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By G. J. McDougall

After defining activated carbon, the author describes its structure and outlines the physical characteristics distinguishing one type of activated carbon from another. The adsorptive properties of these carbons, the raw materials used, and the manufacturing processes-chemical activation, and physical or thermal activation-are outlined. The high-temperature thermal route (which is the most important for the products employed in gold recovery) using coconut shells or coal as the raw material is then discussed In some detail.

Jan 1, 1991

By J. P. Hugo

Nuclear energy - its interactions with mining and metallurgy - PRESIDENTIAL ADDRESS given by J. P. Hugo Pr. Eng., B.Sc (Eng.) (Rand), Ph.D. (Sheffield) Energy is the life blood of the modern technological era in which we live and it was, I think, Benjamin Franklin who said that the manipulation of energy was the basis of all science and technology. This is perhaps an oversimplification, but there can be little doubt that our life today, and the improved standard of living we aspire to, are governed almost entirely by our ability to generate and manipulate energy. This ability has made it possible for Man - each specimen a feeble twentieth of a horsepower - to travel to the moon, to recover valuable minerals from the depths of the earth, to do arithmetic at unbelievable speed, to lessen the drudgery of manual labour. For these and virtually every aspect of our life we are dependent on energy from external sources. It is, therefore, not surprising that the per capita consumption of energy, and more particularly electricity, has become one of the most reliable criteria by which to measure the standard of living and technological advancement of a country.

By M. H. Marsden, R. A. Laybourne, J. D. Flint

Operations of the strip mine at Arnot Colliery are described, and the improved volumetric extraction of the in situ coal reserves that has been obtained by the application of strip-mining techniques is highlighted. An account is given of the major problems encountered during the early stages of the operation with particular reference to overburden removal. coal and parting handling, and transportation. The techniques used in dealing with the problems and the current degree of success in overcoming them are outlined.

Jan 1, 1980

By J. A. Tyser

The pumping of water from mines in the Central Witwatersrand by J. A. TYSER, Pr. Eng., B.Sc. (Min.) (Associate) This paper describes a system for the removal of underground water in the mines of the Central Witwatersrand, some of which are defunct. The water is pumped by a pump station on 24 level at E.R.P.M. to a surface lime plant and then to a surface treatment plant, where it is treated so that it meets the specification of the Department of Water Affairs relating to the deposition of water in public streams.

Jan 5, 1977

By H. L. Monro

CONTRIBUTION BY J. R. F. HANDLEY Mr Monro is to be congratulated on his concise treatment of a very complex subject. As a graduate with only Mathematics I in my curriculum, I am unable to comment on the mathematical treatment of the factors affecting his supply/demand model, but the logic does not escape me. The main conclusion is that any excess of supply to the spot gold market will depress the price in a normal market, and particularly in a falling market.

Jan 1, 1993

By A. C. Lawrence, B. Econ, D. Com

The importance of human factors in mining productivity by A. C. Lawrence, D. Corn., B. Econ. (Member) The paper outlines some of the views on the relationship between work attitudes and performance, and examines evidence derived from relevant research done in the mining industry. It is suggested that higher productivity within any given system of mining can be attained if attention is paid to the four factors that represent the CORE of human work performance: Competence, Opportunity (or Organisation), Recognition (or Rewards), and Expectations (or Enrichment).

Jan 7, 1974

On Friday, 18th April, 1986, Stefen Kenneth de Kok passed away peacefully at his home in Johannesburg after a short illness. New President of FSPE Mr R.G. (Bob) St Leger took office as President of The Federation of Societies of Professional Engineers on 1st July, 1986.

Jan 1, 1986

By C. van Loggerenberg, P. E. Venter

The paper covers a wide range of modifications that are of potential interest to the practical coal-preparation engineer. Unfortunately, the paucity of performance data does not permit one to draw conclusions. The authors do not appear to have a clear understanding of the Tramp (or partition) curve concept.

Jan 1, 1992

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 R. D. Hancock

The loading and selective properties of a number of commercial and experimental resins developed for the extraction of base metals were evaluated. Particular applications that ",:ere considered included the extraction of copper from artificial dump liquors, the treatment of Iow-grade copper, nickel, and cobalt liquors, and the removal of nickel from a cobalt electrolyte. Reagents that showed promise were two experimental resins developed at Mintek containing pyridyl imidazole active groups and two Dow resins, XF4195 and XF4196.

Jan 1, 1982

By J. W. de Kock

The estimation of some properties of South African coals from proximate analyses by J. W. de KOCK, Pr. Eng., Ph.D. (Chem. Eng.) Cantab. (Fellow) and J-P. FRANZIDIS, B.Sc. (Chem. Eng.) (Visitor) Correlations have been obtained whereby calorific values, ultimate analyses, and Hardgrove Indices can be estimated from proximate analyses of South African coals. This has been done by the application of stepwise multiple linear-regression analyses of a mass of data published by the Fuel Research Institute.

The First International Symposium on Seismicity in Mines, organized by the South African National Group on Rock Mechanics in collaboration with the South African Institute of Mining and Metallurgy, was held in Randburg (near Johannesburg) from 13th to 17th September, 1982. It was the first attempt to provide an international forum for the consideration of seismic problems specifically affecting mines or associated with mining. Numerical mathematics The South African Society for Numerical Mathematics and the Computer Science Department of the University of Natal are organizing the Ninth Symposium on Numerical Mathematics to be held in Durban from 18th to 20th July, 1983.

Jan 1, 1983

By D. J. Adams, R. G. Gürtunca

This paper describes the results obtained from a rock-engineering monitoring programme carried out at West Driefontein gold mine, where dewatered and classified tailings have been used as backfils for local and regional support. The in situ behaviour of these backfils and the surounding rockmass were determined, and it was found that the backfil used on this mine has provided significant regional support. The underground observations also showed less rockburst damage in backfiled panels than in unfiled panels, provided the backfil had been placed properly in the stopes.

Jan 1, 1991

By Johanna van Deventer, Sean Scott, Rene du Preez, Steven R. Izatt

In order to meet the stringent specifications associated with the production of LME Grade A cobalt cathode, producers need to ensure that a number of impurities, including Cd, are removed from the advance electrolyte to ppb levels (~0.1 mg/L). Conventional options include ion exchange using amino methyl phosphonic acid resin and solvent extraction using D2EHPA. More recently a Cd-selective resin, employing Molecular Recognition Technology (MRT), became available from IBC Technologies, Inc. These three potential unit operations were evaluated in parallel at Mintek. MRT was identified as the most technically feasible option. Results obtained on a cobalt advance electrolyte, containing 55 g/L Co, 6 mg/L Cd and 60 g/L Na2SO4, are presented in this paper.

Jan 1, 2007

By J. N. Baloyi

"In atomic emission and atomic absorption spectrophotometry, the sample is heated to a high temperature and thereby decomposed into atoms and ions that absorb or emit visible or ultraviolet electromagnetic radiation at energies characteristic of the elements involved. The flame test is a very simple form of this technique. The yellowing of a flame by the addition of salt, for example, occurs because the sodium in salt emits strongly in the yellow portion of the visible spectrum. These methods are especially useful for low concentrations of metallic elements in both qualitative and quantitative analysis.Interference on Iep-OES has not always been considered a serious problem, especially in the beginning, when compared with Atomic Absorption Spectroscopy. This was due to the euphoria created by the new technique. It meant that criticism was subdued. The Iep was vastly superior to the Atomic Absorption technique, that the interferences suffered by the Atomic Absorption technique dwarfed the little interferences suffered by the rep-OES technique. This is how rep-OES has had a reputation as an interference free technique."

Jan 1, 2014

By J. D. Flint

The geological conditions in the Vierfontein area ~re such that conventional pillar extraction ~stooping) cannot be practised safely or efficiently. Both the open-end lift and the pocket-and-fender methods of pillar extraction have been tried with little success because of problems with roof control and ground stability. The main reasons for the difficulties are the coarse-grained sandstone roof, local weaknesses in the coal seam, and the rate at which the pillars were extracted. The mine has practised bord-and-pillar mining since it started production in 1952, and considerable reserves of coal are contained in the pillars. As an alternative to total pillar extraction, in which hand-loading methods were practised, a system of partial pillar extraction using mechanized-mining methods ~11"modified goaf-line support has been evolved. These remnant coal pillars (snooks) remaining after partial extraction ofthe pillar, together with the installation of 1,2 m" matpacks and a double line of fullcolumn resin roofbolts, ensure control of the edge of the area that has been mined out (goaf). Where roof conditions preclude the use of conventional pillar-extraction methods, this method holds promise as a safe and efficient alternative for the recovery of coal from pillars and for an increase in the volumetric extraction of the reserves within a mining panel.

Jan 1, 1984

By K. A. G. Blendulf

The paper describes tests on horizontal-belt filters for the filtration of gold and uranium. The promising results led to the installation of 17 such filters (ten of them 120 m2 in size) in the mine's metallurgical plants, and their operation is discussed. Although several problems were encountered both in operation and maintenance, it is concluded that, with correct operation and suitable filter cloths, exceptionally good metallurgical recoveries can be achieved at filtration rates twice to three times higher than those on rotary filters.

Jan 1, 1997

By C. A. Hunt

The problem of materials balancing is reviewed with particular reference to the minerals industry. A broad statistical framework is established that, besides extending the classical estimation problem, allows questions concerning the value of sample information to be addressed. The following are examples of such questions: How much money should be spent on sampling? Which streams in a plant should be sampled? What should be sampled? The approach adopted makes use of Bayesian analysis. The discussion includes an illustrative example involving a simple flotation circuit.

Jan 1, 1985

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 G. J. Kringe

The results of a series of measurements of accelerations and guide-roller loads made on mineshaft conveyances are given, together with the predictions of these accelerations and loads based on a computer programme. The analysis of the measurements is described, and the results of the measurements and computer predictions when compared show reasonable agreement. Some parameters that increase the guide-roller loads are identified, and their effects are studied, together with some comments on the total loads. Finally, a possible format for a design specification is discussed, and some tentative design values are given.

Jan 1, 1986