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By C. R. Speers, M. I. Forsyth

The paper describes how stress analyses were used to show the defect of a tunnel's shape on the overstressing potential of its periphery. The best profile was found to be that of a horizontal ellipse, for which there was little significant scaling, permitting temporary support to be incorporated into a permanent tunnel support system. This investigation was followed by the modeling of several support systems for tunnels with a horizontal-ellipse profile, which showed that such a profile can reduce the installed support required for a tunnel of different cross section by an average of 57 per cent.

Jan 1, 1994

By F. Ma, F. Yang, T. Zhao, P. Dai, Z. Shao, D. Zuo

With the development of modern digital technique, computers have been widely used to monitor and control in retrofitting traditional industries. In Chinese coal industry, some analog monitoring and control systems have been replaced by the modern computer digital systems. According to the development status of Chinese coal industry, this paper presents some technique and its applications of modern digital computer monitoring and control for safety mining production process. The technique has been used in the full digital monitoring and automation control for hoists, coal mining machines, belt transport machines, and whole coal mining production process. With the technique, it has been achieved the better economical and social benefits in safety mining production in China.

Jan 1, 2003

By R. C. Dunne, W. A. Gilbert, I. J. Corrans, K. S. Liddell

After bench-scale and pilot-plant tests in which it was shown that wet high-intensity magnetic separation (WHIMS) can achieve good recoveries of gold and uranium from Witwatersrand residues, a production size machine was installed at a gold mine. The mechanical and metallurgical performance of this machine have been satisfactory, and the economics of the process are attractive. WHIMS can be combined with other unit operations like flotation for the optimization of overall gold and uranium recoveries. This concept is shown to be relevant, not only to operations for the retreatment of tailings, but to processes for the treatment of coarser material. In the latter, there is a saving in energy consumption compared with the energy required for the fine grinding of the total feed, and a material suitable for underground backfill can be produced. Improved. more cost-effective WHIMS machines currently under development are also described.

Jan 1, 1983

By J. Zwartendyk, A. Azis

Optimizing the public gains from the exploitation of mineral resources By Dr A. AZIS and Dr J. ZWARTENDYK Every nation must decide how it should exploit its mineral resources so as to contribute most to its national objectives. It is argued that the present value of the future corporate income tax flow derived.from mineral exploitation may serve as a useful indicator in moving toward a taxation policy that would contribute optimally toward the greatest public benefit. The future stream of corporate income taxes depends largely on the mineral endowment, consisting of deposits now being mined, known unmined deposits, and unknown deposits. Unknown deposits may be estimated by geological inference. Both known and unknown deposits can be categorized according to grade and size, and divided into economic and uneconomic deposits on the basis of certain prices, costs, rate of return and taxation levels. Computer simulations can be run of discounted cash flow models at various taxation levels to showthe impact of taxation changes on future tax revenues.

Underground mining and particularly dipping narrow tabular orebodies are difficult to mechanize appropriately, given the low gold price and other external factors. Particularly in the deep level mines in South Africa, there is little choice left but to mechanize if the industry is to remain competitive and a significant global player. This paper presents a design philosophy for appropriate mechanization intended to generate solutions that can be implemented using the people currently employed in South Africa mines. The design philosophy is based on the ability of high-pressure water (hydropower technology) to deliver enhanced performance to users and on simplicity in the eyes of the user. Four examples of systems and equipment are described to illustrate the approach to Appropriate Mechanization. These include: • The Development End System, • The Monorail Raise Climber, • Automatic Pump Control Valves, and • The Energy Recovery Pump. The equipment is presented with the following critical issues foremost in mind: Safety, Working Environment, Performance, Cost effectiveness and Implementation. Although the appropriate mechanization approach is described in the context of the South African underground mining industry, much of the Appropriate Mechanization equipment has worldwide applications. Key Words: Hydropower, Mechanization, Tunnel Development, Raise Development, Monorail, Raise Climber, Pump Control Valve, and Energy Recovery

Sep 1, 2001

By W. F. Nothard, J. R. C. Hill

The Rhodesian approach to the vegetating of slimes dams by J. R. C. HILL, B.Sc.(Agric.) (Visitor) and W. F. NOTHARD (Visitor) To prevent environmental pollution from mine dumps, it is necessary to stabilize them either mechanically or biologically. In the long term biological stabilization is more attractive because of its permanent nature. Initially, the basis of stabilization is in the correct siting and construction of the dump. The main toxic factors influencing plant growth on Rhodesian mine dumps are arsenic, antimony, copper, nickel, a high ratio of magnesium to calcium, excessive soluble salts, high pH, and Iow macronutrient content. Root-growth studies in culture solution and pot experiments are used to supplement information on the suitability of plant material obtained from replicated field trials on mine dumps. In addition to the selection of plants for toxic tolerance, it is advisable to provide multiple-layer protection with trees, shrubs, and grasses. Further, a range of different plant species gives greater biological stability. Protection must be provided for young plants against wind erosion and the abrasive effects of windblown sand. Planted wind breaks are preferred to mechanical forms; windrows of garden refuse make good wind breaks and at the same time introduce organic material to the dump and provide a good environment for seedling establishment. The use of artificial fertilizers and sewage effluent is recommended to hasten the development of a complete and protective plant cover.

Jan 12, 1973

Notices COMPETITION FOR STUDENT MEMBERS OF THE SOUTH AFRICAN INSTITUTE OF MINING AND METALLURGY Each year the Institute offers a prize (or prizes should the entries warrant it) of up to RlOO for the best paper or dissertation on a topic appropriate to the interests of the Institute. The competition is open to all Student Members of the Institute. APPLICATION AND PRACTICAL OPERATION OF HYDROCYCLONES Dr H. F. Trawinski of Amberger Kaolinwerke, Hirschau, West Germany, gave a very interesting lecture on this subject to an audience of over one hundred, composed largely of members of the Institute, on 15th August, 1973, at the University of the Witwatersrand. ROTARY INTERNATIONAL Applications are invited before 15th March, 1974, for the following awards of The Rotary Foundation: Post-graduate Fellowships Under-graduate Scholarships Awards for Technical Training Awards for Teachers of the Handicapped. NIM REPORTS Report No. 1509 The instrumentation developed for electrochemical studies of the le(Whing of uranium dioxide. Report No. 1550 A fundamental study of the dissolution in (Wid solutions of uranium minerals from South African ores. Report No. 1552 The preparation and analysis of minerals for use as reference material.Progress report No. 2. Report No. 1556 The spectral analysis of solutions.2. The analysis of leach liquors, concentrates, slags, and residues. Report No. 1559 A cost assessment of the production of elemental sulphur by chlorination roasting. Report No. 1562 Application of a flotation model to an industrial plant

Jan 11, 1973

Performance testing is often used by project owners and financiers to provide protection from, or assessment of, technical aspects of project design, procurement, construction and commissioning. The performance tests can range from comprehensive performance warranties relating to process performance and production in the case of lump sum turn key (LSTK) projects to less onerous demonstration tests for cost reimbursable contracts. This paper will discuss performance testing from both the contractor's and owner's perspectives and focuses on: ? when performance tests are required, ? what type of performance test/warranty is optimum for each type of project, and ? how project performance should be evaluated. The requirement for performance testing can be driven by the project financiers, particularly in the case of smaller resource development companies. In such cases, differentiation between owner's risk and contractor's risk can become contentious. At the other end of the spectrum, larger mining houses may choose to heavily influence the engineering and design process with the contractor supplying services on a reimbursable basis. In that case, the performance testing process is often limited to demonstration tests that validate performance for the owner's corporate governance requirements. This paper was prepared due to the lack of published benchmarking of performance testing and the resultant differences in expectations between a contractor and a project owner that often surface late in the contract negotiation process. The paper provides a checklist of requirements for both the owner and the contractor that may be used to provide `common purpose' early in the contract negotiation process.

Jan 1, 2007

International Solvent Extraction Conference 1971 ISEC '71, which will be held in The Hague, The Netherlands, from 18th to 23rd April, 1971, is being sponsored by the Society of Chemical Industry in association with the Koninklijk Instituut van Ingenieurs, the Institution of Chemical Engineers and the Koninklijke Nederlandse Chemische Vereniging. The Working Party on Distillation, Absorption and Extraction of the European Federation of Chemical Engineering is participating in the Conference, which is the 101st event of the Federation. The scope of the Conference covers the entire science and technology of liquid-liquid extraction as applied in all branches of industry. Thus sessions will cover both chemical and chemical engineering aspects of the subject as applied to both inorganic and organic solutes. The conference aims to bring together academic and industrial workers in the field from all parts of the world. The programme includes over 100 papers by authors in 26 countries. Full details of the papers, together with registration forms, are contained in a detailed programme, copies of which are now available from: ISEC '71, 14 Belgrave Square, London, S.W.1, U.K. Department of Mining and Mineral Technology of the Royal School of Mines Postgraduate Courses Technical and economic challenges facing the minerals industry, together with progressive change in methods and equipment, increasingly necessitate re-training of experienced professional engineers who aim for top places. In order to meet this need, this Department has for some years run one year M.Sc. courses. Engineers, often sponsored by their employers, have a choice of three courses which are respectively devoted to mining, applied rock mechanics or mineral process design. The course in Mining is divided into five subjects, which are treated from the business management point of view. It is intended to provide middle management with a knowledge of those techniques that are required by the mining engineering function in the preparation of modern projects. The course in Mineral Process Design provides a systematic use of mineral sciences, engineering and economics for ore testing and process design, so as best to balance the technical and financial requirements for specific mineral resources. The course in Engineering Rock Mechanics is designed to provide a specialized training in the engineering applications of rock mechanics for engineers and geologists, so that they are equipped to treat a wide variety of problems in mining and civil engineering. Prerequisite qualifications are a good first degree in a related subject, plus industrial experience: The rewards include an M.Sc. of the University of London and the Diploma of the Imperial College (DIC). The limited number of places available (12 in each group) makes early application advisable. Full details are available from the Registrar, Imperial College, London, S.W.7.

What is the role of The South African Institute of Mining and Metallurgy at a time when so much is developing and changing in South Africa? The minerals industry is represented through employers, employees, government, education, research, public views, and even pure political interests. The role of the Institute is to represent the mining and metallurgical profession. In this role the Institute has aligned itself with Associated Scientific and Technical Societies, the Council of Scientific Societies and the Engineering Association. The Institute is also active on the Engineering Council of South Africa.

Jan 1, 1996

[Council for 1993/94 President Dr H. Scott-Russell President Elect J.A. Cruise Vice Presidents Senior D.A.J. Ross-Watt Junior P.D.K. Robinson Immediate Past President J.P. Hoffman Honorary Treasurer J.A. Cruise]

Jan 1, 1994

By S. Neilson, M. G. Demmer, K. McCarogher

The Phoenix Programme takes the Mining and Mineral Processing Industry into the Science Classroom In the early years of mining, methods were crude, simple, labour-intensive, and very slow. Human resourcefulness, however, created innovations (mechanization, and computerization), that resulted in faster development, greater tonnages of ore, more efficient separation, and a superior final product. This expansion occured an ever-increasing rate, and resulted in a booming mining industry and a growing economy.

Jan 1, 1989

Past work on the ignition of methane-air mixtures by coal-cutting picks is reviewed, with special reference to the factors that contribute to ignitions and ways of reducing them. The main conclusions obtained from this review are outlined for the following aspects: mechanisms of ignition, methane concentrations, and the roles of rock types, cutting parameters, cutting tools, and water. However, many of these factors have been investigated on a qualitative, rather than on a quantitative, basis. A considerable amount of effort over a long period has been expended in this area of research. It is shown that a number of the factors influencing ignitions by machine picks have been researched adequately, but that there is still work to be done. Research is continuing in this area, being concentrated primarily upon the ignition potential of the coal-cutting pick.

Jan 1, 1985

In August 1978, the National Productivity Institute invited entries for productivity awards, which it intended making as a recognition of firms and individuals who were contributing to the prosperity of South Africa by effecting outstanding improvements in productivity.

Jan 1, 1979

Petrus (Peter) Lambooy was born in Johannesburg of Dutch-speaking parents on 13th November, 1911, and died in August 1988. These are the bare statistics, which obviously tell nothing of the years between and the man who lived them to the full.

Jan 1, 1988

Tunnel Construction 90. London, Institution of Mining and Metallurgy, 1990. Reviewer: J.A. Cruise This is the published volume of papers presented at the Tunnel Construction 90 Conference, which was held in London in April 1990 under the auspices of The Institute of Mining and Metallurgy. Twenty papers are presented and their titles are listed below.

Jan 1, 1991

By P. R. Jochens

It is interesting to note that, when the Technical Programme Committee-Mining first decided on this particular topic for a colloquium, the proposed title was different in that it used the words 'rising price of gold'. The very fact that the title was reworded to use the words 'fluctuating gold price' highlights the problem that faces the South African gold-mining industry.

Jan 1, 1981

By A. de Souza

On Thursday, 6th February, 1992, D. Jan Visser, the Executive Director, NPI (National Productivity Institute), addressed the Productivity Breakfast of the SAIMM-Vaal Triangle Branch in Vanderbijlpark. The Breakfast was held at the Riverside Holiday Inn, and was attended by 50 senior and middle managers in organizations in and around the Vaal Triangle, as well as by Richard Beck, the President of the South African Institute of Mining and Metallurgy.

Jan 1, 1992

By A. A. Bradley, P. J. D. Lloyd, A. J. Freemantle

Developments in centrifugal milling by A. A. BRADLEY,B.Sc. (Rhodes) (Visitor), A. J. FREEMANTLE, B.Sc. Hons. (Wits) (Visitor), and P. J. D. LLOYD, B.Sc. (Chem. Eng.), Ph.D. (Cape) (Fellow) The theoretical and experimental results of a study of centrifugalmills are reviewed. Means for the scaling up of such mills are suggested, and tests on a prototype mill are described. Despite the high lining wear in the centrifugal machine, which reduces its productive availability, its other advantages suggest that there is merit in pursuing its further development.

Jan 6, 1974

By L. S. Belyayeva, A. S. Chumak, N. N. Boyko, A. V. Bondarenko

Analysis of results of many years concerned study of the fire hazard parameters of the material of the mine conveyor belts come in for use at the mines of the Ukraine in 1984-2002 that was carried out in the laboratories of the Scientific-Research Institute of Mine-Rescue Work is adduced in the paper. The basic tendencies on raising the fire safety of the conveyor belts that are retraced in their world production are shown.

Jan 1, 2003