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By A. Nicotra, E. H. Roux, J. H. du Plooy, D. H. de Jagger, P. De Waal, G. J. van der Linde

This paper reviews the geology, history, current beneficiation practices, uses, marketing, and future outlook of phosphate in South Africa. The vastness of the reserves, and the industry's efficiency and competitiveness in world terms, are highlighted.

Jan 1, 1989

By P. W. Ocerbeek

The occurrence, properties, and uses of andalusite, and its advantages over other refractory minerals and materials, are discussed. Ore reserves are given for the five producing areas, and statistics on production, export sales, and prices are included to illustrate the growth of the industry since the early 1960s. The mining and beneficiation procedures are described, with special reference to new techniques in concentration and magnetic separation. As fines dumps represent a considerable source of andalusite, possible methods of recovery are discussed. . The outlook for the future appears favourable, and possible competition from other sources and substitute refractory minerals are mentioned. It is concluded that the industry is in a sound position to maintain South Africa's status as the world's foremost producer and supplier of andalusite.

Jan 1, 1989

By M. A. Ford

This paper reviews the history, sources, mineralogy, extraction metallurgy, conversion, and enrichment of uranium in South Africa. Over the past 40 years extraction plants were built at 27 sites, an9.over 140 kt of uranium have been produced. Older plants have had to adapt to changing market conditions, no single technology has had the opportunity to become entrenched, and costs have been reduced to a third of those of the original flowsheet. The research efforts aimed at developing the country s nuclear raw materials have been particularly rewarding, as they have enabled South Africa to become a world leader in the extraction of uranium from low-grade ores and to develop methods for uranium enrichment and the production of nuclear fuels.

Jan 1, 1993

By J. K. E. Douglas

PRESIDENTIAL ADDRESS Given by Mr J. K. E. DOUGLAS, M.Se. (Eng.) (Rand) SYNOPSIS Lime is the most widely used and the cheapest chemical alkali known to man and virtually every product we use or eat has required lime in some phase of its manufacture. Its use goes back to the earliest days of man and many ancient buildings and writings bear testimony to this. The manufacture of lime involves quarrying, crushing and screening of limestone and the burning of the sized stone in kilns of which there are several types. The earliest kilns were of very crude design and only in comparatively recent times have large capacity, automated and scientifically controlled kilns been developed. The history of the South African lime industry is largely that of the three main lime companies and their story is briefly told. No other material used in industry has a greater diversity of uses or more varied functions and lime has applications in most South African industries. The main applications are in the production of gold and uranium, iron, steel and ferrochrome, carbide, sugar and paper and for water treatment, agriculture and building. The Republic is well endowed with high quality limestone and the conclusion is drawn that many other minerals will have been exhausted before we run out of limestone with which to process them. The expansion of the lime industry has in the past kept pace with the requirements of industry and the future demand is expected to grow in parallel with the growth of these industries. Since the war this growth has been phenomenal and with our expanding populations and abundance of raw materials it should continue in the years ahead. Limiting factors are the shortage of skilled labour and the distance from export markets. Confidence is expressed that the challenges of the future will be met and that the lime industry will continue to make an important contribution to the growth and prosperity of South Africa. INTRODUCTION Lime, gentlemen, is known to all of you. Like myself, most of you have undoubtedly found it to be, on the appropriate occasion, a most pleasant flavouring for gin. But this lime, or rather its juice, was in earlier days more than just a flavouring. In the days of sail it was vital to the health of sailors as a deterrant against the scourge of all sea-going men-scurvy. It thus played a small but important role in the opening-up of trade routes around the world on which was based the original wealth of many of today's more advanced nations. I propose to address you on the subject of lime this evening, not the citrus variety I have just mentioned, but the most widely-used and cheapest alkali known to man, which, largely unsung, plays an even more vital part in modern industry than did its namesake in the development of inter-continental trade. In the time at my disposal, I propose to tell you something of the history, geology and technology of lime manufacture. Then I will briefly sketch for you the development of this industry in South Africa and indicate the role it plays in supplying the requirements of many of our important industries. Finally we will attempt to look into the future. The importance of this chemical alkali to our modern civilization is seldom fully appreciated-virtually every product we use or eat has required lime in some phase of its manufacture, either directly or indirectly. It is one of those basic materials, along with iron, coal, sulphur, salt and petroleum without which industry and, in fact, our modern way of living could not exist. Fortunately, nature has endowed the world with a plentiful supply of the limestone from which lime is derived and most countries have deposits adequate for their requirements. As a result, not only has there been little trade in lime products between countries but in the past the widespread occurrences of limestone have set a pattern of numerous small plants each serving a limited area. These plants were generally crude affairs incapable of producing a quality product. It is not surprising that, in an industry comprised of small producers with limited financial resources and in fierce competition with each other, there was little interchange of information. Technological development was therefore slow and the industry tended to be regarded as a backyard operation. Its popularity was not enhanced by the fact that lime is difficult and unpleasant to handle if proper facilities are not provided. In recent years the lime industry has undergone very radical changes to meet the more exacting requirements of today's more sophisticated consumers. Only since the war have the larger companies emerged with proper management, highly mechanized plants and a scientific approach. HISTORY Lime was one of the first chemical reagents used by man and consequently lime burning is one of the oldest of the chemical industries. The use of limestone dates back to the stone age when primitive man used limestone to build fireplaces, construct shelters and make crude tools and weapons. It is probable that lime was first discovered by him when the stone in these fireplaces disintegrated to a white powder which he could use for decorative purposes. The first recorded use of limestone was when huge blocks of limestone were used to build the pyramids of Egypt in 4,000 to 2,000 RC. It was not long after this that the beauty of marble, which is in fact a limestone, came to be appreciated and it found wide application in sculpturing and for decorative wall construction. Originally lime, mixed with sand, was used mainly as a mortar for building purposes, the earliest record of its use for chemical purposes being in 350 B.C. in a report of the wreck near Marseilles of a ship carrying a cargo of linen and lime 'for its bleaching'1. Cato mentioned the burning of lime kilns in 184 B.C. and the Romans made extensive use of both limestone and lime for highway construction. A treatise on architecture by Vitruvius who had an official position in the rebuilding of Rome under the Emperor Augustus remained for nearly two thousand

By D. D. Hawat

The locations of potential reserves of chromite ores throughout the world are discussed. Reference is made to the marked changes in international trade in chromite ores during the past ten to fifteen years, and to the change in locality of the production of ferochromium aloys, which is curently largely carried out in the country of origin of the ores. The influence of these changes has been very profound in South Africa, which has the largest smelting capacity and the largest production of ferochromium aloys in the world. A proportion of South African ore is stil exported to meet the demands for the production of chromium chemicals and refractories, including a large tonnage of foundry sands. Ferochromium smelters in South Africa have a capacity of virtualy 1 Mt of aloy per annum. Nearly al this development has taken place since the introduction of the argon-oxygen decarburization (A.O.D.) process for the smelting of stainless steels. Formerly, expensive Iow-carbon ferochromium aloys were required as raw materials, but the AO.D. process, which is being used world wide, permits the use of high-carbon ferrochromium, the main product of the smelters in this country. The production in South Africa of chromium-containing corrosion- and heat-resistant steels is stil on a relatively smal scale, but serious atention is being paid to the exploitation of low-carbon weldable feritic chromium steel.

Jan 1, 1986

By A. A. Snodgaass

This paper reviews lead as a commodity, starting with a brief historical outline and dealing with the various uses of lead in some detail. It then goes on to discuss some statistics in relation to the production and reserves of lead, before sketching its mode of occurence. The topics are approached in regard both to the world and to South Africa, with the emphasis on the later. The mining and concentration of lead at Black Mountain Mine at Aggeneys in the north-western Cape Province are detailed, before a general account is given of the smelting, hydrometalurgical extraction, and refining of lead, together with the processes used in these activities. The paper concludes with a discussion of safety and health in regard to lead and a brief look at the commodity's future.

Jan 1, 1986

By C. J. Van Niekerk, C. C. Begley

SYNOPSIS The paper opens with brief descriptions of the history, occurrence, and regional geology of South Afri¬can zinc deposits, and follows with descriptions of the resources, mining methods, and processes for the concentration of the sulphide minerals and the extraction of zinc as practised in South Africa. The end uses in the form of alloys or as salts are given in some detail. Statistics on the production and consumption of zinc in South Africa are given, and the current market situation and future prospects are discussed briefly.

Jan 1, 1991

By A. M. Sage

This paper reviews the metallurgical functions of vanadium in high-strength Iow-alloy steels, and discusses the ways in which vanadium is used in various types of steel supplied as reinforcing bars, plates, sections, and strip. Potential developments to meet new engineering requirements are discussed briefly.

Jan 1, 1984

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

By P. R. Janisch

This paper reviews the sources, production, and technology of gold in South Africa. First of al it details the geographical distribution of gold-bearing materials, together with the mineralogy and distribution of gold within those materials. It goes on to the geological origins, and to the discovery and early exploitation, of the gold deposits. The laws relating to the mining and disposal of the metal are explained, after which an outline is given of gold exploration, processing, and refining. The economics of gold production are discussed briefly, and it is concluded that, although present expertise in the financial and technological aspects of a gold-mining venture have largely reduced the risks involved, one severe risk remains: that the rate of cost inflation will not be matched by the rate of escalation in the gold price.

Jan 1, 1986

By F. S. A. de Frey, F. C. Kruger

Personnel management has undergone a remarkable change over the course of the past ten years. Personnel departments have played an increasingly important role, which today requires highly trained people and cannot be adequately served by the lesser qualified officials of yesteryear. Changes in the mining industry that stem from the demand for skilled labour to keep pace with technological developments and the mechanization of mines today demand that emphasis should be placed on the maximum utilization of manpower. Maximum utilization of manpower calls for more scientific and effective methods of recruiting, selecting, training, and placing workers so as to offer them the best opportunities for development and promotion, which naturally ensure a minimum labour turnover and eliminate labour unrest. This can be achieved only if well-qualified and properly trained personnel administrators are prepared to accept the challenge and apply themselves purposefully by assisting line mangement with the attainment of the company's corporate objectives.

Jan 1, 1982

By J. M. Stewart

Mining fatality rates in many countries have not changed substantially over the past ten years. This demonstrates not only that there is an inherent risk in mining, but also that current approaches to improving safety need to be rethought. An analysis of productivity and fatality data in the United States, United Kingdom, and South 4frican coalmining industries shows that the impact of legislation on safety is overlain by other significant factors. Although improvements in safety and productivity usually occur together, the data warn that safety legislation can sometimes cause a significant reduction in productivity. Based on the data and experience considered, it is concluded that legislation should be aimed at creating a framework within which a positive attitude towards the implementation of more productive and safer mining methods, work practices, and technology can flourish, rather than attempting to enforce excessively prescriptive provisions. This later approach is even more problematic when safety standards and legislation are transferee from well developed to less developed countries. A legislative framework in which the mine manager is required to take al reasonably practicable measures to procure safe working conditions in accordance with mine-specific codes of practice is outlined. Within that framework, the value of adopting widely accepted standards is recognized. A performance-based external audit arrangement is outlined as a basis for ensuring that detailed attention is focused on those areas most needing improvement.

Jan 1, 1995

By H. E. Parkinson, Y. P. Chugh

About 90 percent of the coal mined underground in the U.S.A. today is mined by the room-and-pillar system. The productivity of the system dropped from about 14,1t per man-day in 1969 to about 7,3 t per man-day in 1978. Since 1974, the U.S. Department of Energy (formerly the U.S. Bureau of Mines) has been engaged in research to improve the production and productivity of the room-and-pillar system. The effort involves the development of integrated, automated, and remote-controlled equipment and systems including remote-controlled continuous miners, automated miner-bolters, automated extraction systems, continuous haulage systems for use behind miners, and remote-controlled equipment for miners, bolters, and shuttle cars. These systems are discussed briefly, the discussion being related primarily to coal winning, although the concepts could be utilized in room-and-pillar systems in mines other than coal mines.

Jan 1, 1981

P.W.D. ROSTER OF CONSULTING ENGINEERS (Extract from a letter from the Secretary for Public Works) In recent years a large number of professional engineers has entered the consulting field. Although the names of most of these have been placed on the Department's roster of consulting engineers either as a result of representations made by the South African Association of Consulting Engineers or by applying direct to the Department there are still some who seem to think that canvassing through an influential person is necessary to obtain commissions from the Department. The Department's roster is open to all registered professional engineers who are suitably experienced to undertake consulting work and commissions are awarded strictly on merit. I shall appreciate it, therefore, if registered professional engineers who wish to be considered for commissions by the Department could be advised that they must apply, in the first instance, to be placed on the Department's roster. On receipt of such an application a questionnaire listing all the information required by the Department will be forwarded to the applicants for completion and returning to the Department for record purposes. All names which appear on the roster are taken into account when a commission has to be awarded, due consideration being given to factors such as geographical position, seniority, capability and compatibility. AMERICAN SOCIETY OF MINING ENGINEERS 1970 FALL MEETING AND EXHIBIT The Secretary for Commerce has passed to us a letter received from the American Society of Mining Engineers, reading as follows: "We would be delighted to have South Africa attend our meeting next year and to exhibit some of their mining equipment in our Technological Information Exchange. The 1970 SME Fall Meeting and Exhibit will be held in St. Louis, Mo., October 21-23, 1970, at the Kiel Auditorium. The AIME WorId Conference on Lead & Zinc Mining and Metallurgy will be an integral part of our meeting-and an added incentive to attend. It should be understood that we discourage the showing of actual mining equipment and encourage the manufacturers and suppliers to send their engineers to man the booths. We hope that the exhibits will endeavour to put across their story by means of photographs, drawings, models and literature, rather than by display of prototypes of the actual equipment. We will be happy to welcome manufacturerers from South Africa as well as the mining engineers who, from time to time, have registered at our meetings." For further particulars, interested parties may write to the Society of Mining Engineers, 345 East 47th Street, New York, N.Y. 10077, D.S.A.

By S. Wakita, K. Aoki, Y. Mito, K. Date

It is of great importance to prevent a leakage of hazardous substances from underground storage plants, because this certainly leads to a fatal disaster for human societies. Therefore, effective grouting system needs to be developed, which can inject cement grout into low-permeable rock masses. Authors have carried out a series of laboratory injection tests using a fracture model and field tests in low-permeable rock masses. In these tests, not only was the superiority of dynamic grouting confirmed, but also the relationship between grouting-efficiency and injection parameters was investigated. In this paper, the results of laboratory injection tests and field tests together with theoretical approaches to them are mentioned. L’empêchement de la fuite des substances dangereuses des galeries de stockage est un traitement très important pour protéger la société humaine contre la comtamination catastrophique. Par conséquent, un procédé d’injection efficace doit être mis au point, qui peut injecter du coulis de ciment dans le rocher ayant une perméabilité basse. Les auteurs ont effectué une série d'essais d'injection en laboratoire en utilisant un modèle de rupture et d'essais sur le terrain dans le rocher ayant une perméabilité basse. Dans ces essais, était non seulement la supériorité du l’injection dynamique confirmée, mais aussi le rapport entre l’efficacité de l’injection et les paramètres d'injection a été étudié. Dans cet article, les résultats des essais d'injection en laboratoire et des essais sur le terrain ainsi que les méthodes théoriques pour les essais sont mentionnés. Es ist wichtig, Durchsickerns gefährlicher Substanzen aus unterirdischen Lagerstellen zu verhindern, weil dies für die menschliche Gesellschaft unter Umständen zu verheerenden Unfällen führen kann. Daher muß ein effizientes VerfugesSystem entwickelt werden, welches erlaubt den Mörtelschlamm in wenig durchlässige Felsenmassen einzuspritzen. Die Autoren haben eine Serie von Laboreinspritzungsversuchen mit einem Bruchmodell und Feldversuche an wenig durchlässigen Felsenmassen durchgeführt. Diese Versuche zeigten nicht nur die Überlegenheit des dynamischen Verfugens, sondern wurde dabei auch das Verhältnis zwischen Verfugen und Leistungsfähigkeit sowie den Einspritzungparametern untersucht. In dieser Studie werden die Ergebnisse der Laboreinspritzungtests und die Feldversuche zusammen mit den entsprechenden theoretischen Ansätzen erläutert.

Jan 1, 2003

By Adams. M. D.

Most of the cyanide lost in carbon-In-pulp plants is due to the reaction of cyanide with base metals and sulphides during leaching. Some cyanide is also lost in the adsorption tanks as a result of oxidative and adsorption reactions with the activated carbon. The high rates of cyanide loss in the elution and electrowinning stages are atributable to hydrolytic decomposition and anodic oxidation, respectively. However, the relative amount of cyanide lost during these two stages is small for a given amount of ore treated.

Jan 1, 1990

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.

Primary roof support represents the first line of defence against rockrelated falls of ground in underground mines, and improper utilization or misunderstanding of the applicability and behaviour of primary support can be costly from a safety standpoint. This is a major concern for underground mines, as roof support is the single most costly expense from a mining operational perspective. This is further backed by the evidence that, in the USA, hundreds of injuries and fatalities still occur each year because of rib, roof, and massive roof falls. Additionally, the fully-grouted passive rebar, fully-grouted tension rebar, and resin-assisted mechanical anchor bolts, which constitute a large portion (89%) of the 68 million bolts installed each year in underground mines in the USA can vary in cost quite dramatically. To mitigate this concern a study was conducted in 2010 by the National Institute of Occupational Safety and Health, in conjunction with Southern Illinois University of Carbondale, to assess the performance of primary roofbolts in underground coal mines for improved safety and cost. This was accomplished using underground roofbolt monitoring solutions, field data, and numerical modelling to better understand the quasi-static behaviour of underground coal mine roofs and the response behaviour of the bolts. In particular, over 170 instrumented extensometers, closure meters, shear meters, fully-grouted passive rebar, fully-grouted tension rebar, and resin-assisted mechanical roofbolts were installed at three coal mines across the USA. Of these three mines, two used the room and pillar extraction method and the other used the longwall extraction method. There was no evidence to indicate a difference in performance of the active primary roofbolts compared with the passive primary roofbolts. Additionally, in the initial loading phase, the active bolts showed no difference in loading, indicating that tension bleed-off is of more of a concern than originally thought. Lastly, for the initial computer modelling studies, challenges still remain in obtaining a good match to the in situ bolt measurements and replicating the discontinuous roof rock and in situ bolt behaviour over time.

Jan 1, 2014

By P. J. Petit

Financial evaluation is necessary to investigate the viability of implementing and/or utilising new technology in mining projects. It establishes a techno-economic base for decision-making and justifies capital expenditure. This paper aims to present a monetary appraisal of the electric rock drilling system in a typical feasibility project, whose purpose is to increase the production rate. The in situ environment is a platinum orebody, and the stoping operations occur in UG2 reef. The results are a function of production requirements, technical parameters and financial outlay of the drills. The costs involved in implementing and operating electric rock drills are assessed to the current method of drilling, namely the compressed air operation. A comparison of the electric and pneumatic rock drills in terms of financial outlays for drilling and service requirements, peripheral equipping and training is discussed. Other factors that affect the business case are technical advantages, safety and risk management and the environmental objective of the company.

Jan 1, 2006

By Phil Morriss

During the last 12 months, Sandvik?s Technical Service Group has carried out nine Scoping and Pre-feasibility studies for the application of In-pit crushing and conveying (IPCC) for large mining companies; the majority in conjunction with the Snowden Consulting Group. During these studies several key and recurring drivers have been identified: 1. Mining schedule issues ? there are several issues which crop up repeatedly, including: ?the unnecessary curvature of pit walls, ?very high rates of vertical advance which are (created by schedule optimisers to minimise stripping at all times) which are at the limit of what can be realistically achieved (and which of course make it harder for IPCC to achieve any impact), and ?The allocation of material to semi-mobile systems to maximise the ability for IPCC to be an effective alternative. 2. IPCC productivity issues ? the key issues are the IPCC system operating hours achievable, and the system throughput (both instantaneous and the average). 3. IPCC Risk issues ? there are perceptions about the risks associated with the use of IPCC which are a mix of reality and fiction, but which nonetheless create negativity towards the use of IPCC. In this paper, the authors wish to address specifically the factors affecting the IPCC productivity.

Jan 1, 2008