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By L. C. Woollacott

Some of the factors that may influence the reliability of a consistent material balance derived from plant data were investigated, data taken from a sampling of the Iow-grade tin-flotation circuit at Rooiberg A Mine being used as the basis for the investigation. The importance of subjecting a calculated balance to a thorough analysis of its sensitivity to erors in assay and flow rate measurements is highlighted. Several simple guidelines are derived from the analysis of the Rooiberg data, and these appear to be generaly applicable to process-evaluation exercises and to the technique used for the smoothing of material balances.

Jan 1, 1987

By C. I. Ware

The phrase ?back to basics? is used to describe the fundamental principles and philosophies on which a successful mining operation is based. At Richards Bay Minerals (RBM), ?back-to-basics? (BTB) has been implemented as a continuous process to probe operational functions with a view to increase production without capital expenditure. It also ensures that the fundamentals of dredge mining are understood and adhered to. BTB is based on the principle that people drive organizations, necessitating an interactive implementation approach. At the RBM mine this entails a three-pronged approach, namely practical training, teamwork initiatives and the use of lean Six Sigma methodology. It is the latter on which this paper will focus. The lean Six Sigma methodology is successful in identifying, managing and documenting BTB projects, while team work initiatives are integral to successful project implementation. This paper describes two examples of how the Six Sigma methodology can be applied to a dredge mining operation. The first example focuses on the improvement of Mining Pond Echo (MPE) plant throughput by reducing the lost opportunity (non-production) due to tails downtime. The project was successful in increasing plant throughput by 4.5%. This was achieved by increasing the tails disposal system availability by running MPE as a four tails lines operation and focusing on causes of tails production downtime. Subsequently, the tails system at MPE is no longer the production bottleneck. Second, the Six Sigma methodology was successfully applied at Mining Pond Charlie (MPC) to increase the primary dredger throughput by 4.6% through focusing on the dredging technique and maintenance issues. This project highlighted the need for trend analyses to ensure an effective dredging technique, coupled with simple production documentation, which also ensures a focus on maintenance. Keywords: Back to basics, Six Sigma, training, teamwork, throughput improvement, tails, dredger.

Jan 1, 2007

By J. O. Jensen

A method is described for the determination of cyanide in gold slurries, based on amperometry. The measured current is proportional to the concentration of cyanide, and is not effected by pH or by the concentration of oxygen in solution. It is also unaffected by other ions that may be present in gold-leaching solutions, including sulphide, thiocyanate, and thiosulphate. The current depends on the temperature, and an activation energy of 17,9 kJ/mol was determined Since the current is controlled by the mass transfer of cyanide to the anode, it depends on the conditions of agitation. In tests on an operational gold plant, slurry was pumped directly from the top of the leaching tank, through the measuring cell and back into the tank. The results indicate that the instrument is a promising alternative to the instruments currently available. The readings from the instrument remained in calibration for at least two days, showing that the instrument would need to be re-calibrated by the operating staff at regular periods.

Jan 1, 1994

By A. Ball

A fully instrumented laboratory drilling machine is described. It is designed to produce realistic drilling conditions with diamond microbits of 20 mm diameter. A computer-controlled data-logging system records the net power consumption, rotational velocity, bit thrust, torque, and penetration rate. Tests can be conducted under conditions of set thrust and rate of advance. In the tests reported, there is a significant correlation between the rock drilability and the measured rock properties of relative abrasion resistance and uniaxial compressive strength. Wear of a diamond bit is a crucial factor that cannot be determined simply from rock properties. Realistic drilability testing with appropriately scaled microbits is a convenient and economical way of evaluating diamond-bit performance and determining rock drilability.

Jan 1, 1990

By J. J. van Vuuren

Pipe-stick support in deep-level gold mines is first described and illustrated, a pipe-stick being a mine pole trimmed to the required size and sleeved by a pipe. An account is then given of an investigation into this form of support that involved load-compression tests in a 1000-ton press, tests in a rapid loading machine simulating rock-burst conditions, a study of the load-compression behaviour of pipesticks installed underground, and a cost evaluation. Pipe-stick support was found to be very effective on the face and to cost less than conventional matpacks.

Jan 1, 1979

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

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

Jan 1, 1981

By S. A. C. Liedberg, M. H. Fricker

The conference was divided into a total of 12 different sessions. Apart from the keynote addresses, the papers covered many aspects of open-pit mining, from mine design and blasting techniques to mining operations and equipment, as well as water management and rehabilitation. A number of case studies were also presented. Most of the 68 papers originated from Australia; however, presentations were also made by representatives from Chile, Indonesia, Papua New Guinea, and South Africa. The keynote papers dealt with subjects such as the economics of open pits, project planning of a new large copper deposit, management principles, and rehabilitation strategies.

Jan 1, 1993

By R. D. Hancock

The loading and selective properties of a number of commercial and experimental resins developed for the extraction of base metals were evaluated. Particular applications that ",:ere considered included the extraction of copper from artificial dump liquors, the treatment of Iow-grade copper, nickel, and cobalt liquors, and the removal of nickel from a cobalt electrolyte. Reagents that showed promise were two experimental resins developed at Mintek containing pyridyl imidazole active groups and two Dow resins, XF4195 and XF4196.

Jan 1, 1982

By J. N. van de Merwe

CONTRIBUTION BYH. WAGNER AND T.T. OZAN The paper by Dr J.N. van der Merwe makes an important contribution to the design of bord-and-pillar workings in the Vaal basin. It has been recognised for some time that the strength of coal seams in the Vaal basin is markedly lower than that of coal seams in other coal-mining districts in South Africa. However, there was insufficient data to quantify how much weaker the extensively jointed coal the Vaal basin is. A number of recent pillar collapses that occurred at Sigma colliery, the only remaining underground colliery in the Vaal basin, provided Dr Van der Merwe with an opportunity to make this assessment.

Jan 1, 1993

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

Council and Standing Committees, 1979-1980 President: D. A. Viljoen. Senior Vice-President: Dr P. R. Jochens. Junior Vice-President: G. Y. Nisbet. Honorary Treasurer: Dr D. G. Krige. Immediate Past President: Dr M. G. Atmore. Members of Council: J. D. Austin, A. N. Brown, J. A. Cruise, C. E. Fivaz, J. S. Freer, P. N. Harris, H. E. James, Dr R. P. King, Prof. F. Q. P. Leiding, Dr B. K. Love¬day, D. G. Malan, C. S. Macphail, J. C. Mostert, H. G. M. Rose, G. C. Thompson, R. A. von Maltitz, Dr H. Wagner. Past Presidents Serving on Council: R. J. Adamson, H. Britten, J. K. E. Douglas, Prof. D. D. Howat, Dr J. P. Hugo, D. G. Maxwell, Prof. R. P. Plowman, Dr R. E. Robinson, Dr M. D. G. Salamon, P. W. J. van Rensburg, P. A. von Wielligh. Chairman, Witbank-Middelburg Branch: R. B. Smith. Chairman, Orange Free State-Klerksdorp Branch: W. C. Mather. Materials Engineering Division, Chairman: Dr J. P. Hugo. Secretary: G. Pienaar. Standing Committee Chairmen: Membership, G. Y. Nisbet; Technical Programme Metallurgy, H. E. James, (Prof. R. P. King) ; Technical Programme Mining, H. G. M. Rose; Vacation School Metallurgy, J. C. Mos¬tert; Vacation School Mining, J. D. Austin; Awards, Dr M. G. Atmore ; Excursions, A. N. Brown ; Adjudications, Dr M. G. Atmore ; Constitution, Rules, and Policy, Dr M. G. Atmore ; Monograph Series, Dr M. G. Atmore ; Training and Career Guidance, P. A. von Wielligh (D. G. Malan) ; National Phoenix Committee, Dr R. E. Robin¬son; 1982 Council of Mining and Metallurgical Congress, Dr M. G. Atmore ; Mines and Works, Dr M. G. Atmore.

Jan 1, 1980

By I. M. W. Preston

A new shaft system was required to replace stope face for the North Section of Harmony Mine and to allow for systematic opening up of the North Eastern Section. Owing to the economic circumstances at the time the project started, it became vital to alter the original planning and to sink the service shaft first. The MATLA coal-sinking headgear, a novel presinking arrangement, allowed sinking to continue to 108 m concurrently with the erection of the permanent sinking headgear and sinking winders. It is estimated that this arrangement resulted in a saving of two months on the overall project.

Jan 1, 1983

This report describes the investigational work on the development of a fire-assay method capable of concentrating, in a button of nickel sulphide, all six of the platinum-group metals present in samples of ores, concentrates, and mattes. In the method adopted, the sample is fused with a mixture of sodium carbonate, sodium tetraborate, nickel carbonate, and sulphur. The nickel sulphide formed during fusion collects the noble metals and carries them to the bottom of the crucible. The nickel sulphide button is dissolved, and the noble metals are isolated and determined. The coefficients of variation range between 1,0 and 4,9 per cent for the various platinum-group metals when they are present in concentrations between 0,3 and 75 p.p.m.

Oct 15, 1971

By D. M. C. Valbom

The introduction of new diamond sorting technologies as well as additional manufacturers I vendors, has increased the equipment selection and combinations available for recovery flowsheet design. This paper describes the methodology used and the benefits realized in the design of recovery plants by ensuring a fundamental understanding of the advantages and limitations of the technology embodied in the equipment, a comprehensive knowledge of the ore body characteristics, and the effective matching of this information in combination with operational commercial requirements.

Jan 1, 2010

By J. L. Taylor, E. N. Lawson, Hulse. G. A.

It is generally recognized that a large proportion of the gold remaining in the residues from metallurgical plants on the Witwatersrand is occluded in pyrite. The conventional flotation-roasting process typically recovers approximately 40 per cent of this gold. The process described here is an unconventional route involving bacterial oxidation, which can achieve a gold recovery of approximately80 per cent. The paper describes tests carried out in the laboratory, as well as on a slimes dam. The results show that recovery of gold can be noticeably enhanced through the use of bacteria under conditions of controlled pH, moisture, and aeration. Biological oxidation of the pyrite releases the occluded gold, which then becomes amenable cyanidation.

Jan 1, 1990

Council and Standing Committees, 1978-1979 President: Dr M. G. Atmore. Vice-Presidents: D. A. Viljoen and Dr P. R. Jochens. Honorary Treasurer: J. K. E. Douglas. Immediate Past President: P. A. von Wielligh. Members of Council: J. D. Austin, A. N. Brown, H. E. James, Prof. R. P. King, Dr D. G. Krige, Prof. F. Q. P. Leiding, D. G. Malan, C. S. McPhail, J. C. Mostert, G. Y. Nisbet, H. G. M. Rose, W. T. Ruhmer, G. C. Thompson, R. A. von Maltitz. Chairman, Witbank-Middelburg Branch: T. S. Wilmot. Chairman, Orange Free State-Klerksdorp Branch: H. M. W. Eschenburg. Past Presidents Serving on Council: R. J. Adamson, H. Britten, J. K. E. Douglas, Prof. D. D. Howat, Dr J. P. Hugo, D. G. Maxwell, Prof. R. P. Plewman, Dr R. E. Robinson, Dr M. D. G. Salamon, P. W. J. van Rensburg. Standing Committee Chairmen: Membership, Dr P. R. Jochens ; Technical Programme - Metallurgy, Prof. R. P. King ; Technical Programme - Mining, H. G. M. Rose; Vacation School - Metallurgy, J. C. Mostert; Vacation School - Mining, D. G. Malan/J. D. Austin; Awards, P. A. von Wielligh; Excursions, D. A. Viljoen; Adjudication, P. A. von Wielligh; Constitution, Rules and Policy, P. A. von Wielligh; Monograph Series, Dr R. E. Robinson; Professional and Technician Train¬ing Committee, Dr M. D. G. Salamon; Career Guidance, D. G. Malan; Phoenix National Committee, Dr R. E. Robinson; 1982 World Congress, Dr M. G. Atmore; Witbank Coal Colloquium, Dr P. R. Jochens; Mines and Works, P. A. von Wielligh.

Jan 1, 1979

Council and Standing Committees-1984/85 President: J.D. Austin Vice Presidents: H.E. James and Dr H. Wagner Immediate Past President: Prof. R.P. King Honorary Treasurer: Prof. D.G. Krige Members of Council: B.C. Alberts, Prof. S. Budavari, E.B. Crocker, N.J. Devine, C.E. Fivaz, J.S. Freer, Prof. G.G. Garrett, J.J. Geldenhuys, Dr A.K. Haines, R.W.O. Kersten, Dr B.K. Loveday, I.D. Matthews, G. Maude, H.G. Mosenthal, B.E. Protheroe, Dr O.K.H. Steffen, Dr P.T. Wedepohl Chairman, Witbank/Middelburg Branch: W.C. Mather Chairman, Orange Free State/Klerksdorp Branch: Dr M.A. Orridge Past Presidents Serving on Council: Dr M.G. Atmore, Prof. A.N. Brown, Dr P.R. Jochens, G.Y. Nisbet, Prof. R.P. Plewman, Dr R.E. Robinson, Prof. M.D.G. Salamon, P.W.J. van Rensburg, D.A. Viljoen, P.A. von Wielligh Standing Committee Chairmen: Adjudication, Prof. R.P. King; Awards, Prof. R.P. King; Constitution, Rules and Policy, Prof. R.P. King; Excursions and Banquet, B.E. Protheroe; Journal, H.E. James; Membership, Dr H. Wagner; Phoenix National Committee, Dr M.G. Atmore; SAIMM School-Extractive Metallurgy, J.S. Freer; SAIMM School-Mining, Prof. S. Budavari; Special Publications, J.D. Austin; Technical Programme¬Extractive Metallurgy, Dr B.K. Loveday; Technical Programme-Mining, J.J. Geldenhuys; Technical Programme-Physical Metallurgy, Dr P.T. Wedepohl; Training, Career Guidance and Education, Prof. R.P. King; World Mining Congress-National Committee, Prof. R.P. Plewman; Working Group Physical Metallurgy, Prof. G. G. Garrett

Jan 1, 1985

By A. M. Starfield

SYNOPSIS A description is given of a new computer programme that has been developed for the rapid computation of the changes in temperature and humidity of air passing through mine airways. The programme enables the ventilation engineer to calculate air temperature increases along airways with an ease that is comparable with that of looking up a set of graphs or tables in an engineering hand-book. The pertinent information for a particular airway can be fed to the computer either on a standard punched card, or by typing directly into the computer at a remote terminal teletype unit.

By A. K. Haines

The status of the South African research and development programme on continuous ion exchange, which was aimed at the technical and economic assessment of that process for the recovery of uranium, is reviewed. The first phase of this programme, which has now been completed, involved development investigations on various pilot plants and culminated in the successful operation of a large-scale demonstration plant and the incorporation of the system in a number of new South African uranium plants. This account highlights the engineering aspects and the design fo the system, its adaptation to process flowsheets, and plans for future development.

Jan 1, 1978

O.F.S. Branch Minutes of the Committee Meeting held in the Committee Room at the St. Helena Club at 4.45 p.m. on Wednesday, 3rd September, 1975. Book reviews JONES, M. J. (ed.). Minerals and the environment. London, Institution of Mining and Metallurgy, 1975. Mining Companies of the world.. 1974/75. London, Mining Journal Books Ltd (15 Wilson Street), 1975. £12. 303 pp. NIM reports Report no. 483 Summary of the mineralogical investigation of pegmatites. (11th April, 1969; re-issued October 1975). Report no. 1697 A petrographic and mineralogical investigation of silica samples from the farm Elandskraal 470JQ, Rustenburg district. (24th Jan., 1975; reissued October 1975). Report no. 1761 The determination, by atomicabsorption spectrophotometry, of minor elements in anode sludges and residues. Report no. 1762 The determination, by instrumental neutron-activation analysis, of some elements in the NI M ROC standard reference materials. Report no. 1770 The spectrophotometric determination of vanadium in chromiumbearing materials. Foundry conference An international foundry confcrence, spomored and organized by South African Institute of Foundrymen, will be held in Johannesburg from 23rd to 27th February, 1976. The themes for each day are follows: Coordination chemistry A symposium on coordination chemistry in extractive metallurgy is to be held in Kelvin House, Johannesburg, on 18th and 19th March, 1976. Practical jet cutting The third international symposium on jet-cutting technology to be organized by BHRA Fluid Engineering will be held in Chicago from 11th to 13th May, 1976, in conjunction with the lIT Rese:uch Institute of Chicago. Hydraulic transport The fourth international conference on the hydraulic transport of solids in pipes (Hydrotransport 4) is being organized by BHRA Fluid Engineering.

Jan 12, 1975