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A Seminar to discuss 'Reactivity of Line in Steel Making' was held in the auditorium of Iscor's Headquarters Building in Pretoria on the 5th August, 1971. The Institute organised this Seminar on the occasion of the visit of Dr Obst of the Rheinische Kalkstein Werke GMBH, Wuelfrath, West Germany. The latter is one of the largest lime companies in the world and Dr Obst is in charge of their research laboratory. He and his co-workers have earned a reputation for their research into reactivity of lime in steel making. This work is also of great importance to the steel industry in this country, particularly with the changes which are occurring with the introduction of basic oxygen furnaces. Some 80 persons representing most of the major steel companies attended this Seminar. Dr Obst presented his most interesting paper which he illustrated with projector slides. This paper is printed in full in this journal. This was followed by several contributions and active discussions. The first contribution was made by Dr T. B. Beeton of the Research and Development Department, Iscor. He gave a brief summary of the studies on reactive lime carried out at Iscor since 1968. Their work was particularly related to the selection and definition of the various reactivity tests and the correlation of these with plant results. He demonstrated that the DIN methods, particularly the Din (40°) test, gave the best results and reported that good agreement had been reached between Iscor, Highveld and Northern Lime on future test procedures. Mr B. Lowther of The Northern Lime Company then dealt with problems associated with the production of high reactive lime. The rotary kilns at The Northern Lime plant at Lime Acres are particularly suitable for the production of high-reactive lime, because this type of kiln lends itself to accurate control of temperatures and retention times. Several problems, however, exist. Because of the long haul distances and the deterioration of reactive lime by absorption of CO2 and water, high reactive lime is not suitable for most customers. To constantly be changing kiln conditions to produce relatively small quantities of high-reactive lime, therefore, causes problems. Highveld Steel at present is the only company requiring high-reactive lime and a satisfactory product is now being produced at a cost because kiln capacity is reduced and fuel costs are higher. Dr P. R. Jochens, of the National Institute for Metallurgy then submitted data to show how the reactivity of soft burnt reactive lime deteriorated due to long railage hauls. Detailed sampling of trucks had been carried out leaving the lime works and on receipt at Highveld and it was demonstrated that there was deterioration in the top layers of the truck. This top layer protected the balance of the lime which is still in good condition on arrival at Highveld. Exposure to atmosphere by further handling and storage into the bunkers at Highveld, however, resulted in further severe deterioration in the lime reactivity and the lime when finally fed to the Basic Oxygen Furnace is reduced to one third to one quarter of the original reactivity value. The same deterioration does not occur with normal run of kiln lime, which is burnt harder, but still has a satisfactory reactivity for most purposes. Mr A. A. Hejja of the Department of Metallurgy, Witwatersrand University then made a contribution on the metallurgical aspects of the use of lime of different reactivities in the Basic Oxygen Furnace and the effect on desulphurization efficiencies. He gave a wealth of data on actual tests which had been carried out and came up with the surprising conclusion that the deterioration of high-reactive lime due to transport did not have as serious an effect on the efficiency of desulphurization as one would have expected. The efficiency was good provided high-reactive lime in the first instance had been produced, irrespective of whether it had deteriorated thereafter. Poor efficiency was obtained only when the lime in the first instance was produced in an unreactive form. The temperature rise in the Basic Oxygen Furnace also has a definite effect. If lime is introduced when the temperature is too high, soft burnt reactive lime becomes hard burnt and unreactive before it can dissolve in the slag. Use of ferromanganese slag assists dissolution of lime. There was a great deal of discussion following these contributions. Particular interest was expres8ed in the special lime described by Dr Obst. This consists of a mixture of fine lime which is premixed with fluxes and either briquetted or pelletised. The question of injecting finely ground lime as an alternative was also discussed. Both these systems eliminate the necessity for highly reactive lime. With smaller lime particles, larger surfaces are exposed thereby ensuring more rapid dissolution in the molten slag. The discussions generally were lively and informative and all present derived benefit from learning of the experiences of others. The valuable contribution made by our German visitor, Dr Obst, was particularly appreciated. The instantaneous English-German translation service which was provided, greatly facilitated discussions.

By J. de V. Lambrechts

A critical comparison of specific cooling power and the wet kata thermometer in hot mining environments By J. de V. Lambreehts. D.Sc. (Eng.) (Rand) A new formula for the wet kata thermometer has been established in place of the currently used one which is believed to be fundamentally wrong and the new formula is compared with the recently proposed specific cooling power concept. Apart from a constant multiplier, it is concluded that the difference between. the two concepts lies solely in the value of 'n' in the function vn and that this value for the cooling power of air on the sweating human body remains to be established reliably. The kata thermometer might yet be found to be a reliable predictor of heat stress in hot environments.

By J. Bal, V. D. Dao, W. Li

"SynopsisThis study proposes a methodology for evaluating the risk of coal bumps in multiple-seam longwall mining. Both the stress field and the total energy release (TER) during retreat were evaluated in the specified case involving multiple-seam mining using the LaModel program. The results of numerical simulations indicated that both the peak vertical stresses on the panel edges and the peak TERs in the outby longwalls increased significantly as the horizontal offsets were reduced from 60 m to zero. With the comprehensive consideration of the stress field and TERs, a conservative offset of 60 m was ultimately adopted when developing the gateroads of the lower panel in the field. The field measurements indicated that coal bumps were avoided completely by employing the proposed design, and the maximum roof-to-floor and rib-to-rib convergences of the tailgate during retreat were only 360 mm and 576 mm, respectively.IntroductionCoal bumps – sudden, violent bursts of coal – pose a serious threat to the safe excavation of coal. Their occurrence depends on the properties of the surrounding rocks, stress field, and dynamic disturbance. The complexity of the mechanism of coal bumps is further enhanced in multiple-seam mining due to seam interaction. Multiple-seam mining is most frequently found in the coalfields in eastern China, such as Xuzhou, Xinwen, Zaozhuang, and Huainan. In the past, due to issues of availability, economics, and ignorance of the potential risk in multipleseam mining, coal seams in such conditions were mined without proper planning to account for seam interaction. Fortunately, studies published over the past three decades have raised awareness of the problems associated with multiple-seam mining, and indicated that the ground control issues induced by multiple-seam mining can be avoided and/or minimized with proper planning.A number of technical studies pertaining to the design of multiple-seam mines have been published. These studies can be divided into two groups based on their methodologies of design: empirical (Chekan and Listak, 1993; Haycocks and Zhou, 1990, Matetic et al.; 1987a, 1987b) and numerical approaches (Li et al., 2000; Maleki, 2007; Mark, 2007; Peng, 2007; Zipf, 2005). The majority of the extant studies on the interaction mechanisms in multiple-seam mining have focused on the load transfer during operation, resulting in the proposal of the pressure bulb theory (Forrest et al., 1987; Haycocks and Karmis, 1983; Peng, 2008; Peng and Chandra, 1980) and pressure arch theory (Holland, 1973; Oram and Ponder, 1997) to guide multiple-seam mine design. However, neither, of these theories can be used to evaluate the potential for coal bumps."

Jan 1, 2015

By Wilson. D.

The Vaal Triangle Branch of The South African Institute of Mining and Metallurgy was established on 20th November, 1986, at a meeting enthusiastically supported by local members. In attendance were special guests Dr H. Wagner (President, SAIMM) and Dr O.K. H. Stefen (Junior Vice-President, SAIMM).

Jan 1, 1987

By J. Hadjigeorgiou, J. Wesseloo

Mining companies employ a multitude of risk management tools. The effectiveness of these tools for decision-making and communicating risk has not been addressed. This paper investigates the use of verbal probabilistic expressions in communicating geomechanical risk. Analysing survey data obtained from a group of mining geomechanics professionals, it identifies limitations of common probabilistic expressions. The paper concludes by making specific recommendations to avoid the use of certain expressions that may result in increased uncertainty, thus compromising the use of risk management tools.

Jan 30, 2026

Fathi Habashi, Chalcopyrite. Its chemistry and metallurgy. New York, McGraw-Hill, 1978. 165 pp. RI9,95. Loss prevention and safety promotion The Proceedings of the 2nd International Symposium on Loss Prevention and Safety Promotion in the Process Industries, Heidelberg, 6th to 9th September, 1977, are now available. Chemical reaction engineering The Proceedings of the 4th International/6th European Symposium on Chemical Reaction Engineering (4th ISCRE) held at Heidelberg, Federal Republic of Ge rmany, from 6th to 8th April, 1976, are available from DECHEMA Deutsche Gesellschaft fur Chemisches Apparatewesen, P.O.B. 970146, D-6000 Frankfurt/ Main, West Germany, at the price of DMlOO plus postage and packing. Books received The Institution of Mechanical Engineers Proceedings Volume 190. Tribos abstracts on friction lubrication wear. Published by BHRA Fluid Engineering, Cranfield, Bedford MK 43 OAJ England. Price £30 (UK), US$72 (Europe), Seawater corrosion handbook, edited by M. M. Schumaker. Noyes Data Corporation Publicity Department, Mill Road at Grand Ave., Park Ridge, NJ 07656. 494 pp. Australian mineral industry quarterly 31(1) 1978 and 31(2) 1978. Bureau of Mineral Resources, Geology and Geophysics, Box 378, Canberra City, ACT 2601 Australia. Subscriptions $8, individual number $2. Mineral and NIM reports Report no. 1996 The extraction of gold from chloride solutions. (10th Nov., 1978). Report no. 1898 Batch and pilot-plant tests on M erensky Reef ore from the Western Platinum Mine. (8th Jun., 1977; reissued 30th Jan., 1979). Report no. 1920 A mineralogical investigation of Mamatu'an and Wessels manganese ores. (15th Sep., 1977; reissued 3rd Jan., 1979). Report no. 1978 The preparation and certification of a referencesample of magnetite ore. (22nd Dec., 1978). Report no. 1998 Electrode response to the addition of zinc during the cementation of gold. (25th Jan., 1979). Report no. 2002 The spectrochemical determination of phosphorus, magnesium, and iron in phosphate rocks and sulphuric acid leach liquors. (26th January, 1979). Report no. 1992 The use of emission spectrometry for the determination of impurities in metals. (24th Jan., 1979). Report no. 2003 An electrodeless conductivity meter of improved sensitivity and reliability. (28th Feb., 1979). Report no. 2005 The spectrometric analysis of manganese-bearing materials with particular reference to ferromanganese slags and metals. (16th Mar., 1979). Report no. 2006 An examination of procedures for the analysis of dry powders by atomic-absorption spectrophotometry. (28th Feb., 1979). Report no. 2007 The instrumentation and computerization of a 25 MV.A submerged -arc furnace. (25th Mar., 1977; reissued 16th Mar., 1979). Corrosion The International Corrosion Council has decided to hold the next Internat ional Congress on Corrosion in Mainz, Federal Republic of Germany, from 6th to 11th September, 1981. Process control The First European Symposium on Real -time Datahandling and Process Control will be held in West Berlin from 23rd to 25th October, 1979. Geomechanics The 28th Geomechanics Colloquy, organized by the Oosterreichische Gesellschaft fur Geomechanik, is to be held at Salzburg on 18th and 19th October, 1979. Geosta tistics A short course on 'Geostatistics for exploration and production planning' is being conducted by the Applied Earth Sciences Department, Stanford University, California, from 27th to 31st August, 1979. Business administration The Twelfth Executive Development Programme of the Graduate School of Business Administration, University of the Witwatersrand, is to be held from 9th July to 17th August, 1979. The engineer and the law A series of four meetings on the above subject is being conducted by the Measurement, Computation and Control SubCommittee of The South African Institute of Electrical Engineers. Lead smelter for South Africa? The National Institute for Metallurgy and Gold Fields of South Africa are making a comprehensive joint investigation of the technical and economic viability of an integrated lead smelter. Conference on titanium The Fourth International Conference on Titanium will be held from 19th to 22nd May, 1980, in Kyoto, Japan.

Jan 1, 1979

By L. Bloch

Most mine safety initiatives in South Africa are doomed to limited success because of one simple fact: they are a-historical and un-cultural and do not deal with the serious ?legacy issues? that still negatively impact on safety, production, and relationships. We in the SA mining industry continually use imported, foreign safety concepts and systems that will not work fully in a South African context. ?The 4th Wave: Culture-Based Behavioural Safety?, as developed by Lance Bloch, an international award-winning clinical psychologist with 12 years? experience in the mining industry - focused mostly on Platinum - is making waves. He has been very successful in creating people-centred, empowered, high-performance safety cultures wherever he has worked. Not only does the 4th Wave transform the corporate culture of a mine, improving safety and production and building an environment of Ubuntu, but it also uses people?s cultures as a means of winning hearts and minds in the battle for safe production. Powerful relationships are built through engagement at all levels, leading to all being focused on the best needs of the company and its constituents as a whole. The programmes are no less than nation-building - something most necessary in the industry, with the pressures from community, unions, the DMR, and politicians. This presentation will describe and discuss the 4th Wave as an advance on previous safety technology and programmes, as particularly relevant to platinum mining in South Africa today.

Jan 1, 2012

By I. Ince, S. Kahraman, M. Rostami, B. Dibavar

The density, porosity, and strength of rocks are fundamental in the design of geo-engineering projects. Determining these properties requires the preparation of smooth core samples, which is usually impossible for soft rocks. Besides, only fragmented samples may be available in some projects. A method for predicting rock properties from rock particles such as drilling debris would therefore be useful. This study was undertaken to develop prediction equations for compressive strength (UCS), tensile strength (BTS), density, and porosity values from the crushability index (CI) obtained from rock fragments. The results showed that UCS, BTS, density, and porosity were strongly correlated with the CI. The physical characteristics and strength of rocks may be predicted with the help of the derived equations. The CI test is a valuable tool for estimating rock properties in drilling projects and in situations where core specimens are not available.

Mar 14, 2024

By M. A. El-Sayed

"Double oxide films (bifilms) are significant defects in light alloy castings that occur when, during melt handling, the oxidized surface of the melt is folded over onto itself and then entrained into the liquid metal, encapsulating a portion of the local atmosphere. These defects create crevices in the final castings and have been shown to decrease tensile and fatigue properties, and also to increase their scatter, making casting properties unreproducible and unreliable. This paper reports on two different experiments performed to study the behaviour of such defects in Al alloys. In the first experiment and as a proxy for a bifilm, air bubbles were held in an Al-5Mg alloy melt for varying periods of time before the melt was allowed to solidify. The composition of the gas content of the bubbles was subsequently analysed using mass spectrometry to ascertain how it changed with time. In the other experiment the influence of the age of bifilms on the mechanical properties of Al-5Mg castings was assessed by holding castings in the liquid state for different times before solidification, followed by mechanical property testing and SEM and EDX studies of the fracture surfaces of tensile test bars. This research could provide a better understanding of the behaviour of double oxide film defects, and may lead to the development of new techniques by which these defects could be eliminated, or at least deactivated, in light alloy castings. Introduction One of the major structural defects affecting the reproducibility of mechanical properties of aluminium castings is the double oxide film defect (El-Sayed and Essa, 2017; El-Sayed and Ghazy, 2017). This type of defect is usually created as a result of poor filling system design. Owing to the very high reactivity of liquid Al-Mg alloy with oxygen in the air, the surface of the liquid metal can be considered to be permanently coated with an oxide film (Weigel and Fromm, 1990). As a consequence of surface turbulence, the oxidized metal surface can become folded over onto itself, but not fused, and then submerged into the bulk liquid, with a portion of the mould atmosphere being entrapped within it (Campbell, 2003; Al- Sayed, 2016; El-Sayed, Hassanin, and Essa, 2016)."

Nov 1, 2018

By Nielen van der Merwe

Mr Janisch' s comment' in the August issue on Dick Stacey's remarks about safety factors indeed requires wider debate. The example he quoted to illustrate the successful application of the safety factor concept in coal mining, namely the Salamon formula, is to my knowledge the only recognized application of that concept. Not only that, but that particular formula should be used only for what it was intended, namely to prevent major disasters. It was never intended to indicate long-term pillar stability, and it should not be used for that.

Jan 1, 1993

By B. K. Loveday

The South African Institute of Mining and Metallurgy hosted a School on 'The Practical Design of Comminution Processes' at Megawatt Park (near Johannesburg) on 14th to 16th May, 1991 Derek Barratt, a Senior Consultant of Wright Engineers, Canada, and the main speaker, provided a good insight into how Wright Engineers design milling circuits, particularly large semi-autogenous mills. He was ably assisted by Jens Lichterof Allis Mineral Systems, who described some interesting examples of pilot-plant testwork and summarized South African milling practice. Mike Moys of the Witwatersrand University spoke on the influence of pulp viscosity on mill performance, and Johan Engelbrecht and Jeremy Bosman of Multotech

Jan 1, 1991

The following letter has been received from Professor P. A. Young, Head of the Department of Mining and Mineral Engineering at The University of Leeds, England. Extractive and process metallurgy The first annual TMS-AIME Extractive and Process Metallurgy Fall Meeting:1983 International Sulfide Smelting Symposium, will be held from 6th to 9th November, 1983, in San Francisco.

Jan 1, 1982

The October General Meeting of the Institute was held in Kelvin House, Johannesburg, on Wednesday, 21st October, 1970, at 4.30 p.m. V. C. Robinson (President) was in the chair. There were also present 25 Fellows, including J. K. E. Douglas, Prof D. D. Howat, D. G. Maxwell, Dr R. E. Robinson, P. A. von Wielligh (Council Members). D. Ayres, G. Burrow, E. H. D. Carman, D. L. Carson, M. E. E. Douglas, S. A. Finney, W. R. Flook, A. J. Freemantle, W. A. Gilbert, E. B. Gordon, B. W. Gray, J. M. Jacobs, P. H. Kitto, C. H. Kruger, Dr P. J. D. Lloyd, D. G. Malan, W. Pilkington, W. G. Pyne-Mercier, K. S. Rae, W. T. Ruhmer, D. J. Tutt and D. T. Watt. Seven Members, including E. J. Dominy, S. I. du Preez, L. V. Grobler, D. R. Lings, G. D. Louw, J. S. A. Oelofse and O. B. Prentis. Fifteen Visitors, including J. R. Coppin, Dr A. Faure, P. E. Franzl, G. P. Hart, D. van Heerden, A. W. Hunt, A. R. F. MacDonald, B. G. Meyburgh, P. H. Radcliffe, J. M. Shirley, T. H. Tunley, A. D. Vellema and R. E. Wheeler. Secretary, D. C. Visser. Total present: 49. OBITUARIES The President: "It is my sad duty to announce the death of the following: Sir George Arthur Davenport, Honorary Life Fellow, who joined the Institute in 1930 and passed away on 17th September, 1970. The late Sir George was also, for many years, our corresponding member for Rhodesia. Andrew Malcolm Carmichael, Associate, who joined the Institute in 1944 and passed away on 22nd August, 1970. Cyril John Douglas Veal, Life Fellow, who joined the Institute in 1929 and passed away on 27th August, 1970. As a mark of respect to the memory of the deceased and in sympathy with the bereaved I would ask you all to rise and observe a few moments' silence." CONFIRMATION OF MINUTES The President: "May we confirm the minutes of the Annual General Meeting held on 26th August, 1970, and the minutes of the monthly general meetings which were held on the 20th of May and the 17th of June, 1970, as published in the August Journal." Agreed. MEMBERSHIP The President: "I have much pleasure in announcing that the names of the undermentioned candidates, having been published in accordance with By-Law 5.2.2., Council has elected them to membership of the Institute in the following grades: Members: Nikolaos Lalakakis, Gordon Phillips Rundle. Associates: Henry du Preez, James Robert Forbes, Johannes Stephanus Albertus Oelofse, Casper Vorster van Heerden. Graduates: Michael Harold Crosbie, Graham Robert Wallis Walker, Gary Walker Braithwaite. Students: Mohammad Ali Kazemzadeh, Gerhardus Petrus Benade. APPLICATIONS FOR TRANSFER From Graduate to Member: James Wormald. From Student to Graduate: Peter John Cook, Pieter Willem Greeff. "I welcome the newly elected members to the Institute and congratulate the members who have been transferred to a higher grade." PAPER FOR PRESENTATION The President: "This paper is entitled 'The Design, Erection and Operation of a Purlex Plant at Buffelsfontein Gold Mining Company Limited'. It is presented to the Institute by Mr B. G. Meyburgh, a visitor to our Institute. He is a graduate of the University of the Orange Free State and is the Uranium Plant Superintendent at Buffelsfontein and he, therefore, is in a very strong position to describe this very excellent job which is being done as he has been associated with this plant from the inception." After the presentation of the paper the President said: "Gentlemen, the paper you've heard from Mr Meyburgh is a very concise and interesting account of an important piece of work, and I think the title is so completely descriptive of the subject, which is admirably set out in the paper which you have heard. You probably haven't all had the opportunity of reading it, but you very soon will. I found it interesting to note that the results predicted were surpassed in the operation of the plant to date. The actual results obtained are significantly good, I think. Any process which, in this country, increases production and decreases costs, is to be welcomed, particularly when it is so necessary for South Africa almost to bend over backwards to utilise every avenue available in order to increase the scope of the production for overseas' markets, of her metallurgical and mineral potential. In lighter vein-and there is no reason why we should always be so serious-I am glad to see that, in a scientific journal like this, such words as the American word 'crud' which I have been picked out about so often, because my grandchildren use it, is now given an aura of respectability. Thank you very much, Mr Meyburgh, for an interesting paper. We have a long list of contributors, and I am not going to waste any more time. I am going to call on Mr Tunley of the N.I.M. for the first contribution." T. H. Tunley, P. de Bruyn (read by A. D. Vellema), E. J. Dominy, E. H. D. Carman, A. R. F. MacDonald D. C. Streicher (read by P. H. Radcliff), Dr A. Faure and Dr P. J. D. Lloyd then contributed to the discussion. (This discussion will appear in a later issue of the Journal.) The President: "I wish to thank members and visitors for their attendance, and now declare the meeting closed." The meeting closed at 6.05 p.m.

By D. Moses, J. A. Onyango

Carbonatites are generally competent rock masses with rock mass rating class II rating 60–74. In spite of their competency, they tend to be affected by weak features like manganese-iron veins and/or in situ rock damage due to brecciation associated with carbonatite complexes. Rock slope failure in such hard rocks is complex since such structures within the rock mass form weak links that could potentially control slope instability. In this contribution, a numerical simulation using phase2 v 7.0 was carried out to investigate the influence of in situ rock damage on the stability of mine pit walls. The outcome reveals that, the existence of breccia in the competent rock mass has the capability to reduce the slope stability performance particularly at gentle dipping angles of emplacement in close range to the slope toe. However, as the emplacement position of breccia moves away from the pit wall, the stability performance increases at gentle dipping angle <50º. On the contrary, at the dipping angle of 50° the performance of slope reduced, and at steeper angles >50° the impact becomes negligible. Thus, from a series of analyses, mine design in brecciated rock masses, the ratio of 1:5 between the breccia distance from slope toe and pit depth should be implemented to counter its impact, and if the breccia is within or close to the pit limit, a deliberate effort must be made to mine it out.

Sep 1, 2025

By M. Abdellatif

"SynopsisCalcined basic nickel carbonate (BNC) concentrate was smelted in a pilotscale DC arc furnace to produce a nickel metal. The furnace was continuously operated for 12 days (24 hour/day), during which twelve different smelting conditions were investigated, with the major variables being reductant type and feed rate, flux composition and addition, and BNC feed rate.The 200 kW DC arc furnace was operated at power levels between 110 and 165 kW and at a total feed rate of 78 to 96 kg/h, resulting in an average slag and metal tapping temperature of about 1650°C. A total of 7.2 t of BNC were smelted, producing about 5.44 t of nickel metal and 2.94 t of slag. Nickel recoveries of 96.4% and higher were achieved, and the slag nickel content was as low as 0.1%. The major impurities in the metal were iron (mostly from oxygen lancing) and carbon. The calculated feed carry-over was less than 0.85% and the graphite electrode consumption was between 2.8–3.3 kg/MWh.IntroductionOne of the most distinctive advantages of DC open-arc smelting is the ability to process fine raw materials without any major issues with regard to the operability of the furnace, metal recovery, and metal quality. This has been demonstrated in Mintek’s DC arc pilot plant facilities over a period of about three decades (Curr et al., 1983). The materials that have been processed include laterite (Kotze, 2002), chromite fines (Curr et al., 1983), manganese fines (Lagendijk et al., 2010), PGM concentrates (Shaw et al., 2013), electric arc furnace (EAF) dust (Denton et al., 2005; Abdellatif, 2002a) and stainless steel (SS) dust (Denton et al., 2005; Abdellatif, 2002a; Goff and Denton, 2004), and petroleum fly ash (Abdellatif, 2002b). The top particle size of such materials can vary from a few millimetres (e.g. laterite) to micrometres (EAF and SS dust). Dusting, whether due to physical carryover of feed or to the arc side reactions, has been proven to be a non-issue. As such, the applications of DC open-arc furnaces have the potential to be extended to other raw materials such as particulate nickel oxide, which has a particle size much less than 100 µm.Nickel oxide is typically produced from laterite ore by sulphuric acid leaching, purification, and precipitation as basic nickel carbonate (BNC) (Rhamdhani, Jak, and Hayes, 2008) or as mixed hydroxide precipitate (MHP) (Mackenzie, Virnig, and Feather, 2006), and finally calcining at moderate temperatures (800–1200°C). The NiO product is very fine, with an average particle size in the range of 10–20 µm and a NiO content of more than 99%."

Jan 1, 2015

By M. H. Moys

I had the good fortune to attend the above Conference which was held in Kanpur, India, on 11-15 December, 1995. The Conference was held in honour of Professor P.C. Kapur of the Indian Institute of Technology in Kanpur. Professor Kapur was one of the early students of legendary teacher and researcher of mineral beneficiation, Professor Doug Fuerstenau of the Department of Materials Science and Engineering at the University of California at Berkeley. I have attended my fair share of international conferences and this one certainly rated at the top of the list on several counts. With an open-hearted hospitality which one might almost take for granted once you have spent some time in India, the organizers of the Conference looked after every need of their guests, including breakfast and transport to and from the conference centre, wonderful traditional lunches and dinners and outstanding entertainment in the evenings. The papers were generally of a high standard, and debate flowed enthusiastically and freely. Several international guests delivered seminal papers in their fields as discussed below.

Jan 1, 1996

1. Book reviews Physiochemical properties of molten slags and glasses, by E.T. Turkdogan. London, Metals Society, 1983.516 pp. £35. Reviewer: A.F .S. Scboukens Microstructural characterisation of metals and alloys, by P.E.J. Flewitt and R.K. Wild. London, Institute of Metals, 1984. £14. Reviewer: M.P. Sbaw Metallurgical applications of magnetohydrodynamics, edited by H.K. Moffatt and M.R.E. Proctor. London, Metals Society, 1984.346 pp. U.K. £35, U.S. $70. Reviewer: N.A. Barcza Extractive metallurgy symposium. Proceedings of a meeting on 12-14 November, 1984, organised by the Melbourne Branch. Parkville (Victoria), Australasian Institute of Mining and Metallurgy, 1985. Reviewer: B.K. Loveday Conference on gold mining, metallurgy and geology. Proceedings of a meeting on 9-11 October, 1984, organisedby the Perth and Kalgoorlie Branch. Parkville (Victoria), Australasian Institute of Mining and Metallurgy, 1985. Reviewer: B.K. Loveday Corporate policies for the 1980&apos;s in the steel industry, by Patrick Genevaz in collaboration with B.A. Bloom. La Chambre des Cartes, 26 rue de Piepus, 75012 Paris (France). U.S.$7oo, additional copies $140. Reviewer: D.C. Maree Mineral processing technology, by B.A. Wills. Oxford, Pergamon Press, 1984 (3rd edition). 629 pp. Hard cover £31.50, soft cover £9.75. Reviewer: B.K. Loveday Ma1lllgement information-ma1lllging for improYement, volume 2: symposium proceedings and additional papers. edited by M. Hammond. Doncaster (England), The Institution of Mining Engineers, 1984. 86 pp. £60 for vols. 1 and 2 (124 pp.). Reviewer: M.J .R. Meyer 2. Recent publications Tins and its and its uses no. 144, 1985. This issue by the International Tin Research Institute (Fraser Road, Greenford, Middlesex, UB6 7AQ, Canadian minerals yearbook 1983-84. Department of Energy, Mines and Resources Canada, Mineral Report 33. Ottawa, Canadian Government Publishing Centre, 1985. $35.40. 82 Year 1984, edited by 1.0. Jones and RM. Louthean. Kalgoorlie (Australia), Western Australian School of Mines, 1985. 100 pp. Johnson Matthey Chemicals 1984-85, issued by Matthey Catalogue Sales (Orchard Road, Royston, Hertfordshire SG8 SHE, England). 416 pp. South Africa&apos;s mineral industry 1984. Johannesburg, Minerals Bureau, 1985. 190 pp. Coal 1985. Operating and developing coal mines in the Republic of South Africa. Johannesburg, Minerals Bureau, Directory 2/8S. 1985. 72 pp. Gold 1985. Operating gold mines and gold recovery plants in the Republic of South Africa. Johannesburg, Minerals Bureau, Directory 3/8S. 98 pp. 3. New journal Pergamon Press, New York, have announced the publication of a new quarterly known as the International Journal of Plasticity. 4. Mintek reports Report M93D Hydrochloric acid leaching and low-temperature roasting of tin-tungsten concentrates from Van Roois Vley. (First issued April 1983.) Report M99D The upgrading of coarse kyanite crystals. (First issued Report M105D The development and installation of a microcomputer based data logger, and the analysis and evaluation of data. (First issued July 1983.) Report M109D The remelting ofsi/iconfines. (First issued July 1983.) Report M180 An assessment of available corrosion inhibitors for the reticulation systems of South African gold mines. Report MW1 Quantitative assessments of abrasive and impactive wear from ball-size distributions in rotary mills.

Jan 1, 1985

By Mike de Wit

Of the approximately 6,500 kimberlites known to date, less than 3% are diamondiferous and less than half of those are economically viable. Admittedly, this is a global figure and varies from area to area much depending on geological, logistical, and political circumstances. The number of diamond-bearing kimberlites is an important geobarometer, and an age-frequency profile has been compiled in order to identify diamond metallogenic epochs and provinces. Four primary diamond clusters have been recognized: Siberia (332-370Ma), Kaapvaal South(114-144Ma), Kaapvaal Southwest(84-95Ma), and Slave (52-55Ma). In addition, three secondary clusters are the Kaapvaal Central (S06-S38Ma), the Man Craton (139-lS3Ma) and the Kasai Craton (120-130Ma). The Kaapvaal is the only area where kimberlites with diamonds were discovered between 1870 and 1925, except for the Prairie Creek discovery in North America in 1906 and Colossus in Zimbabwe in 1907. Between 1906 and 1940 no major diamondiferous kimberlites were discovered, but many of Africa&apos;s alluvial deposits were found and exploited in that period. Advances in scientific prospecting in the 1940&apos;s rapidly accelerated the discovery rate that peaked in the 1990&apos;s; 39 diamondiferous occurrences were found in the 1980&apos;s, of which 8 became mines and 5 are in feasibility, and nearly 450ha of kimberlite was added to the global resource base. Despite the accelerated exploration expenditure, the last decade (e.g. 2000-2009) has been the leanest since the 1940&apos;s. The most important reason for this decline in exploration success is that any undiscovered deposits are largely buried by younger cover. Understanding complex and geophysical noisy basement geology, as well as decomposition of path-finder minerals are major challenges to further exploration success. Major investments in basic geological expertise and field research will have to be made in order to secure future diamond resources. Integrated geophysical studies, geochemistry diamond forensics, and improved imaging of Earth&apos;s upper mantle are perhaps foremost in this requirement, but the costs of these activities are such that government support will be required if countries are to sustain their diamond mining industry.

Jan 1, 2010

INTRODUCTION This paper was originally presented at the Platinum Adding Value Conference, held at Sun City from the 4th to 6th October 2004. Narrow reef mining may not be applicable to the base metal operations in Zambia, however, it is considered that the methodology used is equally appropriate to the development of technology and mining methods in mining environments other than narrow reef mining. The purpose of this paper is to explore the integration of technology and stoping systems. For the last hundred years the South African narrow reef mining industry has battled to control working costs in a labour intensive industry. It is only through the application of appropriate technology that change will occur. Stoping systems, because it is the stoping method and methodology that is at the heart of the mining system. Introduce a different technology that results in a more efficient stoping system and the mining system will look after itself. The technology applied to stoping in narrow reef mining, over the last 100 years, can be categorised as follows: ? The introduction of pneumatic rockdrills early this century. The cumbersome rig mounted units being replaced by smaller, lighter, hand held units that were then made easier to use with the addition of an air leg. (The so called Swedish method of mining.) As late as the early 1970s some drilling was still being carried out without the assistance of an air leg. ? Scraper winches to replace gravity and shovels to move rock both in the face and the gullies were first introduced in the late 1920s. ? Hydraulic props installed close to the face and capable of applying force against the hangingwall as well as yielding in a controlled manner under dynamic load arrived in the 1960s. In many instances these have now been replaced by yielding elongates fitted with water hydraulic tensioning devices. ? Some people argue that the introduction of tungsten carbide inserts, to improve drilling, was equally important.

Jan 1, 2005

By G. C. Thompson

&apos;Increased underground extraction of coal&apos; was the theme selected for the 1981 mining vacation school, which was held at the University of the Witwatersrand in January and February. The response of the industry to the invitation to register was so good that three separate schools of one week each were arranged between 26th January and 13th February. In terms of the total number of delegates, some 225 actually attending, the school can be described as the most successful ever organized by the Institute.

Jan 1, 1981