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Carbon-concentration Meter The latest of these, the ultrasound-based carbon concentration meter, was developed by Mintek with original sponsorship by the Chamber of Mines Research Organization, and is now being manufactured and marketed worldwide by Debex Electronics in Johannesburg. Testing of detonators* The Chief Mining Engineer has asked the South African Bureau of Standards to monitor locally manufactured, as well as imported, detonators. This could ensure greater safety in fiery mines.

Jan 1, 1990

By H. W. Glen

In the hope of finding out what the readers of the SAIMM Journal want of our Journal, we sent out a questionnaire with the October 1979 issue. The 2500 copies of the questionnaire sent out elicited 228 responses, which represents a return of 8,8 per cent. The number of responses received from overseas was 24, i.e., approximately 10 per cent of the total. The following is an analysis of the responses received.

Jan 1, 1980

COLLOQUIUM ON SHAFT SINKING The 'Star' published a report on the colloquium on 15th November, 1972. As this will be of interest to members, it is re-printed by kind permission of the 'Star'. Mac Thain The super-Mines of the future envisaged by Mr Jeff Goode, president of the Chamber of Mines, in his Gold Symposium address in London, will be entirely different from those producing today - not merely amalgamations of properties into bigger units.

By A. N. Brown

Professor D. G. Krige, of the Department of Mining Engineering of the University of the Witwatersrand, received the degree of Doctor of Engineering (honoris causa) from the University of Pretoria at the Autumn Graduation Ceremony in April 1981. He was honoured an outstanding engineer for his world-renowned pioneering work in the field of statistical methods of ore valuation, or geostatistics as it has become known. Metalliferous Ore Deposits A short course on the 'Evolution of Metalliferous Ore Deposits' will be held at Rhodes University, Grahamstown, from 8th to 13th February, 1982.

Jan 1, 1981

By H. C. Voges

The use of heavy-medium separation in the processing of iron ores by H. C. VOGES. B.Sc. (Visitor) The paper discusses various aspects of the application of heavy-medium separation to the processing of hematite ore at Sishen and Thabazimbi. The two main factors to be borne in mind in the design of a plant for such beneficiation are the Iow unit value of the iron ore produced and the high separation densities required. The four factors of importance in the avoidance of high viscosity in the ferrosilicon medium are discussed in turn.

Jan 6, 1975

By P. W. J. van Rensburg

The Institute was privileged to receive an invitation from the Armaments Corporation of South Africa (Armscor) for members to visit one of their plants. As these are factories, the number of visitors who could be accommodated was limited. As the opportunity seldom arises to learn something of this very large industry, there was great interest among members and many were disappointed in not being able to go. Underwater mining The 16th Annual Underwater Mining Institute will be held at Halifax, Nova Scotia, Canada, from 20th to 23rd October, 1985.

Jan 1, 1985

By W. C. Mather

The Witbank/Middelburg Branch of The South African Institute of Mining and Metallurgy hosted a colloquium entitled 'Recent Mining and Metallurgical Developments in the Eastern Transvaal', at the Witbank Civic Centre on Wednesday, 25th September, 1985. An attendance of close on 300 delegates bore testimony to the popularity of the theme. Two well-attended cocktail parties were held at different venues on the evening prior to the Colloquium. These were hosted at the South African Coal Estates Recreation Club and Middelburg Country Club.

Jan 1, 1986

By N. E. K. Schuttler

Experience with Mars pumping of underground water by N. E. K. SCHUTTLER (Visitor) As the result of a planned increase in production, Vaal Reefs Exploration & Mining Company Limited increased the hoisting capacity of their existing equipment to its fullest extent and installed Mars pumps and a washing plant. The layout of the installation is described, and details are given of the modifications made to overcome its weaknesses. Plans to change the present four-stage system to a seven-stage system are outlined.

Jan 3, 1977

By I. Satola, J. Aromaa

In this work we have reviewed methods to classify corrosivity of ground waters. Weight loss and stress corrosion cracking (SCC) corrosion tests have been done for rebar and steel strand. No clear indication of SCC was found. The application of tensile stress to 85 % of yield strength increased general corrosion rate significantly in very corrosive waters. The effect of corrosion protection on the axial behavior of steel strands was determined by double pipe axial tests with different embedment lengths. The results showed a significant difference on behavior between epoxy-coated steel strands, galvanized steel strands and plain steel strand. Dans la présente étude, nous avons passé en revue des méthodes permettant de classifier la corrosivité des eaux souterraines. Des tests portant sur les pertes de poids et sur la corrosion FCC (la fissuration par corrosion sous contrainte) ont été effectués pour les barres d’armature et les torons. Aucune indication nette de FCC n’a été constatée. L’application d’une contrainte de traction allant jusqu’à 85 % de la limite d’élasticité a accru de manière significative la vitesse générale de corrosion dans les eaux très corrosives. L’effet de la protection contre la corrosion sur le comportement axial des torons en acier a été déterminé au moyen de tests axiaux à double tube avec des longueurs d’enrobage différentes. Les résultats ont mis en évidence une différence significative quant au comportement entre les torons en acier à revêtement époxy, les torons en acier galvanisés et les torons en acier standard. In dieser Arbeit haben wir Methoden geprüft, die korrosive Wirkung des Grundwassers einstufen. Gewichtsverlust- und SCC-Korrosionstests wurden für Stahlstäbe und Drahtlitzen durchgeführt. Es wurden keine sicheren Hinweise auf Spannungsrisskorrosionsbrüche gefunden. Bei Anwendung einer Dehnbelastung von 85 % der Streckspannung bzw.Ergebnisstärke stieg die allgemeine Korrosionsrate in stark korrosivem Wasser deutlich an. Die Wirkung des Korrosionschutzes bei axialem Verhalten von Stahldrahtlitzen wurde durch axiale Tests an Doppelleitungen unterschiedlicher Versenkungslänge determiniert. Die Ergebnisse zeigten im direkten Vergleich von epoxidbeschichteten, galvanisierten und normalen Stahldrahtlitzen beachtliche Unterschiede im Verhalten auf.

Jan 1, 2003

By H. E. James

The 13th Congress of the Council of Mining and Metallurgical Institutions (CMMI) was held in Singapore from 11th to 16th May, 1986. Tours to Australia, Malaysia, Thailand, South Korea, and Japan took place the week before and the week after the Congress. Registrations By far the largest contingents at the Congress were from Australia (157 delegates and 65 affiliates) and South Africa (127 delegates and 99 affiliates). The other 25 countries represented at the Congress accounted for 118 delegates and 37 affiliates. Thus the total registrations amounted to 402 delegates and 201 affiliates.

Jan 1, 1986

To B. K. Martus I discussed several points raised by Mr Martus in my reply to Professor Krige*. Mr Martus discusses several possible interpretations of optimum South African sales, but in my paper these sales refer to the sales level that maximized the working profit of the whole South African gold-mining industry over the past eleven years. Mr Martus also seems to be under the impression that the paper deals with the future. While there may be references to the future, and some implications for the future may be obvious, the paper deals essentially with the past eleven years.

Jan 1, 1984

Notices THE FEDERATION OF SOCIETIES OF PROFESSIONAL ENGINEERS The following letter has been received from the Secretaries of the above Federation. Ref. EHvdL/MM/27 13/11/1973 TO THE SECRETARIES OF ALL MEMBER AND AFFILIATE SOCIETIES Dear Sir/Madam, ENTRIES IN TELEPHONE DIRECTORIES PAPERS OF INTEREST The following recently published papers may be of interest to memo bers. DIE FEDERASIE VAN VERENIGINGS VIR PROFESSIONELE INGENIEURS Die volgende brief is van die Sekretarisse van die bogenoemde Federasie ontvang. verw. EHvdL/MM/27 13/11/1973 AAN DIE SEKRETARISSE VAN ALLE LlD- EN GEAFFILIEERDE VERENI GIN GS Geagte heer/dame,

Jan 1, 1974

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

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 J. D. Smit, K. C. Garner, P. C. van Aswegen

The initial results obtained from the implementation of computer-controlled strategy on the milling circuit are reported. An analysis of these results showed that a peak-power pebble-mill controller on a high throughput hardrock wet-milling circuit reduces the stability of the system. It was concluded that the milling circuit should be regarded as a single system in which the measurement of grinding efficiency, circulating load, product size distribution, and feed rate should minimize the product variance and maximize the feed rate according to the grinding power available. Work is proceeding on such a system.

Jan 1, 1980

By R. Hutchings

The paper reviews current understanding of the effect of ion implantation on the wear process, and the state-of-the-art of ion implantation as a commercially viable treatment to impart wear resistance. Ion implantation involves the firing of high-energy ions into the surface of a material, which modifies the surface properties and so causes a transition in the dominant wear mode. The process is best suited to specialized engineering applications involving critical dimensional tolerances or surface finishes, but has gained little industrial acceptance because of its poor reproducibility and the lack of a suitable method of inspection.

Jan 1, 1986

By R. M. Morris, G. A. Matthesius, M. J. Desai

Slow pyrolysis experiments were caried out on samples of coal from north em Natal having a volatile mater content ranging between 10 and 25 per cent by mass and a constant particle-size distribution. The tests were conducted at atmospheric pressure in a helium atmosphere, and ata heating rate of 10 KImin and a final temperature of 1220 K. The pyrolysis products were taken as coke and volatile mater (tar and eight other species), and tMir respective yields were measured. The experimental results were used in the modification of an existing mathematical model and in the derivation of new corelations for some of the parameters of the model, so that the volatile products of a coal can be predicted from ultimate and proximate analyses of the coal. The pyrolysis tests showed good agreement between the model predictions and the experimental results.

Jan 1, 1987

The established shared laboratory facilities between the Departments of Metallurgy and Chemical Engineering of the Vaal Triangle Technikon and the University of Potchefstroom are already proving to be a great success.

Jan 1, 1992

COLLOQUIUM PRACTICAL APPLICATIONS OF INSTRUMENTATION IN THE MINING AND METALLURGICAL INDUSTRIES Rapporteur: J. Laschinger A colloquium and general meeting of the Institute held jointly with the Instrument and Control Society of Southern Africa at Kelvin House, Johannesburg on 18th October, 1972, had as its theme "Practical Applications of Instrumentation in the Mining and Metallurgical Industries" Dr J. P. Hugo (President) was in the chair and about 200 members and visitors were present.

By H. V. R. Von Rahden

The expertise of the industrial mineralogist has not always been sufficiently used in decision-making in the minerals industry in South Africa. The mineralogist can make a contribution at al stages of the exploration programme, from the time of discovery of a geological target area, through metallurgical testwork and pilot-plant studies, to the production of a saleable product. This indicates that the activities of the industrial mineralogist should be more closely integrated with those of the exploration geologist and the extraction metallurgist in order to provide management with a meaningful picture of the economic potential of an ore deposit.

Jan 1, 1997