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For many of us, formal academic education slows abruptly when we leave a tertiary institute of learning. We start applying and connecting newly acquired knowledge with the practicalities of a career, and begin to think in a manner that is technology-oriented. Subsequent vocational advancement is offered by the .many mining and professional journals that circulate through departments, and by conferences and schools that are organized in-house and via the SAIMM and other professional institutions. The importance of these schools cannot be overstated: they combine people and developing technology to the benefit of the industry as a whole.

Jan 1, 1992

By O. K. H. Steen

Significant political and economic changes have taken place in our society in the past year that are going to impact on our minerals industry, and therefore also on our members. Surely, it is not coincidence that the economic and political changes have occured simultaneously? South Africa, by virtue of its infrastructure and technology, is strategically placed to develop the potential of Africa's mineral wealth. In this address, I give my personal views on the ability of the mining industry to participate in the wider mineral resources of the African continent.

Jan 1, 1989

By L. Woollacott, R. P. King

Although several models for the carbon-in-pulp (CIP) or carbon-in-leach (CIL) processes have been published, most of these models do not consider in detail the way in which the carbon phase flows on large-scale plants. This paper illustrates the importance of these details if the CIP or CIL process is to be modeled correctly. An appropriate model, based on population-balance techniques, is then derived. Suitable mathematical techniques for the solution of the model equations are also described. Finally, a method for estimating the model parameters for a full-scale plant is described.

Jan 1, 1990

By Peter Smith

The construction of one of the world's largest goldrecovery plants to treat run-of-mine ore is progressing on schedule at the President Brand Gold Mine in the Orange Free State. Designed to treat 390 kt per month, the plant will recover 96 per cent of the gold from the ore at a capital cost of 160 million rands in terms of January 1983 money. It will replace the existing gold-treatment installation, as well as provide a 30 per cent increase in capacity. Mintek reports Report M161 Improved recoveries of gold from auriferous calcines and pyrites by fine milling. Report M171 The development of a versatile computer programme for the evaluation of batchflotation results. Report M178 The reduction of chromite in a transferred-arc plasma furnace. Report M179 Optimization of an inductively coupled plasma by the simplex method.

Jan 1, 1985

By E. H. R. Schümann, H. Wagner

SYNOPSIS The paper gives a detailed overview of the history of subsidence engineering on South African collieries. Surface displacements resulting from total-seam extraction are discussed, and the important role of local geology is highlighted. It is shown that the differences in subsidence behaviour between South African and European collieries can be attributed to the presence of competent strata in the overburden of South African coal seams. Criteria are given for the prediction of the most important subsidence parameters, and a new model for the simulation of surface subsidence above total-extraction panels is introduced. The final section of the paper deals with the damage to surface structures caused by total-seam extraction. A brief summary of the most important undermining experiments on South African collieries is given, and it is concluded that local experiences of damage compare with those in Europe.

Jan 1, 1991

By A. Chryss, L. Pullum

Shear-thickening suspensions abound throughout the hydraulic conveying industry; at least this is the perception of many engineers running plants where hydraulic conveying is commonplace. In reality, shear thickening behaviour is limited, in the main, to high concentrations of fine particles, including colloidal and biological suspensions, at moderate to high shear rates. In the authors? experience most cases of shear-thickening behaviour have been either simple ?coarse? particle interactions, poor instrumentation techniques, or both. In some cases these were obviously heterogeneous flows, while in others flows that were homogenous, or were thought to be homogenous. Examples, which illustrate this erroneous perception are given. However, the trend towards pastes and complex suspensions that use high concentration carrier fluids means that the underlying slurries for many of these flows may now be truly shear-thickening. Unfortunately, suspensions that might exhibit shear thickening also invariably exhibit slip, or wall-particle depletion. These separate phenomena are difficult to resolve experimentally and many observations of apparent shear-thickening behaviour are in fact obscured or convoluted by slip effects. A method is presented whereby the true flow properties of these high concentration suspensions, and hence accurate prediction of pipeline flows, can be made using a parallel plate rheometer.

Jan 1, 2007

Project evaluation is completed through individual studies covering technical and financial aspects of the mine to market. These studies are completed at various levels of detail depending on where the project evaluation is in the project's life cycle. The competency of the studies varies in relation to the quality of data, level of the skills employed, control, management and reporting structure. The focus of this paper is managing elements of the study, looking at the cost of opportunity to influence the project, against the value added. Selection of the study manager and study teams is central to getting an integrated project evaluation addressing the correct issues completed on time. Retention of key personnel can reduce rework which, in turn, can reduce time and cost impacts. It is important to have a work breakdown structure at the outset so that the study teams have a common numbering and naming system that will integrate areas, equipment, budgets estimates and accounts. Having set up the evaluation groups and provided training in the study procedures, understanding the scope and schedule are vital elements in producing a project evaluation that addresses the opportunities and the risks of the final project. Arriving at an accurate capital budget requires integration of the research controlled through common systems. Project evaluation process must also address how the project is to be delivered.

Jan 1, 2007

The established shared laboratory facilities between the Departments of Metallurgy and Chemical Engineering of the Vaal Triangle Technikon and the University of Potchefstroom are already proving to be a great success.

Jan 1, 1992

By L. B. McRae

The following papers were presented at a seminar that was organized by the SAIMM and held at Mintek during 1991. The occasion was a visit by 12 members of the Committee for Metallurgical Fundamentals of the Verein Deutscher Eisenhitenleute.

Jan 1, 1991

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 R. F. Botha

I want to thank you for inviting me to deliver this, the closing address at the final plenary session of the 15th Congress of the Council of Mining and Metalurgical Institutions. Your Council has an impressive title, and justly so. Consider the expertise, the skill, the capacity, the achievement, that is gathered together here in this room this afternoon.

Jan 1, 1994

By J. L. Taylor

The belt-filtration plant at Chemwes Limited has been in operation for three years. The plant design is discussed. Operational and engineering problem areas are reported, and where possible the modifications or practices that led to their solution are mentioned. Capital and operating costs, together with selected general operating data, are also included.

Jan 1, 1983

By N. Boegman

The meteorological conditions in South Africa are not conducive to the effective dispersion of air pollutants. In the light of this, and because of the magnitude, concentration, and future growth potential of the metallurgical industry, control of air pollution is essential. Methods of abatement are discussed for each branch of the metallurgical Industry, as well as for open-cast mining and bulk ore storage. Some recommendations are made regarding potentially rewarding research and development.

Jan 1, 1978

By W. J. Whiten

Models of cone crushers and vibrating screens are described. These models have been constructed from actual plant data using a systematic model-building technique. Included in this technique is regression analysis using multi-dimensional spline functions. The models have been used too simulate complete crushing plants and hence to design and evaluate a control system for crushing plants.

Papers and Contributions Since the Institute's inception, it had been our practice until some years ago to meet regularly for discussion of new developments, using as a basis a paper read by one of the members. Usually, the Journal issue containing the paper would have been circulated well before the meeting, giving members plenty of time to absorb it and perhaps to prepare contributions. Discussion was generally lively, often controversial. The author always had an opportunity to reply.

Jan 1, 1991

By A. A. Oakes, P. M. C. Wilson

This paper describes some aspects of the planning of a new colliery which commenced production in the Middleburg district in 1966. An account is given of some of the problems encountered in the early years of operation and of what was done to solve them. The conclusion is reached that design of plant and machinery should be flexible to permit multiplication of units.

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

By J. N. Van der Merwe

The South African coal-mining industry uses a uniform safety-factor formula for non-squat pillars, incorporating a coal-strength constant that was derived empirically by Salamon and Munro in the 1960s. The constant is 7,2 MPa. Since that time, collapses of pillars at relatively high safety factors have occurred in the Vaal Basin. Analysis of the post-1960s' collapses indicated that the strength constant for the Vaal Basin is 4,5 MPa. A crude method for the prediction of the minimum life span of pillars in the Vaal Basin is presented.

Jan 1, 1993

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 G. W. Donaldson

Theoretical and engineering aspects of slimes-dam construction by G. W. DONALDSON, M.Sc. (Eng.)(U.C.T.), D.I.C. (Visitor) Tile paper reviews the recommendations made in 1959-60 as a result of research into slimes-dam construction and finds that these recommendations are still valid. The requirements for pollution control, vegetating, in situ leaching, and future development of slimes dams as building areas are considered as they affect the engineering aspects of slimes-dam construction, and it is found that these requirements can be met without any major changes to current recommended slimes-dam construction practice.

Jan 12, 1973