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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 A. Morley

It is difficult to evaluate exploration properties in a manner that is transparent, repeatable and easily re-calculated to cater for different geological interpretations, but the risk-based assessment methodology, the Geological Risk Method, developed and described by Lord et al (2001) attempts to satisfy all these criteria. This paper examines a case study example based on valuations of exploration projects conducted by SRK Consulting using this methodology, and describes some of the advantages and limitations of the method.

Jan 1, 2007

By D. A. Viljoen

An account is given of the development of man's interest in the recovery and working of minerals from Palaeolithic times to the present. This is followed by a discussion of future production trends for the more important minerals, and of likely technological developments in the recovery of various minerals. The crucial importance of energy minerals is stressed, as are several other factors of significance to a flourishing minerals industry: manpower, education, financial climate, Industrial health and safety, and preservation of the environment.

Jan 1, 1979

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 J. D. Smit, K. C. Garner, P. C. van Aswegen

The initial results obtained from the implementation of computer-controlled strategy on the milling circuit are reported. An analysis of these results showed that a peak-power pebble-mill controller on a high throughput hardrock wet-milling circuit reduces the stability of the system. It was concluded that the milling circuit should be regarded as a single system in which the measurement of grinding efficiency, circulating load, product size distribution, and feed rate should minimize the product variance and maximize the feed rate according to the grinding power available. Work is proceeding on such a system.

Jan 1, 1980

By A. B. Holland-Batt

The application of Reichert spirals and cone concentrators within the South African mineral industry is discussed, and the procedures used in the acquisition of design data are outlined. Computing techniques developed by Mineral Deposits Limited for the processing of test data for use in the design of production circuits are described.

Jan 1, 1982

By H. A. D. Kirsten

The paper reports on loading tests conducted on shotcrete reinforced with mesh and various types of steel fibre, and compares the results with the energy absorbing capabilities of 16 mm rebar shepherd's crooks. It is concluded that mesh-reit1forced shotcrete has sufficient energy-absorbing capabilities to contain rockbursts of significant magnitude, having greater energy absorbing capabilities, even at a thickness of 50 mm, than 16 mm rebar shepherd's crooks. Fibre-reinforced shotcrete has energy absorbing capabilities of the same order as, or better than, those of 16 mm rebar shepherd's crooks, but its performance is erratic.

Jan 1, 1995

By J. A. C. Diering

The simulation of mining in faulted ground was recently described by Crouch. His method is extended here to enable a wide range of non-homogeneous mining problems to be modelled. Essentially, the boundary conditions at geological interfaces are incorporated into the overall iterative solution, which is necessary if faults and joints are to be modelled realistically. Two examples are given to demonstrate the method: the mining of coal a seam below a thick dolerite sill, and the mining of a flat reef in close proximity to a vertical fault where hangingwall and footwall rocks have different properties.

Jan 1, 1980

Infacon 74 Members are reminded of the International Ferro-Alloys Congress that is to take place in Johannesburg between 22nd April and 1st May, 1974. The Congress is being held jointly by the National Institute for Metallurgy, the Ferro Alloy Producers' Association of South Africa, and the South African Institute of Mining and Metallurgy. Correspondence and enquiries should be addressed to The Secretary, Organizing Committee, INFACON 74, Private Bag 7, Auckland Park 2006. The gold deposits of the farms Lisbon and Berlyn in the Eastern Transvaal by v. c. H. R. BRERETON. Published in the Journal November 1973. AUTHOR'S CORRECTIONS The following amendments should be made.

Jan 2, 1974

By D. Brazier, W. Laing, D. Nixon

Keywords: Pyrometallurgy, furnace, smelter, copper, Palabora The Palabora copper smelter has operated for the past 38 years, treating concentrates produced at the mine site. Palabora has reduced captive material by almost 40 per cent with the transition from a large open-cast to a smaller underground mine. The smelter and refinery complex was designed to treat 120 kt contained copper units per annum, with the underground only supplying 70 per cent of the feed. The agreed strategy was to import enough concentrates to maximise production and reduce operational unit costs. This transition has presented the Palabora management with new challenges both in technical and financial aspects.

Jan 1, 2006

By A. A. Hazell

Mine management by objectives By A. A. HAZELL The author discusses the objective areas of mine management. Setting objectives is seen to be a conscious process which starts at the highest level of management. This enables clear objectives to be set at each lower management level. The methods of setting objectives in the areas of stope production, productivity and manager performance are set out in detail. In the area of manager performance emphasis must be placed on the practice of management. It is concluded from results obtained that "management by objectives" produces better than average perormances.

By W. K. Brinsden

The Electrometallurgy and Electrochemistry Workshop organized by Dr Ian Corans was held at two venues: .Perth on 9th May, 1990, attended by 30 people . Kalgoorlie on 11th May, 1990, attended by 28 people. The workshop had four speakers: Dr Roger Paul, Director of the Process Chemistry Division at Mintek, who introduced the course with the theory of basic electrochemistry and electrowinning; Dr Peter Spencer of Bactech, who spoke on direct slurry electrolysis; Professor lan Ritchie of Murdoch University, who spoke on Zinc cementation; and Mr. Mike Costelo of Minproc, who gave an address on practical aspects of gold electrowinning in Australia. Dr Paul spoke throughout the first session and shared the remaining sessions with the other speakers.

Jan 1, 1990

By K. C. Wilson

Recent experiments and analyses have provided greater understanding of friction losses for the size distribution of the particles forming the slurry. Wilson and Sellgren (2001), Wilson et al. (2006) and Sellgren and Wilson(2006) have proposed a multi-component model consisting of carrier fluid and pseudo-homogeneous, heterogeneous and fully stratified solids. The technique presented here was found to estimate friction losses well when compared to reported experimental results with pipelines with diameters mainly from 0.2 to 0.5 m for various mixtures of fine sand to coarse gravel and products from mineral processing and phosphate mining.

Jan 1, 2007

By S. J. Bluhm

Recommendations are given for the design of multi-stage spray chambers in which air flows horizontally through water sprays. A detailed description is given of one such spray chamber at Hartebeestfontein gold mine that is used for bulk cooling of the incoming ventilation air, and that has been constructed according to these recommendations. A method for predicting the performance parameters of horizontal multi-stage spray chambers is given, and the method is illustrated with some examples. The method is equally applicable to spray chambers in which the water, rather than the air, is cooled.

Jan 1, 1979

By A. D. Thomas, K. C. Wilson

Some years ago, the authors developed an analysis of non-Newtonian pipe flow based on enhanced turbulent microscale and associated sub-layer thickening. This analysis, which can be used for various rheologic modelling equations, has in the past been applied to smooth-walled pipes. The present paper extends the analysis to rough walls, using the popular Bingham plastic equation as a representative rheological behaviour in order to prepare friction-factor plots for comparison with measured results. The conditions for laminar-turbulent transition for both smooth and rough walls are also considered, and comparisons are made with earlier correlations and with experimental data.

Jan 1, 2007

By I. M. W. Preston

A new shaft system was required to replace stope face for the North Section of Harmony Mine and to allow for systematic opening up of the North Eastern Section. Owing to the economic circumstances at the time the project started, it became vital to alter the original planning and to sink the service shaft first. The MATLA coal-sinking headgear, a novel presinking arrangement, allowed sinking to continue to 108 m concurrently with the erection of the permanent sinking headgear and sinking winders. It is estimated that this arrangement resulted in a saving of two months on the overall project.

Jan 1, 1983

From a consideration of the functional requirements of a stope-support pack, simple design principles were developed. The material and dimensional properties of the different components of the pack were determined from a series of laboratory tests. The most important requirement for an adequate pack is that the cushioning layers of timber between the concrete brick layers should provide sufficient transverse reinforcement. The tendency of the compressed timber to creep is shown to be a serious limitation to pack performance and must therefore be an important consideration in the overall design of supports.

Jan 1, 1978

By D. F. Williams

The modelling, simulation, and design of processes for the recovery of gold from solution by absorption on carbon require the combination of a suitable rate expression with a description of the flow conflguration of the system. By the use of a suitable rate expression from the literature, methods are presented for the design of multi-stage countercurrent absorption systems corresponding to the commonly used carbon-in-pulp and carbon-in-column contacting systems. The sensitivity of the recovery to various design parameters is illustrated. These results have important implications in the choice and design of equipment.

Jan 1, 1985

By H. Wagner

The paper points out that bord-and-pillar mining is the most important method of coal extraction in South African underground coal mines, and advocates that pillar design procedures should be refined to make more rational allowance for the differences in strength properties between various coal seams and roof and floor strata. However, any deviations from well-established design procedures must be based on sound engineering principles and reliable data on the strength properties of the seams and strata concerned. Recent information indicates that practices for the protection of surface structures against underground mining should be revised.

Jan 1, 1980

By T. A. Claasen

Exceptionally low yields in the coking-coal fields of the Soutpansberg area in the northern Transvaal, are taxing the skill and ingenuity of preparation engineers. The coals are highly intergrown, and a series of crushing and washing steps may be required to extract the maximum usable tonnage. In addition, novel preparation techniques may have to be employed. This paper, which is a case study of work recently undertaken, gives a general account of raw coal properties, emphasizing those related to maximum recoveries, and outlines the steps involved in the design of appropriate flow sheets based on laboratory studies.

Jan 1, 1980