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By G. R. Addie

The Hydraulic Institute has completed the task of developing a new ANSI/HI standard 12.1-12.6 (2005) for rotodynamic (centrifugal) slurry pumps covering nomenclature, definitions, applications, and operation. The standard provides examples of the different slurry pump types and contains an extensive section on pump and slurry definitions. The effect of slurry on pump performance is covered along with the pumping of froth. Reference is also made to ANSI/HI standard 9.6.7 (2004), which contains a new method for pump performance correction when handling viscous fluids. Classification of slurry services is established and then is used to determine limitations on velocities and total head per pump in order to obtain acceptable wear performance. The new service class, head per stage and other limits are directly related to capital and other cost considerations that will affect solids transport system economics. The writers review the contents of the new standard, highlight the main points, and discuss the reason for the slurry classification, corresponding limits and expected implications, particularly with respect to operating costs of the pumps in solids transport systems.

Jan 1, 2007

By G. J. C. Young

The new metallurgical plant has a simple, compact layout, being designed for a small team of operators. The reasons for building the new plant are given, and its various sections are briefly described. These include the conveyor plant, milling plant (for run-of-mine milling), thickener plant, agitator plant, filtration, clarification, smelthouse, and central core joining the mill and filtration sections.

Jan 1, 1978

By B. Genc, C. Gous

Spontaneous combustion during coal mining operations is a major problem that affects the health and safety of workers and causes environmental problems. The phenomenon is associated with the presence of coal, coal shale, and pyrite. In 2020, a premature detonation incident occurred at an iron ore mine where the waste material contains black carbonaceous shale units known to be associated with pyrite. The spontaneous combustion propensity and properties of samples of the black carbonaceous shales from the mine were examined and compared with samples from the Witbank Coalfield. The spontaneous combustion liability indexes of these samples were correlated with X-ray fluorescence (XRF) and proximate and ultimate analyses using linear regression. The Wits-Ehac Index classification results show that the samples were between medium and high risk. The linear regression analysis showed very poor correlations between the Wits-Ehac Index results and the XRF and proximate and ultimate results. The most valuable relationship found is between the presence of relatively high sulphur (greater than 3%) and ground reactivity with nitrate-bearing explosive emulsion.

Jun 5, 2023

By S. Swanepoel, A. V. Cherkaev, Q. G. Reynolds, M. Erwee

Ferrochrome (FeCr) is a vital ingredient in stainless steel production and is commonly produced by smelting chromite ores in submerged arc furnaces. Silicon (Si) is a componrnt of the FeCr alloy from the smelting process. Being both a contaminant and an indicator of the state of the process, its content needs to be kept within a narrow range. The complex chemistry of the smelting process and interactions between various factors make Si prediction by fundamental models infeasible. A data-driven approach offers an alternative by formulating the model based on historical data. This paper presents a systematic development of a data-driven model for predicting Si content. The model includes dimensionality reduction, regularized linear regression, and a boosting method to reduce the variability of the linear model residuals. It shows a good performance on testing data (R2 = 0.63). The most significant predictors, as determined by linear model analysis and permutation testing, are previous Si content, carbon and titanium in the alloy, calcium oxide in the slag, resistance between electrodes, and electrode slips. Further analysis using thermodynamic data and models, links these predictors to electrode control and slag chemistry. This analysis lays the foundation for implementing Si content control on a ferrochrome smelter.

Mar 14, 2024

The President: "It gives me great pleasure to call on Professor Howat to present the paper written jointly with P. R. Jochens and C. W. Wolhuter entitled, 'Utilisation of slags for the manufacture of cement.' After the presentation of the paper the President said: "Thank you, Professor Howat, for so ably introducing the paper prepared by yourself, Dr Jochens and Mr Wolhuter. Once again we are deeply indebted to you for bringing to our attention a new development in the metallurgical field, this time a technique for assessing the suitability of slags for the production of slag cement, and thereby providing a means of turning a waste material into a valuable asset. May we hope that this will lead to an end to unsightly slag dumps and, at the same time, to some conservation of our local limestone resources. Discussion within this Institute on the problems of cement manufacture, has of recent years been all too infrequent, and we thank you for bringing this interesting and important subject again to our notice. We are doubly grateful to you and your co-authors. May I now call on Dr Stutterheim, Deputy Director of the Council for Scientific and Industrial Research, to contribute to your paper, and to tell us something about the Conference on the Chemistry of Cement which he attended in Tokyo towards the end of last year." (Applause.) Dr N. Stutterheim, Mr B. F. van der Merwe and Dr F. S. Fulton then contributed to the paper. (These contributions will appear in a later issue of the Journal.) PAPERS OPEN FOR DISCUSSION The President: "Listed on the agenda are papers open for discussion. I would suggest that anyone wishing to contribute to these papars, submit their contributions to the Secretary in writing." CONCLUSION The President: "I would like to thank everybody for their attendance here tonight, and on your behalf I am sure you would like me to thank the authors and the contributors for the most interesting time that we have had this evening. Thank you very much." The meeting closed at 6.00 p.m. NOTICE SYMPOSIUM ON THE RECOVERY OF PYRITE A symposium on the recovery of pyrite will be held on 12th and 13th June, 1969 at Kelvin House, Johannesburg under the auspices of the Institute and the National Institute for Metallurgy. Notices will be sent to members as soon as more details are available as regards the papers and the programme.

1. Book review . Australasian coal mining practice, edited by C.H. Martin. Reviewer: R.B. MacGilIivray This book is an extremely comprehensive coverage of coal-mining practice in Australasia, the countries covered being Australia, New Zealand,and Papua New Guinea. 2. From The Institute of Metals The folowing are available from The Institute of Metals, 1 Carlton House Terace, London SWl Y 5DB. Physical and elastic characterisation, edited by M. McLean. 1989. 228 pp. £25.00. High nitrogen steels, edited by J. Foct and A. Hendry. 1989. 461 pp. £49.50. Proceedings of the First International Calcium Treatment Symposium. 1988. 116 pp. £15. New cored-wire injection techniques, particularly as Design for recyc/ability, by Michael E. Henstock. 1988. 150 pp. £15. Solidification processing. 1988. 549 pp. £45. Marine engineering with copper-nickel. 1988. 103 pp. £18. Characterisation of High Temperature Materials. 3. New journal FMJ International Publications Lid have announced a new quarterly publication, Aluminium Today. 4. Other new publications Algorithms in real algebraic geometry, edited by Denis S. Arnon and Bruno Buchberger. London, Academic Press, 1988. 274 pp. £15.95. Proceedings, Foundry and Heat Treatment 88. R150 per set of 5 volumes, or R40 per volume.

Jan 1, 1989

NEW BOOKLET FOR POTENTIAL ENGINEERS A new booklet "Professional Careers in Engineering" for issue to high school students who are considering engineering as a profession has been prepared for general distribution. The booklet is intended to help high school students to decide whether a career as a professional engineer would appeal to them, and to tell them how to set about becoming a professional engineer. Copies of the booklet may be obtained free of charge by writing to: The Federation of Societies of Professional Engineers, P.O. Box 5907, Johannesburg.

Now a new generation of computerized drill rigs has been launched and they are based on modern standard PC-computer technology. The rigs have been well embraced by the market and more than 100 units have left the assembly line. The new generation has taken a quantum leap forward with respect to drilling accuracy, logging capabilities, reduction of manpower in some types and serviceability compared to the previous generation of drill rigs. The Can bus technology, well proven in the automobile products, is the backbone in the new generation control system of Atlas Copco. The short-term development is now focused on establishing this new automation platform on other product lines of Atlas Copco products. The long-term objectives is to offer the mining industry Atlas Copco products with one common automation platform. Essential for Atlas Copcois to contribute to the work with the on-going Data Exchange standard between mining machines and mining computer systems (IREDES). Our belief is that an accepted standard will make mine automation programs affordable for a wider base of the mining industry, because of the possibilities to a cost effective integration of different equipment with a minimum of system integration problems and machine specific interfaces.

Sep 1, 2001

By D. G. Krige

By use of models based on the South African gold-mining industry, analyses are made of the effects of changes in the mining tax structure on the .State's tax income from potential new mines; also on the percentage of such mines likely. to be proceeded with. The percentage is affected by the correlation between changes in taxation and in the flotation pay limits !or new mines. It is shown that the State stands to gain both directly and indirectly from raising the level of the capital allowance and from its extension to all mines; and that the reduced taxation resulting from a lowering of the discriminatory high tax formula for the gold mines, would, in respect of potential new mines, be compensated for by a significant increase in the percentage of such mines that would be proceeded with.

Jan 1, 1979

By J. P. Coetzee

There is an ample supply of all the raw materials required for the future development of the industry, with the possible exception of coking coal. Improved methods of coke production are being developed. It is anticipated that steel production will reach eight million tons per annum by 1980. New techniques and equipment for refining steel will be installed, together with new processing equipment. The most serious problem now facing the industry is the acute shortage of labour.

By S. K. Gilman, P. S. Marcos

There are basic areas of importance within a concentrator or mineral separation plant, which require focus to ensure acceptable recoveries, throughputs remain at an acceptable level and product grades meet specification. Professional and para-professionals within the mineral sands industry are in demand due to the booming resource sector. Added to this, new mineral sands operations are being commissioned straining the industry further. These factors have increased staff turnover and introduced many new people to the industry. It is essential these new entrants are armed with basic plant troubleshooting skills relevant to the minerals sands industry to minimize production lost through poor recoveries. Mineral sands processing does not involve highly technical or sophisticated unit processes. However, success is often slow to arise due to a lack of detailed understanding, as well as managing multiple interrelated unit processes within a plant. Fundamental background physical conditions (such as equipment loading and water quality) must be met for unit processes to be efficient. Technical management of these process plants should always include observation of these background conditions for they often provide the answer to underperformance. Examples are presented with an indication of the possible effects on recovery and product grade.

Jan 1, 2007

By M. C. Harris

Float-sink analysis has wide application in the coal laboratory. This paper evaluates the established methods used for the float-sink analysis of fine coal, and then describes a new method and apparatus that can be used for material down to a few micrometres in size. The method is rapid and accurate, and requires only a small amount of sample. The results presented show close agreement with the float-sink analyses obtained by the more classical technique using separating columns. The new centrifugal method reduces the time required for the analysis by a factor of ten.

Jan 1, 1986

By H. W. Read

The South African platinum industry finds itself in the midst of a rapidly evolving society that is no longer characterized by the apparent stability of the previous decades. The features of this society include increasing global competition, rapid technological innovation, a declining skills pool, major political transformation, a more challenging working environment as the mines reach deeper into the earth?s crust and a greater concern for human welfare. It is therefore axiomatic that new ways will have to be found to engage the all-pervasive change in the mining environment. Although in general terms project management is a universal endeavour for managing change, it takes place in a specific socio-techno-economic environment and geographical setting that gives it a particular context. The argument of this paper explores, analyses and synthesizes the impact of these changes on the emerging project management methodology. In essence, the management of change will inevitably contribute to the emergence of new dilemmas, issues and challenges. The change management process and procedures will also be affected by this change and in response, drive internal change of its own structures and organization. And, therefore, a new paradigm of project management will become apparent. A new project management model will then be proposed to the industry.

Jan 1, 2006

By A. L. Bleloch, A. M. Starfield

This paper is concerned with heat flow in the plane of a typical cross-section of a deep underground airway. A new algorithm, called the quasi-steady method, is presented for the calculation of rock temperatures in that plane. The algorithm is used in the computation of heat and moisture transfer rates from the rock to the ventilating air for an airway that is wet on part of its circumference and dry elsewhere. The speed and accuracy of the new method are demonstrated on a microcomputer, and it is argued that this method offers a considerably more versatile and physically meaningful alternative to previous methods for the prediction of increases in air temperature along mine airways. The algorithm is also used to explore the concept of a uniformly wet airway that is equivalent to a partly wet airway in terms of its effect on the ventilating air. The concept is shown to be reasonable, but more complex than one might have anticipated. Finally, several useful extensions and applications of the new method are suggested.

Jan 1, 1983

The Gold Medal of the Institution for Mining and Metallurgy for 1978 was awarded to Adriaan Louw at the Annual General Meeting of that Institution in London on 17th May, 1979. The award was made for distinguished services to the mining industry in South Africa.

Jan 1, 1979

Each year the South African Institute of Mining and Metallurgy offers a prize (or prizes should the entries warrant it) of up to RlOO for the best paper or dissertation on a topic appropriate to the interests of the Institute. The competition is open to all Student Members of the Institute. A Student Member who is in fulltime study at a university may submit the dissertation or thesis he has to write in part fulfilment of his university degree, provided that it is presented in a manner and on a topic suitable for publication in the journal. Entries for 1976 should reach the Institute by 31st December, 1976.

Jan 10, 1976

The possibility that type 430 stainless steel can become sensitized during annealing after hot-rolling was studied by simulated cycles of continuous-annealing heat treatments, and by calculation of the carbon solubility. It was found that the lower-carbon steel could be sensitized at lower annealing temperatures than the higher-carbon steel, which is in line with plant experience. The difference in sensitization behaviour is ascribed to the lower rate of recovery of the lower-carbon steel during cooling, since recovery is sensitive to the grain size. At practical heat-treatment temperatures, austenite formation does not play a role.

Jan 1, 1996

A prize awarded by the SAIMM for outstanding academic achievement by 4th-year and 5th-year diplomates at technikons was instituted several years ago. The Senior Vice-President, Mr J.D. Austin, accompanied by the Institute's Secretary, Mrs D. Gardner, attended a prize-awarding function in the form of a luncheon at the Hotel School of the Technikon Witwatersrand on the 25th May.

Jan 1, 1984

World refrigeration expert Professor Gunter Heinrich, at the invitation of the School of Mechanical Engineering at the University of the Witwatesrand (Wits), recently addressed industry representatives in Johannesburg on alternative refrigerants.

Jan 1, 1994

By L. Thomson

"The smelter at Sudbury Integrated Nickel Operations, located in Sudbury, Ontario, operates a single electric AC furnace. This furnace treats nickel sulphide concentrates produced by Glencore and third-party feeds and as such its performance is key to the company’s nickel supply chain. Currently the plant has two shutdowns per year in order to carry out significant repairs on matte tap-holes.Improved monitoring systems that enable better prediction of tap-hole wear have been a continued focus. The electric furnace is an essential piece of the smelter flow sheet requiring the need for planned tap-hole maintenance along with robust systems for management according to to this plan.The ability to meet our goal of zero harm is ensuring that safe practices are in place. Detailed procedures and cool-down practices have been implemented to ensure that required matte chemistry and temperature criteria can be met during the period leading into a shutdown for tapblock maintenance.A significant repair of the electric furnace will take place in 2015. During this rebuild, the sidewalls and matte endwall will be replaced. There is work underway to improve wall and matte end performance in an attempt to extend the time between rebuilds. This paper will review the approach taken towards this end."

Jan 1, 2014