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By W. C. Meyer

In an effort to conserve and extend oil resources, the use of powdered coal-in-oil mixtures (COM) as an alternate fuel in oil-fired boilers is receiving increasing attention. For the approach to be successful, some degree of stability of the suspension against settling is needed. The variety of means available to achieve stability of this nonaqueous slurry is reviewed along with some of the physical and chemical concepts which underlie each method.

Jan 1, 1983

By R. Stratton-Crawley

Flotation-related processes utilizing an oil phase for processing fine mineral particles have been described and various applications discussed. The problems associated with the techniques are varied, but may be summarized by the following areas; (1) applicability to fine particle beneficiation, e.g. collector extender and emulsion flotation. (2) major 'mechanical' problems, e.g. emulsion breakage and oil recovery in oil flotation. (3) complex interfacial chemistry, e.g. empirical nature of pigment flushing .

Jan 1, 1979

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

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

By Lewis Stockett

During the year 1903, a building having machinery corresponding to ail anthracite-coal breaker was erected at the town of Stockett, Cascade county, Mont., for the purpose of breaking-up and cleaning bituminous coal. The coal is mined from a vein of the Kootenai group of the Lower Cretaceous measures having the following section: The vein is nearly horizontal in position, and each bench differs in quality as shown in Table I.

Jan 1, 1905

By W. Julian Parton

General Crushed Stone Co. operates a dozen quarries in such rock types as gabbro, basalt, granite and limestone. Drilling characteristics and problems vary from one operation to another so that a variety of equipment and methods must be employed. In addition, it has been found that equipment improvements make it advisable to continuously look for and experiment with new machines and accessories. This article discusses drilling progress at some of the Company's more interesting operations.

Jan 1, 1963

By T. O. Olsen, R. Henriksen

Aggregated models of a bank of flotation cells have frequently been used, assuming that a single-cell model can be used for control and estimation purposes. In this paper we investigate the feasibility of this approach, and show that single-cell aggregated models may very well be used in order to estimate the aggregated net flotation rate constants of the bank. These estimates would usually be very crucial in order to control the plant.

Jan 1, 1981

By William P. Dyrenforth

The principle of electrostatic separation is discussed and elaborated on by dividing into the three main mechanisms of electrification as applied to separation of solid substances, i.e., (1) contact electrification, (2) electrification by conductive induction, (3) electrification by ion bombardment. Types of equipment used for electrostatic processing are described and the effects of humidity mentioned. Processing of iron ore, titanium minerals, rare earths and cassiterite is discussed and some existing plants are described.

Jan 1, 1978

By Edward T. Koch

A new concept involving the use of a crawler-mounted slurrifier for open-pit ore mining and overburden removal is dealt with. The design and application are discussed. Based on field experience, the area and type of operation where this machine would be effective is indicated. The slurrifier is also compared with draglines, shovels, and bucket wheel excavators. A number of the design concepts, as well as the mechanical and operational parameters, are discussed.

Jan 1, 1976

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 Michael K. O’Leary, William D. Coplin

Risks from political instability and government policies restricting equity ownership, local operations and transfers of payments affect the profitability of foreign mining ventures. More than seat-of-the-pants judgments and old-boy networks are required to anticipate these risks and to take actions appropriate to offsetting them. A system for making political forecasts, called the Prince System, and a series of charts relaying risks to a production of key minerals has been developed.

Jan 1, 1985

By I. Iwasaki, R. Titi-Manyaka

Chlorination and chloridization behaviors of pyrite, pyrrhotite, marcasite, chalcocite, covellite, galena, sphalerite, heazlewoodite, and elemental sulfur were investigated by thermogravimetric analysis. The possible reaction mechanisms are discussed on the basis of the theoretical weight changes and thermodynamic considerations. Chlorine is a more effective chloridizing agent than hydrogen chloride. In the light of the experimental results, a scheme for producing nonferrous metal chlorides, molten sulfur, and ferric oxide from complex sulfide flotation concentrates is discussed.

Jan 1, 1974

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

By Raphael Titi-Manyaka, I. Iwasaki

Chlorination and chloridization behaviors of pyrite, pyrrhotite, chalcocite, covellite, chalcopyrite, bornite, heazlewoodite, millerite, and pentlandite in chlorine, gaseous ferric and sulfur chlorides were investigated by thermogravimetric analysis. The reaction mechanisms are discussed in terms of theoretical weight changes, thermodynamic calculations, and X-ray analyses of reaction products. The experimental findings are in direct application to the development of a scheme for producing nonferrous metal chlorides, elemental sulfur, and ferric oxide from complex sulfide flotation concentrates.

Jan 1, 1977

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 Joseph D. Weeks

The primary problems of civilization are material ones; their answers are writ in fire. When these problems in their higher aspects have pressed for solution, it has been out of the burning bush that the Divine voice has spoken, or in the cloud and smoke that the Divine finger has traced the rules by which these problems shall be solved. It is with the material problems, however, that we, as engineers, have to deal.

Jan 1, 1896

By Charles Morgan

AN increased demand for brown iron ore in the Birmingham district during the past 18 months has caused renewed activity both in prospecting and mining these ores. In recent years the production in Alabama has ranged from 41,559 tons in 1932 to 639,351 tons in 1928. During the last 9 years about 83 per cent of the total brown ore produced in the United States has come from Alabama (Tables 1 and 2).

Jan 1, 1937

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

By Jonathan Ludlow, Paul J. Guay

Based on two studies that were funded by the U.S. Department of Energy, the authors provide an overview of the benefits expected from mining deeper webs on United States longwalls. The first study, completed in November 1979, identified the limits and potential gains from taking deeper webs with presently available equipment. The second on-going study discusses the conceptual design and benefits of a future system for taking very deep webs.

Jan 1, 1981

By Robert D. Coale, Reinhart P. Ehrlich, Terry L. Thompson

The copper concentrate slurry pipeline and pumping system of the Bougainville Copper Ltd. facilities on Bougainville Island in Papua New Guinea, is discussed. Development work necessary for the pipeline design is dealt with including a description of the 17-mile by 6-in. pipeline and pumping system as it was installed. The commissioning of the pipeline is reviewed as well as current operating performance, including data on corrosion, pump parts life, and manpower requirements.

Jan 1, 1977