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By R. Morris, W. D. Clough

SYNOPSIS The design of an opencast coal mine over areas previously mined by underground mining methods presents several potential methods of mining the coal. The paper describes some basic methods of mining for the No. 2 seam of the Witbank Coalfield, which had previously been mined by the bord-and-pillar method.

Jan 1, 1985

By G. L. du Plessis

This paper describes the design, installation and operation of an endless rope haulage system recently built for and commissioned at Evander Gold Mines in Mpumalanga, South Africa. The factors which lead to the choice of such a system and the advantages gained over more commonly used winding systems are outlined.

Sep 1, 2001

A General Meeting, followed by a Colloquium on 'Pilot plants and problems of scale-up', was held on 22nd March, 1978, in the Main Hall, Kelvin House, Johannesburg. The President, Mr P. A. von Wielligh, opened the meeting at 09h15. He thanked the authors and contributors for their co-operation, and announced the names of the undermentioned candidates, who had been admitted to membership of the Institute:

Jan 1, 1978

By R. C. More O’Ferrall

The author mentions some of the problems he has encountered, together with their solutions. These include the stoping of isolated pillars, the reduction of the size of shaft pillars, the stoping of a new horizon above or below a horizon that has already been stoped out, and the mining of thick bands of reef left behind in the footwall or hanging wall.

Jan 1, 1981

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 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 R. D. Agrawal, M. L. Kapoor

Cementation has been used extensively by chemists and metallurgists as an economical process for the purification and recovery of metals from dilute solutions. The paper deals. firstly. with the thermodynamic aspects of cementation. and. secondly, with the effects of various process variables, such as temperature. stirring speed. initial concentrationof copper ions. pH of the solution, atmosphere, and surface area of the precipitant metal. on the kinetics of the process in the light of the rate expressions.

Jan 1, 1982

Today's conservation thinking is becoming increasingly polarised-a widening gap that could eventually be to the overall detriment of mankind, one way or the other. In one corner, stand the disciples of the untainted wilderness, moral protectors of the natural world who subscribe to the doctrine that the fragile balance of nature is threatened by man's very existence. On the opposite side of the ring, stands the relentless developer, with the megalomaniac notion that nature is purely there to serve humanity and civilisation, under the auspices of 'progress',

Jan 1, 1996

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 C. F. Hews

Trackless mining at the International Nickel Company of Canada, Limited by C. F. HEWS* (Visitor) An account is given of the evolution and advantages of trackless equipment in the underground operations of International Nickel's Ontario Division, with special reference to fill-method mining, development practice, sublevel caving, and induced block caving. Details of maintenance, environmental control, and operator training are also given.

By G. J. G. Juby

The Chamber of Mines Research Organization has been evaluating three membrane-desalination processes for use within the South African mining industry. These processes are electrodialysis reversal (EDR), tubular reverse osmosis (IRO), and slurry precipitation and recycle reverse osmosis (SPARRO). The evaluation of EDR and TRO is complete, and the operating costs (1988) associated with each process are expected to be about 50 cents per kilolitre for a plant of 50 l/s (4 Ml/d) installed capacity. The SPARRO process is still being evaluated. Pilot plant results, water Qualities, and expected capital costs are presented where appropriate.

Jan 1, 1992

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

By J. A. Cox, R. P. H. Willis, J. R. Dixon, A. D. Pooley

The paper describes the issues that should be considered when introducing mechanization to a mining operation. In South Africa, traditional methods of mining are well entrenched after more than a century of mining. To successfully change from these methods requires an integrated holistic approach that considers all aspects of a mining operation including setting of objectives, selection of personnel, recruitment, training and remuneration policies, organizational design, mine design, equipment selection, maintenance philosophy, standards and procedures, and monitoring and control. The paper makes reference to experience gained during a variety of on-mine case studies in drawing generic conclusions and making recommendations.

Jan 1, 2004

By John Austin, Graham Pingram

The idea of GOLD 100, an international conference on gold, was first conceived by Mr Les Haughton of Mintek in mid 1984. By the beginning of 1985, plans were well advanced to hold what was to be the most comprehensive conference on gold ever organized. Appropriately, GOLD 100 was timed to coincide with the celebration of Johannesburg's centenary. Leaching The South African Institute of Mining and Metallurgy will hold a two-day colloquium on the topic of leaching on 8th and 9th November, 1988, with the objective of bringing the latest developments in leaching technology to the attention of the mineral-processing industry.

Jan 1, 1988

By D. G. Wymer, A. G. du Plessis, N. C. Joughin

The use of a dense hangingwal-support configuration extending right up to the face would enable greater levels of safety and productivity to be achieved in stopes, and becomes a practical proposition if water jets are used for stope cleaning. Such an arrangement opens the way for extending the use of water hydraulic power to the whole stoping operation. This, in turn, can provide further productivity benefits and significant savings in working costs. With al the necessary equipment being available, such a system could be introduced immediately, although the designs of props and rockdrills are not yet ideal.

Jan 1, 1989

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

Four engineering products and three consumer products have received awards in the 1978 Shell Design Awards competition organized by the Design Institute of the South African Bureau of Standards. Norman Hanson Visiting Fellowship The Norman Hanson Visiting Fellowship, supported jointly by the National Development Fund for the Building Industry (inaugurated by the Building Industries Federation (8.A.)), the Institute of S.A. Architects, the Association of S.A. Quantity Surveyors, and the National Building Research Institute of the CSIR exists to finance fully or wholly visits by eminent authorities from overseas to South Africa for the purposes of seminars, informed discussions, consultation, and possible active participation in scientific, technological, and development projects of importance to the building industry.

Jan 1, 1979

By R. P. King

An Analytical Solution to the Batch comminution Equation R. P. King, Pr. Eng., B.Sc. (Eng.), M. Se. (Eng.), Ph.D. (Visitor). An analytical solution to the batch-grinding equation is presented in terms of the generalized hypergeometric series and the confluent hypergeometnc function. This solution is valid for selection functions that are describe~ piece-wise by functional forms of the type KOXB and by normalized breakage functions of the type B(x,x') = (x/x')x. These functional forms are sufficiently general to Include most practical cases. In particular, they can be used to describe selection functions that have a maximum.

By P. H. Botha

An account is given of the procedures used by the South African Iron and Steel Industrial Corporation (Iscor) for tests on the flotation of coal fines, and some of the beneficiation problems encountered with coal from Durnacol, Grootegeluk, and the Soutpansberg area are discussed. These, and other South African coals differ from overseas coals in that they contain a high percentage of fixed ash, which means that they have to be crushed more finely for liberation and that they then contain more fine material (smaller than 0,84 mm). In addition, the coal from the three areas mentioned occurs in fine layers and seams, and contains many intergrown particles.

Jan 1, 1980

By W. F. Lorch

Growing use of deionised water in surface coating techniques by w. F. LORCH Production engineers in the metal plating, paint, plastics-coating and printed circuit industries are increasingly aware of the cost of sub-standard or blemished items which have been poorly processed. An area where quality control can quickly produce higher efficiencies is in the choice of suitably purified water for making up solutions, for rinse baths and 'drag-out' baths, for cleansing lines and electrophoresis tasks, for maintaining electrolyte density and hence consistency, and for facilitating the recovery of valuable minerals. The author of this article examines the general problems of using nonpurified water, and shows how purified water has become accepted by the principal surface coating industries to improve processes and effect economies.