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By F. Shaw, E. C. Chemaly, A. F. S. Schoukens

Steel-plant dusts are hazardous waste materials, containing toxic constituents such as lead, cadmium, and hexavalent chromium. These dusts can be treated by a number of thermal processes, which are described as used in Western Europe and the USA. A detailed description is then given of the thermal Enviroplas process, which as developed at Mintek and produces disposable slag and valuable byproducts such as ferroalloys containing chromium and nickel, and fumes high in zinc oxide.

Jan 1, 1993

COLLOQUIUM PRACTICAL APPLICATIONS OF INSTRUMENTATION IN THE MINING AND METALLURGICAL INDUSTRIES Rapporteur: J. Laschinger A colloquium and general meeting of the Institute held jointly with the Instrument and Control Society of Southern Africa at Kelvin House, Johannesburg on 18th October, 1972, had as its theme "Practical Applications of Instrumentation in the Mining and Metallurgical Industries" Dr J. P. Hugo (President) was in the chair and about 200 members and visitors were present.

By A. O. Filmer

A study of the dissolution of gold from a pyrite concentrate and from various calcines is reported. The percentage extraction of gold was found to decrease with increasing sulphur content in the material leached because of the porosity of the materials, and particularly because of the passivation of the anodic dissolution of gold when the gold was In contact with other conducting minerals. This is explained in terms of the current-potential curves for the oxidation of gold and the reduction of dissolved oxygen.

Jan 1, 1982

By P. Wiesner, H. –M. Stonner

A brief account is given of the influence of sulphuric acid and chloride ions during the recovery of uranium by solvent extraction, followed by a discussion of the settling behaviour of dispersions and models to represent that behaviour. The paper ends with a description of various methods for the recovery of solvent, which is lost in the solvent-extraction process by entrainment and adsorption on solids and by dissolution.

Jan 1, 1982

By G. Nino de Guzman, L. C. Woollacott

The isotherms that are usually taken to represent the force 'driving' the adsorption in carbon-in-pulp processes may change from contactor to contactor. This paper reports on an investigation into the extent to which this Isotherm shift is Influenced by the changes in oxygen and cyanide concentration that occur in operating plants. The impact of the isotherm shift on the reliability of simulation results is examined.

Jan 1, 1993

By I. R. Phimister

'Ancient' mining near Great Zimbabwe I. R. PHIMISTER. B.A. Hons. (Nottingham). B.A. Spec. Hons. (Rhodesia) (Visitor) In proposing reasons for the geographical location of Great Zimbabwe, the paper re-examines the popular assumption that Zimbabwe is comparatively remote from the known areas of 'ancient' goldmining. The lack of 'ancient' workings in the neighbourhood of Zimbabwe is pointed out, and it is suggested that the mining of placer deposits of gold may have played some part in the development of Zimbabwe on its particular site.

Jan 1, 1974

By J. P. Hoffman, A. S. M. de Jesus

Additions of boron have been found to increase the hot workability of stainless steels. Boron forms complex chromium-iron borides, primarily at grain boundaries but also on delta-ferite stringers. This paper describes how a nuclear technique based on the track-etch method was used to distinguish between borides and chromium carbides on grain boundaries and to investigate the distribution of boron in stainless steels. The method was found to be sensitive for boron, and made it possible for boron precipitates to be identified on grain boundaries and interphase boundaries.

Jan 1, 1989

By R. G. Jurd

This paper considers the introduction of large-scale longwall mining into South African coal mining, instead of the conventional mechanized bord-and-plllar mining that is widely practised at present. The two methods are compared, and longwall mining is found to have the advantage in several respects in some seams. The most cogent reasons for the introduction of the longwall method In some seams are associated with safety strata control and increased labour costs.

Jan 1, 1978

By P. van Niekerk, V. J. Solomon

Improvements in the drilling and blasting techniques used in the stopes of narrow reefs have caused the clearing of broken rock to become the major cause of delay in the achievement of a regular cyclic operation. This paper discusses the development of a scoop in accordance with a predetermined set of performance parameters. The test results obtained to date have shown that the basic objectives have been achieved within tolerable limits of variation.

Jan 1, 1979

By J. G. Goodey, G. J. van der Linde

This paper describes pilot-plant tests on the recovery of apatite from a hitherto untapped material. This materialhydro- separator overflow-is very fine (80 per cent smaller than 45 µm and 32 per cent smaller than 10 µm). . The pilot-plant tests proved that the recovery of apatite from this material is economically and technically viable. This was confirmed by plant trials, which, in the early stages, produced concentrate assaying 36,6 per cent P2O5 at a recovery of 65,5 per cent.

Jan 1, 1983

By A. W. de Villiers

This paper explores the behaviour of methane in the goaf during longwall mining, together with some methods for the control of methane emissions into the goaf, the working face, and the ventilation system. Experimental work done at Twistdraai Colliery, Sasol Coal, is referred to, as well as the gas-drainage system being practised at West Cliff Colliery in New South Wales, Australia. Gas drainage is discussed briefly, and certain suggestions are made in regard to coal mining in South Africa.

Jan 1, 1989

By G. H. Grange

Details are given of three legal controls for the pollution of the air, the water, and the land, together with brief histories of the developments leading up to these controls. Attention is drawn to the fact that legal action may be instituted against a mine under common or other laws where pollution causes proveable damage or loss. It is suggested that an international conference should be held to define the philosophies and principles on which to base not only the necessary legislation for environmental control but also the machinery by which the controls can be administered.

Jan 1, 1978

By H. P. Coetzee, V. J. Solomon

As the price of gold increased, so did the viability of mining previously abandoned unpay areas of Stilfontein Mine. After an assessment to confirm the profitability of mining these areas, it was necessary to re-establish access-ways such as haulages, cross-cuts, and travelling ways. Openingup is a labour-intensive, relatively slow operation, and attempts were made to mechanizeand speed it up. Some of the techniques applied and the results achieved, whether successful or not, are discussed.

Jan 1, 1982

COUNCIL FOR 1990/91 President H.G. Mosenthal President Elect RD. Beck Senior J.P. Hoffman Vice Presidents Junior Or H. Scott-Russell Immediate Past President Or O.K.H. Steffen Honorary Treasurer OrH. Wagner

Jan 1, 1991

By B. C. Alberts

An international conference on 'The Planning and Operation of Open-pit and Strip Mines' was held at University of Pretoria from 9th to 13th April, 1984. The Conference was organized by the Mining Alumni Society the University of Pretoria and The South African Institute Mining and Metallurgy. Delegates of the mining fraternity from all over the world and Southern Africa attended the Conference. These included more than 400 delegates from Australia, Austria, Botswana, Brazil, Canada, Germany, Holland, SWA-Namibia, the United Kingdom, the United States of America, Zimbabwe, and South Africa.

Jan 1, 1984

By E. J. Boome, A. C. Schmidt

Pert, and how Pert techniques can be used in modern mine management By E. J. Boome, A. C. Schmidt C.A. (S.A.) This paper covers the stages of planning required to be performed and the implementation of the plan from grass roots to the partial completion of the sinking of a mine shaft system. The various steps involved in the planning are also examined in some detail. The experience gained in this project and the conclusions reached convince the authors that Pert Planning is a valuable aid to top management.

By C. J. Van Niekerk, C. C. Begley

SYNOPSIS The paper opens with brief descriptions of the history, occurrence, and regional geology of South Afri¬can zinc deposits, and follows with descriptions of the resources, mining methods, and processes for the concentration of the sulphide minerals and the extraction of zinc as practised in South Africa. The end uses in the form of alloys or as salts are given in some detail. Statistics on the production and consumption of zinc in South Africa are given, and the current market situation and future prospects are discussed briefly.

Jan 1, 1991

By B. Rohrmann

The paper deals briefly with the history of vanadium, and its uses, price movement, and world resources. It then describes the titanomagnetite ore of the Bushveld Complex, and the production of vanadium from this ore at Highveld Steel & Vanadium Corporation Limited, giving details of the various processes used, including the roast-leach, rotary-kiln, electric-smelting, shaking-ladle, and basic-oxygen-furnace operations. The paper concludes with a very brief account of the treatment of Highveld slags in Europe for the production of vanadium pentoxlde and ferrovanadium.

Jan 1, 1985

By R. Rubin, P. A. Laxen, G. S. M. Becker

An account is given of developments in the use of activated carbon for the recovery of gold from cyanide solutions. The carbon-In-pulp process employed at the Homestake Mine is described, and its various applications in South Africa and their effectiveness are discussed. Probable future work on the carbon-in-pulp process and other possible applications of carbon for the recovery of gold are outlined.

Jan 1, 1979

By A. L. Hinde, P. J. D. Lloyd, A. R. Atkins, J. G. MacKay

The control of milling circuits by A. R. ATKINS, M.Se. (Elee. Eng.) (Visitor), A. L. HINDE, S.Se., Ph.D. (London) (Visitor), P. J. D. LLOYD, S.Se. (Chem. Eng.), Ph.D. (Cape) (Fellow) and J. G. MACKA Y, S.Se. (Chem. Eng.) (Visitor). The general behaviour of mills is described in an attempt to find a control philosophy that will permit milling circuits to produce a constant particle size. Although the experimental work has been confined to a single section of the milling circuit of one mine, it is felt that the findings are applicable to other milling circuits.

Jan 6, 1974