Search Documents

By F. C. Harvey

The Annual General Meeting of the Orange Free State Branch was held on Wednesday evening, 30th July, 1986, in the VIP Lounge of the Freegold North Region Canteen. The meeting was well attended, a total of 73 members, guests, and visitors being present. It was extremely pleasing to have such a large number of lady visitors present.

Jan 1, 1986

This list of corrosion-related terms was compiled to encourage the use of the correct terminology, and to serve as a handy reference for students. It Is based on a similar list compiled by the National Association of Corrosion Engineers (NACE). To promote bilingualism, the Afrikaans terminology is included (in italics at the end of each entry).

Jan 1, 1991

By W. Bleloch

In the process described, hydrogen is used to generate high-temperature steam and oxygen in the molten bath. Steel is decarburized to low levels to produce a pearlite-free steel suitable for deep drawing. The process makes use of the favourable thermodynamics in the reactions between steam, carbon, and iron, as well as providing high-temperature oxygen for the decarburizing reaction. The process can easily be incorporated in existing BOF (basic oxygen furnace) plant but can also be contemplated as a greenfield process.

Jan 1, 1987

By G. E. Blight

The load-compression characteristics of mine supports are usually evaluated by means of relatively rapid tests, whereas in the mine they are subjected to much slower strain-controlled compression. The effects of slow strain rates on the load-bearing properties of mine supports were explored by means of straincontrolled tests on model timber packs and timber-filled steel telescopic props. It is shown that the load-compression characteristics of these supports are considerably influenced by the rate at which they are compressed. The species of timber influences the behaviour, but to a relatively minor extent. Preloaded supports are shown to lose a significant proportion of their preload by relaxation.

Jan 1, 1978

By B. Strohmeier

An account is given of the use of a computer to control the performance of three ultra-high-powered electric-arc furnaces in Iscor 5 steelmaking plant at Vanderbijlpark, South Africa. Several of the reports and graphs printed by the computer are reproduced.

Jan 1, 1985

By P. A. Laxen, P. J. van Staden

In situ leaching tests with thiourea as the lixiviant were caried out in two worked-out stopes at the No. 6 shaft at Rand Leases Gold Mining Company. Dissolution rates of 0,9 and 0,7 9 of gold per week per 100 m2 of footwal area were achieved. A major disadvantage of the method seems to be the slow rate of dissolution of the gold, which is probably caused by poor contact and slow mass transfer between the lixiviant and the gold surfaces. Under full-scale application, the loss of lixiviant by leakage could also be a very important factor. Furthermore, the oxidation products of thiourea may 'poison' the activated carbon that is used for the recovery of the gold. The method may therefore be economically viable only in stopes that contain high values of residual gold.

Jan 1, 1989

By D. H. C. Griffiths, D. R. Davis, D. B. Paterson

Consolidated Murchison Limited is the only primary producer of antimony in South Africa, producing approximately 18 per cent of the total world production. This paper gives a technical review of the history, occurrence, mining, and metallurgy of antimony at Consolidated Murchison. World antimony markets are also discussed, together with the end-uses.

Jan 1, 1986

By M. Andersson, R. Elsrud

The quality and the production rate for the mining operations in the Garpenberg mine has been much improved due to a new system, that presents the latest exploratory and planning data for the driller at the moment he deploys the drill rig at the face. Other components in this improvement work are better planning procedure, large-scale production system with longer rounds and introduction of new drill rigs in the mine. The new Rig Control System (RCS) for the new series Atlas Copco Boomers L2C has made it possible to develop this system for production drilling in the Garpenberg mine. The ABC Regular has been extended with map navigation and drill plan generator. The driller will have the best estimate of the orebody in front of him and the best drill plan for that orebody. The customer’s specific system will also become a standard Atlas Copco product for the Boomer ABC drill rig family.

Sep 1, 2001

By B. W. Wallace

Permitted explosives in South Africa are those explosives approved by the relevant State authority for use in fiery coal mines. The main tests that an explosive must pass for this approval are the gallery tests derived from the Buxton (U.K.) classification. These tests are described briefly. In addition, the safety of permitted explosives is affected by their ability to deflagrate, and to produce a naked flame after blasting, rather than to detonate fully. Tests done on this phenomenon are discussed. A further potential hazard of explosives is after-blast fume. The testing and behaviour of several permitted explosives in this respect are covered, both in the laboratory and in the field. Performance testing of permitted explosives, specifically the double-pipe, underwater, and ballistic mortar tests, and their relationship to field use, are considered in some detail. The application of traditional and new tests to permitted explosives leads to guidelines for the safe and efficient formulation and use of these products.

Jan 1, 1986

By W. J. Van Den Berg, J. G. Taylor

The paper discusses the introduction of blindhole boring on the South African gold mines of Anglo American Corporation. It covers the boring trials conducted, and outlines the progress made in the development of blindhole borers. The operating costs, and performances, of the latest 1,52 m diameter borer are given. Future trends and requirements In the application and design of blindhole borers are discussed, as well as factors that are of importance in the design of future machines.

Jan 1, 1978

By N. T. Halgreen

The use of coal for combustion, carbonization, and the production of synthetic fuel is discussed briefly, highlighting the effect of certain physical and chemical properties of coal on these processes. The effect of consumer specifications of properties such as calorific value, ash content, moisture content, and size consist on the planning and operation of a mine are discussed, including the influence of coal degradation through time or mechanical means. The effects of various mining methods on these parameters and on the utilization of coal reserves are discussed.

Jan 1, 1984

By C. Kliem

Geological, tectonic, geochemical and geophysical data were utilized for the mineral resource assessment of the Biga Peninsula in NW Turkey. During the deductive phase of the project multivariate statistical methods were applied to accentuate characteristic parameters which sufficiently describe the different types of Pb - Zn mineralization. The parameters most likely to be indicative of mineral occurrences were determined. In the following prognostic phase these parameters were further statistically treated to determine favourability indexes for the occurrence of a deposit within each cell of the training area. Preliminary results of probabilistic, univariate and multivariate methods are presented.

Jan 1, 1987

By O. Bazhko

Regular analysis of different streams is important for the control of hydrometallurgical processes. Various physical and physical-chemical methods are applied for this purpose. Many modern methods require costly equipment and are subject to interferences. Therefore, redoxtitration methods remain of interest. The use of different types of oxidizing and reducing agents as well as redox indicators enables many cations and anions to be rapidly and accurately analysed. Sometimes redox titrations require the prior preparation and addition of masking agents. Selective, sensitive and low-cost methods of redoxtitration of copper and SO2 in plant conditions are described.

Jan 1, 2009

By J. J. Schoeman

In South Africa and in the rest of the world, the two mica minerals that have the most important commercial value are muscovite and vermiculite. Muscovite has been making a comparatively small but steady contribution to South Africa's mineral exports since about 1960. Vermiculite mining and concentration were started by the late Or Hans Merensky at Phalaborwa during 1946. Vermiculite has enjoyed good overseas sales since then, and during the past four years has become an important earner of foreign currency for South Africa. The various aspects of the micas that could be of general interest are briefly reviewed, such as the history of their exploitation, their mineralogy and chemistry, and their mining, concentration, production, sales, and future

Jan 1, 1989

By J H. Sullivan

Contents Background information Locality of Kumba?s Iron Ore Mines Sishen?s Product Specifications Geological Description of boreholes Sample Preperation Block delineations Production Geology Process Laboratory information Turnover times reached Inter Laboratory Comparisons Quality control activities in lab Purpose of laboratory Results attained Standard samples Monitoring of processes with QA/QC standards Mean paired difference of duplicates Duplicate samples Conclusion

Jan 1, 2005

By A. V. L. Narasimham

The practice of refractory lining in Fe Cr furnaces is purely based on the behavior of various refractories used in different parts of the Furnace at elevated temperatures. The choice of the pattern of lining is mostly done on traditionally based concepts. Refractory Lining of a furnace is the most crucial enabler for operational excellence for Ferro Alloys production. During the last few years, no major technological change has taken place in ?Refractory Lining Management?, only freeze lining concept is becoming popular. Many ferro chrome furnaces today, have the refractory lining problems especially at tap holes, resulting in shutdowns and production losses. The author with his experiences for the last 37 years in furnaces of all sizes tried to attempt to investigate into the reasons for premature failure of lining.

Jan 1, 2007

By R. V. Ramani

Managers need quality information for effective decision making. This demand, at the present time, is being fulfilled by the increased use of computers via information systems, decision support systems and management information systems. The idea of incorporating intelligence into computers to aid decision-makers has been evolving for over two decades. In recent years, significant progress is reported on applications to business and sciences. In engineering functions, the Artificial Intelligence approach that seems to have great potential is the application of Knowledge Based Systems. The primary objective of this paper is to identify domains in mining engineering where application of knowledge based systems could be beneficial. In- corporation of the expertise required during the analysis and interpretation stages of an engineering design problem through knowledge based systems is recognized as an area of significant benefit. To this end, the components of knowledge based systems for mine ventilation and strata control design are described. The potential applications and limitations of knowledge based systems are outlined.

Jan 1, 1987

By A. M. Copeland, A. J. Barrett

The use of hydraulically placed backfill in the deep gold mines of South Africa has increased rapidly over the past decade. The backfill that is delivered to the placement areas has a relatively high moisture content, and it is therefore pumped into geotextile containment bags that allow excess water to drain out but retain solid particles. The specific problems associated with this process that are addressed in this paper include the loss of solid particles entrained in the excess water, the rate of strength gain of the backfill, and the post-placement shrinkage of the backfill. The results of laboratory, surface stope, and underground tests are described. The parameters that were varied included the slurry density, the particle-size distribution, and the feed rate of the slurry the concentration of added flocculant; and the type of geotextile used as containment. Suggestions are given for the optimization of the placement properties of backfill.

Jan 1, 1994

By H. A. D. Kirsten

Written contribution by L.J. Besaanst I am a Mechanical Engineering Technician (T3), and wish to further my education to at least NHD (T4) level. I read your paper in the Journal of The South African Institute of Mining and Metallurgy with great interest, and must compliment you on its brilliance. However, there are some questions I should like to ask, and certain points I should like to highlight. I should appreciate your comments. Written contribution by J.F. Curtis The comprehensive and finely detailed survey of, and proposals for, engineering education in South Africa reflects the author's wide experience in the needs for, and the provision of, such education. This paper wil make a major contribution to the enhancement of the profession of engineering and the improvement in quality of engineering activities in South Africa. Contribution by G.W. Annandalet I have studied your paper in some detail, and am of the opinion that it makes an important contribution to the topic of the development of technological manpower, which is currently being debated in South Africa at al levels. Debate on this topic has risen above the level of academic discussion; it has been discussed by the Economic Advisory Council of the President, and is being considered at Ministerial level. Author's reply to L.J. Besaans Thank you for your contribution and complimentary remarks. As you have pointed out, there are certainly many aspects that will have to be addressed in the resolution of the crisis in engineering education. I trust that the following comments satisfactorily answer the queries you have raised. Author's General Comments Since publication of the paper, attention has become focused on the provision of employment opportunities an aspect not dealt with specifically in the paper. The following comments serve to indicate some of the directions in which job opportunities will have to be developed in the numbers that will be required.

Jan 1, 1991

By C. A. Garzonio, A. M. G. Affuso

The paper describes the analyses and the tests carried out on representative slabs of white Carrara marble which have highlighted the correlation between the micro fabrics and physical and mechanical parameters. The aim is to determine the conditions which indicate the triggering and evolution of the deformation phenomena. La note écrit l’analyse et les epreuves effectuée sur un echantillon représentatif de nombreuses dalles en marbrede Carrara. Les études montrent la correlation entre la minéralogie et les paramètres physiques et mecaniques. Le but est déterminer les conditions qui indiquent l’amorçage et l’evolutions des phénomènes de déformation. Diese Arbeit gibt eine Beschreibung der experimentalen Untersuchungen und der Analysen über die Marmorplatten von Carrara. Daraus resultiert, dass die Charakterisierung der Mineralogie und die Porosität der Gesteinsmaterialien die physikalische mechanische Degradation beurteilen und die Krümmungen bestimmen.

Jan 1, 2003