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In August 1978, the National Productivity Institute invited entries for productivity awards, which it intended making as a recognition of firms and individuals who were contributing to the prosperity of South Africa by effecting outstanding improvements in productivity.

Jan 1, 1979

By C. S. Erasmus, L. C. Woollacott

The distribution of gold loaded onto carbon particles from a carbon-in-pulp operation was measured by neutron activation analysis. The nature of the distribution is examined, and the implications for operating plants and CIP simulators are discussed.

Jan 1, 1992

By G. Dhakal, J. -I. Kodama, K. Neaupane, T. Yoneda

ABSTRACT Durability tests and evaluation of sub-zero temperature effects to some argillaceous clastic rocks were carried out. Welded tuff, limestone, sandstone and schist samples collected from different parts of Japan were tested and results are presented. Schist and dolomite from Ganesh Himal area along the higher Himalayas of Nepal were also tested, and the results are compared. The slaking tests were performed on all samples in pure water. The results reveal that the slaking index of schist from Japan is lower than that of schist from Nepal. Regarding carbonate rocks, the slaking index of limestone from Japan is higher than that of dolomite from Nepal. A tendency of decrease in slake durability with an increase in porosity is also observed. Freezing and thawing experiments conducted on welded tuff and schist reveal that crack initiates earlier but extends slower in schist than in welded tuff. It is also observed from the freeze-thaw experiment that the welded tuff deteriorates and wears faster than the schist. However, sandstone remains relatively intact for a long run of freeze-thaw cycles. Zusammenfassung Beständigkeitstests sowie die Bewertung der Auswirkungen von Minusgraden auf Tonschiefer Trümmergestein wurden durchgeführt. Dabei wurden geschweißter Tuff, Kalkstein, Sandstein und Schiefer aus verschiedenen Gebieten Japans sowie Schiefer und Dolomitgestein aus dem Ganesh Himal Gebiet, dem höheren Himalaya Nepals, untersucht und die Resultate verglichen. Für alle diese Gesteine wurden Slaking-Tests in reinem Wasser vorgenommen. Die Resultate zeigen, dass das Slaking von Schiefer aus Japan höher als das von Schiefer aus Nepal war, wohingegen bei kalkhaltigem Gestein das Slaking von Kalkstein aus Japan niedriger als das von Dolomitgestein aus Nepal ausfiel. Es wurde dabei auch eine Tendenz zur Löschbeständigkeitsverringerung bei gleichzeitig erhöhter Porosität beobachtet. Gefrier- und Tautests an geschweißtem Tuff und japanischem Schiefer zeigten, dass Risse in Schiefer schneller auftraten, aber sich langsamer ausweiteten als in geschweißtem Tuff. Bei Gefrier- und Tautests wurde ebenfalls beobachtet, dass geschweißter Tuff schneller verfällt und verschleißt als Schiefer. Sandstein hingegen blieb über lange Tau- und Gefrierzyklen intakt Résumé Des tests de solidités et l’évaluation de l’effet des températures en dessous de zéro sur les rocs argileux ont été effectués. Les rocs d’origine volcanique (cendre), les rocs calcaires, sableux et les schistes de différentes régions du Japon, ont été étudiés. Les schistes et les dolomites de la région de Ganesh Himal le long du haut Himalaya (Népal) ont été étudiés et comparés à ceux du Japon. Les tests de désintégration sur les rocs ont été effectués dans l’eau pure. Les résultats montrent que l’index de désintégration des schistes du Japon est inférieur aux schistes du Népal. En ce qui concerne les rocs carbonyles, l’index de désintégration des rocs calcaires du Japon est supérieur à ceux des dolomites du Népal. Une décroissance de la résistance à la durabilité est observée avec une plus grande porosité des rocs. Les tests de congélation-décongelation sur les schistes et les rocs d’origine volcanique (cendre) du Japon montrent une apparition précoce des fissures mais l’expansion des fissures est plus rapide dans les rocs volcaniques. Des tests similaires montrent que les rocs volcaniques (cendre) se désagrégent plus rapidement que les schistes. Cependant, les rocs sableux restent intacts après plusieurs cycles de congélation-décongélation.

Jan 1, 2003

By A. G. R. Coreejes, G. Ferreira

The paper sets out briefly the methods used for the planning and control of the construction work at Grootegeluk Coal Mine near EIIisras, Transvaal. It includes a discussion of the programming, the updating of programmes, and the progress reporting.

Jan 1, 1982

By A. Morley

It is difficult to evaluate exploration properties in a manner that is transparent, repeatable and easily re-calculated to cater for different geological interpretations, but the risk-based assessment methodology, the Geological Risk Method, developed and described by Lord et al (2001) attempts to satisfy all these criteria. This paper examines a case study example based on valuations of exploration projects conducted by SRK Consulting using this methodology, and describes some of the advantages and limitations of the method.

Jan 1, 2007

By Gernot Beer, Christian Dünser, Marcos Noronha

The main findings of the joint research initiative “Numerical Simulation in Tunnelling” and a follow-on project on efficient numerical simulation models for tunnelling are presented. Die wichtigsten Resultate des Forschungsschwerpunkts „Numerische Simulation im Tunnelbau“ und einem Folgeprojekt über effiziente numerische Simulationsmethoden werden präsentiert Les résultats les plus importants du point principal de la recherche "simulation numérique dans la construction de tunnels" et un projet consécutif sur des méthodes de simulation numériques efficaces sont présentés

Jan 1, 2003

By C. Van Rhee

In dredging practice sand is eroded at very high flow velocities using water jets. The existing pick-up functions overestimate erosion. By taking the permeability into account conventional pick-up functions can be made suitable for high velocity erosion. This can be achieved by modifying the critical Shields parameter. The procedure is demonstrated using the pick-up function of Van Rijn. The theory is compared with experiments and agreement is good.

Jan 1, 2007

By A. C. Wingrove

The paper outlines the selection of a dewatered tailings backfill system for the Johannesburg Consolidated Investment Gold Division, and covers the following aspects: (i) 16 Shaft pilot testwork; (ii) engineering design problems relating to the Cooke 3 Shaft backfill operation; (iii) in-line mixing - applications with respect to the Randfontein Estates Gold Mine and Western Areas Gold Mine backfill operations; and (iv) pipeline friction losses.

Jan 1, 1988

By I. H. Clark

In some mining situations, backfills are not only required to be free-standing but are also expected to provide hangingwall support. It may therefore be specified that the backfill withstand a certain calculated stress within a given time. Given the materials available, the choice of backfill composition is not always straightforward, and an approach to the evaluation of cemented tailings backfill is therefore proposed. The general use of such a method will greatly assist in both the scientific analysis of the material properties for industry-wide purposes of comparison and decision-making as regards the choice of fill.

Jan 1, 1988

By Milton Syamujulu

In 1994, Nkana smelter commissioned a Multimillion US$ Dollar Chilean Teniente converter (CT) in its operations in order to improve its smelting technological base. The main objective was to reduce the overall smelting energy costs and increase the sulfur capture for sulphuric acid production to support the company?s leaching operations at Nchanga Tailings Leach Plant. A decade of CT operations have since ensured following its installation and startup. This paper provides a Technical and Operational Audit of the performance of the CT in the first 10 years of its operations at Nkana smelter.

Jan 1, 2005

By C. Musingwini, M. Woodhall

An often overlooked factor in the analysis of mine layouts and schedules is technical operating flexibility, mainly due to its nebulous nature. If one glosses over technical operating flexibility the resultant mine layouts and schedules tend to be sub-optimal. The need to incorporate technical operating flexibility into the analysis and comparison of mine layouts and schedules is increasing in importance. This paper illustrates the nature of technical operating flexibility, reviews previous work on valuing operating flexibility and proposes how technical operating flexibility can be quantified for tabular reef mines by using a platinum reef deposit as a case study. Once technical operating flexibility is quantified it becomes possible to explore its incorporation into the analysis of mine layouts and schedules and subsequent optimization processes. The work described in this paper is part of a current PhD study at the University of the Witwatersrand. Keywords: mine plans, layouts, schedules, technical operating flexibility, ore availability.

The January General Meeting was held at The Moth Hall, Witbank, on Thursday, 30th January, 1969. Mr C. G. Sowry (Chairman of the Witbank/Middelburg Branch) was in the chair. There were also present: Fourteen Members: Messrs A. Bain, A. W. L. Brereton, J. Meintjes, G. Langton, A. C. Hofmyer, J. H. Moore, T. S. Wilmot, B. F. van der Merwe, H. A. Williams, O. T. Wright, J. E. van Aswegen, P. J. Beukes, I. Botha. Six Associate Members: Messrs B. T. Hosking, R. E. Powell, J. B. Cornish, R. Ladner, W. Weber, P. J. Muller. Two Affiliates: Messrs P. B. Cass, W. K. C. Bremer. Nine Visitors. Apologies were received from Messrs G. R. Canny, E. J. Jackson. MINUTES OF THE PREVIOUS GENERAL MEETING It was proposed and accepted that these be taken as read. Proposer, J. Meintjies; seconded, A. W. L. Brereton. 75TH ANNIVERSARY CELEBRATIONS OF THE S.A.I.M.M. The Chairman reminded members of the functions arranged to mark this occasion. It was also mentioned that members desirous of forming parties to travel to Johannesburg should either make arrangements amongst themselves or inform the Secretary who would assist in arrangements. PAPER FOR PRESENTATION The Chairman then called upon Mr S. Selmer-Olsen to present his paper, 'Lectures on electro-smelting of ferro-alloys'. After Mr S. Selmer-Olsen had presented his paper, he answered questions arising from contributions from the floor. The Chairman then thanked Mr S. Selmer-Olsen for presenting his paper. CONTRIBUTIONS TO PREVIOUS PAPERS Contributions to the paper 'Photo-electric readings. Their significance for dust control on collieries,' presented by Messrs G. H. J. Kitson (Member) and Y. J. F. Haven (Visitor), were read by Messrs A. Bain and A. W. L. Brereton.

NOTICES PROCEEDINGS OF THE SECOND INTERNATIONAL CLEAN AIR CONGRESSThis massive volume of 1,380 pages contains all the papers presented at the congress held in December 1971. INDEX TO SOUTH AFRICAN PERIODICALS This bibliographical work has been produced by the Johannesburg Public Library since 1945, and is of interest to all our readers. THE CONTROL OF GASEOUS SULPHUR COMPOUND EMISSION An international conference on this theme will be held at the Salford University from 10th to 12th April, 1973. COLLOQUIUM ON SLlMES DAMS The South African Institute of Mining and Metallurgy have great pleasure in advising members that two-day colloquium on Slimes Dams is being arranged for the 14th and 15th November, 1973. NATIONAL INSTITUTE FOR METALLURGY / NASIONALE INSTITUUT VIR METALLURGIE REPORT. VERSLAG No. 1424 REVIEW OF THE WORLD'S FLUORSPAR INDUSTRY, WITH PARTICULAR REFERENCE. TO SOUTH AFRICA Ist August, 19n Investigator: H. H. Gossling SYNOPSIS The consumption of fluorspar has increased significantly during the last three years, and a consumption of approximately 5,76 million tonnes per annum is projected for 1975. REPORT. VERSLAG No. 1432 LABORATORY METHOD No. 44/2 THE DETERMINATION OF RUTHENIUM AND OSMIUM IN THE RESIDUES RESULTING FROM THE LEACHING OF MATTES 5th July, 19n Investigators: Magdalena M. KrUger R. V. D. Robert SYNOPSIS The method described involves the sintering of the residue with barium peroxide, and the distillation of ruthenium and osmium from the sinter. REPORT. VERSLAG No. 1439 THE REACTION OF SULPHIDE MINERALS WITH THIOL COMPOUNDS 29th June, 19n Investigator: L. A. Goold SYNOPSIS A selected group of thiol reagents was reacted with a wide range of sulphide minerals, and products that were formed at the surface were extracted and identified by infrared spectrophotometry.

Professor R. N. Pryor, AR.S.M., B.8c., C.Eng., F.I.C.E., F.I.Min.E., F.I.M.M., who died on 14th July, 1979, after a short illness, was President of the Institution of Mining and Metallurgy for the session 1978-1979. Weld pool metallurgy A high level of current interest in welding characteristics and behaviour and in the properties of welds was amply demonstrated by the large attendance at The Welding Institute's 1978 Conference on 'Trends in Steels and Consumables for Welding' and by the overwhelming number of papers offered for the International Conference on 'Arc Physics and Weld Pool Behaviour' in May 1979. Mine ventilation The First International Mine Ventilation Congress was held in September, 1975, in Johannesburg, South Africa, at the University of the Witwatersrand. It was organized by the Mine Ventilation Society of South Africa. Occupational accidents and diseases The IXth World Congress on the Prevention of Occupational Accidents and Diseases will be held in Amsterdam from 6th to 9th May, 1980. Rock mechanics The 21st U.S. Symposium on Rock Mechanics is to be held at Rolla, Missouri, from 27th to 30th May, 1980. Protection against noise An International Symposium on the Protection of Workers Against Noisewill be held in Dresden (German Democratic Republic) from 27th to 30th November, 1979. Management of mineral resources A joint meeting of the Institution of Mining and Metallurgy, the Society of Mining Engineers of AIME, and the Metallurgical Society of AIME is to be held in London from 27th to 30th May, 1980. INFACON 80 During 1970 various South African institutes and associations agreed to organize an international ferroalloys congress. It was recommended that this should be made a continuing forum, where ferroalloy people could meet and discuss matters of mutal interest.

Jan 1, 1979

By J. M. Paull, J. B. See

The rate of reaction between different carbonaceous reducing agents and silicon monoxide gas was studied by the use of a technique developed in Norway by Tuset and Raaness. Argon carrier gas was used to pass a known fixed concentration of silicon monoxide gas through an I1 cm3 sample of precalcined reducing agent at 1650°c. Silicon monoxide gas was generated by the heating of a mixture of silica and silicon carbide, and the progress of the reaction was followed by monitoring the carbon monoxide in the off-gas with an infrared spectrometer. The reactivity of silicon monoxide gas towards a number of carbonaceous reducing agents (charcoal, Iscor coke, Lurgi char, and petroleum coke) was shown to be similar to results obtained with the carbon dioxide reactivity test. The silicon monoxide reactivity test was able to indicate the extent to which fines were generated when the reducing agent was converted to silicon carbide. Of the reducing agents studied, Lurgi char appeared to be the most suitable for the production of ferrosilicon because it has a high reactivity towards silicon monoxide gas and high strength when converted to silicon carbide. So that industry could be given some indication of the suitability of certain reducing agents for the production of ferrosilicon and silicon metal, a reactivity scale similar to that of Tuset and Raaness was constructed that compares the volume of silicon monoxide gas required by a reducing agent to reach a carbon monoxide content of 10 per cent in the off-gas during the conversion of the reducing agent to silicon carbide. This scale assists in the selection of those reducing agents that require less silicon monoxide gas for conversion to silicon carbide, and that give savings in material and power costs because less silicon monoxide gas need be generated in the furnace.

Jan 1, 1979

By M. C. Mulligan

Counter current decantation (CCD) thickener circuits are used to recover soluble metal as pregnant liquor solution from ore leach residue. The basis of CCD operation is to concentrate suspended solids thereby minimizing liquor content in underflow slurry that flow in one direction. Then the underflow slurry liquor is diluted with wash liquor that flows in the opposite direction and the suspended solids are concentrated again and again. The amount of liquor in the thickener underflow contributes to determining the number of CCD stages required to recover the desired amount of soluble metal. Furthermore, similar results could be achieved at a lower wash quantity, reducing the size of downstream equipment. High density thickeners (HDT) are designed to use gravity and compression, and minimize the amount of liquor in the underflow thus minimizing the number of CCD stages. This paper reviews the process used to select HDTs rather than high rate thickeners (HRT) for the Ruashi II copper-cobalt hydrometallurgical process in the Democratic Republic of Congo (DRC), using laboratory HDT simulations, to CCD simulations and thickener design details.

Jan 1, 2009

By D. Bessinger, N. Rughubir

Exxaro Sands KZN produces?among other heavy mineral products?high titania slag, which is used as feedstock to the pigment industry. The titania slag is produced from the smelting of ilmenite in two 36 MW DC furnaces. In this smelting process carbon monoxide gas is produced. This gas is cooled, scrubbed and washed to remove entrained dust. This paper provides details on the gas cleaning plant system and the chemistry, mineralogy and size distribution of the particulate material contained in the off-gas stream. Characterization of the dust shows that is consists mainly of ilmenite, but with relatively high levels of SiO2and MnO. Smelting of the dust in a 500 kW DC furnace was carried out to investigate the potential for recovering valuable elements from the dust.

Jan 1, 2007

By A. J. S. Benade, N. B. Strydom, W. H. Van Der Walt

The influence of two weeks of microclimate cooling on the state of heat acclimatization by N. B. STRYDOM, M.Sc., Ph.D. (Illinois) (Fellow), A. J. S. BENADE, M.Sc. (Potch.) (Visitor), and W. H. VAN DER WALT, B.Sc. (Potch.) (Visitor) Five volunteer Black subjects were acclimatized according to the climatic-room acclimatization procedure, and their states of heat acclimatization were determined by the usual heat-stress test. The subjects thereafter wore pre-frozen jackets in a somewhat higher environmental temperature (33,9/35,6 °C). stepping at the same rate as before for four hours a day for fourteen days. The heat-stress test was repeated and followed by a similar test at the higher environmental temperature. It was found that fourteen days of microclimate cooling in a very hot environment had no adverse effect on the degree of heat acclimatization. The sweat rates during microclimate cooling remained high, even though no sweating is possible beneath the pre-frozen ice-jacket. which indicates that there is an increase in sweat rate from the areas of exposed skin.

Jan 7, 1975

By Z. Weisheng

The lift system is the main part in manganese nodule mining on the ocean bed. It connects the nodule collection system (miner) with the surface platform (mining vessel) and transports the nodules from the ocean bed to the surface. China started the research on lift technology in deep ocean mining in 1991, and a slurry pump hydraulic lift method has been developed for the nodule mining system. The detailed slurry pump hydraulic lift experiments have been undertaken with crushed nodules in the vertical pipe. The lift parameters to lift coarse particles in the lift pipeline have been discussed, including the pressure drop, the solid concentration, and the mixture velocity. The author of this paper not only took part in all these studies on the lifting technology, but was also responsible for some of this research. This paper will present the component parts of the lift system and the research results of coarse particle mixture flow in the vertical lift pipeline. Keywords: deep sea mining, slurry pump lift, lifting parameters.

Jan 1, 2007

By D. Limpitlaw

As coal mining often results in the generation of acid mine drainage (AMD), careful planning and management of the water on such mines is required. A colliery in Mpumalanga recently sponsored independent research into the pollution-ameliorating potential of a natural wetland that has been receiving AMD for at least two decades. Samples of the sediment collected in the wetland were subjected to nine stages of sequential extraction in a determination of the distribution of the metal species present. The samples were then analysed for aluminium, iron, and manganese. The concentrations of sulphate-reducing bacteria (SRB) were also determined. The SRB concentration was found to increase with distance downstream (away from the source of pollution). An analysis of the sediment speciation data indicated that metal immobilization may be optimal in areas where the organic adsorption of metals is at its greatest. The analysis also provided evidence of the biogeochemical improvement of the water quality as the AMD passed through the wetland environment. The metal species present did not correlate strongly with the SRB populations; nor did the soluble species correlate with the species formed over long periods of time.

Jan 1, 1996