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By J. C. David, G. Coetzer

The effect of varying aliphatic, olefinic, and aromatic groups in the N- and S-positions of dithiocarbamates was investigated in the selective and bulk flotation of a mixed copper-lead-zinc-iron ore. Selective and bulk flotation were found to be dependent on the type of functional group, as well as on the position of substitution.

Jan 1, 1989

By G. Coetzer, J. C. Davidtz

The substitution of functional groups in covalent trithiocarbonate collector molecules influences the selective and non-selective bonding of collector molecules to mineral surfaces, as well as flotation efficiency in a mixed sulphide ore. These effects were concluded to be related to the metal-sulphide solubility products and electron densities on the sulphur atoms in the collector

Jan 1, 1989

The 88th Annual General Meeting of The South African Institute of Mining and Metallurgy was held at Kelvin House, Johannesburg, on Wednesday, 14th August, 1985. Mr J.D. Austin (President) was in the chair and declared the meeting open at 16h00.

Jan 1, 1985

By G. E. Blight

Rates of erosion have been measured for the slopes and top surfaces of a number of gold-tailings dams in the Germiston-Johannesburg-Roodepoort area of the Transvaal. Preliminary results were given in an earlier paper. The present paper gives results for a four-year period of observation, and identifies the major factors affecting the rates of erosion from the surfaces of gold-tailings dams.

Jan 1, 1989

By J. H. Lazarus

The evolution of backfill-distribution systems for deep gold mines is examined. The status of current technology for the design of backfill-distribution systems is considered with reference to pipeline pressure gradients, pipeline wear rates, and slurry flow regimes. The effect of an increase in the relative density of the slurry on the performance of backfill-distribution systems is illustrated. Future trends regarding the design of backfill-distribution systems are discussed.

Jan 1, 1993

A back-propagation model, which is typical of the models used in the science of artificial neural networks, was applied to the prediction of gossans from the southeast area of Habei Province in China. A success rate of 100 per cent was achieved. The results show that the neural-network approach is good, and that it can be used effectively in the prediction of multi metallic deposits.

Jan 1, 1995

By S. Neilson, M. G. Demmer, K. McCarogher

The Phoenix Programme takes the Mining and Mineral Processing Industry into the Science Classroom In the early years of mining, methods were crude, simple, labour-intensive, and very slow. Human resourcefulness, however, created innovations (mechanization, and computerization), that resulted in faster development, greater tonnages of ore, more efficient separation, and a superior final product. This expansion occured an ever-increasing rate, and resulted in a booming mining industry and a growing economy.

Jan 1, 1989

By A. N. Brown

Professor D. G. Krige, of the Department of Mining Engineering of the University of the Witwatersrand, received the degree of Doctor of Engineering (honoris causa) from the University of Pretoria at the Autumn Graduation Ceremony in April 1981. He was honoured an outstanding engineer for his world-renowned pioneering work in the field of statistical methods of ore valuation, or geostatistics as it has become known. Metalliferous Ore Deposits A short course on the 'Evolution of Metalliferous Ore Deposits' will be held at Rhodes University, Grahamstown, from 8th to 13th February, 1982.

Jan 1, 1981

By H. Knorre, A. Griffiths, R. Higgins, S. Gos

Hydrogen peroxide is gaining acceptance as a reagent for the treatment of mining effluents containing cyanide. In this paper some of the chemical and environmental aspects of treatment with hydrogen peroxide are discussed, and one way of improving the economics of the process is described. This is known as selective detoxification, which involves the oxidation of the less stable (cyanide) complexes while not affecting the more stable complexes, which contribute very little to the concentration of free cyanide or to the toxicity of the treated water.

Jan 1, 1987

By Richard J. Robbins

Raise and shaft drilling, a continuing development RICHARD J. ROBBINS* (Visitor) Although the past decade has witnessed many improvements in large-diameter drilling machinery for the boring of raises, there is still room for improvement both in operational use and in the design of equipment. Some of the available machines are described and illustrated, and it is concluded that the possibilities of new systems and designs should continually be re-assessed since the factors that determine their feasibility, such as bore diameter, cutter costs, and penetration rates, are changing rapidly.

By B. R. Broekman, J. P. W. Bennie, P. D. K. Robinson, R. P. Viljoen

The theme of the Congress was 'Resources and Technology', the intention being to highlight those basic technical aspects in the disciplines of geology, mining, extractive metallurgy, and metals technology that are required for successful mineral-based operations. The technical programme covered a fairly broad field, as is appropriate for the CMMI Congress, and was generally considered to be of a high professional standard; informative and, with the exception of some minor hitches, well-run. Parallel sessions were held in the four disciplines. All were well attended, and despite tight presentation schedules, certain valuable discussions developed.

Jan 1, 1994

By P. C. Schutte, N. B. Strydom, A. J. Kielblock

Three groups of unacclimatized men were subjected to five-day climatic-room procedures at wet-bulb temperatures of 29,30, and 31 C respectively. The findings indicated that individuals reach a satisfactory level of heat acclimatization for work in environmental temperature conforming to those at which they were acclimatized. It is, therefore, superfluous to acclimatize men at wet-bulb temperatures that exceed those at which they are destined to work. These methods of acclimatization can be linked advantageously to heat-tolerance testing at mines with suitable underground temperatures.

Jan 1, 1983

A new branch of the Institute-the Zululand Branch- was formed at the end of last year. After many months of preparation and perusal of address lists, it was realized that branch serving our members north of the Tugela was long overdue. A small steering committee consisting of Messrs John Selby, Dawid de Wet Smith, and Bill Kluckow got the branch of to a roaring start. They organized the inaugural meeting, which was held at the Richards Hotel in Richards Bay on 28th October,1993. Out of a possible 70 members residing in a 100 km radius, over half attended that first meeting!

Jan 1, 1994

By G. L. Smith

[Research and development conducted by CSR.-Mining Technology in the areas of active continuous miner based coal dust/methane explosion suppression systems, passive 'bag based, atone dust barriers systems, din and positioning of refuge bays, integrated escape and rescue strategies, and neural network based coal dust/methane explosion risk assessment is briefly described. It is concluded that effective catastrophic risk management of coal dust/methane explosions is dependent on an integrated, systems approach drat encompasses fundamental understanding of hazard sources, qualitative and quantitative probability of occurrence, magnitude of consequences and efficacy of control and recovery measures.]

Jan 1, 1999

By C. T. Connor, O&apos

The 10th Annual UCT -US Minerals Processing Symposium was held at the Van Riebeeck Hotel at Gordon's Bay from 31 July to 2 August 1991. The conference was attended by 133 delegates representing a broad cross-section of the mining and metallurgical industry in South Africa. For the first time the Symposium, which was celebrating its 10th anniversary, was extended to two days. A cal for papers was announced and the organizers were inundated with responses resulting in a very full technical programme which consisted of 29 oral and 15 poster presentations.

Jan 1, 1991

By I. E. Lane

Conventional demand management techniques invariably fail to offer optimum control flexibility in an operationally complex gold mining environment. An improved control system for electrical demand management is proposed. The system is designed to provide more effective load scheduling and control strategies by means of a computer aided demand management system (CADMS). The objective of the CADMS is to provide a responsive computational aid and adaptive control system for effective demand management. The system consists of a short term load forecasting module, an interactive load scheduling module, an incentive based electricity cost allocation module and a power management information module.

Jan 1, 1987

By N. von Stade, G. du Plessis, W. van Niekerk, H. Bosman

Exploration, and other, boreholes are drilled to obtain information about the geological environment. Knowledge of the exact position (dip and direction) of the holes is important to ensure compatibility between the hole and the geological information. Kumba Resources traditionally used mechanical methods to determine the hole characteristics. These are cumbersome and expensive, and as a consequence a new method, the IVEC (Iscor Video Exploration Camera), was developed which utilizes a charged coupled device (CCD) image sensor focused on a three-dimensional compass. This system is rugged, relatively inexpensive and gives real-time results during borehole logging. Keyword: Borehole inclination, deviation, dip and direction, geophysics, exploration.

Sep 1, 2001

By C. T. Connor, O&apos

The fifth University of Cape Town (UC1)/University of Stelenbosch (US) Minerals Processing Symposium was held at the Faculty of Engineering, University of Stelenbosch on Friday, 8th August, 1986. This series was initiated in 1982, the symposia being held alternately in Cape Town and Stelenbosch. The South African Institute of Mining and Metallurgy has kindly agreed to sponsor this event for the next three years. Cokemaking On the initiative of the European Cokemaking Commitee, the First International Cokemaking Congress will be held in Essen (F.R. Germany) from 13th to 19th September, 1987. It is being organized by the Steinkohlenbergbauverein, together with the Verein Deutscher Eisenhitenleute.

Jan 1, 1986

By D. R. Hardman

Coal mining has been practised in South Africa for over one hundred years. The total production increased gradually in the early pat of the twentieth century, but over the past twenty years the rate of growth has been considerable. Although opencast mining has contributed largely to this increase in production in recent years, underground bordand- pillar operations still contribute slightly less than 50 per cent of the total production. The paper highlights problems arising from old bord-and-pillar workings, and an indication is given of how some of the problems have been addressed.

Jan 1, 1990

By D. A. Fenton

The structural design of large grinding mills, with reference to shell-mounted bearings by D. A. FENTON*, P. Eng. (Visitor) The paper outlines the advantages of shell-mounted grinding mills over mills having a conventional trunnionsupported shell. The growing use of larger mills in the past decade has led to a significant number of mechanical and structural failures, the most common being those at the junction of the head and the shell. Larger mill diameters favour the use of shell-mounted bearings. The elimination of castings, which have an inherent weakness to fracture, makes the shell-supported mill lighter and stronger than a conventional mill of the same shell thickness.

Jan 9, 1976