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By W. F. A. T. Meihack

The scope of this paper is confined to gas-fluidized beds in pyrometalurgical applications. After considering the general characteristics of these fluidized beds, the author deals with their potential applications, using the following processes, which are currently under investigation, as examples: pretreatment of chromite, prereduction of manganese-ore and iron-ore fines, roasting and prereduction of ilmenite, and roasting and pyrolysis of gold-bearing pyrite. He concludes that fluidized beds are potentially of great benefit to the metallurgical industry, although much developmental work remains to be done.

Jan 1, 1986

By P. H. S. W. Kulatilake

The paper introduces a computer simulation technique to estimate the target detection probabilities associated with search surveys. The technique takes into account the inherent randomness associated with the distributional properties of geologic targets. Use of the technique is illustrated through examples. The paper provides information as to how this technique can be used in obtaining the optimum sampling pattern and optimum spacing associated with target detection surveys.

Jan 1, 1987

By H. A. Uys

The metallurgy of tin smelting In a submerged arc furnace By H. A. UYS, Ing. Metallurgy (Pretoria) (Visitor) The control of tin smelting demands a knowledge of slag characteristics and of the equilibrium reaction that governs the process. These factors are explained by reference to the tin-smelting operation at Iscor, Vanderbijlpark. In the primary cycle, it is important to obtain the highest possible FeO content in the slag. In the secondary cycle, a primary slag high in FeO gives a hardhead (iron-tin alloy) high in iron, which is essential if a high ratio of FeO to SnO is to be obtained in the secondary slag. This determines the economy of the smelting operation: the iron that is introduced into the system from the ore concentrate must go out in the secondary slag. Additions of lime are necessary in the secondary cycle but must be limited if the volume of slag is to be kept Iow.

Jan 1, 1977

By N. B. Strydom, H. H. E. Schroder, A. van der Linde

This paper describes a study of the destination of the mercury that is present in the ore during the recovery of gold. It was found that over 96 per cent of the mercury passed through the process untouched. A small amount finds its way into cyanide solution, and is concentrated with gold in Zinc dust as Merrill precipitate. When the precipitate is calcined, the mercury is driven off and finds its way into the atmosphere. However, dilution of the stack gas in the atmosphere appears to be sufficient to prevent hazardous concentrations arising at ground level. No other significant concentrations of mercury were found at any stage of the process. The amount of mercury lost to the atmosphere by this mechanism appears to be less than 200 kg per year throughout the gold-mining industry in South Africa. Virtually no mercury vapour could be detected in the air in the smelt-house. Slight increases in mercury concentrations above background level were observed in soils around the reduction plants and in the discharge or return waters, but no environmental stress is anticipated from these increases.

Jan 1, 1982

By L. C. Stilwell

The paper will attempt to identify the threats, however obscure, that could confront the South African platinum industry. South Africa has the largest reserves of platinum group metals in the world, and is the largest producer of those metals. This situation is no different from that which existed in the gold sector fifty years ago. Since then South Africa?s share of world gold production has dwindled, and the gold mining industry has lost its dominance. Unlike gold, platinum has widespread use as an industrial commodity. Its investment value is a minor portion of its total value. It is therefore subject to different market forces. The sheer magnitude of the industry in South Africa obscures the fact that it is a wasting industry, and that South Africa exports almost all its production as a refined metal in the form of autocatalyst. Since Hotelling published his seminal work The economics of non-renewable resource in 1931,the science of mineral economics has developed exponentially. The paper will present a background of mineral economic theory and compare to this the development of the South African platinum industry. Of particular concern to a mineral exporting country is the question of mineral rent?its definition and employment. This will be the mail theme of the paper.

Jan 1, 2006

Jan 1, 1981

By R. R. Maclachlan

The Estimation of Fragmentation in Blast Muckpiles by Means of Standard Photographs, by H. van Aswegen and C.V.B. Cunningham. Journal of the South African Institute of Mining and Metallurgy, vol.86,no. 12. pp. 469-474. Dec.1986.We have recently read the above paper and wish to make a number of observations.

Jan 1, 1988

A. Sutherland Brown (ed.). Porphyry deposits of the Canadian Cordillera. The Canadian Institute of Mining and Metallurgy, Special Volume 17, 1976. C. G. Down and J. Stocks. Environmental impact of mining. G. B. Rothenberg. Refractory minerals. Park Ridge (V.S.A.), Noyes Data Corporation, 1976. Geology, mining and extractive processing of uranium. London, Institution of Mining and Metallurgy, 1977.

Jan 1, 1978

Dr c. J. Fauconnier, Pr. Eng., has a D. Eng. from the University of Pretoria, an M.RA. from the University of Oregon, and an M.Sc. (Eng.) and B.8c. (Min. Eng.) from the University of Pretoria. Dr B. K. Loveday obtained a degree in Chemical Engineering at the University of Natal, where he also obtained a Ph.D. in the kinetics of froth flotation.

Jan 1, 1983

By N. Gibson

The application of oxygen in a copper smelter by N. GIBSON* (Visitor) This paper describes how the problem of increasing the capacity of the Rokana copper smelter was handled, and how oxygen was found to be technically and economically the best solution. The first phase of its implementation is outlined.

Jan 3, 1974

By G. P. L. van der Linde

EVERY OREBODY IS UNIQUE [ ] GEOLOGY AND MINERALIZATION DIFFERENT [ ]

Jan 1, 2005

By H. J. de Klerk

The metallurgical phenomena in the design and manufacture of high-strength low-alloy (HSLA) steels are reviewed, and some aspects of the production of Supraform TM (thermo-mechanically processed) steel are discussed. . The weldability of Supraform TM is related to changes in the microstructure of its heat-affected zone.

Jan 1, 1984

By M. H. Kirchner

Trackless mining at Thabazimbi Mine by M. H. KIRCHNER*. Pr. Eng.. B.Sc.. B.Sc. (Elec. Eng.}(Stellenbosch). Dip. Mining (Pta.) Certain aspects ?f the' methods used in the exploitation, by sub-level caving, of a wide, tabular, steeply dipping orebody are described, reference being made to the use of modern mechanized equipment. Statistics relating to production and labour, as well as some geological details, are given.

By D. O’Beirne

Union Corporation are experimenting with a high-pressure water jet to remove blasted rock from short panels. The advantages are that the jet provides a highly efficient, flexible, and mobile cleaning tool that eliminates much of the lashing. Cost estimates show it to compare favourably with the existing system, with potential savings of 30 cents per ton milled. Equipment and method trials are continuing with the ultimate objective of eliminating hand lashing entirely while retaining the flexibility of the present method of mining.

Jan 1, 1979

By C. J. Van Niekerk, D. R. Allen

The electrolytic extraction of zinc at the Zinc Corporation of South Africa Limited by C. J. VAN NIEKERK, B.Se. (Hons.)(Poteh.), M.Se. (Unisa)(Fellow) and D. R. ALLEN, A. Met. (Sheffield) (Member) This paper gives a brief account of some modifications that were made to the process of zinc electrowinning practised by the Zinc Corporation of South Africa Limited. Some changes in the materials of construction are also described.

Jan 2, 1977

By M. H. Kirchner

Trackless mining at Thabazimbi Mine by M. H. KIRCHNER. Pr. Eng.. B.Sc.. B.Sc. (Elec. Eng.)(Stellenbosch). Dip. Mining (Pta.) Certain aspects of the' methods used in the exploitation, by sub-level caving, of a wide, tabular, steeply dipping orebody are described, reference being made to the use of modern mechanized equipment. Statistics relating to production and labour, as well as some geological details, are given.

By B. P. Christos

The improved rate of stope-face advance at Buffelsfontein Gold Mining Company Limited by B. P. CHRISTOS (Associate) To achieve a higher rate of stope-face advance. it was necessary to examine al.1aspects of the stoping operation, to identify bottlenecks, and to eliminate them or reduce their effect. The cleaning cycle was fund to be the most significant bottleneck. and this problem was aggravated by long panel lengths. under-capacity winches In strike gullies. and excessively long strike scraping distances.

Jan 12, 1975

By J. E. Forbes

Oxygen enrichment of the converter air at Rustenburg Platinum Mines by J. E. FORBES (Associate Member)* An account is given of the adoption of oxygen enrichment to accelerate converting operations and so permit the handling of larger quantities of feed materials. In addition to achieving its object, the use of oxygen-enriched air (6 per cent oxygen by volume) results in an increase in the concentration of sulphur dioxide in the converter off-gas. The slags have the same composition as those produced without oxygen enrichment, and the operation of the converters is easily controlled.

Jan 1, 1977

By H. V. R. Von Rahden

The expertise of the industrial mineralogist has not always been sufficiently used in decision-making in the minerals industry in South Africa. The mineralogist can make a contribution at al stages of the exploration programme, from the time of discovery of a geological target area, through metallurgical testwork and pilot-plant studies, to the production of a saleable product. This indicates that the activities of the industrial mineralogist should be more closely integrated with those of the exploration geologist and the extraction metallurgist in order to provide management with a meaningful picture of the economic potential of an ore deposit.

Jan 1, 1997

Notices THE FEDERATION OF SOCIETIES OF PROFESSIONAL ENGINEERS The following letter has been received from the Secretaries of the above Federation. Ref. EHvdL/MM/27 13/11/1973 TO THE SECRETARIES OF ALL MEMBER AND AFFILIATE SOCIETIES Dear Sir/Madam, ENTRIES IN TELEPHONE DIRECTORIES PAPERS OF INTEREST The following recently published papers may be of interest to memo bers. DIE FEDERASIE VAN VERENIGINGS VIR PROFESSIONELE INGENIEURS Die volgende brief is van die Sekretarisse van die bogenoemde Federasie ontvang. verw. EHvdL/MM/27 13/11/1973 AAN DIE SEKRETARISSE VAN ALLE LlD- EN GEAFFILIEERDE VERENI GIN GS Geagte heer/dame,

Jan 1, 1974