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By O. K. H. Sheff

Despite many years of a successful policy for our Journal, the Journal Committee is in the course of adopting a new approach with which to enter the present decade. The objectives are to improve the readability of the Journal, without forfeiting the quality achieved in the past, by adding an extra dimension through the inclusion of applied-engineering papers, i.e. technically oriented papers.

Jan 1, 1990

By T. B. S. Giddy

The advantages to be gained from the use of a high-density ion-exchange resin in a uranium recovery circuit are shown. It is concluded that, in existing fluidized-bed plants, the throughput of solution can be increased by up to 40 per cent at the same uranium recovery. Alternatively, the values in the barren solution can be improved at the same flow-rate of solution.

Jan 1, 1980

By M. Splaine, M. A. Field, S. J. Browner

In the field of operational control, Shewhart Control Charts and Cusum Charts have long been available to management. These techniques provide help by detecting rogue values of a control variable and changes in the underlying mean of that variable respectively. This paper describes a new technique for identifying changes in the trend of a control variable, particularly when that variable is subject to large inherent variance.

Jan 1, 1983

By R. J. Dippenaar

In his inaugural lecture (delivered in Afrikaans at the University of Pretoria on 16th February, 1995), Professor Dippenaar defends his doctrine, philosophy, objectives, and methodology, as was required of a newly appointed professor in the days of old. Briefly, he recounts the growth and achievements of the Department of Material Science and Metallurgical Engineering at the University of Pretoria; he sketches its strategic guidelines and the obstacles encountered; he outlines the opportunities for the metallurgical industry in South Africa and the need for environmental control; and he describes how modeling techniques, together with expert systems, can aid both the industry and the community. He ends on an optimistic note, saying that his Department will continue to strive to transform adversities into opportunities, and to give its students a view of new horizons beyond the foundations laid by their teachers.

Jan 1, 1996

By R. S. Sarracino, M. J. Louw, S. M. Vather

Two detonation models, IDeX for ideal VOD and CPeX for non-ideal VOD, were used to predict the velocities of detonation (VOD) of five explosives: ANFO, a bulk emulsion, and three repumpable emulsions (R100 Gold, R100 Diamond, and R105). The theoretical VODs were compared with the in-hole VODs of the explosives, and the predicted and actual values were found to be within experimental error for ANFO and the bulk emulsion. The results were not consistent for the repumpable emulsions. The discrepancies can be explained as being due to variations in mining and loading practices. The results show that the detonation models can be effective tools in predicting the behaviour of explosives in different diameters and rock confinements, provided that the user is aware of the factors that can affect the optimal usage of explosives and equipment.

Jan 1, 1993

By S. Nana, M. B. Cortie

Duplex stainless steels containing high levels of manganese and copper and lower-than-normal levels of nickel were produced and evaluated. The experimental alloys containing 3 per cent copper by mass could not be successfully hot-rolled. Alloys containing less than 2 per cent copper could be hot- and cold-rolled without difficulty. The wrought experimental alloys that contained copper were found to offer some advantages over the 2205- type duplex stainless steel in sulphuric acid at 52°C. Resistance to pitting attack was governed primarily by the chromium, molybdenum, and nitrogen contents, and one of the experimental alloys was superior to the 2205-type alloy in the ferric chloride test. It is concluded that manganese is a useful substitute for nickel in duplex alloys, but that further work is required before the present alloys, or variations of them, could be commercially viable.

Jan 1, 1993

A description is given of a simple, cheap device that enables the intact shear strength of rock to be determined quickly and inexpensively. Thin rock plates, prepared with a diamond saw, are tested in double shear by a linear punching action. By varying the direction of the diamond-saw cut in a number of specimens, the change in shear strength can be measured for different orientations relative to the rock fabric.

Jan 1, 1980

By G. T. van Rooyen

Materials for Winding Plant Components By Prof. G. T. van Rooyen (ScD) (MIT). Materials for critical applications such as winding plant components are reviewed in terms of the basic requirements which have to be complied with. It is shown that tensile testing alone is not sufficient and that impact testing also is necessary if the incidence of brittle fracture is to be avoided. As a criterion it is suggested that the brittle transition temperature (B.T.T.) determined by impact testing should in all cases be well below the lowest anticipated service temperature. A number of steels were evaluated by impact testing and it is shown that a small ferrite grain size, obtained either by chemical means such as by the use of appropriate alloying elements in the steel or by means of a quenching heat treatment, is effective in attaining a Iow B.T.T. The speed of strain aging as well as the influence of strain aging on the B.T.T. was also evaluated. On the basis of the results obtained it is recommended that steels for critical applications must conform to an appropriate grade and class of steel according to BS 4360 specification. It is further recommended that such steels be exempted from the customary six-monthly heat treatment prescribed by the Mines and Work Act, Regulation 16,18.

By W. J. Murray

Tests were conducted during the middle of this year to evaluate techniques and the equipment used in a novel continuous mining system for use in narrow reef tabular orebodies. Equipment was designed and supplied to test a mechanized drilling rig, a selection of rock breaking techniques and an integrated rock removal system, mounted on a self-advancing reciprocating flight conveyer. As the rock breaking techniques do not depend on the use of large quantities of conventional explosive the systems and equipment employed here have the potential to run continuously for 24hours per day. Whilst the tests carried out use simple prototype equipment employing established technologies, the long-term objective remains the use of sophisticated machinery capable of running continuously and un-manned, only interrupted by brief service intervals. Keywords: Hydro-fracturing, Rock breaking, Low energy, Propellant, Non-explosive, Safety, Continuous mining, Rocksplitter, Boulder buster, Ro-bust.

Sep 1, 2001

By J. J. Geldenhuys

The Institute revived a valuable tradition when, on the 19th of March, 1983, it held its first 'annual' banquet in some fifteen years. It was such a sparkling success that it is sure to be held more frequently in future. The success of the occasion was borne out by the fact that the main banqueting hall at the Wanderers Club was filled to capacity, with over four hundred members and guests.

Jan 1, 1983

H. W. Glen (ed.). Proceedings of Asbestos Symposium, Johannesburg, South, Africa, 3rd-7th, October, 1977. Randburg, National Institute for Metallurgy, 1978. 158 pp. (Copies obtainable from the Department of Mines, P.O. Box 4584, Johannesburg, 2000 South Africa.) This Symposium, which concentrated on the theme of dose-response relationships for asbestos-related diseases, was attended by an internationally representative group of experts in this field. Bulk solids The Powder Advisory Centre announces its third annual International Conference on Bulk Solids Swrage, Handling and Flow, to be held at the Holiday Inn, Liverpool, on 7th to 9th November, 1978. This sequel to the extremely successful November '76 Stratford and November '77 Nottingham Conferences is again to be co-sponsored by a number of internationally acknowledged professional societies, including the Institute of Materials Handling (through its Bulk Solids Panel), the Institution of Production Engineers, and the American Society of Mechanical Engineers (through its Materials Handling Engineering Division). NIM reports Report no. 1943 A review of the literature on the separation and determination of rare-earth elements. (23rd Mar., 1978.) Report no. 1947 The cation- and anion-exchange behaviour of various base-metal chlorides in polar organic solvents. (lOth Mar., 1978.) Report no. 1948 The measurement of trace amounts of gold in solution by atomic-absorption spectrophotometry and carbon-rod atomization. (28th Feb., 1978.) Report no. 1949 The kinetics of the leaching of zinc sulphide concentrates in acidic solutions containing ferric sulphate. (23rd Mar., 1978.) Report no. 1950 Factors affecting the carbon contents of alloys formed during the prereduction of chromite ores. (31st Mar., 1978.) Report no. 1952 The effect of slag composition on copper losses to silicasaturated iron silicate slags. (31st Mar., 1978.) Report no. 1953 A fundamental investigation into the depression of copper-activated sphalerite. (28th Apr., 1978.) Report no. 1956 An improved ion-exchange separation of rare-earth elements for spectrographic analysis. (10th Mar., 1978.) Report no. 1960 The recovery of ferrochromium from furnace slags and related products. (20th Aug., 1976; declassified 31st Mar., 1978.) Process instrumentation The National Institute for Metallurgy and the South African Institute of Measurement and Control are organizing a symposium that will draw the attention of researchers and industrial workers to the importance of metallurgical process instrumentation.

Jan 1, 1978

By F. S. A. de Frey, F. C. Kruger

Personnel management has undergone a remarkable change over the course of the past ten years. Personnel departments have played an increasingly important role, which today requires highly trained people and cannot be adequately served by the lesser qualified officials of yesteryear. Changes in the mining industry that stem from the demand for skilled labour to keep pace with technological developments and the mechanization of mines today demand that emphasis should be placed on the maximum utilization of manpower. Maximum utilization of manpower calls for more scientific and effective methods of recruiting, selecting, training, and placing workers so as to offer them the best opportunities for development and promotion, which naturally ensure a minimum labour turnover and eliminate labour unrest. This can be achieved only if well-qualified and properly trained personnel administrators are prepared to accept the challenge and apply themselves purposefully by assisting line mangement with the attainment of the company's corporate objectives.

Jan 1, 1982

By N. B. Strydom

Die bedryfsfisioloog en lugbesoedeling N. B. STRYDOM, Ph.D. (Phys.) (Illinois) (Genoot) Although the industrial physiologist can still be regarded as a rarity in South African industry, it is obvious that he could make a positive contribution to the control of air pollution. For the past twenty-two years, the gold-mining industry has invoked the aid of industrial physiologists in solving various problems that continually crop up in the more effective and safer utilization of man-power. Air pollution is only one facet that has received attention. It can be stated emphatically that other industries could gain many advantages from the employment of this type of specialist. Because of inadequate opportunities for academic training, however, the industrial physiologists available might not be enough to fill all the possible posts in industry at present, but confidence is expressed that interested persons will soon be able to follow a full university course in this field of study.

As a token of their gratitude, former pupils of Professor Lucien Denoel, a lecturer on coal-mining in the University of Liege, over a period of forty years, have founded the LUCIEN DENOEL prize. It is awarded, regardless of nationality and diplomas, to the author of a thesis dealing with coal-mining, ventilation, mine-draining methods, the use of explosives in the mine or coal-preparation. The thesis must show a truly scientific approach and considerable originality, and must not have been dealt with in a previous publication. The prize is 60.000 Belgian francs. The articles must be written in French, Dutch, German or English, and contain not more than 10,000 words, figures included. They must be forwarded, in triplicate, to the 'Jury du Prix Lucien DENOEL, c/o A.I.Lg., 22, rue Forgeur, Liege, Belgium,' before 1st July, 1970. The examining board reserves the right to publish the winning thesis in a Belgian magazine.

Prediction of the performance of explosives In bench mining by C. M. LOWNDS, B.Se. Hons (Rhodes), Ph.D (Cape) (Visitor) Some of the problems encountered in the calculation of the relative weight strength of explosives are discussed, and a realistic model of the behaviour of explosion products in a borehole is proposed. The heat flow from condensed to gaseous products is calculated as a function of time, and the relationship between the pressure and the volume of the product gases is found by a consideration of the compression of the rock between radial cracks. Work done on the burden is assumed to cease when the cracks first appear at the face. Reasonable values of burden and crack velocities are obtained from the model. Calculations of the relative weight strengths of aluminized mixtures of ammonium nitrate and fuel oil show that the increased density resulting from the addition of aluminium is the main advantage to be gained.

Jan 2, 1975

W. C. J. van Rensburg and D. A. Pretorius (H. Glen ed.). South Africa's strategic minerals - pieces on a continental chessboard. Johannesburg, Valiant Publishers, 1977. 170 pp. RI2,00. (Obtainable from The Librarian, Foreign Affairs Association, P.O. Box 26410, Arcadia, 0007 South Africa.) This book provides the answers to many questions relating to what minerals South Africa produces and in what quantities, what mineral industries and trade she practises, and what mineral resources and reserves she possesses.

Jan 1, 1978

NOTICES The Institution of Mining and Metallurgy The Institution is to hold a one day meeting entitled "Sampling in the mineral and metallurgical processing industries" at Imperial College, London, on 2nd July, 1973. International Conference on Air Pollution This Conference is organised by the Department of Health and the National Association for clean air. Consas 74 The Fifth Conference of Southern African Surveyorswill be held in Salisbury, Rhodesia, from 3rd to 9th February, 1974.

By P. Greenfield

The German steelmaking industry has come up with a novel solution to the problem of waste plastics-grind them into particles and use them in the steelmaking process. Plastics make ideal agents for removing oxygen from iron ore in blast furnaces, and save on oil and coal as well. The aim of replacing heavy oil and coal with plastics in blast furnaces is to use them as reducing agents as well as an additional energy source.

Jan 1, 1996

By E. O. M. Hanisch

Copper working in the Messina district E. O. M. HANISCH. B.A. (Pretoria) (Visitor) By reference to the available literature, an account is given of the manufacture of metal ingots by the Messina copper workers. These workers are thought to have been Balemba tribesmen, of the Musina Clan, who came from across the lebombo Mountains. A description is given of their methods of mining, smelting, and casting, and of the vlrious types of ingots they produced.

Jan 1, 1974

By M. A. von Below

Environmental activists have targeted the mining industry in an attempt to prevent development, which has resulted in the industry's becoming defensive and retro-active. This paper argues that mining managements should go on the offensive and champion the environment through leadership in environmental policy and research and development, rather than reacting to anti-mining campaigns. In the formulation of an environmental policy for the mining industry, a clear understanding of the concept of sustainable development is of paramount importance.

Jan 1, 1993