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By P. F. S. Jackson, A. Strasheim

In the survey "Analysis of South African raw bullion" the distribution of trace elements within the bullion have been shown to be distinctively dependent on the extraction process. In general the amalgamation process produces the more impure bullion with respect to trace elements. Some chemical and physical explanations are given for the differences that have been observed in the raw bullion as received at the Rand Refinery. The value of the spark source mass spectrographic technique in the study of the elemental impurities in bullion is demonstrated.

By E. L. Atkinson, G. W. Leach

The paper discusses the reasons for the introduction of load-haul-dump (LHD) units into Greenside Colliery, and the circumstances leading to the replacement of conventional mechanized equipment on a trial basis in the mining operations on No. 2, 4, and 5 seams. An outline is given of the factors governing the selection and introduction of these units into coal mining, and the associated mining and engineering aspects involved in the optimization of their use. Operating statistics comparing the performance of conventional and LHD equipment are included.

Jan 1, 1979

Advances in extractive metallurgy, 1977. Proceedings of the third symposium organised by the Institution of Mining and Metallurgy held from 18-20th April 1977. London, the Institution of Mining and Metallurgy, 1977. 244 pp. £18,50. Coal preparation A meeting of the Organising Committee of the Eighth International Coal Preparation Congress took place in Moscow on 24th and 25th May, 1977. Representatives NIM reports Report no. 1906 An automated instrument for measuring the effects of impurities on cathodic-current efficiency during the electrowinning of zinc. (2nd Sep., 1977). Report no. 1908 An analysis of the replies to a questionnaire on materials of construction for ore hoppers. (16th Sep., 1977). Report no. 1913 The mechanism and rate of reduction of Mamatwan manganese-ore fines by carbon. (2nd Sep., 1977). Report no. 1914 The thermodynamics of the formation of sulphate complexes of iron (111), cobalt (11), iron (11), manganese (11), and copper (11) in perchlorate medium. (15th Sep., 1977). Report no. 1924 The composition of chromite grains from varwUB Witwatersrand reefs. (23rd Sep., 1977). Atomic absorption The Perkin-Elmer Corporation of South Africa is planning to hold an Atomic Absorption Autumn School in Cape Town from 10th to 13th April, 1978. Travel bursaries Two Atlas Cop co travel bursaries for study tours of Swedish mines may be awarded annually to young mining graduates. Stability in coal mining The First International Symposium on the above subject is to be held in Vancouver (Canada) on 5th to 7th April, 1978.

Jan 1, 1978

By R. S. Sanders, J. Schaan

Syncrude Canada Ltd. produces synthetic crude oil from Canada?s vast oil sand reserves by mining the oil sand, then separating and upgrading the ultra-viscous crude oil, or bitumen (~ 106mPa s @ 10ºC). At Syncrude?s Aurora Mine, about 16 000 tonnes oil sand per hour are mined and then transported 5 km by slurry pipeline to the extraction plant. The waste tailings stream is then transported about10 km by pipeline to a settling/sand storage basin. Oil sand slurries are reasonably concentrated (> 35%solids by volume), typically have a sand particle diameter between 0.18 and 0.3 mm, and are transported at reasonably high velocities (3 to 5.5 m/s). As one would expect, pipeline wear is a significant problem in this industry, in terms of both unplanned production outages and maintenance costs. In order to develop strategies to extend pipe life and to focus more on condition-based maintenance scheduling (as opposed to preventative maintenance), Syncrude has implemented an ongoing pipe wear measurement programme. Regular measurements of pipe wall thickness are obtained at various circumferential positions at a number of axial locations along each pipeline, using an ultrasonic scanning technique. In this paper, we show how wear rates vary as a function of axial location and circumferential position for oil sand hydro transport and coarse particle tailings pipelines. The specific positions at which peak wear rates occur are explained by considering the characteristics of the coarse particle slurry flows to which the pipelines are exposed.

Jan 1, 2007

By Donald Sir Tebbit

To have been invited to deliver this second CMMI lecture is an honour that I deeply appreciate. But, when I contrast my qualifications for delivering it, with those of Sir Alistair Framet, who delivered the inaugural lecturet in the series, or with those of other members of the Council, I feel rather an imposter. Far from having been a miner al my life, I have been associated with the mining industry on a part-time basis for a mere eight years. However, I encourage myself with two recollections. The first is the admission of the great Sherlock Holmes that he was often guided to the truth by the erroneous opinions expressed to him by Dr Watson. I may be able to perform a similar service for you. Secondly, I recall that, when I was a member of the Diplomatic Service, I was quite often asked to address representative gatherings of such professional people as the police, architects, dress designers, teachers, doctors, funeral directors, bird fanciers, and so on. Since it would have been pointless to pretend that I was expert in any of their businesses, I used to resort to the technique of announcing as my theme' A diplomat looks at the police' or whatever profession it was. They fortunately took it as a compliment that their profession was apparently one that diplomats spent a lot of time brooding over. They could also afford to laugh of any criticism that I might make because it could be ascribed to ignorance rather than informed malice. I hope that you will do the same.

Jan 1, 1988

By D. Duncanson, R. J. Davidson

The elution of gold from activated carbon using deionized water by R. J. DAVIDSON, M.Sc., Ph.D. (Rhodes) (Visitor) and D. DUNCANSON, H.N.C., B.Sc. Hons. (Strathclyde) (Visitor) The pretreatment of gold-loaded activated carbon with a relatively strong sodium cyanide solution prior to elution with deionized water at 90 to 125°Chas been shown to have a most beneficial effect on the elution of gold. The findings emphasize the important role played by the calcium cation and the hydroxyl anion in effecting efficient elution of gold. The elution of the relatively unstable complexes of silver and base metals with cyanide was also significantly affected by the ratio of the sodium cyanide to sodium hydroxide in the reagents used in the pretreatment stage. It was demonstrated that the use of 0,5 bed volume of a pretreatment reagent comprising 10 per cent sodium cyanide stabilized with I per cent sodium hydroxide for safety reasons resulted in a virtually 100 per cent recovery of adsorbed gold, silver, and base metals on subsequent elution with deionized water. The elution procedure takes a relatively short time, about 14 hours at 90°C (7 bed volumes) or 3 hours if pressure elution at 125°C (4 to 5 bed volumes) is used. Because the mechanism of elution after pretreatment entails the shifting of a physical rather than a chemical equilibrium, the higher the gold loading on the activated carbon, the more efficient is the elution procedure. When compared with other elution procedures, the proposed method appears to have several economic advantages.

Jan 7, 1977

From 19 November 1996, South African companies will be able to manage the impact their activities have on the environment in terms of international standards. The establishment of a registration scheme for environmental management systems was formally announced by the South African Bureau of Standards (SABS) (19 November 1996). At a function held at the SABS head office in Pretoria, Dr Jean du Plessis, President of the SABS, announced the launch of the SABS ISO 14001 registration scheme which is based upon ISO 14001, 'the internationally recognized yardstick for environmental management'.

Jan 1, 1997

By Deur T. A. M. Saayman

Die sesde jaarlikse Ingenieursimposium is in September by YSKOR, Vanderbijlpark gehou. Rierdie simposium, wat deur Ingenieurs-in-Opleiding georganiseer word, bied aan die Ingenieurs-in-Opleiding die geleentheid om referate te lewer oor projekte wat gedurende hul drie jaar opleidingsperiode uitgevoer word. Continuing education courses The following courses are to be given in the near future in The Netherlands. Coal trade, transportation, and handling . The 4th Coal Trade, Transportation and Handling Conference and Exhibition, CoalTrans '86, will take place the Rai Congress Centre, Amsterdam, from 10th to 12th June, 1986.

Jan 1, 1986

Die Suid-Afrikaanse Instituut vir Mynbou en Metallurgie het 'n paar jaar gelede 'n toekenning vir voortreflike akademiese prestasie deur vierdejaarstudente aan technikons ingestel. Disinvestment campaign by COLIN M.SPENCE As President of the Federation of Societies of Professional Engineers, which is an organization representing twelve institutions of the engineering profession comprising over 18 000 engineers of all kinds-of whom over 15 000 are either professional engineers or engineering graduates-I have been asked to make a statement on the disinvestment campaign on behalf of the profession.

Jan 1, 1985

By D. Menne

A comminution model and a quick laboratory milling test procedure are presented. These allow the determination of milling parameters for the - optimization of ball size and pulp density in operating mills estimation of the performance of new feed stocks in an existing mill - estimation of the expected milling performance for a new project. Information on the estimation of the size of mills to deliver specified amounts of comminution energy, and amount of expected ball, rod, and liner wear to allow cost estimates for new projects, is also included.

Jan 1, 1983

By David J. Haddock

On Wednesday, 6th July, 1988, 28 members of the Johannesburg Branch of The South African Institute of Mining and Metallurgy and their guests assembled at the Rand Refinery Sports Club, which is situated within the Refinery complex, to hear Dr Daniel Polnow, General Manager of the Refinery, give a very interesting lecture on the Rand Refinery Complex and its activities. Accounting for gold The South African Institute of Mining and Metallurgy will be holding a 3- or 4-day school in the third week of May 1989 on the topic 'Accounting for Gold'.

Jan 1, 1988

By B. R. Broekman, J. P. W. Bennie, P. D. K. Robinson, R. P. Viljoen

The theme of the Congress was 'Resources and Technology', the intention being to highlight those basic technical aspects in the disciplines of geology, mining, extractive metallurgy, and metals technology that are required for successful mineral-based operations. The technical programme covered a fairly broad field, as is appropriate for the CMMI Congress, and was generally considered to be of a high professional standard; informative and, with the exception of some minor hitches, well-run. Parallel sessions were held in the four disciplines. All were well attended, and despite tight presentation schedules, certain valuable discussions developed.

Jan 1, 1994

By P. C. Schutte, N. B. Strydom, A. J. Kielblock

Three groups of unacclimatized men were subjected to five-day climatic-room procedures at wet-bulb temperatures of 29,30, and 31 C respectively. The findings indicated that individuals reach a satisfactory level of heat acclimatization for work in environmental temperature conforming to those at which they were acclimatized. It is, therefore, superfluous to acclimatize men at wet-bulb temperatures that exceed those at which they are destined to work. These methods of acclimatization can be linked advantageously to heat-tolerance testing at mines with suitable underground temperatures.

Jan 1, 1983

By P. J. Kinver

The paper presents details of the costs and outputs being achieved by South African mechanized tunneling and stoping drillings. The information was gathered from various hard-rock mining and tunneling operations ranging from deep-level gold mines to shallow base-metal mines. The survey included older pneumatic rigs and the newer electro-hydraulic rigs, but excluded shaft drilling and the stope drillings that were developed recently for narrow reefs. The information presented is intended as a guide to those having to decide whether to use mechanized drillings and, if so, what type and quantity

Jan 1, 1990

By A. Smith

The practice of leaving barrier pillars between adjacent longwall panels at The Durban Navigation Collieries (Pty) Ltd (Dumacol) has resulted in a considerable loss of coal reserves. Dumacol has now modified the layout of its longwall panels to allow the concurrent mining of barri9f pillars and the extraction of the longwalls. The Implementation of the new panel layout has increased the percentage extraction of reserves and will result in an extension in the life of the mine. The method of extracting barrier pillars between adjacent longwall panels is described in this paper.

Jan 1, 1985

By B. J. Ralph, I. J. Corrans, B. Harris

In the first section, a brief background to the practical and theoretical aspects of bacterial leaching is presented. Descriptions are given of present and potential methods for exploiting bacterial leaching in metal-winning. In the second section, the results of recent research are presented. The aim of this work was to obtain a greater understanding of the mechanism of bacterial leaching of sulphide minerals. Bacteria were observed to catalyse leaching reactions by oxidising ferrous ions to ferric ions, by removing protective films at the mineral surface and by depolarising cathodic areas.

This International Mine-Surveying Conference will take place in Budapest (Hungary) from 5 to 14 June, 1972. Detailed information can be obtained from the Mine-Surveying Working Committee of the Hungarian Mining and Metallurgical Society. Write: OMBKE Bányaméröi Munkabizottsag Budapest, V., Szabadsag ter 17, Hungary. SYMPOSIUM ON NICKEL The 'Gesellschaft Deutscher Metallhiitten-und Berglaute' is holding a Symposium on nickel on 24-25 September, 1970 at Wiesbaden, on the occasion of the G.D.M.B. Annual Meeting. Some 24 papers will be presented by metallurgists from many important companies around the world. Information may be obtained from The Secretary, G.D.M.B., Postfach 210, 03392 Clausthal-Zellerfeld, German Federal Republic. VISIT TO THE COUNCIL FOR SCIENTIFIC AND INDUSTRIAL RESEARCH On 23rd June, 1970, members of the Institute visited the C.S.I.R. in Pretoria. More members had booked for this tour but the current flu epidemic caused cancellations which was unfortunate. The visit was organised with military precision, which prevented detailed discussion of any particular subject, but provided a bird's eye view of a large number of interesting projects. The visit was packed with interest for all and those requiring further information were invited to contact the relevant divisions afterwards. Or Denkhaus welcomed the delegates and stressed the importance of integrating research efforts with industry's requirements. An excellent colour and sound film was shown which depicted the work of the Rock Mechanics division. This showed very clearly methods used for preparing rock samples and demonstrated the machines and instruments for the various tests. It made one realise the extent to which this research has been integrated with the actual mining situation. The fullscale experiments underground showed the failure of pillars under applied loads and were very interesting. This is undoubtedly a film which all mining people should see. After the film the rock mechanics laboratories were visited where the actual machines were seen and described. We then visited the metal and strength mechanics sections where the metallurgists were able to see some interesting experiments and tests. We also visited the Aeronautics Research group where a large 1 000 hp wind tunnel was inspected. We were told enough about this to realise something of the complexities involved in the design and operation of a closed circuit tunnel of this type. The tunnel is used for tests on models which are necessary for the design and modification of aircraft. After a very excellent lunch at the C.S.I.R. recreation centre, the delegates attended two lectures-one by Mr. Mandersloot of the Chemical Engineering group, who outlined the varied functions of this group and told us something of their work. Of particular interest was the research into the suitability of various South African manganese ores for dry cell batteries. Work on the thickener settlement studies interested the metallurgists. The second lecture was given by Mr Donaldson of the National Building Research Institute. This Institute has about ten divisions each of which covers a particular aspect of building research. The work of the soil mechanics division was described in detail and illustrated by coloured slides. This was particularly interesting and demonstrated clearly how building failures result from lack of attention to detail of construction where unstable soil conditions exist. Cracks in walls of compound blocks brought the subject home forcibly to the mining delegates. This division has also caried out important work on sinkholes and sUmes dams and produced some positive results. Altogether the visit was most interesting and enjoyable. It was made more worthwhile because the emphasis was on the work being carried out and not on just seeing the laboratories. The Institute is greatly indebted to the C.S.I.R. and its staff for the very excellent arrangements made.

By S. Carter

this paper describes an innovation in computer software that permits mining professionals to collaborate on exploration and mining projects regardless of geographic location. Growth of mining companies through merger and acquisition has created a greater need for mining professionals to collaborate, especially as projects and project participants are becoming geographically remote. Surpac NetVision, the name given to this new collaboration technology, satisfies this need by deploying interactive 3D graphics sessions across computer networks. It achieves this by using common web browser technology as the deployment medium. A plug-in architecture that supports diverse file formats permits transparent read and write of foreign data to further enhance the collaboration process. Surpac NetVision supports any number of connections from web browsers on remote computers using existing networks. Software components required to enable the collaboration session are deployed to the remote computer as required and cached for future sessions. The collaboration session at each computer is characterized by a fully functional replica of the user interface for Surpac NetVision from which any function can be executed by any client, at the owners discretion. All geometry and display attributes deployed to remote clients to render 3Dgraphics are highly compressed to reduce bandwidth requirements. The key benefits of this collaboration technology is improved communication in regard to exploration and mining projects leading to: •More informed decision making •Improved deployment of project objectives and plans beyond the technical planning group to project management and operations staff •Improved technical support for software users. Keywords: 3D graphics, project collaboration, interactive graphics, internet 3D graphics, mining software

Jan 1, 2003

By G. G. Rogers, A. Vna Der Linde, N. B. Strydom, W. H. Van Der Walt

Changes in the level of serum vitamin C in mineworkers by N. B. STRYDOM, M.Se., Ph.D. (Illinois) (Fellow), G. G. ROGERS, M.Se. (Pta) (Visitor), W. H. VAN DER WALT, B.Se. (Poteh.) (Visitor), and A. VAN DER LlNDE, B.Se. (O.F.S.) (Visitor) The levels of serum vitamin C in the blood of mineworkers were determined on the first and fifth days of the normal heat-acclimatization period (i.e., before and after exposure to heat) and again after I, 2, and 4 months of underground employment. Supplementary vitamin C was administered to the men during the heat-acclimatization period. Six groups of 20 men featured in the study and, except for one of the two 4-month groups, all the values were obtained after a full shift of underground work. It was found that adequate levels of serum vitamin C were maintained during the heat-acclimatization period, and the 250 mg of vitamin C given daily to each man must therefore be regarded as sufficient. The serum vitamin C decreased significantly with time of exposure to underground conditions, showing that the vitamin C utilized during heat stress is more than that provided in the men's diet. At the end of 4 months, not a single subject had more than 0,4 mg of serum vitamin C per 100 ml, most of them having only 0,3 mg per 100 ml; 90 per cent of the men had had more than 0,4 mg per 100 ml during the acclimatization period. It is therefore recommended that the mineworkers' diets should be supplemented with 100 to 200 mg of vitamin C per man per day.

Jan 5, 1977

By G. G. Garrett, J. A. Peters, J. V. Bee, M. W. Atkinson

The development of steels with improved abrasion-corrosion resistance for use in underground components in South African gold mines is described in terms of design, manufacture, and performance. Based on the concept of microstructural design, new compositions were formulated to provide the optimum structures and properties. Extensive laboratory tests were conducted, and an industrial melt was produced. The resultant materials were tested for fabricability and machinability, and various components were manufactured. According to the preliminary operational results, these alloys exhibited outstanding performance in wear-plate tests, and are very promising for general application in underground components.

Jan 1, 1987