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By P. C. van Aswegen

The Schools A school on 'Measurement, Process Control and Optimization in the Minerals Industry', organized by The South African Institute of Mining and Metallurgy, was presented twice by course leader Dr Ken Garner, ably assisted by the staff of the Measurement and Control Division of Mintek. The first school was held from 16th to 20th July, 1984, at the University of the Witwatersrand, and the second from 11th to 15th February, 1985, at Mintek. Project development The Sydney Branch of the Australasian Institute of Mining and Metallurgy will hold a second Project Development Symposium in Sydney between 7th and 10th October, 1986. This second symposium will extend the range of topics covered by its predecessor in 1983 to emphasize planning (including strategic planning), construction, and project commissioning.

Jan 1, 1985

By R. J. E. Stewart

Another very successful evening meeting was organized by the Johannesburg Branch of The South African Institute of Mining and Metallurgy on 20th November, 1990, when Mr R.D. MacPherson, General Manager of Richards Bay Minerals, gave a presentation on the Richards Bay operations. The function was held in the Ballroom of the Johannesburg Country Club, and the very high attendance (some 250 people) was indeed a reflection of the high profile of the subject mater. It was also a fitting reward for the efforts of Mr MacPherson and his team, who spent a considerable amount of time and effort traveling the country to present 'the other side of the story'.

Jan 1, 1991

Tests were carried out in a Hallimond microflotation cell and a Denver D12 cell on typical residue material from a gold mine in the Orange Free State (South Africa), in which 50 per cent of the kerogen was larger than 100 µm in size. Although kerogen is naturally hydrophobic, the observed unexpectedly poor flotation reponse may be due to occlusion of the kerogen by a slime coating and subsequent depression of the slime by guar gums. The recovery of gold from samples spiked with kerogen increased, with no significant reduction in grades, when a petroleum-based collector and tetrasodiumpyrophosphate (a dispersant) were used.

Jan 1, 1985

By S. W. Evans, G. Pienaar

Weldable steel plate with a good combination of strength and toughness is currently produced from 0,12 to 0,28 per cent carbon low-alloy steel heat-treated by roller quenching and tempering. Alternatively, steel plate of the same strength can be produced at a lower production cost by the use of very-low-carbon steel (0,03 to 0,08 per cent carbon) processed by in-line quenching without tempering. This paper reports the results of experimental work on these steels, and compares them with the properties of conventional steel. On thinner sections, it was found that the properties of the experimental steels compare favourably with those of conventional grades.

Jan 1, 1989

By R. J. Dippenaar, W. H. Van Niekerk, D. A. Kotze

It is generally accepted that alkalis attack and degrade the carbon fraction of coke in a blast furnace. Because South African cokes contain relatively high amounts of ash, the influence of alkalis on the ash fraction was investigated, the carbon and ash fractions being separated and studied separately. Potassium engenders the formation of liquid, with a resultant expansion of volume and a decrease in the strength of the coke ash. However, the ash did not play a significant part in the degradation of the coke, and it was found that the catalytic effect of potassium on the Boudouard reaction was the overriding factor in the coke-degradation process.

Jan 1, 1986

By R. Hummel

In the quest to reduce overall costs and improve operating efficiency, the application of GPS based technology in open pit mining has evolved significantly in recent times. Venetia Mine has been leading the way in the De Beers group in the implementation of these systems and the realization of significant benefits from them. Following on from the successful results and the notable benefits obtained from the Wenco Truck Dispatching system and the Caterpillar CAES system on the loading and dozing equipment, Venetia has implemented the first fully functional and integrated GPS based drill monitoring system in southern Africa to its drilling operations. This paper elaborates on the concept of drill monitoring and how the vision for the application of the system at Venetia has developed and been implemented. The paper further describes the workflow involved, beginning with the initial test work done with SSI Kaltex and the Australian Drill Advisor system through to the final details of the integration of the Aquila system with the CATERPILLAR Computer Aided Earthmoving System (CAES) and the alliance with SandvikRock Tools. Most importantly, the paper details the benefits that are derived from drill monitoring and the use of the information generated by such a system. Venetia has pioneered the move towards smart partnerships and alliances with strategic suppliers within the De Beers group. The area of drilling, as the important start of the entire mining process, has been no exception and the final part of the paper covers how drill monitoring provides vitally important information that enables a supply partnership, to function cost-effectively and profitably for both parties involved. By having the type of accuracy, detail, validity and timeousness in the information being received as a result of the implementation of such a system, better management decisions can betaken, creating a more focused and efficient mining environment. In these times of increasing costs and reduced commodity prices, the mining industry will be required to continue pushing the boundaries on these technology applications in order to remain competitive.

Sep 1, 2001

By P. R. Jochhens

The Past. In the past, large metallurgical companies (for example the mining houses) had the necessary infrastructure both to develop metallurgical flowsheets and to undertake the construction and project management of metallurgical plants. Effectively, the sole contribution by contracting companies was the supply, and possibly the installation, of specific items of equipment. OBITUARY: AUSTIN WHILLIER (1927 - 1981) On Thursday, 13th August, 1981, Dr. Austin Whillier passed away peacefully in Johannesburg after a long illness. This event has been a serious blow indeed, and its effects will be felt, not only by the Chamber of Mines of South Africa and the South African mining industry, but also throughout many scientific and technical spheres both in South Africa and further a field.

Jan 1, 1981

By O. S. Lubbe, G. Annandale, J. W. van Wyk

This paper deals with the development and evolution of room and pillar mining in the South African chromitite and platinum mining industry over the past sixteen years. The paper describes the need for cheaper, more effective and safer mining methods in hard rock mining. It also describes how a mining method traditionally only applied in coal mining in South Africa evolved into a method ideally suited to conditions in chromitite and platinum mines. The paper also touches on joint efforts from mining houses, mine management and equipment manufacturers to design and build mechanized equipment custom designed and unique to South Africa in order to overcome challenges presented by the harsh operating conditions encountered in the mines in the Bushveld Complex.

Sep 1, 2001

By K. C. Sole

The International Solvent Extraction Conference takes place every three years, under the auspices of the international Solvent Extraction Committee. ISEC '96 held in Melbourne, Australia, in March 1996, was attended by delegates from 34 countries. South Africa was well represented, with delegates from Amplats, De Beers, Mintek, Western Platinum Refinery, and independent consultant Phillip Lloyd (who represents South Africa on the International Committee). The theme of this year's conference was 'Value Adding through Solvent Extraction'. Five plenary lectures were presented. Dr E. Blass of Germany gave the opening presentation entitled 'Solvent extraction-a historical review', which traced evidence for the use of solvent extraction (SX) from the time of the ancient Egyptians, through the Middle Ages and Renaissance, to the Industrial Revolution.

Jan 1, 1996

By R. R. Mankowski

The work described here attempts to underscore the importance of the time lag between the end of a loading phase and the instant a winding drum begins its acceleration phase. Traces generated from a computer-simulation model show that the amplitude of the stress oscillations occurring in mine hoisting cable during the constant velocity-of-ascent phase is a direct result of the temporal sequence employed between the loading and the raising phases. While current and early literature indicates that extensive work has been undertaken on the isolated effects of these two independent sequences, the literature does not appear to contain any documented evidence to suggest an optimal control or interfacing between these two dynamic regimes.

Jan 1, 1995

The 86th Annual General Meeting of the South African Institute of Mining and Metallurgy was held in Kelvin House, Johannesburg, on Wednesday, 17th August, 1983. Professor A. N. Brown (President) was in the chair, and declared the meeting open at 16h05. This account of the proceedings includes only those matters that are not reported under the heading `Annual report and accounts' elsewhere in this issue.

Jan 1, 1983

By R. Hemp

The first part of this paper describes the collection of barometric pressure measurements in a mine and their statistical analysis, which shows the effect of variations in barometric pressure, both on the primary emissions of methane gas into the workings (whether from fissures or from the surrounding strata), and on the flow of air to and from large unventilated, or poorly ventilated, areas. The second part of the paper deals with a study, based on computer simulations, of leakage flows of air into and out of sealed areas, and the reduction of such flows by the use of adequate seals.

Jan 1, 1994

By D. A. Holtum

On Tuesday, 10th November, 1987, The South African Institute of Mining and Metallurgy held a colloquium attended by some 120 delegates on 'On-Stream Analysis' at Mintek, Randburg. Mr John Moore, Consulting Metallurgist of Anglo American Corporation of South Africa Ltd, introduced Mr Gene Fivaz, the President- Elect of the SAIMM, who read an address by Mr B.C. Alberts, the current President. Mr Alberts was unable to attend the Colloquium owing to urgent business overseas. Opening The opening address emphasized the important role of minerals in the South African economy. In particular, it was noted that 20 per cent of the work force were employed in the minerals industry or associated industries. In recent years, production costs had risen as a result of inflation, and sanctions had had some effect on the exportation of minerals. Thus, there was continuing pressure on the industry to improve recoveries and increase efficiency.

Jan 1, 1988

By W. K. C. Boemer, G. A. Davies

Vanadium slag production in the shaking ladles started in April 1968, steelmaking was begun in July 1968 and the first continuously cast blocks were produced soon after on the 29th July, 1968. Nominal monthly production of over 20 000 tons was reached in seven months and by December 1970 about 12 000 heats were cast and a monthly production of 35000 tons has been achieved.

By M. G. Demmer

South Africa ranks among the top three mineral producing countries in the world, and yet the country's teaching and student population have a very limited knowledge of the mining and metallurgical industry. This is probably one of the major reasons why so few scholars elect to study mining-related disciplines at local universities, or to consider a career in the industry. Small mines Much interest in the development of small mines has been evident in the past few years, with junior companies taking the bull by the horns and moving in where larger companies found it uneconomic to tread or, indeed, where large companies are foresighted enough to see the advantage of smaller operations. Examples of small mines are to be found from Europe to Australia, in the Americas, and in

Jan 1, 1986

The sixth University of Stelenbosch (US)/University of Cape Town (UCT) Minerals Processing Symposium was held at the University of Cape Town on Friday, 7th August, 1987, and was sponsored by The South African Institute of Mining and Metallurgy (SAIMM). Once again the Symposium attracted a large number of delegates from the mining, metallurgical, and chemical industries. Uranium and electricity A symposium on 'Uranium and Electricity- The Complete Nuclear Fuel Cycle' will be held in Saskatoon, Canada, during 18th to 20th September, 1988. The Symposium is sponsored by the Canadian Nuclear Society. Electric steel The Institute of Metals, organizers of the 3rd European Electric Steel Congress, have announced that this important international event will take place in October 1989 at the Bournemouth International Centre.

Jan 1, 1987

By R. Van Rijswick

Crankshaft driven piston and piston diaphragm pumps inherently generate a varying flow each crankshaft revolution. Depending on the system connected, this flow variation results in a pressure pulsation. This pressure pulsation may, depending on the structural design, result in structural vibrations. In order to limit the level of pressure pulsations, volume absorbing devices, mostly gas filled vessels, are used. The standard selection of these so-called dampeners is based on the flow variation of the pump but does not incorporate the interaction with the connected system. The paper discusses the application of a pulsation analysis tool developed by WEIR Minerals Netherlands, manufacturer of GEHO positive displacement slurry pumps. The paper first discusses the basics of pressure pulsation analysis, such as flow variation generated by crankshaft driven pumps, and hydraulic effects such as capacitance, inductance and resistance and their influence on the hydraulic response of a system. Furthermore, the relation between pressure pulsations and structural vibrations, known as fluid structure interaction, will be discussed. Additionally, the capabilities of the pump pulsation analysis tool are presented, illustrated by examples of simulation results and experimental verification.

Jan 1, 2007

The increasing transportation of solids by pipeline, in South Africa and internationally, replacing the conventional transportation methods of rail, road, and conveyors, has resulted in much research into this area of solids transportation. Pipeline wear continues to be an area of specific concern, since it constitutes a major cost during the life of a pipeline installation. Wear data from an accelerated wear test and actual pipeline tests are presented. Trends in the performance of the pipeline materials tested are discussed, and possible solutions to the problem of pipeline wear are presented.

Jan 1, 1992

By M. J. Deats

Your article on page 202 of the August 1993 Journal refers. I was surprised to read that this grant was first introduced in 1984 as it was awarded to me (albeit under the auspices of The Institution of Mining and Metallurgy, London) as long ago as 1964, and I spent two very profitable months in Sweden at that time. Training in job-skills * A South African mine is leading the way in providing alternative job-skills to staff in a bid to upgrade services in local communities and create greater economic empowerment. In recent months, 85 employees of the Associated Manganese Mine (ASSMANG) in the Western Cape have learnt skills as diverse as candlemaking, shoemaking, concrete-product manufacturing, and brick production through a newly established community training centre.

Jan 1, 1993

By K. R. Vost

Most theoretical methods for the prediction of air-temperature gradients in underground airways always assume that the temperature of the entering air either remains constant or has only a slow seasonal variation. Large changes of temperature, caused by variations in atmospheric conditions on the surface, were measured in a fourteen-day period in air entering a horizontal airway. The changes in wet-bulb temperature were damped along the airway less uniformly than the dry-bulb changes; significant variations occurred in the wet-bulb temperature of the air leaving the airway. The damping was .associated with large variations in air-temperature gradients. Other causes of rapid changes In temperature are discussed. These changes must be taken into account in predictions of the frequency with which undesirable conditions can be exceeded at critical points in the ventilation circuit of a mine to allow proper planning of ventilation and refrigeration requirements.

Jan 1, 1977