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ENERGY 73 The First International Energy Exhibition will be held in Brussels from 13th to 18th May, 1973. Vllth INTERNATIONAL CONGRESS ON CYBERNETICS This congress will be held in Namur, Belgium, from 10th to 15th September, 1973. GRADUATE SCHOOL OF BUSINESS ADMINISTRATION University of the Witwatersrand The Sixth Executive Development Programme is scheduled to take place from 2nd July to 24th August, 1973. IFAC SYMPOSIUM 1973 Second announcement ofthe International Symposium on AUTOMATIC CONTROL IN MINING MINERALS AND METAL PROCESSING to be held at the University of New South Wales, Sydney, Australia, from 13th to 17th August, 1973. MINERALS AND ENVIRONMENT The effect ofthe mineral industry on the environment and mineral resources The Institution of Mining and Metallurgy, with the co-operation of the Institute of Quarrying and the Institution of Mining Engineers, will hold a Symposium "Minerals and the environment" at the Institution of Electrical Engineers, Savoy Place, from 4th to 7th June, 1974. COLLOQUIUM ON SLlMES DAMS The South African Institute of Mining and Metallurgy have great pleasure in advising members that a two-day colloquium on slimes dams is bei ng arranged for the 14th and 15th November, 1973. INTERNATIONAL SOLVENT EXTRACTION CONFERENCE This conference will be held at Lyon from 8th to 14th September, 1974. Particulars may be obtained from the Secretary: Dr A. Naylor, British Nuclear Fuels Ltd., Windscale and Carder Works, Seascale, Cumberland CA20 IPG, United Kingdom. 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 RIOO for the best paper or dissertation on a topic appropriate to the interests of the Institute. Proceedings of the Tenth International Symposium on Application of Computer Methods in the Mineral Industry (APCOM) The Proceedings of the APCOM Symposium held in Johannesburg from April 9th to 14th, 1972, have now been published. Members of the Institute may buy the Proceedings at a special price of R12,50 as against the list price of R25,00 to non-members. Verrigtinge van die Tenth International Symposium on Application of Computer Methods in the Mineral Industry (APCOM) Die Verrigtinge van die APCOM Simposium, wat op April 9 tot 14, 1972, in Johannesburg gehou is, is gepubliseer. Lede van die Instituut kan die Verrigtinge teen 'n spesiale prys van R12,50 koop, in teenstelling met die prys van R25,00 vir nie-Iede.

By A. Bain

The use of plastics in the coal mining industry is making slow progress whereas these materials could make a greater contribution to safety, to a reduction of working costs and to the higher productivity of mine workers. Possibly the reluctance to experiment with the new material of our age is due to the low profit margin of coal mining. This note has been prepared to present a brief survey of what has been done in the last few years and to mention some of the investigations the author has made and is making in an attempt to develop more use of plastics in the industry. Some of the plastics used on the mines have taken their place in the industry in the same manner that they are used in everyday life while others have been introduced because there has been a need for them. New uses and applications are being developed and these are the ones that are most interesting. The plastic that is specially developed to give the maximum benefit and not the one that is a modification of some other everyday product is the next development in the field. Many manufacturers are keen to promote such investigation but are not aware of the problems the mines wish to solve and therefore it is only through management itself that this development can be carried out. This note deals with plastic material under three headings: (a) Plastic as the superior material, and briefly describes how plastic has replaced a few major items which are better when made from plastic. (b) Plastics of necessity, being a short summary of how plastics had to be introduced because of laws and conditions making it a necessity. (c) Development of new ideas, being briefly some of the ideas being developed overseas and some of the ideas being tried by the author. Plastic items in common use such as in housing, electric cables, laboratory equipment, awnings, nylon bearings, locomotive brake linings, etc. being well known are not discussed. PLASTIC AS THE SUPERIOR MATERIAL Plastic belting underground Following a fire in a belt road in England resulting in the deaths of many workers, and subsequently a fire accompanied by fatalities in a belt road in a mine in this country, a law was introduced which states that only flameproof belting is to be used underground. This ruling forced the mines to use P.V.A. belting as no other was available. This belting has non-inflammable characteristics that are superior to rubber. Due to the high tension on long-distance belts used today the need for stronger belting material called for something better than cotton and the answer to this was nylon. Nylon also has the ability to withstand dry-rot which reduces the life of a belt very quickly.

By R. S. Francis

There are no manuals or handbooks for budding mill superintendents or process plant managers. Most who obtain this level of responsibility have gained their training from watching the good and bad of their predecessors and the successful ones have themselves graduated from the school of hard knocks. This paper attempts to provide some helpful guidelines and direction for those who aspire to better manage a mineral processing facility. The authors have 20 years combined experience in senior management roles at nine different mineral processing operations in Australia and overseas, covering gold, base metals and mineral sands. This summary of tips and pitfalls will hopefully benefit future leaders in mineral processing and metallurgy.

Jan 1, 2007

By use of a finite-difference model of an experimental galvanic cell, the effect of a resistance in the metalic conduction path on the potential and current distributions in the cell was predicted. The model predictions were compared with experimental measurements of potential profiles (measured by use of a scanning reference electrode) and galvanic currents. The predictions agreed well with the experimental measurements. Apart from this model, which is applicable in macroscopic cells (Le. with an electrolyte of low conductivity), a calculation procedure was developed to predict the effect of an external resistance on the galvanic current in a microscopic cell (high conductivity). The responses of the galvanic currents in the microscopic and macroscopic cells to changes in the external resistance were compared. From the similarity of the responses, a simple practical procedure for the evaluation of the external resistance (meter resistance) that can be tolerated is proposed.

Jan 1, 1989

By D. F. Howarth, F. F. Roxborough

Some important aspects of the design of rock-cutting systems remain relatively unexplored. Two areas of practical significance in this context form the subject of this paper: cutting in jointed or fissured rock, and groove-deepening. A series of controlled laboratory experiments on the performance of disc cutters in jointed rock showed that the spatial and geometrical configuration of jointed rock masses needs to be taken into consideration in the design of mechanized rock excavating systems. One series of experiments showed that, under favourable geometric conditions, the energy required to cut in a jointed rock mass is at least half that required to cut otherwise intact rock. Groove-deepening-the progressive deepening of a groove by successive passes of a cutter-is a potential operational feature with most mechanized rock-excavating systems. Laboratory experiments revealed an important fundamental cycle of events associated with disc cutters when progressively deepening a groove in intact rock. Furthermore, in contrast to pick cutting, groove-deepening by discs is shown to be an efficient operation and one that should not necessarily be avoided. This can be directly attributed to increased interaction between the disc cutters as the result of an increase in magnitude of the lateral forces generated as a groove is deepened.

Jan 1, 1982

By P. Horrell, K. Rhodes, G. Harrison, J. Dean, D. Sammons, M. Stander

Anglo Platinum have perceived a need to increase the rate of reef development both for new mechanised stoping technology and on conventional new developing mines. The Research and Development Division of Anglo Platinum therefore initiated an experimental reef raise project with a tunnel boring machine (TBM) at Bafokeng Rasimone Platinum Mine (BRPM). The scope of the trial was for the boring of a reef raise 340 metres in length on the Merensky Reef. The boring phase of the trial took place over six months and the average rate of penetration of the TBM was 0,47 metres/hour. TBM utilisation was 22%. The TBM used in the trial was a Jarva MK6 manufactured in 1972 and its design with its backup system was not considered to be an ideal machine for reef development. However it was the intention of the trial to prove the concept of developing with a TBM on reef. In this respect the trial was unequivocally a success. There were many problems and long delays did occur during the boring phase. Nevertheless there is every confidence that a new TBM can be designed specifically for this type of work that will achieve high rates of advance up to (say) 400metres/month and with a more flexible steering system in order to negotiate reef changes. It can therefore be expected that TBMs will be used in the future for reef development on South African platinum mines.

Sep 1, 2001

By R. Heunis

The hazard of rock bursts and rock falls as experienced in South African gold mines is examined in the light of recent research findings. The problem areas include high fatality rates, losses in production and equipment, and a detrimental influence on the recruitment of labour. The nature of the hazard is analysed, and it is shown that rock bursts are strongly related to the spatial rate of energy release by mining but that rock falls are not. The role of blasting and geological discontinuities is discussed. Practical rock-burst control strategies are compared, including the use of stabilizing pillars, back-filling and, in particular, techniques for reducing the frequency and severity of accidents resulting from large rock bursts. The latest stope-support experiments and their potential implications to mining are consid~red. It is concluded that a better understanding of the rock-burst and rock-fall hazard has resulted from the industry's research efforts. The findings can be applied towards obtaining an improved underground environment for men and machines.

Jan 1, 1980

By J. W. de Kock

The estimation of some properties of South African coals from proximate analyses by J. W. de KOCK, Pr. Eng., Ph.D. (Chem. Eng.) Cantab. (Fellow) and J-P. FRANZIDIS, B.Sc. (Chem. Eng.) (Visitor) Correlations have been obtained whereby calorific values, ultimate analyses, and Hardgrove Indices can be estimated from proximate analyses of South African coals. This has been done by the application of stepwise multiple linear-regression analyses of a mass of data published by the Fuel Research Institute.

By J. A. Tyser

The pumping of water from mines in the Central Witwatersrand by J. A. TYSER, Pr. Eng., B.Sc. (Min.) (Associate) This paper describes a system for the removal of underground water in the mines of the Central Witwatersrand, some of which are defunct. The water is pumped by a pump station on 24 level at E.R.P.M. to a surface lime plant and then to a surface treatment plant, where it is treated so that it meets the specification of the Department of Water Affairs relating to the deposition of water in public streams.

Jan 5, 1977

By M. Kilfoil

Many minerals processing operations result in crushed rock being mixed with a liquid. Sometimes, the rock particles have to be dried before the next process begins and there may be a considerable distance between the equipment carrying out these processes. Bateman Engineered Technologies (BET) developed, patented and commercialized a method of simultaneous pneumatic conveying and drying. A joint project to assist with optimizing the process is under-way. Part of it is a numerical simulation of the process. The simulation is done using a dedicated program written in MATLAB, (commercial software which is widely used in engineering). It accounts for heat and mass transfer as well as particle transport. The main part of the program consists of a loop containing a series of equations which are evaluated sequentially. During any particular iteration, the properties are changed one at a time. Since the properties are changing relatively slowly, this method gives good results. The outputs of the simulation are consistent with the operational experience of BET’s engineers. The output is very comprehensive and all numerical. Since the program is currently being used for research purposes, flexibility is very important. Thus the output is converted into a spreadsheet file. Variations in the output quantities are displayed graphically using MS Excel. Some simulation could have been done using computational fluid dynamics (CFD) software. The advantages and disadvantages (technical, financial and skills requirements) of the two approaches for this particular type of simulation are compared briefly. Keywords: Pneumatic conveying, Heat and mass transfer, Computer model

Jan 1, 2003

By W. S. Nel

Training in the mining industry by W. S. Nel, B. A. (Wits) (Visitor) After defining training and discussing the present level oftraining in the South African Mining Industry, the paper proposes the adoption of a centralized training system for the Industry and suggests several ways in which this should function. The finance required for the implementation and running of such a system should be obtained from State aid and from the institution of a levy and grant system for the whole Industry.

Jan 7, 1974

By D. H. C. Griffiths, D. R. Davis, D. B. Paterson

Consolidated Murchison Limited is the only primary producer of antimony in South Africa, producing approximately 18 per cent of the total world production. This paper gives a technical review of the history, occurrence, mining, and metallurgy of antimony at Consolidated Murchison. World antimony markets are also discussed, together with the end-uses.

Jan 1, 1986

By E. J. Boome, A. C. Schmidt

Pert, and how Pert techniques can be used in modern mine management By E. J. Boome, A. C. Schmidt C.A. (S.A.) This paper covers the stages of planning required to be performed and the implementation of the plan from grass roots to the partial completion of the sinking of a mine shaft system. The various steps involved in the planning are also examined in some detail. The experience gained in this project and the conclusions reached convince the authors that Pert Planning is a valuable aid to top management.

By M. C. Harris

Float-sink analysis has wide application in the coal laboratory. This paper evaluates the established methods used for the float-sink analysis of fine coal, and then describes a new method and apparatus that can be used for material down to a few micrometres in size. The method is rapid and accurate, and requires only a small amount of sample. The results presented show close agreement with the float-sink analyses obtained by the more classical technique using separating columns. The new centrifugal method reduces the time required for the analysis by a factor of ten.

Jan 1, 1986

By B. C. Alberts

This. paper indicates how the South African Iron and Steel Industrial Corporation Limited (Iscor), as a major consumer of raw materials, determines the tonnage and quality of essential raw materials required to satisfy an increasing demand for steel and how this led to the establishment of a coal mine with a highly sophisticated beneficiation plant in the Waterberg coalfield, near Ellisras in the Transvaal. The planning of the project, with specific reference to the limited reserves of metallurgical coal in South Africa, the quality and quantity of the coal to be produced, and the way in which the project was managed is discussed briefly.

Jan 1, 1982

By J. H. Bulloch

A short review is given of the effects of corrosion fatigue on the materials used in pressurized water-reactor vessels. Selected topics such as testing procedures, test data, and mechanisms in simulated environments are discussed. The main fact that emerges is that most of the data on the growth of fatigue cracks reside below the ASME X1 1980 High-R 'Wet' design-code lines, Le. they fall within that specification. Finally, some recent advances in the understanding of the corrosion-fatigue behaviour of such materials in pressurized water reactors are highlighted.

Jan 1, 1987

By B. Strohmeier

The role of large, ultra-high-powered arc furnaces in a fully integrated steelworks for the production of flat products is outlined, and an account is given of the technological improvements that have been implemented over the past few years to enable the arc furnace to remain competitive against the conventional route using blast furnaces and top-blown-oxygen steelmaking (LD). Modern secondary refining facilities have been installed, enabling the arc furnace to operate at high production rates in the manufacture of high-quality flat products.

Jan 1, 1985

By J. Keyser

The realization of an Integrated Technical Resource Asset Management System (ITRAMS) has so far evaded all software developers in the mining industry. The major factors that have prevented the development of such a system are limitations on software, hardware and network systems. Several factors have come together at Venetia Mine, which has made the undertaking of such a project both possible and desirable. This has led to the formation of a strategic partnership between Venetia Mine and Gemcom Software International Inc. This partnership is dedicated to develop and provide an Integrated Technical Resource Asset Management System based on Microsoft Back Office architecture, Gemcom for Windows™ and the MinRas system. This paper will elaborate on the phased approach of the integration of systems into the core repository, mechanisms of integration, the functionality of the system, final results, techno-economic benefits and general project management issues.

Sep 1, 2001

Infacon 74 The National Institute for Metallurgy, the South African Institute of Mining and Metallurgy, and the Ferro-Alloy Producers' Association of South Africa extend a cordial invitation to participate in the International Ferro-alloys Congress to be held in Johannesburg, South Africa, in April 1974. Obituary RICHARD AUSTIN COOPER On the 31st March 1972, a once very active member of the Institute, R. A. Cooper, died at the age of 82. He had served on the Council for many years and was Vice-President in 1933/34. ALEXANDER JEREMIAH ORENSTEIN CB., CM.G., C.B.E., LLD., D.Se., M.D., M.R.C.S., F.R.CP., F.R.S.H. Dr Orenstein, who died on the 7th July 1972 at the age of 92, was so well known and so widely acclaimed during his lifetime that it is difficult to add to the tributes which have already been paid to him.

By R. G. B. Pickering, H. H. Haase

Few innovations in the South African gold mining industry could have a more significant impact on improving profitability than non-explosive methods of mining. The far-reaching benefits of this approach are explained and the progress made through development work funded by the industry is described. Three methods are considered: impact ripping, sloting with abrasive waterjets and diamond saws, and breaking from drilled holes with waterguns and electric pulses. Of these methods, impact ripping is the most advanced and requires only minor refinements before production applications can be initiated. Although this method, based on current performance, is expected to yield considerably increased profits, it is predicted that it could perform several times better than at present with further development. The other methods of rockbreaking also show potential. Waterguns and electric rockbreaking would be attractive in unfractured rock for difficult geological conditions, and for confined areas such as gullies and development ends. Methods based on sloting could be combined with any of the other methods to enhance their effectiveness and thus yield further improvements in profitability; also, they could be used to advantage in specific applications. Al the discussed methods, therefore, deserve to be developed further.

Jan 1, 1991