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By A. García-Gutiérrez, A. Aragón-Jerónimo, R. Salazar-Mendoza

A theoretical analysis of a two-region solid-liquid flow system in horizontal pipes is presented, which considers a stationary bed of drill cuttings as a porous medium (-region) below of a two-phase dispersed flow (-region).The method of volume averaging was applied in this study to derive a rigorous mathematical model in which each variable is precisely defined. This model includes the volume-averaged transport equations for both the two-phase dispersed flow and the porous medium regions and terms from a macroscopic forces balance. The solution of the two-region model allowed evaluation of the behaviour of pressure gradient as a function of velocity, total volume fraction of cuttings and the relationship of the height of the stationary bed and pipe diameter. The solution is based on a backward finite difference explicit scheme. The simulated physical system is a pipe of 4.135 m in horizontal length and 0.0508 m in diameter. A one-dimensional, mesh-centred grid, consisting of 100 nodes, is used. The numerical results were compared with experimental data on slurry flows and a good agreement was found. Keywords: two-phase, cuttings transport, solid-liquid flow, drilling modelling, volume averaging.

Jan 1, 2007

By A. V. L. Narasimham

The practice of refractory lining in Fe Cr furnaces is purely based on the behavior of various refractories used in different parts of the Furnace at elevated temperatures. The choice of the pattern of lining is mostly done on traditionally based concepts. Refractory Lining of a furnace is the most crucial enabler for operational excellence for Ferro Alloys production. During the last few years, no major technological change has taken place in ?Refractory Lining Management?, only freeze lining concept is becoming popular. Many ferro chrome furnaces today, have the refractory lining problems especially at tap holes, resulting in shutdowns and production losses. The author with his experiences for the last 37 years in furnaces of all sizes tried to attempt to investigate into the reasons for premature failure of lining.

Jan 1, 2007

By T. K. Roy

INFACON XI has no doubt earned the distinction as the first such Congress in India. This prestigious occasion could become a reality of a long cherished dream of the Indian Ferroalloy Producers, consumers and ex-porters. The International Committee of Ferro Alloys (ICFA), South Africa, the august body for organising INFACON, every three years, could be convinced by the Indian Ferro Alloy Producers? Association (IFAPA) to award INFACON (XI) to India. This Congresss, organized by IFAPA, has opened a window for the Ferroalloy Community of India, the up-coming Asian Tiger, to register their strength and weakness to the world forum with the principal objectives of evolving long and short-term optimum road-maps for development. It is to be reckoned that India is poised to be a steel giant by 2020 when it is envisaged that the steel production may reach a level of 120 million tons of which significant proportion has to be in the categories of alloy and special steels, requiring standard and high grade ferroalloys. Keeping the above objective in view, the theme of this Congress has been rightfully designed as ?Innovations in Ferro Alloy Industry.? This Congress has also earned a distinction of more than eighty papers, finally selected for inclusion in the Proceedings. More than 100 internationally and nationally reputed experts in the field of ferroalloys (technology and manufacturing practices as well as world scenario) have been approached for critical review of abstracts and selection for the proceedings. It needs to be mentioned without the cooperation received from ICFA the high standard of INFACON could not have been assured. The papers are suitably grouped under seventeen heads, starting from world situation to production and operation followed by present and future technologies and finally to modelling and simulation. It is a Herculean task to the Technical Committee to fit these papers in proper sequence. The Commit-tee members kept no stone unturned to ensure the cogency with the subject matters and at the same timekeeping the flexibility of interests of the participant, especially in the context of three parallel sessions. The Proceedings containing only refereed papers of high quality, will serve the entire gamut of ferroalloy industry and will also highlight the present status of concerned countries. The areas of attention to make the industries globally competitive and at the same time laying emphasis on the prevailing practices, will help the industry leaders to formulate an appropriate global approach. Following the break-through step, instilled by INFACON XI, the Proceedings will be available both in bound and in searchable electronic CD-ROM format. I, as the Chairman of the Technical Committee would like to express thanks and high appreciation to all the Committee members for their whole hearted efforts in all respects without which it would not have been possible to complete these proceedings in the scheduled time. Technical Committee desires to place on record their gratitude to Organising Committee for their synergic cooperation all through in successfully executing multifarious tasks, associated with such a grand international technical Congress.

Jan 1, 2007

By R. P. King

Held on the 22nd March 1972 at Kelvin House. Four papers were presented at this colloquium, which was attended by approximately 120 people. The first paper, 'Flotation Research Work at the N.I.M. research group, University of Natal on the modelling of a Flotation Process' was presented by Dr R. P. King, the leader of the N.I.M. Research Group in the Department of Chemical Engineering at the University of Natal. A discussion panel, under the chairmanship of Dr R. E. Robinson with Mr M. Dawson (PMC), Mr E. Roux (FOSKOR), and Dr B. K. Loveday (NIM), discussed the potential application of the theoretical work on flotation modelling to industrial processes, and alternative approaches to providing a way of control of flotation plants. The second paper, 'Fundamental Studies of the Flotation Process the Work of the National Institute) for Metallurgy', was presented by Dr N. P. Finkelstein. The discussion panel for this paper was under the chairmanship of Professor D. D. Howat,and had as its members Mr H. P. Carlisle (JCI), Professor D. le Roux (University of Pretoria), and Mr E. Rudolph (Anglo American Research Laboratories). A lively discussion on this paper ensued, with several contributions from the floor. After lunch, Mr S. K. de Kok, Assistant Consulting Metallurgist, Anglo Vaal, presented a paper on 'The Flotation of Copper and Zinc Sulphide from Prieska Ore'. The paper was discussed by a panel comprising Dr V. C. Lovell (NIM), Mr A. Gilbert (General Mining), and Dr D. Legge (Anglo Vaal), under the chairmanship of Dr L. Bushell. This discussion, in which many members of the audience participated, revolved around the difficulties associated with the production of copper and zinc concentrates and the lack of fundamental information on the behaviour of copper and zinc sulphides in flotation. The final presentati0n was a paper, 'The Recovery by Flotation of Cassiterite contained in Gravity Concentration Plant Tailings', presented by Mr E. B. Viljoen (Metallurgy Department, Goldfields South Africa Limited). The discussion, led by a panel consisting of Mr O. Tant (Goldfields Laboratories), Mr J. Levin (NIM), and Mr R. I. Shanks (NIM), under the chairmanship of Mr H. Cross (Goldfields South Africa Limited) referred particularly to the use of new reagents for the flotation of tin, with particular emphasis on the fundamental relationship between reagent composition and its ability to float this type of mineral.

Jan 4, 1972

By R. E. Phillips, L. A. Cramer, R. T. Jones

Atomaer (Pty) Ltd is a technology-driven company with interests in Western Australian nickel. Atomaer (RSA) Pty Ltd is a process technology company operating in Southern Africa. It is a subsidiary of Atomaer Holdings Pty Limited (Atomaer), which has operating companies in Australia, Africa, South America, and Europe. In addition, Atomaer has substantial shareholdings in Braemore Resources Plc, a nickel company with interests in sulphide nickel projects in Western Australia and Southern Africa listed on the Alternative Investment Market of London Stock Exchange (AIM); Mintails Limited, a gold company with interests in gold operations in South Africa listed on the Australia Stock Exchange; and Brinkley Mining Plc, a uranium company with interests in Southern Africa listed on the AIM. Independence Platinum Limited (IPt) has been formed by Atomaer to undertake the commercial development and exploitation of Mintek's ConRoast technology with the strategic objective of providing independent smelting and refining facilities with lower capital and operating costs for the treatment and processing of platinum concentrates, including those with high chrome and/or nickel and/or low platinum group metal values, for the development of platinum projects by junior resource companies in South Africa. The platinum mines of South Africa have traditionally exploited the Merensky Reef of the Bushveld Complex for platinum production. However, the mining of this reef is reaching depths that require significant vertical shaft systems and costly refrigeration for access to the ore bodies at deeper levels. In the past decade, all of the platinum producers have begun to mine the UG2 reef because of its cheaper mining costs. UG2 ore usually has lower platinum group metal contents and higher chrome values. The new junior resource companies have gained access primarily to UG2 reefs. Consequently, platinum mining is becoming more UG2-based and the resulting concentrates contain high levels of chromitite. UG2 concentrates are difficult to smelt in the current six-in-line submerged arc furnaces, and this leads to increased capital and operating costs for those smelting operations. The platinum mines of South Africa produce the majority of the world's platinum metal used in automotive catalysts and jewellery. As the platinum market is forecast to grow at a healthy rate into the future, the SA producers Anglo Platinum, Impala, Lonmin, and Northam are planning to expand mining operations in the next decade. Furthermore, a number of smaller new producers who are accessing other mineral resources are entering the buoyant market and will produce platinum concentrates for purchase or toll treatment. Hence, a shortage in both smelting and refining capacities is anticipated. Further smelting and refining facilities independent of the major platinum producers will be required in South Africa by 2010. Mintek's ConRoast technology is best suited to fill the need to treat a high proportion of UG2 concentrates in a cost-effective and technically efficient manner. Atomaer base metals technology has been developed for rapid leaching of nickel and other base metals from alloy. Significant reductions in capital and operating costs are expected from the combination of the two advances in process technology compared with that installed at the existing smelters and refineries that were established over 20 years ago. Independence Platinum will be listed on AIM and the Johannesburg Stock Exchange (JSE) in 2007, and developed as an independent, vertically-integrated platinum company using its independent smelting and base metals refining facilities as a strategic platform to promote the development and mining of platinum projects by junior resource companies in South Africa through technical co-operation, strategic alliances, joint ventures, off-take, toll-refining, and marketing agreements.

Jan 1, 2006

By G. S. Hansford, J. W. de Kock, C. D. Levy

Rheological measurements on pulps from South African gold mines by G. s. HANSFORD, Ph.D. (Pennsylvania), M.Sc. (Cape Town), C. D. LEVY, B.Sc. (Eng.), and J. W. DE KOCK, Ph.D. (Cantab.), B.Sc. (A.I.C.) (Visitors) A method is described for the determination of the rheological parameters of a fast-settling slurry with conventional viscometric measuring equipment. The effect of concentration, temperature, and pH on these parameters is investigated. The results agree with those obtained by previous workers using different viscometers, but this method allows a more detailed characterization of all the properties. From a literature survey, two semi-empirical equations were found that allow the effect of concentration, temperature, or pH on the rheological parameters to be correlated.

Jan 3, 1976

The 96th Annual General Meeting of The South African Institute of Mining and Metallurgy was held in the Gold Room of the Transvaal Automobile Club in Johannesburg on Wednesday, 11th August, 1993. OBITUARIES The President announced the deaths of the following members of the Institute during the past year. Life Fellow E.F. Laschinger. Other Members R.K. Boright, J.S. Jacobi, R.D. Power, J.H. Cannon, C.J. du Plooy, L.B. Mcrae, C.P. Rossouw, A.L. Sillars, A.W. Heugh, R.K. Briggs, P.J. Stark, and C.S. Stott. As a mark of respect to the memory of the deceased and in sympathy with the bereaved, all rose and observed a moment of silence.

Jan 1, 1993

By N. C. Joughlin, D. K. Hallbauer

The size distribution and morphology of gold particles in Witwatersrand reefs and their crushed products by D. K. HALLBAUER, Dr. rer. nat., Dipl. Min. (Visitor) and N. C. JOUGHIN, B.Se. (Eng.), Ph.D. (Rand) (Member) Undistorted gold particles were obtained from samples of a variety of Witwatersrand reefs by dissolution of the quartz in hydrofluoric acid. The size distribution of the gold particles and their shapes and association with thucholite and pyrite are discussed. Gold particles with a natural flat, plate-like appearance occur in varying proportion in all reefs. The effect of a number of different comminution processes on the gold particles was investigated, and the shape of gold particles in mill pulp from a number of mines was examined.

By J. Svoboda, W. J. C. Venter, R. N. Guest

The use of gravity or magnetic separation followed by upgrading on a shaking table recovered about 25 per cent of the copper and lead minerals, at a combined metal grade of 20 per cent, from the final flotation tailing at the Tsumeb Mine. Magnetic separation recovered the copper minerals more efficiently than the lead minerals; it also recovered finer particles more efficiently than standard gravity separators. However, the grade of the concentrate produced by magnetic separation was not of sufficiently high grade, and further upgrading by gravity separation was necessary. It was decided to install an 'all-gravity' plant, which would have the added advantage of acting as a monitor or 'policeman' on a plant that receives a fairly variable feed.

Jan 1, 1988

By A. E. Landsberg, K. C. Corin, G. Stroebel, J. A. Miller, M. Becker, H. J. J. Gordon

Geometallurgy represents an integrated approach to mine planning and operation whereby the naturally occurring ore variability and its effects on all key downstream activities in the mine life cycle are considered. Process mineralogy is one of the key components of this integrated approach. This paper focuses on understanding some of the mineralogical variability across the Swartberg Cu-Pb-Zn sulfide ore in South Africa and its consequent effects on flotation performance. This process mineralogy project is motivated by the planned changeover and expansion of the Black Mountain Mines concentrator to process solely Swartberg ore compared to the run-of-mine blend currently being treated at the plant. Eight samples spanning the main lithological units of the ore body are described using quantitative mineral-textural data and bulk sulfide batch flotation performance to establish five process mineralogical or geometallurgical units comprising: quartz-pyroxmangite-magnetite, quartz-amphibolemagnetite, quartz-magnetite, garnet-magnetite-quartzite and mica-quartzite ores. Important mineralogical characteristics affecting Cu, Pb and Zn recovery, grade and selectivity specific to the different ore samples are discussed. Ultimately, the use of ore-specific process mineralogical and geometallurgical knowledge allows for better mine planning and plant optimisation. Keywords: Flotation, polymetallic base metal sulfide ore, process mineralogy, ore variability

Jan 1, 2020

By M. Rudolph, J. Sygusch

Froth flotation is well-established and efficient in the selective separation of valuable particles from unwanted material with sizes ranging from 10 μm to 200 μm. However, when it comes to the separation of ultrafine particles (< 10 μm) there are still some challenges, or rather opportunities. This research aims at developing a method for the separation of ultrafine particles based on multiple particle properties. Amongst such properties are wettability, morphology (shape or roughness) and size with applications not only in mineral processing but in general chemical engineering. In this study, three differently shaped fractions are used as valuables for testing: spherical particles, elongated particles and irregularly shaped particle fragments; together with ultrafine magnetite as the gangue material, in order to investigate the effect of particle morphology on ultrafine particle flotation, as well as wettability, which is varied by esterification using alcohols. Flotation tests are carried out using a novel flotation device that was designed especially for the flotation of ultrafine particles, combining advantages from machine-type froth flotation and column flotation. The results showed that, in contrast to previous studies, recoveries for ultrafine spheres were higher than for ultrafine fragments for all wettability conditions, and hydrophobisation generally increased particle recoveries for said morphologies. Tests using fibres showed different behaviour as hydrophobisation had negative effects on their recovery, despite increased selectivities and kinetics. These findings suggest that apart from influences of particle properties within the suspension zone, their effects on the froth characteristics should be studied in more depth. Keywords: Ultrafine particles, Flotation, Particle shape, Wettability, Esterification of glass, Hydrophobisation

Jan 1, 2020

On 8th August, 1973, 57 members of the Institute visited Prieska Copper Mine at Copperton in the North Western Cape. After tea, the group was welcomed by the Management of the Mine, and Mr Grobler, the General Manager, gave an introductory talk. After they had been taken on a bus tour of the property, the members split up into groups and proceeded underground or to the concentrator. Of special interest to the mining members were the rock-handling methods in use at the mine. The stoping method that has been adopted is the continuous, long-hole sub-level open stoping system. The broken ore is moved with rubbertyred front-end loaders from the stope drawpoints to the ore passes. On the main tramming levels, the ore is collected by electric locomotives and discharged into the main shaft system at the bottom. At the shaft ore-pass system, a gyratory crusher that can accept rocks up to 1 m in diameter has been installed. The crushed product (minus 150 mm in diameter) will then be hoisted by a Koepe winder, which has a rated capacity of 900 tons per hour. The mine is also served by a declined roadway from surface, which facilitates the movement of heavy equipment. The most striking aspect is the productivity that can be achieved by the use of a trackless-mining system. For the production of 230 000 tons per month, it is estimated that 6 stopers and 7 developers will be required. The total labour force will be approximately 2500-2000 Bantu, 200 Coloured, and 300 Europeans. Training of maintenance and operating personnel is of the utmost importance, and it was interesting to note the extent to which non-White labour is being used in these occupations. Lunch was served at the single quarters, after which the group proceeded to the airfield for the return trip to Johannesburg. On behalf of the visitors, Professor de V. Lambrechts thanked Mr Grobler and his staff for the most interesting morning and for their hospitality,

Jan 10, 1973

1. Journals Marine Geotechnology, edited by R.C. Chaney. London, Taylor & Francis (Rankine Road, Basingstoke, Hants RG 24 OPR, OK), 1988. vol. 8, $50. Published quarterly. Mineral Resources Engineering, edited by C.T. Shaw. London, Taylor & Francis (address as above), 1988. vol. 1, $99. Published quarterly. 2. New publication World mining map of non-ferous metals (with 4 regional maps and a booklet). Reinhard Ryborsch (Postfach 2105, D-6053 Obertshausen bei Frankfurt am Main, West Germany). International edition: bilingual, English and German. 7 colour-print: Size (unfolded) 138 X 100 cm. US$ 19 (excl. mailing) for folded map with hard cover (Order No. 61-4); US$ 25 (excl. mailing) for unfolded (flat) map with hanging strip (Order No. 62-2). 3. Mintek reports Report M326 Crevice corosion and other localized corosion behaviour of 3CR12 corosion-resisting steel in synthetic minewaters, by D. Howarth. May 1988. 28 pp.Report M332 The carbon-regeneration furnaces at Mintek, by P.M. Cole and P.J. van Staden. Nov. 1987. 31 pp. Report M344 The flotation of pyrite with amine colectors, by R.D. Hil, E.W. Giesekke, and P.J. Haris. Mar.&apos;1988. 25 pp.Report M345 The substitution for chromium in steels: Progress and trends, by M.B. Cortie. Mar. 1988. 14 pp.Report M346 The direct reduction of sulphur dioxide to elementalsulphur, by I. Henderson. Mar. 1988. 30 pp.Report M349 The optimization of a process using weak-base resin for the recovery of gold from plant solutions and pulps, by A. Mehmet. Apr. 1988. 17 pp. Report M353 The determination, by ion-interaction chromatography, of sulphur species in cyanide solutions, by Pohlandt-Watson, M.J. Hemmings, D.E. Barnes, and a.w. PansL Jun. 1988. 7 pp. Report M355 A laboratory-scale continuous-feed resistance furnace, by K.P.D. Pery, A.S.E. Kleyenstiber, andC.T. Logan. May 1988. 9 pp. Report M357 The determination of minor and trace elements in activated charcoal, by RT. Eddy and G.J. Wal. Jun. 1988. 14 pp. Report M358 The sensitive determination of germanium by atomicabsorption spectrophotometry using electrothermal atomization, by G.D. Marshal. Jun. 1988. 11 pp. Report M92D The recovery of tin and tungsten from various zones of the Van Roois Vley deposit, including setling and filtration, by C.F.B. Coetzee. First issued Apr. 1983; reissued Apr. 1988. 40 pp. World Environment Day Symposium* Mintek auditorium in Randburg was the venue on Thursday, 2nd June, 1988, for more than 200 interested delegates at the annual World Environment Day Symposium, organized jointly by the Federation of Societies of Professional Engineers (FSPE), The Environmental Planning Professions Inter-disciplinary Committee (EPPIC), The Habitat Council, and The Associated Scientific and Technical Societies of South Africa (AS&TS). The theme &apos;Cultural and Historical Conservation&apos; was adapted from the theme of the Department of Environment Affairs for the 1988 Environment Week.

Jan 1, 1988

By P. J. H. de Graaf, S. D. N. Wessels

"Rio Tinto’s Western Australian expansion, combined with mining within structurally complex geology and increasingly below the water table, presents challenges in effective slope management to ensure safe and economic mining.The Geotechnical Management System (GMS) was developed by Rio Tinto Iron Ore (RTIO) to manage geotechnical risks identified during the design process and implementation, and to ensure feedback based on the ‘as-found’ conditions. The GMS utilizes a risk-based approach to geotechnical risk management and is centred on the geotechnical risk and hazard assessment management system (GRAHAMS). GRAHAMS is used to assess pre- and post-control risk for future potential risks (planned slopes), current risks (as-built slopes), and actual geotechnical hazards (realized risks) identified in the pit. This serves as a core operational risk management tool in identifying and prioritizing key risk sectors and management of critical controls. The system’s database reporting functionality supports effective communication of operational risks to operational personnel, as well as reporting the risk profile across operations to management.A rigorous engagement process between design engineers and sitebased engineers is implemented to ensure that key design assumptions, limitations, risks, and opportunities are understood by the site teams. This information, together with mine plan schedule details, is used to assess the design risk and develop appropriate controls. These controls typically include slope performance monitoring and slope reconciliation. The design feedback loop is closed through sharing of key slope performance and reconciliation data with the design teams.The GMS has been successfully implemented in RTIO pits and is fundamental to successful geotechnical slope management. Improved characterization of design assumptions has allowed for re-assessment of the pit design and improved hazard management in high-risk pits. The GMS, GRAHAMS, and other processes reduce the incidence of unexpected slope instability. Improved understanding of rock mass conditions has allowed for economic optimization through redesign of slopes, allowing for an improved understanding of risk and fewer unexpected conditions (surprises), hence an increased realized value."

Jan 1, 2016

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&apos;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&apos;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 &apos;for its bleaching&apos;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

The 90th Annual General Meeting of The South African Institute of Mining and Metallurgy was held at Kelvin House, Johannesburg, on 19th August, 1987. Dr H. Wagner (President) was in the Chair and declared the meeting open at 16h00. Obituaries The President read out the names of the departed Members as follows: N.M. Airey, F.J. Kisbey-Green, Dr R.A. Pelletier, C.B. Anderson, A.R. Cator, J. van Heerden, P.J. Burman, C.C. Crosson, M. Livingstone¬Blevins, S.T. Firman, V.E. Kisbey-Green, and A.L. Corna. All stood and observed a moment of silence as a mark of respect. Minutes The minutes of the 89th Meeting of the SAIMM, which was held on 20th of August, 1986, were confirmed.

Jan 1, 1987

By B. E. Protheroe, C. Allen, A. Ball

The results of laboratory abrasive and abrasive-corrosive tests carried out on a range of carbon, Iowalloy, and stainless steels are compared with underground tests conducted on similar materials on prototype shaker conveyors carrying gold-bearing quartzitic rock. The dry-abrasion resistance of all the steels was found to be better than that of mild steel. When the added effect of corrosion was tested, the stainless steels proved to be much superior to proprietary abrasion-resistant alloys both in the laboratory and underground. The ferritic stainless grades were shown to be superior on the basis of cost per unit of volume lost. This investigation has shown that laboratory tests on materials can provide valuable information on their possible performance in situ, and can thus be used to replace lengthy experiments on site.

Jan 1, 1981

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 D. Wines

"Slope stability analyses have traditionally been undertaken in two dimensions assuming plane strain conditions. Although three-dimensional analysis techniques are widely available and used routinely for open pits, two-dimensional analyses are still more common due to the relative ease of model construction and the relatively rapid simulation times.Two-dimensional analyses will often produce different results to three-dimensional analyses for the same slope. It is generally thought that two-dimensional analyses will produce more conservative results. The main reason for the differences is the ability of three-dimensional analyses to account for the three-dimensional nature of the various model inputs, including the slope geometry, the distribution of soil and rock mass domains, the orientation of geological structures with respect to the excavation face, the orientation of the in situ stresses, and the distribution of pore pressure. In some cases, for a long, straight slope in basic geological conditions, two-dimensional analyses can provide a reasonable representation of the problem. However, in many cases, the inability of a two-dimensional analysis to represent the true three-dimensional nature of the problem will lead to unrealistic analysis results.This paper discusses the reasons, as detailed above, for the differences in two-dimensional and three-dimensional analysis results. Work by others is summarized, and additional numerical analyses are performed to provide an improved understanding of the effects of slope geometry, structural orientations, and in situ stresses on predicted stability. Case studies are presented for both stable and unstable slopes, and the behaviour of these slopes is related to the three-dimensional nature of the slope geometry and geology.The previous work, the new analyses performed here, and the case studies show that it is often important to provide a realistic representation of the slope in three dimensions in order to obtain reasonable stability analysis results. This is particularly true for hard rock environments where structurally controlled failure mechanisms are most likely. The paper also highlights the fact that back-analysed properties obtained from one analysis technique are not necessarily applicable to forward analyses using another technique."

Jan 1, 2016

By Stuart Marsland

"Reference materials have always been important for validating and controlling analytical methods&apos;, They have recently become even more important as quality requirements have become more stringent and customer demands for properly verified and controlled results increase. Clients, especially from the resource exploration industry demand critical validation of all results reported. Mintek has been producing geological and semi processed ore references since the early 1970&apos;s and recently due to increase in demand other manufactures have entered the South African Market.This paper describes Analytical challenges from the customer&apos;s perspective. The customer being the metallurgist, mine geologist, environmental scientist and geologists from resource companies. Reference Materials and their appropriate use and good understanding of them can aid greatly in building confidence in the results, choosing the right Laboratory for a project, deciding which set of results arc correct and providing evidence to the customer&apos;s clients that the results obtained are the very best possible.Throughout the world there are hundreds of reference materials produced by over 80 organisations and these are mainly ores, rocks, semi processed ores, metals, and many more. Mintek is one of the top 10 producers with over 75 products. Many of these producers including Mintek and their respective standards organisations belong to the ISO REMCO committee and their respective work groups. This committee&apos;s main task is to draw up guide lines for the use, manufacturing and certifying reference materials. In South Africa a mirror committee has recently had its inaugural meeting the function is to give clear mandate to the South African representative on the main ISO REMCO committee, the South African delegate bas an opportunity to influence the contents of the guides.Tile SARM program has since the year 2000 increased its sale three fold, the question is why? There is more accountability needed in our world. That means Analytical results have to be the very best possible and risks associated to them must be well quantified. Consider that the risk of wrong results of wrong decisions made from a result is trivial to laboratory, in comparison to the laboratories customers. The consequence to a laboratory could be a loss of income or some one may lose their job. To the customer he may dig up 1000 of ton&apos;s of rock with nothing in it or worse still don&apos;t mine it when the grade is high enough. This is seriol1s money."

Jan 1, 2014