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By E. Adlard

This paper sketches an expert system for use underground in pinpointing problem areas in the operation of machines. The system is typically a software 'shell' designed to accommodate a series of 'if-then' rules that are intertinked to systematically search for the cause of the problem. During the search, the system asks a series of questions that have to be answered by the operator and then, when necessary, by an artisan. The rules of the system are generated by a knowledge engineer whose function it is to gather the necessary diagnostic information and prepare it in the required format for the expert system. Much still requires to be done in the development of such systems and in the testing of hardware to withstand the mining environment.

Jan 1, 1990

By P. N. Harris

The Colloquium on 'Recent Mining and Metallurgical Developments in the Orange Free State' was held at the Civic Centre in Welkom on the 4th and 5th May, 1983. The Chairman of the Orange Free StatejKlerksdorp Branch of the Institute and Acting General Manager of Unisel Gold Mining Company, Mr D. A. Parfitt, opened the proceedings, and Professor A. N. Brown gave the welcoming address. Mechanization of mining The South African Institute of Mining and Metallurgy is to hold a one-day colloquium on 'Developments in the Mechanization of Mining Operations' during September 1984. Surfac,e mining and quarrying The Second International Surface Mining and Quarrying Symposium is being organized by The Institution of Mining and Metallurgy in association with the Institute of Quarrying.

Jan 1, 1983

By R. E. Gundersen

Hydro-power-the use of high-pressure water as an energy source-offers tremendous benefits for environmental control in deep, hot mines. The extent of these benefits depends on the mining method, the selection of equipment to be hydro-powered, and the efficiency with which the coolth is extracted from the water and into the working environment. The engineering of hydro-power systems continues to receive much attention. However, this paper considers the environmental implications of using hydro-powered equipment, particularly with regard to positional efficiency. The integration of hydro-power with developments such as backfill, mechanization, and higher face-advance rates is discussed. Layouts are proposed that attempt to minimize the quantity of water in circulation by extracting the maximum coolth from the water.

Jan 1, 1990

By L. M. Falcon

Cassiterite is considered to be the only economically significant tin mineral in the earth's crust, and in its purest form has a tin content of 78,6 per cent. South Africa has limited deposits of the mineral, and by its exploitation contributes about 2 per cent of the world's production. This paper gives a brief history of tin mining in South Africa, which dates back almost 3000 years. Over the intervening years, many tin-mining operations have flourished and as quickly disappeared. At present there are only three tin mines in operation, and a description is given of the methods of mining, concentrating, and smelting that are used. The properties and uses of tin are listed, together with relevant statistics.

Jan 1, 1985

Blasting in a gold mine has to satisfy the following set of techno economic conditions: good fragmentation, minimum stopped width, minimum number of rock falls, cost effectiveness. Results of a comparative study of the performance of a Low Density Anfo (LDA) and a conventional Anfo (ANFEX) are discussed. LDA appears to be more cost effective. The same borehole volume can be charged with material of reduced specific gravity. The velocity of detonation (VOD) is increased in the case of LDA resulting in more breakage as a result of shock energy than from the energy in the gas phase. This leads to less damage to the excavation and more favourable breakage of the excavated rock. As a result the overall economics of the mining operation is improved.

Jan 1, 1995

By I. R. M. Chaston

A full and detailed description is given of the dense-medium cyclone plants used in Africa for the recovery of diamonds.

By A. Marek

The safe and optimal installation of roof support remains one of the biggest challenges in underground mining today. Traditional hand-held, roofbolt installation in conventional mining has been replaced, in a lot of mining operations, by mechanized equipment. This was a first step to moving the operators out of the unsafe working environment and a start on the trend toward a changed support regime in mechanized mining. However, the challenge of handling of the drill steel itself, as well as inserting resin cartridges and bolts, remains a major hazard and the cause of many lost-time injuries. The paper describes and discusses developments in this area, of mechanized bolting and on-board automation, presenting solutions to known problems, achievements to date, and future developments. The solutions presented will identify with addressing customer needs while touching on possibilities for further technology changes, keeping focus on the safety aspect for operators and the need to bring the operators even further away from the unsafe working environment. The-state-of-the-art technology in mechanized bolting equipment is presented and a brief outlook on the past, current, and future developments is given.

Jan 1, 2012

By D. P. Power

The development of an accounting code for the metallurgical industry has been debated for many years. Following the series of tumultuous economic events in the nineties and earlier this century that have affected business, there was much need for legislation to be passed to minimize potential risk. One of the consequences to affect the mining industry was the enhancement of existing geological codes for reporting. In parallel the sponsors of AMIRA have taken the brave step to develop a generic code for metal accounting that embraces the full gamut of industry. In this paper the code will be reviewed in the context of metallurgical accounting as it applies to coal preparation. This paper provides the background for this development and an insight into the mechanism for the debate for the generation of this code. The key elements of the code as it applies to the coal industry are explained but most importantly the key opportunities are highlighted.

Jan 1, 2010

By W. C. Joughin

Modern soil mechanics is generally considered to have begun in 1925, when Karl Terzaghi published his book Erdbaumechanik auf bodenphysikalischer Grundlage (Earthwork Mechanics based on the Physics of Soils). These theories were applied to rocks more than 20 years later and the science of rock mechanics became established. Methods of analysis and design have been introduced and applied, and have evolved over time. More recently, the rapid growth in computing power has resulted in more sophisticated analyses, and together with improved monitoring techniques, our understanding of geomechanics has grown considerably. Despite this, geotechnical failures with major consequences still do occur. This is partly due to failure to transfer and apply the knowledge that has been gained, but also there are aspects of geomechanics that are not well understood.

Sep 1, 2023

By J Taguta, B. McFadzean, P. E. Ngoepe, M. G. Mulaudzi

Computational modelling methods and isothermal titration calorimetry (ITC) were employed to investigate the interaction of a pyrite surface with thiol collectors. Modelling work was conducted in the presence and absence of water. Microcalorimetry was employed to investigate the resultant energy of interaction pyrite as a result of mineral-collector interactions. Sodium ethyl xanthate (SEX), diethyldithiocarbamate (DTC) and diethyl dithiophosphate (DTP) were investigated in this study. The results showed that the calculated surface energies and morphologies for FeS2 showed that (100) and (111) are the most stable surfaces. The morphology also indicated the appearance of the (100) and (111) surface facets and no presence of others. The calculated adsorption energies between thiol collectors and the pyrite surface were always more exothermic than the experimentally determined ones. When comparing different ligand types with the same alkyl chain length, the heat of adsorption of diethyl-DTC was greater than that of ethyl xanthate and diethyl-DTP for pyrite. Experimentally, the diethyl DTP barely adsorbed onto the pyrite surface and this may be due to a different mechanism of action. In computational calculations, water adsorption was found to reduce the reactivity of the Fe atom for the interaction with thiol collectors, and bring the adsorption energies closer to the magnitude of the experimental values. Keywords: Computational modelling, microcalorimetry, experimental and thiol collectors, adsorption energies

Jan 1, 2020

By V. C. Robinson

INTRODUCTION Most presidential addresses are in the nature of a review of some specific topic and this will be no different. In thinking about the subjects which might be suitable for this address I decided that as next month will see my retirement from the gold mining industry I might review the four decades since I started in the industry in 1929. These four decades have been more than usually in',~resting and exciting. They have covered a period when the price of gold increased from the old figure of 84/- an ounce to the price of $35 an ounce today, taking in on the way at least two periods of premium sales from which the producer benefitted. The industry in these four decades has survived the most totally destructive war in history and has seen fundamental changes in the political, economic and governmental life of South Africa. There have been great technological changes and improvements, some of which I shall refer to later, and in addition there have been profound changes in the relations between employer and employee in the industry which have affected not only the economy of the industry but the traditional thinking of both management and labour. I believe that the address presented to this Institute on the occasion of its 75th Anniversary by Mr Goode covered more than adequately the history of the Institute and the part it has played in the mining industry of South Africa. It would be merely repetitive, therefore, to discuss the affairs of the Institute of Mining and Metallurgy. Having said this, however, it is also necessary to point out that the history of the Institute is, and always will be, an important record of the history of mining in South Africa. There are many facets, however, on which we ought to look back and to re-examine. One of the most rewarding, but at the same time one of the dullest, places to look for historical facts is in the annual reports of the Chamber of Mines. I suppose that some of the dullest of these have been the reports for which paragraphs have been prepared by me personally. The notes which follow do not claim to be anything like a full record of this exciting period. RISE AND FALL OF THE GOLD MINING INDUSTRY In talking about the mining industry of South Africa it is inevitable that one talks, particularly in the historical sense, about the gold mining industry - an industry of fundamental importance which has made South Africa what it is and which has been dying since the early part of this century. In Table I is shown the progress of the gold mining industry measured by its output of ounces of fine gold from the beginning of operations until the end of 1969, and if you are interested in the productivity of the men who work this industry the table, composed entirely from figures set out in the Chamber's annual reports, also shows the production of gold expressed as fine ounces per European and fine ounces per Bantu worker over a long period. If you are still minded to think of this industry as dying then the last column in the table shows how uranium has played such a vital part in the prosperity of the country.

By J. van der Walt, A. Whillier

Gravity-fed water systems in mines by A. WHILLlER, Pr. Eng., Se. D. (M.I.T.) (Fellow) and J. VAN DER WALT, Pr. Eng., B.A. Hons. (Bus. Admin.), Ph.D. (Eng.) (Visitor) South African mines often experience significant losses in production because of recurring shortages of water at work places as the result of underground dams running dry. Similar shortages have occurred during fire-fighting operations, and now, with the use of cold service water to aid in the cooling of mines, it is even more necessary that such shortages should be prevented. This paper draws attention to the primary cause of such water shortages, and an outline is given of some of the fundamental hydraulic principles that must be followed in the design of gravity-fed water-supply systems on mines.

Jan 4, 1977

By R. P. H. Willis

This paper describes the economics of backfilling, hydro-power, and mechanization when they are combined in an integrated stoping system. These three technologies have been shown to be viable, and the mines of the Gold Fields Group are introducing backfilling where the depths exceed approximately 2000 m below surface and in other highly stressed areas. addition, a number of mines are installing hydro-powered systems, and the first trackless stope within the Group may soon be a reality. The main emphasis in the paper is placed on the quantifiable effects of trackless stoping, including a basic risk analysis by use of a spreadsheet model. It is concluded that a substantial decrease in working costs and an increase in revenue are possible, resulting in a marked increase in working profit.

Jan 1, 1989

By B. G. Fordyce, W. B. Parker

A description is given of the methods used in management planning, pit-equipment selection and maintenance operator training, and formal organization of mining personnel.

Jan 1, 1979

By R. W. O. Kersten

It was decided that Anglovaal should conduct a course on technical computing to help middle and upper mine management (40 years and older) to use computers. Background This decision was taken against the background of perception that various people have of computers and computer-related processes. People of the older generation Book review Rock mechanics for underground mining, by RH.G. Brady and E. T. Brown. London, George AlIen & Unwin, 1985. 527 pp. Reviewer: S. Budavari Mine safety awards The mining challenge of our time is the maintenance of the very highest safety standards, says a Chamber of Mines Executive. Haulage in surface mines An international symposium on 'Of-highway Haulage in Surface Mines' is to be held in Edmonton, Canada, from 15th to 17th May, 1989.

Jan 1, 1988

The exciting history of gold mining in South Africa haR been told in many different ways - in books, plays, and films, and on radio. But now, there's a new and far more lively way to find out about it and that is by actually participating in living history. Your invitation to go back in time will not take you much further from the centre of Johannesburg than the late-afternoon stretch of the shadows of the skyscrapers. The Gold Mine Museum - a new venture by the Chamber of Mines - brings back all the colour and romance of mining a century ago, and reminders of some of the hardships too. This is not an ordinary museum, but one of the most modem attempts in the world to make the past come to life.

Jan 1, 1980

By G. J. Krige

The extent of ground movements and stress concentrations in the vicinity of the reef in the deep mine-shafts used in the South 4frican gold-mining industry have led to the requirement that special tower structures be developed to span the reef intersection zone in several new shafts. So that structural engineers are able to design these towers, it is necessary to model the dynamic behavior of conveyances traversing them in some way, to provide a means to determine the magnitude of the forces generated. This paper describes the development of two such procedures. The first is a numerical method, utilizing a step by- step integration technique to track the motion of a conveyance through a tower. This technique has been implemented in a computer program, and some results are given.

Jan 1, 1995

The quality of life in many countries of both the developed and the developing world is strongly affected by the products and processes of mining industries. The first Issue in this new series brings together a set of review articles by leading authorities in the field which, taken together, provide a thorough and detailed survey of many of the key topics of current concern relating to the environmental impact of mining. The level of treatment of most topics is at first introductory but evolves through to the advanced level of current research, backed up by extensive citations of relevant primary literature and other sources. Thus the Issue as a whole will be found equally valuable by students of environmental science and those actively engaged in research related to this theme.

Jan 1, 1995

The value of incentive payments in the mining industry by K. SMITH, A.R.S.M., B.Sc. (London) (Member) This paper reviews the history of incentive payments in the mining industry, and gives some indication of the magnitude of improvement that has been achieved by this means in the past. The objective is to promote a more general belief in the efficacy of these methods, and thus to encourage their wider and more effective application by mining engineers in general, and by the rising generation in particular. It is concluded, from a consideration of current productivity levels in the gold-mining industry (still South Africa's leading revenue earner), that further substantial improvement can be achieved by a better understanding of the time-tested principles of incentive payments.

Jan 5, 1974

By S. Budavari

The effects of shaft pillars left in deep-level hard-rock mines during the extraction of tabular deposits were studied some time ago, resulting in the formulation of design principles and procedures, which have been used with success in the design of shaft pillars in the deep-level gold mines of South Africa. The method has not yet been utilized in the design of shaft pillars in shallow and moderately deep hard-rock mines. The purpose of the present study was to remedy the situation since a great number of deposits are worked at those depths. The object of this paper is to present governing equations for the components of stress and differential movement as derived by use of an elastic model. The pillar is taken to be circular in the plane of a horizontal deposit. On the basis of the numerical results obtained, a study was made of the distribution of the vertical strain and tilt along the axis of the shaft, and of the vertical stress along the shaft and across the pillar. In every case investigated, the most adverse geometry was taken into consideration. By use of an empirical criterion and the results of some in situ observations, the determination of pillar dimensions and differential displacement components for South African gold-mining conditions is demonstrated. Pillar dimensions for shallow and moderate depths are compared with those accepted for deep-level conditions.

Jan 1, 1986