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Discussion of the paper of E. S. Moore, presented at the Colorado meeting, Sep-tember, 1918, and printed in Bulletin No. 135, March, 1918, p. 687. W. F. SMEETH, * Bangalore, Mysore, India (written discussion ? )-Before dealing with the air blasts, I would like to clear up a geological point. The author states that the matrix of the conglomerate resembles a hornblende schist. This is a, misapprehension. The conglomerate

Jan 10, 1918

Later this month (June 24-27) in San Francisco, the Society of Mining Engineers of AIME, together with the American Society of Civil Engineers, the Canadian Institute of Mining & Metallurgy and the Engineering Institute of Canada, is sponsoring the second biannual Rapid Excavation and Tunneling Conference. The dominant theme of the Conference is the practical application of techniques and research relating to underground rapid excavation and tunneling. In the following pages, ME gives highlights of many of the 24 technical sessions and some of the papers being presented. The full proceedings of the Conference will be published by SME-AIME later this year.

Jan 6, 1974

In the seven years that have elapsed since the AIME World Symposium on Mining and Metallurgy of Lead and Zinc, there have been a number of significant milling innovations and trends implemented in lead-zinc flowsheets to either improve grade and recovery or to control escalating mill costs. First, mill controls and instrumentation, which only had a foot in the door in 1970, have become increasingly common. In Australia, research into automatic crushing control has been implemented by Mount Isa Mines, and in virtually any large lead-zinc mill worldwide, an assortment of on-stream x-ray analyzers, grinding circuit controls, level detection devices, and reagent metering methods can be found. The increased circuit control offered to mill operators by this new technology points to more efficient flowsheets, as well as to a greater dependence upon computer-controlled operation.

Jan 11, 1977

By Graham P. Crutchfield

The W. I. Cook pool in Shackelford County, Texas, has been the subject of a number of papers and articles. Its unique position both as to operation and development has made it an ideal location for unit repressuring. The major portion of the pool is located on the W. I. Cook ranch and most of the oil leases are owned by Roeser & Pendleton, Inc. and the Continental Oil Co. and operated by Roeser & Pendleton, Inc. The Humble Oil & Refining Co. and Tom James operate producing leases which have a vital bearing on the unity of the pool. Both have cooperated in the repressuring project. Practically the entire royalty is owned by Mrs. W. I. Cook and she has given the operators her entire cooperation in all phases of unit repressuring.

Jan 1, 1931

By G. J. Ballmer

Trucks Are Valuable Auxiliary Haulage Units in Rail Pits For: ( I ) Making railroad grades (2) Establishing benches (3) Making new dropcuts

Jan 10, 1951

By Paul R. Smith

Preparation for flotation begins with dragline mining, pumping, washing, screening, and desliming. Slimes, nominally -150 mesh material, constitute large quantities of phosphate and water which are a disposal problem. Older techniques involve sizing at about 35 mesh for separate coarse and fine treatment. The plus 14 mesh fraction does not require concentration. Coarse treatment includes agglomerate spiralling, belt flotation, thickening, scrubbing with sulfuric acid, de-oiling for reagent removal, and cationic flotation of fine quartz. A recent trend is to screen at coarser than 35 mesh size and eliminate coarse particle treatment, sacrificing some grade of this product. Techniques for flotation concentration of the fine size fraction are discussed.

Jan 1, 1976

By L. L. Davis

Current research by the US Bureau of Mines to develop technology for improving efficiency and productivity in metal/nonmetal mines is described. The research program addresses a wide variety of problems associated with each of the major categories of mining: underground mining, surface mining, m situ mining, and premining investigations. An overview of the Bureau's research activities is given with emphasis on underground mining. In particular, two innovative and promising concepts currently under development are described: a unique shaft sinking system that uses an impact hammer for rock fragmentation, and a low-profile portable crusher for underground hard-rock applications.

Jan 1, 1982

By J. B. Woodworth

Under the above title it is desired to bring to the attention of assayers a short-cut method which has been perfected by Mr. A. S. Warren, of Buffalo, and the writer; has been used several years at three " Lake copper " refineries in occasional alternation with the regular " combination," or a wet and fire," assay; and has proved more rapid, and rather more accurate than the latter on all refined copper—namely, the direct cupellation of the silver chloride (+gold) precipitate, without scorification. No claim of priority is made for this direct method, as it has suggested itself to many others, and was mentioned by Mr. Warren in the symposium of assayers' results brought together in 1895 by the Secretary," after the plan and suggestions of Dr. A. R. Ledoux.† Lately, this important subject of assaying copper-materials seems to have been re-opened for discussion. The shortening of time by 'the direct method is so considerable (nearly 20 minutes on a batch)—to say nothing of the saving

Jan 1, 1902

By Wayne D. Gould

Cities Service Co.'s Pinto Valley concentrator was designed to eliminate excess capital costs without loss of efficiency. The result is a workable plant with some important innovations. These innovations, the equipment used, and plant processes are outlined. Particular attention is paid to the work efficiency and wear of the six ball mills, the largest wet ball mills made. For experiment purposes, four designs of liners were installed. The effectiveness of each design is discussed.

Jan 1, 1977

Jan 1, 1918

By Paul M. Tyler

MUCH information concerning pegmatites which was thought to be true a few years ago has been proved false, and what is now actually known about some pegmatites is not true of many others. The erratic and seemingly unpredictable structure and variable composition of this class of mineral deposits has been widely emphasized. Even parts of the same pegmatite body exhibit marked differences in texture, mineral composition, width, and attitude. Constructive geological thinking in respect to pegmatites now aims to establish general laws rather than to stress the confusing diversity of features having no special economic significance.

Jan 9, 1953

By Renato G. Bautista, Gary A. Beetner, Anthony L. Frey

The flow of material in a pump mixer-settler extractor was studied photographically and visually by injecting dye into the equipment and following its advance through the various sections of the equipment. Volumetric measure of the flow was obtained from analysis of the photographs. The organic portion of the settling chamber, the fluid surrounding the pump mixer, and the pump mixer itself were found to be operating in plug flow. The aqueous portion of the settling chamber was found to be partially mixed. Significant dynamic effect was noted due to density changes in the feed streams. The quantitative and qualitative observations made of the flow within a single stage should be of value in predicting the flow patterns in all similar equipment, including opaque and liquid metal solvent extraction systems.

Jan 1, 1973

By Robert A. Campbell, Robert J. Brison

The problem of optimizing from an economic standpoint the capacity of grinding equipment in the design of a new concentrator is discussed. Although directed specifically to copper flotation mills employing conventional wet, grinding, the material presented is considered applicable with modifications to other types of ores and other grinding methods. A general approach to optimizing the grinding capacity is outlined and illustrated by an example. The' interrelation between grinding capacity and other aspects of the project is considered. The problem of regrind capacity and its relation to preceeding and subsequent processing steps is also discussed. Finally, factors are considered that may, in certain cases, dictate modifications of the suggested approach.

Jan 1, 1974

By D. J. Crouse, W. D. Arnold

The potential behavior of radionuclides released in an underground nuclear detonation to fracture copper ore for subsequent in-situ leaching and copper recovery was studied with regard to contamination of the copper product and hazards to operating personnel. The laboratory test results indicate that only small fractions of the radioactive fission products would be dissolved on leaching the ore. Tritium (as tritiated water) would be the dominant radionuclide in the circulating leach liquor, assuming use of a fusion explosive. The test results showed solvent extraction to have important advantages over cementation for recovering copper from the leach liquors. While the radioactivity of the copper metal product produced by either method should be extremely low, the solvent extraction process provides a more effective separation of copper from the radioactive contaminants and entails fewer radiation protection problems. For these reasons it is the preferred process.

Jan 1, 1976

By R. Kirk

The problems of getting air to the working face of a mine (or perhaps the problems caused by not getting air to the working face) have led to the development of an analogue system in England that reputedly bypasses many of the drawbacks that such systems have encountered in the past. The unit was developed for the Wolstanton Combined mine, an underground operation consisting essentially of three collieries situated in the center of the North Staffordshire coalfield. This combination of workings, which employs a total of eight shafts, brings with it complex ventilation problems, and in order to study these problems and to assist in the control of the established ventilation system, a Ventilation Analogue has been designed and installed to permanently represent the mine's ventilation system.

Jan 4, 1964

STANDING COMMITTEES Executive A, R. LEDOUX, Chairman HERBERT HOOVER EDWIN LUDLOW ARTHUR S. DWIGHT CHARLES F. RAND Membership J. V. W. REYNDERS, Chairman J. V. N. DOER W. H. ALDRIDGE EDGAR RICKARD R. M. RAYMOND Finance MARK L. REQUA CHARLES F. RAND, Chairman J. V. W. REYNDERS Library E. GYBBON SPILSBURY, Chairman ALEXANDER C. HUMPHREYS GEORGE C. STONE JOHN H. JANEWAY BRADLEY STOUGHTON Papers and Publications BRADLEY STOUGHTON, Chairman

Jan 1, 1923

By Larry D. Hartzog

PANELISTS Paul Chamberlin, Nerco Minerals Jim Gourdie, Goldfield Mining Corp. Roger Leonard, Cyprus Northumberland Mining Co. Eric Daniels, Tenneco Minerals John Dasher, Consulting Metallurgist Bob Shoemaker, San Francisco Mining Associates Larry Hartzog, Bechtel Civil and Minerals, Inc.

Jan 1, 1984

By Bailey Willis, George Otis Smith

I. Summary of General Features. Location.—The Clealum iron-ore deposits occur on Clealum river, a tributary of the Yakima river; in the eastern spurs of the Cascade range, Washington.† Mount Stuart, 9470 feet in altitude, is a dominant peak of the district, which will therefore be referred to as the Mount Stuart district. By way of the valley and cañon of the Clealum, the ores are 18 miles from Roslyn, the colliery-town, which is reached by a short branch from the Northern Pacific Railroad. Where they occur the valley has an elevation of 2900 to 8000 feet above sea; that of the end of the branch railroad at Ronald is 2345 feet. The grade of the valley from near Ronald to the junction of the Clealum and Salmon Lasac rivers, 144 miles, is 20 feet per mile; thence to the iron-ores it is 130 feet per mile, through a cañon 241/2 miles long. Abreast of the deposits the western wall of the valley is formed by precipices of sandstone; the eastern slope is comparatively gentle, being cut in easily eroded

Jan 1, 1901

By L. W. Eastwood

PART 1. EFFECT OF HEATING RATE UPON RECRYSTALLIZED GRAIN SIZE OF ALUMINUM AND ALUMINUM ALLOYS AMONG those concerned with the annealing and heat-treating of aluminum and aluminum alloys, it is well known that after cold-working a coarser grain is usually produced by slow heating than by more rapid heating. Consequently, for the control of the grain size produced by annealing or heat-treating cold-worked aluminum and aluminum alloys, the heating rate is of considerable practical importance. References in the current literature on the effect of heating rate are numerous, but it appears neither necessary nor desirable to give here a review of the former work done on this subject. It became evident during some preliminary work on the recrystalliza-tion of aluminum and aluminum alloys that the effect of heating rate depended upon the type of microstructure of the metal. This observation led to the following study of the relationship of the type of microstructure of the alloy to the effect of the heating rate.

Jan 1, 1939

By John W. Tieman

Research on processes to remove sulfur oxides from flue gas has been in progress for many years. Pioneers in this field were the British who, in the early 1930's, installed a full-scale flue gas scrubbing unit on a 120 MW boiler using alkaline water from a Thames estuary plus chalk. Since that time, various methods have been studied by many investigators. Federal laws covering air pollution started with the 1955 Air Pollution Control Act. With the advent of the Air Quality Act of 1967, and subsequent publishing of criteria and available technology for control of sulfur oxides in January 1969, the clamor for information on commercially available control techniques to remove sulfur from fossil fuels has rapidly increased.

Jan 8, 1972