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1. Book review . Australasian coal mining practice, edited by C.H. Martin. Reviewer: R.B. MacGilIivray This book is an extremely comprehensive coverage of coal-mining practice in Australasia, the countries covered being Australia, New Zealand,and Papua New Guinea. 2. From The Institute of Metals The folowing are available from The Institute of Metals, 1 Carlton House Terace, London SWl Y 5DB. Physical and elastic characterisation, edited by M. McLean. 1989. 228 pp. £25.00. High nitrogen steels, edited by J. Foct and A. Hendry. 1989. 461 pp. £49.50. Proceedings of the First International Calcium Treatment Symposium. 1988. 116 pp. £15. New cored-wire injection techniques, particularly as Design for recyc/ability, by Michael E. Henstock. 1988. 150 pp. £15. Solidification processing. 1988. 549 pp. £45. Marine engineering with copper-nickel. 1988. 103 pp. £18. Characterisation of High Temperature Materials. 3. New journal FMJ International Publications Lid have announced a new quarterly publication, Aluminium Today. 4. Other new publications Algorithms in real algebraic geometry, edited by Denis S. Arnon and Bruno Buchberger. London, Academic Press, 1988. 274 pp. £15.95. Proceedings, Foundry and Heat Treatment 88. R150 per set of 5 volumes, or R40 per volume.

Jan 1, 1989

By Daniel W. Kappes, Pierre F. X. Mousset-Jones

"In this paper a discussion is presented of a program designed to produce a 40-day production forecast for an underground stoping system.The program is intended to be a tool for the operations department in an underground mine, and is designed to utilize data readily available from production reports. Brevity of data input, ability to revise slope conditions easily and the accuracy of starting stope status are stressed. Applicability of the program to a wide variety of sloping methods makes the program potentially useful in a large number of mines.The general functions of the program subroutines, and input and output lists are discussed. An example is also given of a stope in operation for a three-day period, which shows how the program can handle production irregularities as they arise."

Jan 1, 2014

By Northrop. I. N.

Hardmetals possess extremely high hardness and wear resistance, which render them ideal for applications such as metal-cutting tools, rock-drilling tools, and industrial wear-resistant parts like dies, punches, and seals. However, hardmetals are britle, and show poor resistance to impact and shock. They can therefore rarely be used unsupported, and it is common practice to attach hard metal working parts to a more resilient tool holder or support, which is normally made of steel. . . . Owing to the widely differing physical and mechanical properties of steels and hard metals, the Joining of one to the other is problematic, and the method used must be chosen with care. This paper reviews several methods available for the joining of hardmetal to steel, and discusses the advantages and disadvantages of each.

Jan 1, 1987

By V. N. Medvedev, A. M. Bryukhanov

Stationary mine air control equipment enables monitoring of CH4 concentration only in sensor locations. CMC-4 individual indicator built into a caplight has been developed in Ukraine, extending CH4 monitoring to manned job sites. Major technical characteristics of the indicator are demonstrated. It features two operation thresholds: 1st threshold 1.0 to 2.0% vol. 2nd threshold 1.5 to 2.5% vol. Basic absolute accuracy ± 0.2% Caplight battery is a common power supply for the lamp and CH4 indicator, providing at least 10 hours of the system non-stop operation. Average pre-failure life is at least 10,000 hrs. It features: an explosion proof design and intrinsically safe test circuit; a small-sized sensor as an integral part of the caplight; a hybrid microcircuit to facilitate functioning of methane monitoring unit. The CMC-4 indicator weight is the weight of the caplight itself and equals 2.4 kg. A two-threshold design makes possible to distinguish between methane sources: slow accumulation due to diffusion or sudden rushes due to a gas-dynamic event. CMC-4 indicators in addition to stationary equipment minimize the risk of CH4 explosion underground determined as a product of accident intensity by calculated time interval.

Jan 1, 2003

By D. R. Hardman, J. W. Oberholzer

Based on information supplied by South African collieries to the Coal Mining Laboratory of the Chamber of Mines since 1978, the paper outlines the general performance of the continuous miners used and gives the results more-detailed studies of the cutting, loading, and transportation processes. On average, the continuous miners produced coal at a rate of 76 t per operating hour, which, at an average machine availability of 67 per cent, resulted in a production of 51 t per total hour. The cutting rates varied between and 250 t/h but, owing to machine and system inefficiencies, the overall production rate varied between 92 and 48 It is concluded that, if the collieries concentrated on improving their machine utilization procedures and operating practices, they could increase the overall production from their continuous-miner sections.

Jan 1, 1987

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 D. Rankin, H. J. Stucke, W. K. B. Loftus

Discussion: H. J. Wright (Member): The authors are to be congratulated on presenting such a comprehensive and lucid account of bringing a large diamond mine into efficient production from the grass roots. When one considers the vast amount of planning and hard work that had to be put into the project the authors have done a praiseworthy job in condensing the story, so as to present all the important technical aspects, the logic behind the major decisions and the future thinking on the operations, in a concise and readable form. This was the first experience of De Beers personnel in starting a large diamond mine as an opencast project and nor do they employ a large planning staff, most of the planning being carried out by the executive staff themselves. It is operating most efficiently on a large tonnage and it is neatly and very well laid out. In fact, with its model townships, both for European and Coloured employees, tarred roads, recreation club and its grass golf course, it is like an oasis in the arid climate of the North-Western Cape. The key operation of opencast mining is, of course, the planning of the geometry of the pit. This has been adequately dealt with by the authors. It is of interest to consider some of the consequences arising from complete lack of open pit planning, based on actual operating mines. I refer of course to the present, four producing mines in Kimberley. The Kimberlite pipes were all discovered in a short span of time from the year 1870, onwards. They soon became a hive of activity with diggers industriously working their claims at varying rates. The country rock comprises from the surface downwards, some 90 ft of decomposed dolerite followed by approximately 260 ft of soft Karroo shales, which in turn is underlain by a hard competent Ventersdorp lava, known locally as melaphyre. The average water table was just below the dolerite at a depth of approximately 90 to 100 ft. Only the blue ground was mined leaving the waste rock sides almost vertical, and as the depth increased beyond 100 ft, large falls of sidewall started to take place. The shale was unstable and the falls covered

Jan 3, 1969

By FJ Fourie

Lack of success in attempts to develop viable large-scale continuous mining techniques (previously reported by MP o?Hare in 2004) led the team at Kopanang to explore alternative solutions to their ongoing need for improved profitability. By calling into question the basic assumptions around the stoping of narrow tabular deposits of gold, fragmentation and more particularly, the range of sizes of blasted rocks eventually became the focus of serious study. This background is briefly covered before the sequence of the investigations is described. So far, some of the ?rules of thumb? derived over the years have been confirmed, albeit for totally different reasons than those from which they arose; some persistent theories on gold loss have been debunked, and some new ones have been developed. Blast optimisation (the means by which desired fragmentation is achieved) has been based on tailoring energy to rock characteristics in an innovative packaging design for explosive charges. Other beneficial consequences arising from the work include increased production volume and gold output, a decrease in milling consumables, and the Mine Call Factor is being maintained at a level previously thought to be unachievable. This is very much a ?work in progress?, and it is empirical in its approach. The authors are the first to recognise that they have yet to determine in absolute measures why some of the innovations have had the effect that has been observed. Also that there other factors which may contribute to the result, but which have not yet been examined. Nevertheless, publication of the work completed so far is felt to be justified; firstly on the basis of the achievements themselves, and secondly for the benefit of others in the industry for whom similar problems exist. Statistical reports of the effects on the business are included at the end of the report. Detailed laboratory test results have been separated into an appendix, leaving salient graph and tabulated data in the main text. For ease of reading, units of measurement for particle sizes below 1mm are described in microns, but millimetres have been retained for those at that size or greater.

Jan 1, 2007

By C. G. Schmidt, N. W. Hanf

Many of the pyrite concentrates produced at South African gold and uranium mines contain economically significant amounts of nickel, copper, and cobalt, apart from gold and uranium. In some cases these concentrates are leached for uranium, followed by roasting and cyanidation of the calcine for the extraction of the gold. Even if their intrinsic value is excluded, the presence of appreciable amounts of base metals can lead to excessive consumption of cyanide and zinc in the conventional process for the recovery of gold from calcines. The extent to which base metals, particularly cyanocides in the calcine, can be made soluble in water or in dilute acid by variation of the pyrite roasting conditions was investigated. An important finding of the investigation was that the conditions producing favourable base-metal sulphation (and hence solubility in water) also produced good sulphation of the uranium values that had not been extracted in a conventional leach of the original pyrite. Thus, if the pyrite is subjected to a sulphating roast followed by quenching in water (or dilute acid), it should be possible for the uranium to be extracted in improved yield. The need for leaching of the pyrite would therefore fall away. It was noted that sulphation roasting also resulted in improved gold extractions when the calcine was subsequently subjected to conventional cyanide-extraction procedures. From well-sulphated calcine, the dissolution of base metals and uranium appeared to be fairly independent of leaching pH, time, and temperature. On an inadequately sulphated calcine, Iow pH values during leaching gave increased extraction of copper and uranium but did not have a significant effect on the dissolution of nickel and cobalt. The extraction of uranium increased with increasing leaching time and temperature, while only longer times at a Iow pH value markedly improved the extraction of copper. The extraction of cobalt was fairly independent of leaching time and temperature, but the results were insufficient for a conclusive evaluation to be made of their effects on the dissolution of nickel. A cursory economic assessment 'indicated that sulphation roasting applied to the pyrites investigated is likely to be very profitable.

Jan 1, 1979

By M. Berjak, D. M. Hawkins, V. E. Marting, R. B. MacGillivray

Contributions to discussion V. E. Marting (Associate Member): The authors of this paper should be congratulated in having pioneered the application of the Sharapov predictor to local data, and in having made a valuable contribution to South African experience in the quantitative treatment of geological information using a digital computer. Although the existing set of three programmes has been described as a 'suite' it does not represent an integrated system in the accepted sense since the communication between runs is made in the form of punched card files to enable the mining engineer to exercise discretion and control over the data entered at each phase. Although the authors are justifiably proud of the successful results obtained through the application of this method, I feel that it is my duty to comment that the computer aspect of the work has not reached full development and is deserving of the financial support needed to increase its widest usefulness. At the present moment a routine to detect 'missing information' has not been commissioned. Due to the lack of documentation the use of the programmes is restricted since the format for the submission of data is known only to the authors. It is very unlikely that a profitable return on the development costs will be enjoyed before the programme is fully documented and made available to wider use. My criticism of the present incomplete state of the work is being voiced purely with the intent of focussing on the significance of this project and the fact that it is deserving of development on an industry basis. It should be noted that at the economical cost of R4.00 per sq ft of computer print-out, a mining engineer can hardly afford to miss the opportunity of using the programmes on other (e.g. metalliferous) mineral deposits of tabular formation. Since the publication of this paper I have had an opportunity to see the results of the programmes developed by Drs M. D. G. Salamon and F. Deist for designing bord and pillar workings. The basic data for these latter programmes are extracted from iso-line plans drawn conventionally by geologists, a task that could be considerably expedited through the use of Mr Hawkins' programmes. It appears that the efforts of these respective teams are complementary and it is in the interests of the industry that these individual components should eventually form part of an integrated system. E. Margo* (Member): This paper is a good example of how and where the backroom scientist-in this case the mathematical statistician-can aid the mining engineer to develop not only more accurate means for dealing with valuation problems but to develop a tool that can also cope with changed geological specifications.

Jan 1, 1969

COUNCIL The following served on Council during the year under review: Office bearers: Prof D. D. Howat (President), Dr J. P. Hugo and P. W. J. van Rensburg (Vice-Presidents), V. C. Robinson (Immediate Past President) and D. G. Maxwell (Honorary Treasurer). Ordinary Members of Council: H. P. Carlisle, R. C. Espley-Jones, G. H. Grange, Dr D. I. Legge, W. W. Malan, Prof R. P. Plewman, Dr R. E. Robinson, Dr M. D. G. Salamon, L. W. P. van den Bosch and P. A. von Wielligh. Branch Chairmen: A. Bain (Witbank-Middelburg Branch), J. M. Meyer (O.F.S. Branch). Past Presidents serving on Council: R. J. Adamson, M. Barcza, H. Britten, H. E. Cross, J. K. E. Douglas, R. C. J. Goode, P. Lambooy, Prof J. de V. Lambrechts, Dr J. T. McIntyre, J. F. Reid and H. Simon (until March 1972). Ten Council meetings were held during the year with an average attendance of nineteen, and the standing committees held 27 meetings. FINANCE The annual accounts which are attached to this report show an excess of income over expenditure of R21 519. It is very gratifying to be able to report that Council's efforts to stop the depletion of our accumulated funds are meeting with success. The most important contributors to our surplus this year are symposia and colloquia, sales of publications, Company Affiliate subscriptions and the profit on the journal. While we do not expect continued profits from all these sources in the future we do feel that we are now in the process of accumulating a substantial financial foundation. This will give the Council the necessary confidence to initiate the new developments in the activities of the Institute which are now under consideration. The decision to create a new grade of membership, Company Affiliate, is dealt with elsewhere in this report. There has been a generous initial response from companies and this is the cornerstone of our improved financial expectations. The MacArthur Forrest Memorial Fund shows an excess of income over expenditure of R91 and the total fund was, therefore, increased by this amount to R4 502. The balance sheet shows that the market value of quoted shares and debentures increased during the year from R9 160 to RH 331, which is R2 134 in excess of the book value. Accumulated funds now amount to RH 529 compared with R23 010 a year ago. MEMBERSHIP Sixteen Fellows, twenty Members, six Graduates, nine Associates, twelve Students and twenty-four Company Affiliates were elected during the year. One Member and two Associates were reinstated. Twelve members were admitted to retired membership. Transfers: Member to Fellow, three. Graduate to Member, seven Associate to Fellow, one. Student to Member, one. Student to Graduate, four. Student to Fellow, one. Your Council records with deep regret the death during the year of the following: Dr A. J. Orenstein (Honorary Life Fellow), R. A. Cooper, R. J. Spargo, H. Simon and F. Meyer (Life Fellows), S. D. Loxton, W. P. Arnold, G. C. Needham, W. G. Pyne-Mercier, J. Innes and O. T. Wright (Fellows), E. P. Mennell and O. B. Prentis (Members), J. Brits (Associate). After careful consideration of all the implications it was decided during the year to create a new grade of membership to be known as Company Affiliate, in order that there might be a formal and permanent channel for companies to contribute to the important work of the Institute. As recorded above, 24 companies had joined by the end of the year and many further applications have been received since. We extend a hearty welcome to all our new members. A comparative statement of membership as at 30th June, 1972, and the end of the previous year is shown in the following tabulation:-

PREFACE During the past year, the Council of the SAIMM undertook a major strategic-planning exercise to review all its current activities, and to redefine its scope and objectives in the light of changing circumstances. The following are the four main concerns that prompted Council to take stock of the situation. (1) Over the past five years, the SAIMM has become heavily involved in a variety of new activities. (There are many examples, of which the expansion in book publications and the establishment of physical metallurgy as a third major discipline with its own colloquia and schools are perhaps the most important.) While these new activities have considerably broadened the SAIMM's scope, they have resulted in a significant increase in the day-to-day workload of the President, Office Bearers, and Council members, and of the secretarial staff based at Kelvin House.

Jan 1, 1986

By B. Kenealy

A typical deep shaft is President Steyn No. 2 in the Free State, where 9 tonnes of ore are hoisted at about 15 metres per second from 2378 metres below surface. The skips and attachments each weigh 7 tonnes and they are connected by 43 tonnes of rope, so that to hoist the 9 tonnes of payload, a total of 66 tonnes is accelerated from stand still to 55 km/h for each cycle, using an average of 3185 kilowatts of power in the process. The cycle time for the hoisting is 3.22 minutes. The peak power consumption is 6954 kilowatts, which determines the size of the motor used. Is this the right approach? Are larger skips moving at higher speeds the answer? Is there another way?

Jan 1, 1996

A prize awarded by the SAIMM for outstanding academic achievement by 4th-year and 5th-year diplomates at technikons was instituted several years ago. The Senior Vice-President, Mr J.D. Austin, accompanied by the Institute's Secretary, Mrs D. Gardner, attended a prize-awarding function in the form of a luncheon at the Hotel School of the Technikon Witwatersrand on the 25th May.

Jan 1, 1984

By M. C. J. van der Merwe

"Carboxymethyl cellulose is an organic binder used in the iron ore pelletizing industry. The basic principles of how carboxymethyl cellulose (CMC) solutions behave during the pelletizing process and how these principles affect the drop and compression strengths of the pellets are poorly understood. The aim of the investigation was therefore to gain knowledge on the behaviour of CMC during the pelletizing of haematite concentrate.Haematite pellets with different additions of CMC (0.1–0.4 wt%), were subjected to drop tests, compression tests, and free moisture content analysis. The relationship between the drop strength, compression strength, free moisture content, elapsed time, and CMC concentration was analysed.The drop strength had a strong correlation with the free moisture content of the haematite pellets, with a correlation coefficient of 0.94. The compression strength of the CMC-bonded haematite pellets increased as the free moisture content decreased, reaching a maximum upon depletion of the free moisture content. Haematite pellets with CMC concentrations of 0.1 and 0.2 wt% developed most of their strength within the first day after pelletizing, whereas pellets with concentrations of 0.3 and 0.4 wt% developed most of their strength between one and two days after pelletizing. The time within which CMC-bonded haematite pellets develop most of their strength is therefore dependent on the CMC concentration. IntroductionFines are produced during the beneficiation of iron ore. These fines are separated from the lump ore and can be upgraded to produce a concentrate, which is used as a raw material for the production of pellets. Pellets in turn form a key burden material for direct reduction processes as well as the blast furnace (Zhu et al., 2015).Inorganic binders such as bentonite have been used predominantly in the iron ore pelletizing process to obtain pellets with suitable properties (Eisele and Kawatra, 2003). These binders, however, have the disadvantage of introducing impurities into the pellets. This has resulted in organic binders being pursued as suitable replacements for inorganic binders, of which carboxymethyl cellulose (CMC) shows good potential. Although CMC has been used as an organic binder in iron ore pelletizing, the fundamental principles of how it behaves during pelletizing and how these impact on pellet properties are poorly understood."

Jan 1, 2017

By F. P. Agterberg, A. G. Fabbri

"A statistical analysis was done on the locations of 718 copper and 1 257 gold deposits in Abitibi. This area of about 20 000 square miles is one of the better-explored metal-producing areas of Canada.Patterns of clusters were studied by harmonic analysis. Several two-dimensional power spectra showed a number of distinct peaks. Sets of crest lines for patterns of interfering waves were constructed on the basis of these peaks. They pass through elongated clusters of deposits which are spaced more or less equally. For copper these periodic regularities in location may coincide with geological structures largely of Archean age (major fractures and sedimentary belts indicating synclinal structures). A directional relationship with swarms of diabase dykes of known ages and distinct attitudes indicates that the gold mineralization is, in part, younger than the copper mineralization."

Jan 1, 2014

1. New books Specialty steels and hard materials, edited by N. R. Comins and J. B. Clark. Oxford, Pergamon, 1983.482 pp. Hardcover £55.50. Papers presented at an international conference on advances in flow measurement techniques, edited by H. S. Stephens and B. Jarvis. BHRA Fluid Engineering (Cranfield, Bedford, MK43 OAJ, England), 1982. £36. Papers presented at Fourth European Conference on Mixing, edited by H. S. Stephens and D. Goodes. BHRA Fluid Engineering (Cranfield, Bedford, MK43 OAJ, England), 1982. £36. Papers presented at an international conference on hydrocyclones, edited by H. S. Stephens and G. Priestley. BHRA Fluid Engineering (Cranfield, Bedford, MK43, OAJ, England), 1982. 248 pp. £27. Controlled atmospheres for heat treatment, by R. Nemenyi. Oxford, Pergamon, 1983. 225 pp. Hardcover 20, flexicover £7.50. Electrochemical techniques in corrosion testing and research, edited by J. S. Scully. Oxford, Pergamon, 1983. 150 pp. Flexicover £9.45 2. Book reviews Off highway truck haulage, by the Newman Combined Group. Parkvine (Victoria), Australasian Institute of Mining and Metanurgy, 1982. Reviewer: B. J. Vorster Elsevier's mineral and rock table, compiled by P. Lof. Reviewer: A. Wedepohl Field geologists' manual, by B. A. Berkman. Monograph Series No. 9, Australasian Institute of Mining and Metanurgy, 1982.295 pp. Reviewer: R. A. G. Cuipers 3. Mintek reports Report M56 A computer programme for the evaluation of process routes in the production of ferrochromium. Report M61 An atomic-absorption programme for the Apple 11 Plus computer. Report M63 A general-purpose data logger. Report M65 A preliminary survey of the corrosivity of water in gold mines. Report M66 A review of corrosion inhibitors: theory and practice. Report M67 The determination of total cyanide in solutions containing uranium and gold. Report M68 The suitability of Doppler flowmeters for use in the minerals-processing industry. Report M70 The preparation and certification of two reference materials of South African manganese ore. Report M78 A n evaluation of the Leeds laboratory-scale flotation cell. Report M79 The determination, by X-ray-fluorescence spectrometry, of gold and uranium on resin. Report M80 The installation and commissioning of a Siemens SRS200 sequential X-ray-fluorescence spectrometer. Report M81 The application of the inductively coupled plasma system to the simultaneous determination of precious metals. Open-pit and strip mines The South African Institute of Mining and Metallurgy and the Mining Alumni Society of the University of Pretoria are organizing an International Conference on The Planning and Operation of Open Pit and Strip Mines in Pretoria from 9th to 13th April, 1984. Other Institutes co-sponsoring the Conference are The Canadian Institute of Mining and Metallurgy, The Institution of Mining and Metallurgy, and The Society of Mining Engineers of AIME.

Jan 1, 1983

By K. W. Falconer

The Witbank-Middelburg Branch of The South African Institute of Mining and Metallurgy celebrated 100 years of coal mining in the Witbank area with a function held at Douglas Colliery on the 5th December, 1989. Two hundred guests associated with the industry attended the occasion, at which Mr A.A. Sealey, Chairman of Rand Mines, Coal and Base Minerals Division, unveiled a plaque presented to the municipality.

Jan 1, 1990

Dr C. M. van Staden (Fellow): Mr President, ladies and gentlemen, thank you very much for this opportunity to contribute to the paper by Dr Stander, and Messrs Henzen and Funke. First of all, my congratulations to Dr Stander on being re-elected President of the International Association of Water Pollution Research. We in South Africa are proud that this honour was again bestowed on our leading scientist in the field of water research. Furthermore, my congratulations to the authors of this paper. The growth of the pollution problem caused by acidic water discharged from abandoned collieries, is known to most of us. However, I am not aware of any case where an abandoned gold mine is directly discharging polluted underground water. I think it is also a debatable point as to what the quality of underground water being discharged from abandoned gold mines would be in the long run. Any reduction works on a gold mine which practises only fairly good housekeeping, should not cause any water pollution by cyanide. First of all, any cyanide solution before gold precipitation would be too valuable to lose. Secondly, the precipitated solution, which contains the cyanide, is used to pump slime to slimes dams. Any cyanide pollution that may occur at the slimes dam, must come from the top and, fortunately, the days when pen stock water was discharged directly from the top of dams into public streams, have gone. Run-off and seepage is usually acidic, thus decomposing the cyanide. The code of practice by the Chamber of Mines is quite clear on the point as to how the tops of dams should be secured, to prevent any process water or storm-water polluting public streams. The general standards are given on page three of the paper. To my knowledge, under certain circumstances a degree of relaxation can be given regarding the faecal coli count; namely a permissible count of 1 000 per 100 ml. I feel very strongly that research aimed at inhibiting the activity of acid-producing bacteria should be encouraged. Success in this field would be of great benefit to the mining industry. I am very thankful that the authors have mentioned vegetation of dumps as a method to combat water pollution, with the full awareness that the key objective in vegetating dumps is to prevent air pollution. A problem that I have not heard mentioned before and on which I would appreciate the views of the authors, is the pollution that may be caused by power-stations discharging

By H. H. McGregor

Introductory remarks by author When Mr R. C. J. Goode suggested preparation of a paper in the area of manpower utilization in South Africa, I was, while keen to accept his invitation, somewhat hesitant for two reasons. Firstly, I recognized the great difficulty of making a factual contribution, because of the lack of really relevant statistical information available, the fact that much of it is out of date, and the difficulty of researching and co-ordinating it and of evaluating a statistically sound resultant viewpoint. Experience in the actual preparation of this paper has done nothing to change my view in this respect. Secondly, it is obvious that a paper presented to a meeting of this Institute, by a member of it, would be expected to devote considerable attention to the subject in the mining industry. I am not directly employed by the mining industry, although my company has carried out extensive assignments for various sectors of it both in this country and in other parts of the world, since the 1939-45 war. I am more conscious than most of the tremendous technical and managerial skills at the disposal of the industry in this country, and consequently am equally conscious of the hazards of publishing facts and figures which might be taken to indicate any criticism of performance. I am aware that some of the information that I am about to present may indeed generate comment, and possibly even critical comment. I would like to be regarded therefore in presenting this information, as a member of the group, rather than an external critic. Under these circumstances, comment can only be constructive, and this is my earnest hope. The contribution of my paper, if contribution there is, will I hope be in the area of assessing labour productivity in mining, and in secondary industry in such a way that the performance of each against its own past results is comparable. This task has not for the present been to my knowledge attempted, and in advance I wish to take out authors' insurance against legitimate criticism from professional economists and others, by stating that I am well aware of possible short-comings in the arguments. Nevertheless I believe that under the circumstances I have, with the important assistance of several people, been able to take the subject further than has been the case in the past. Finally, I have related productivity in the mining industry and in secondary industry to a target of productivity in the Republic of South Africa. I was fortunate recently in being able to attend a series of lectures by a prominent economist in America. He introduced his subject by calling it 'A broad survey of macro-economics'. Perhaps I might be permitted to describe my paper, in the same idiom, as 'The macro-management of labour'.

Jan 6, 1970