Steel Company, one of the largest and most successful Bessemer establishments in England, have recently distributed a report, made by Sir William Fairbairn,

Jan 1, 1874

By C. S. Witherell

THE first feature that strikes one when considering the use of air enriched with oxygen in pyrochemical processes is the conservation of Enriched Air FIG. 1.-TEMPERATURES THEORETICALLY OBTAINABLE BY BURNING PURE AMOR¬PHOUS CARBON IN AN ATMOSPHERE COMPOSED OF AIR ENRICHED WITH OXYGEN, PRODUCING GAS CONTAINING CO. heat due to the partial elimination of the inert heat-carrier nitrogen, as set forth in the report of the committee. The second feature, which

Jan 11, 1924

H. M. BOYLSTON, Cambridge, Mass.-We should feel greatly indebted to Mr. Miller for collecting this admirable series of photographs, but I cannot quite agree with his conclusions as to their significance. He apparently concludes that these needle-like constituents which he has shown in a good many cases, in the welded material at least, are cementite; that is, as we understand it, a carbide of iron. Now there seem to be

Jan 4, 1918

By D. J. Spottiswood, C. N. Robinson, D. E. Spiller, E. G. Kelly

This paper describes the performance of a new design of spiral that is optimized for fine coal cleaning. Reduced Performance (Tromp) curves are presented to compare this spiral with the older design, as well as with other commonly used coal cleaning equipment. As an aid to equipment selection and circuit design, data are also presented to show how variables, such as flow rate, pulp density, and particle size, affect efficiency and the separation specific gravity.

Jan 1, 1985

By Leonard P. Colvin

Like all successful American enterprises, the mining industry is constantly trying to increase production, lower costs and improve working conditions. Companies are, of course, intensely interested in new equipment to help them gain these important ends, and one recent development-the mechanical raise climber--contributes to all three goals. Properly used, it increases production, cuts costs and has a number of important safety aspects all of which are the subject of this article.

Jan 1, 1962

By R. D. Brown

This paper profiles Canada’s current economic, tax, and political environment with respect to its mining industry. Problems that must be overcome if the industry is to attain its full growth potential and are highlighted, some suggestions reflecting the opinion of many in the industry are given. Tables provide some detail on the current Canadian mining tax system, province by province, as well as for the Yukon and Northwest Territories, plus some relevant economic trends.

Jan 1, 1985

By James A. Burns

The challenge to designers of bulk materials handling systems is to apply the existing technology in areas where it has not been used and to foster better, cheaper and safer job performance. The Dashaveyor Co., a subsidiary of The Bendix Corp., built and tested a pilot system at Copper Range's White Pine mine. Based upon this success, a prototype system development was begun in 1967 to test the concepts in a full-scale, realistic environment.

Jan 11, 1973

Only the coal of the Sunnyside district in Carbon county is coked. Two companies, the Utah Fuel Company and the Columbia Steel Corporation, operating adjoining mines at Sunnyside and Columbia, produce coke. The Utah Fuel Company has 81 9 beehive coke ovens at Sunnyside. Only 350 ovens are being operated at the present time, largely because the smelters which had been using Sunnyside coke changed their equipment from blast furnaces to reverberatory furnaces

Jan 1, 1925

Buffalo Society of Natural Sciences, Buffalo Museum of Science, Humboldt Park, Buffalo, N Y. Of the many scientific bulletins issued by the Society only one of those now available is of particular interest in this directory. Vol 7 (1901), Bulletin 1, Guide to the geology and paleontology of Niagara Falls and vicinity, by A. W. Grabau, $1 unbound or $2 bound. The bulletins are distributed through the Research Librarian at the above address

Jan 1, 1933

During February there will be a meeting of the Committee on Technical Nomenclature of the Society for the Promotion of Engineering Education and representatives of the various engineering societies, to do the preliminary work necessary for the adoption of uniform lists of technical symbols. At this time it is expected that lists of symbols in general use throughout the country will be presented and the symbols most generally used will be recommended for adoption.

Jan 2, 1919

By William A. Mitchell

AN X-ray diffraction pattern for "calcined cold precipitated ferric oxide" is reproduced diagrammatically along with data for other iron oxides by R. C. Mackenzie.1 This pattern, which shows spacings higher than those for any other form of iron oxide, was obtained from material prepared and photographed at several different times over a period of weeks, but later attempts to reproduce the results were unsuccessful the pattern of hematite being obtained every time.2

Jan 9, 1953

Use of rock grinding media in a mill at Tennessee Copper Corp. was mentioned in the MINING ENGINEERING Annual Review. (February 1953, page 158). Because interest in use of self-grinding media continues high we asked F. M. Lewis, Superintendent of Concentration at Tennessee Copper, to supply more details on this trial, and of plans to expand use of rock media in their mills that grind marble. Here is what he reports.

Jan 5, 1953

By M. R. J. Wyllie

In a recent publication1 wetting phase relative permeability was exvressed as: and it was stated that a similar expression applied, mutatis mutandis, to non-wetting phase relative permeability; i.e., In Equations (1) and (2), Sw and S0 are respectively the wetting and non-wetting phase saturations as a fraction of the pore volume; PC is the capillary pressure; I; the wetting phase electrical resistivity index; IN, the analogous non-wetting

Jan 1, 1951

By Society of Mining Engineers of AIME

An error has been noticed in one of the figures in the 1974 Jackling Lecture "The Henderson Ore Body-Elements of Discovery, Reflections" by Stewart R. Wallace, published in SME Transactions, Vol. 256, No. 3, September 1974, pp. 216-227. The horizontal scale shown on Fig. 5 of this article is incorrect. The horizontal and vertical scales should be equal, i.e., the horizontal distance shown as 1000 ft should be 2000 ft.

Jan 1, 1976

By M. R. J. Wyllie

In a recent publication1 wetting phase relative permeability was exvressed as: and it was stated that a similar expression applied, mutatis mutandis, to non-wetting phase relative permeability; i.e., In Equations (1) and (2), Sw and S0 are respectively the wetting and non-wetting phase saturations as a fraction of the pore volume; PC is the capillary pressure; I; the wetting phase electrical resistivity index; IN, the analogous non-wetting

Jan 1, 1951

By Junnosuke Yamamoto

Substituting sodium hydroxide for sodium carbonate as a binder in a glass batch yields harder pellets with a lower melting point. This paper explores the degree of NaOH substitution that is feasible, and compares pellet hardness, and amount of dusting with the degree of NaOH substitution. The effects of the the amount of soluble silicate in the pellet and residual hydroxide concentration in the pellet on pellet hardness are also studied.

Jan 1, 1977

By P. R. Kneitz, G. Yoshikado, D. Zayakov

The design and analysis of a circular, domed powerhouse for Pacific Gas and Electric (PG&E) Company's Kerckhoff 2 Project is described. Exploration, geologic stress determinations, mechanical properties, reinforcement and instrumentation are addressed briefly. The analyses of the circular, domed cavern and the comparison of predicted and field deformations are presented in somewhat more detail. The behavior of the completed powerhouse cavern has been found to be substantially as predicted by the analysis.

Jan 1, 1982

Unitization—in some form from simple agreements among operators to complete consolidation of ownerships—is a means of obviating the wastes of unrestrained competition among owners in extracting oil and gas from a common reservoir, as well as of adjusting its output to the current needs of its owners. It offers opportunity for application of improved production methods which are expected to increase recovery, decrease developing and operating costs, and assist in stabilizing output.

Jan 1, 1930

Plans for the Petroleum Division during the ensuing year are in process of development, in contemplation of the usual fall meetings in the Mid-Continent and California areas, as well as the annual meeting to be held in New York in February, 1936. Houston, Texas has been suggested as the place for the Mid-Continent fall meeting, the exact date to be announced shortly. During the past year, the Division's technical programs, as in former years, have emphasized the wide fields of engineering endeavor in the petroleum industry yet remaining for more thorough investigation and discussion. An effort has been made to bring an international interest into the proceedings of the Division by inviting the participation of prominent foreign technologists. This viewpoint should promote a continuation in 1935 of past high standards, afford a more thorough understanding of problems throughout the membership, and maintain the Institute's position among the various technical organizations functioning particularly in the oil-producing and refining areas. In the list of subjects proposed for the fall meetings is the problem of estimating petroleum reserves. Various factors requiring study will include productive sand volume, porosity, average permeability, saturation, and types of recovery. Research papers are proposed dealing with energy consumption per unit of oil recovered, reservoir pressure or energy loss relationship to the usual volumetric method of estimation, and the study of oil and gas segregation within the reservoir. Other subjects tentatively suggested include new casing practice in relationship to wells producing from several productive zones, progress in lifting methods, repressuring, advanced methods in drilling economies, and the economics of conservation. Although the threat of overproduction yet remains, to a lesser degree than during the past few years, intensive activity is now being directed towards the discovery of new petroleum reserves. This situation undoubtedly will influence, in some considerable degree, the channels through which technical activities will be directed. A continuation of the commendable work on production statistics for the various oil-producing states and foreign countries has been effected. The usual papers dealing with the general economics of the industry will be reserved for the annual New York Meeting. The Stabilization Committee maintains its membership of nationwide authorities, and interest is manifest in new developments to meet the changing requirements of the industry.

Jan 1, 1935