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By H. W. Glen

In the hope of finding out what the readers of the SAIMM Journal want of our Journal, we sent out a questionnaire with the October 1979 issue. The 2500 copies of the questionnaire sent out elicited 228 responses, which represents a return of 8,8 per cent. The number of responses received from overseas was 24, i.e., approximately 10 per cent of the total. The following is an analysis of the responses received.

Jan 1, 1980

By P. W. J. van Rensburg

The Institute was privileged to receive an invitation from the Armaments Corporation of South Africa (Armscor) for members to visit one of their plants. As these are factories, the number of visitors who could be accommodated was limited. As the opportunity seldom arises to learn something of this very large industry, there was great interest among members and many were disappointed in not being able to go. Underwater mining The 16th Annual Underwater Mining Institute will be held at Halifax, Nova Scotia, Canada, from 20th to 23rd October, 1985.

Jan 1, 1985

By H. E. James

The 13th Congress of the Council of Mining and Metallurgical Institutions (CMMI) was held in Singapore from 11th to 16th May, 1986. Tours to Australia, Malaysia, Thailand, South Korea, and Japan took place the week before and the week after the Congress. Registrations By far the largest contingents at the Congress were from Australia (157 delegates and 65 affiliates) and South Africa (127 delegates and 99 affiliates). The other 25 countries represented at the Congress accounted for 118 delegates and 37 affiliates. Thus the total registrations amounted to 402 delegates and 201 affiliates.

Jan 1, 1986

By E. J. Magri

This paper describes a geostatistical study of the relative merits of diamond-saw sampling and conventional chip sampling, using results from experimental work carried out on Randfontein Estates Gold Mine and Western Areas Gold Mine. The diamond-saw sampling procedure is described, and it is concluded that this is a very efficient operation and leads to good-quality sampling that is clearly an improvement over conventional chip sampling. The study principally involved the computation of the errors of estimation of the mea gold value of mining panels for the two sampling methods, revealing that, in the normal production environment, the diamond-saw sampling method is a significant improvement over conventional chip sampling, as evidenced by the reduced estimation errors achieved. The question of optimum sample spacing is discussed, and it is concluded that the required spacing for chip sampling needs to be smaller than for the diamond-saw method.

Jan 1, 1986

By A. Ward, A. Smith, D. Harpley

Methods for the prediction of seepage quality from waste-disposal facilities are evaluated for input to the design of desalination treatment facilities. This is done by reference to a waste dump seeping into a near-surface aquifer, the contaminated seepage being collected by scavenger wells. As the quality of contaminated water intercepted by the wells will vary with both space and time, it is necessary for predictive methods to accommodate such variations. One-dimensional and two-dimensional predictive solute transport models are described and applied to the seepage and scavenger-well example mentioned above. The advantages and disadvantages, interims of overall applicability, data requirements, and possible accuracy, are described and discussed. While one-dimensional models have the advantages of speed, simplicity, and cost, the frequent requirement of prediction in both space and time necessitates more complex, two-dimensional simulation.

Jan 1, 1987

By A. Whillier

Recommendations are given for the design of vertical cooling towers for use underground in mines and a method is given for predicting the entering and leaving water temperatures when a given amount of heat has to be dissipated.

By N. Thorp, S. J. Bluhm

It has long been recognized that the provision of an acceptable thermal environment minimizes the danger and the adverse effect of heat stress, which is directly linked to decreased productivity, increased accident rates, and excessive physiological strain in workmen. Refrigeration in one form or another helps to provide this acceptable thermal environment. This paper outlines the problems encountered in a working area, and the steps taken to alleviate environmental conditions in some stopes with the introduction of selective cooling employing small water-chilling units in conjunction with specially designed stope coolers. Performance figures are given for plant and stope coolers, and the effectiveness of the system is assessed from an evaluation of the improvement achieved in the environmental conditions.

Jan 1, 1986

By P. Stevenson

Correlations for the critical velocity needed to hydraulically convey particles in horizontal, or near-horizontal, pipes are either explicitly dependent upon the shear stress imparted by the fluid upon the surface of the particle bed, or require a velocity and hydraulic diameter. Often such approaches are modified to account for pipe inclination by the introduction of simple factors. However, we assert that the physics that underpins the hydraulic conveying of particles in steep pipes (such as a directionally drilled oil well) is dissimilar to that which governs particle behaviour in horizontal pipes. In steeply inclined systems, a sliding sediment induces an upward counter flow and hence an autogenous contribution to the shear rate. The physics underpinning particle hydraulic conveying in steep systems is explored using the separation results of Laskovski et al.10

Jan 1, 2007

By W. F. Heinz

The efficient and effective handling and logistics of materials for underground support is an important part of mine mechanization and automation. Support systems based on backfill material or grout slurries and pastes transported underground through pipelines (ranges) lend themselves to a large degree of mechanization. In contrast the installation of conventional support systems such as props, timber packs, brick packs etc., requires more handling and hence is labour intensive and more costly. RODIO/ROSOND has developed and improved significantly its high density slurry/low density paste conveyance system on surface and underground during recent years. The surface batching and pumping stations are computer controlled and operate with a minimum labour complement. The RODIO/ROSOND grout pack support system has some unique features such as the use of relay stations, which result in the following distinct advantages and benefits to mining operations: • No interference with shaft operations • No grout ranges under high pressure in shaft • Efficient reticulation from underground relay stations • Low capital cost • Better control of quality of materials (high density slurry/low density paste) placed • Proximity of the working place to the relay station facilitates control of installation. These specific characteristics of RODIO/ROSOND’s grout pack support system have resulted in more economical support for several mines in South Africa and Australia.

Sep 1, 2001

By J. D. Flint

A description is given of the extraction of pillars in a seam of coal which normally varies in thickness from 10 feet to 14 feet using conventional trackless mechanised units. By using the pocket and fender method of pillar extraction, the high capital cost of hydraulic supports is eliminated, and a volumetric extraction of 85% to 90% of the seam of coal is possible. This method of mining opens up the possibility of extracting vast tonnages of coal which hitherto would have been left in situ as pillars. The major benefits likely to accrue from this technique are seen as follows: 1. Greater volumetric extraction of the seam; 2. Longer panel life with less frequent transferring of sections; 3. Preservation of our natural resources. The authors deal with the history of this development at Springfield Colliery, discuss the present results and outline the future trends in the light of current experience.

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 J. M. Stewart

Although the incidence of heat stroke in South African gold mines is small, work continues on its reduction. This paper proposes limits of heat stress that are applicable to South African underground conditions, with the warning that they should not be extrapolated to other situations without careful consideration having first been given to their limitations. These limits of heat stress take physical and physiological considerations into account, and they correspond to there being a 10-6 risk of an essentially nude man developing a rectal temperature in excess of 40°C. It is recommended that further work should be undertaken on the development of equations for the calculation of the heat transfer from clothed men, the derivation of equations that quantify the physiological conductance and sweat rate response of humans, and on establishing the frequency distributions that describe variations in rectal temperature response between individuals in different types of environment.

Jan 1, 1981

By J. R. Dixon

Gold mining has been undertaken in South Africa for more than a century. A great proportion of that mining has been from the Witwatersrand Basin; a geological phenomenon that has few parallels throughout the world. It has produced some 47 000 tonnes of gold mainly from underground mines, many of which have been truly world class gold mines. The gold mines of the Witwatersrand Basin have dominated world gold production from their inception and their production has been one of the cornerstones of the development of South Africa as a whole. The mines have some very specific characteristics; their sheer size, the depth of extraction, the nature of the orebodies, and their labour-intensive methods. The mines have also been part of the Mining House concept-a concept unique to South Africa. South African production has declined from a maximum of 1000 tonnes in 1970 to 470 tonnes in 1997. This, as a percentage of western world production, has declined from a maximum of 79 per cent (in 1970) to 21 per cent of world production (in 1997). The nineties' have seen South Africa and its mining companies move onto the world stage and face the harsh realities of having to compete in all spheres of business with their aggressive counterparts principally in Australia, Canada and the USA. The fight is for investment funds with the owners looking for the best returns on their money. In his address Roger Dixon will examine the current situation in the gold mining industry and examine the competitiveness of the mines of the Witwatersrand Basin compared with their peers worldwide. He will also discuss some of the fundamental challenges facing South African gold mines in the areas of legislation, technology, industrial relations, and health and safety. The environment in which the mines operate has changed radically in recent years and their ability to respond to these challenges will determine their future existence.

Jan 1, 1998

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 M. J. Nicol

This paper ,examines the kinetics of the extraction of uranium from acid sulphate solutions by strongbase anionexchange resins. Parameters such as the concentration of uranium in solution. the agitation of the resin beads in solution. the size of the resin beads. and the degree of cross-linking within the resin matrix were varied. and the effec ts on the kinetics are reported. The applicability, of various empirical kinetic models to the description of the data is assessed, and an attempt is made at the modelling of the rate data in terms of established theories about the diffusion of ions through films of stagnant liquid and through spherical beads of resin.

Jan 1, 1980

As a token of their gratitude, former pupils of Professor Lucien Denoel, a lecturer on coal-mining in the University of Liege, over a period of forty years, have founded the LUCIEN DENOEL prize. It is awarded, regardless of nationality and diplomas, to the author of a thesis dealing with coal-mining, ventilation, mine-draining methods, the use of explosives in the mine or coal-preparation. The thesis must show a truly scientific approach and considerable originality, and must not have been dealt with in a previous publication. The prize is 60.000 Belgian francs. The articles must be written in French, Dutch, German or English, and contain not more than 10,000 words, figures included. They must be forwarded, in triplicate, to the 'Jury du Prix Lucien DENOEL, c/o A.I.Lg., 22, rue Forgeur, Liege, Belgium,' before 1st July, 1970. The examining board reserves the right to publish the winning thesis in a Belgian magazine.

By C. Mueller

Automation of mining operations is pushed by cost pressure and cyclical product prices. However, until now the different types of equipment were not able to communicate electronically with each other or with central computer systems. Therefore, the International Rock Excavation Data Exchange Standard (IREDES) was launched by major players in the industry. The task of this initiative is to define a ‘common electronic language’ for easy and standardized data exchange. As in other industries, this standard is expected to have significant impact on the use of automation in general and on the markets for third party components and software. The standard’s technical architecture is open and flexible for future applications. It consists of an ‘horizontal’ structure defining ‘Application Profiles’ for different types of data sets. An additional ‘vertical’ structure (‘Equipment Profiles’) implements equipment dependent definitions for each of the applicable Application Profiles. First profiles will be available for Drill Rigs. The standard bases on the XML language thus enabling easy data exchange with commercial databases. IREDES data sets may use storage media as well as networking infrastructures for information exchange. The IREDES work is carried out by the initiative members working jointly together in the IREDES work groups. It is open for participation of all interested organizations. First prototyping applications are expected to start during 2001, the first products may be available in the following year. Key words: Mine Automation; Machine Automation; Data Exchange; Rock Excavation; Standard; Remote Control; Teleoperation; Ethernet; TCP/IP; Internet Technology; Service; Quality Assurance; Control Centre;

Sep 1, 2001

The first commercial Corex Plant in the world capable of producing liquid iron from a variety of low-grade coals was commissioned in 1990 by Iscor at its Pretoria Works. The Plant has an annual production capacity of 300 kt of liquid iron. Because the compulsory use of coke is eliminated, the new method offers an economic and revolutionary alternative to liquid-iron production. Coke used in traditional blastfurnaces is manufactured from high-grade coal of which the available sources in South Africa are limited.

Jan 1, 1991

A General Meeting and Colloquium on 'Motivation and productivity in the mining industry' was held on May 22nd, 1974, at Kelvin House, Johannesburg. Mr P. W. J. van Rensburg (President) was in the chair. The Colloquium was attended by 170 delegates and was opened by the President at 09h25.

Jan 8, 1974

By A. N. Brown

This title of is not that originally chosen for the Colloquium, which was 'A high gold price'. Such a title would have been unfortunate because it would have related the Colloquium only to the high gold price of the past two years, which reached the dizzy peak of 850 dollars per ounce in January 1980. The chosen title is, of course, the right one because it places the whole problem in the right perspective. It relates to a situation that has occurred many times before. Over the course of the past century, the gold price has periodically been inhibited from rising, so that it has undergone a succession of stepwise increments. With each increase, the relationship of the working cost to the gold price alters, and gives rise to a jump in ore reserves. Award for CMI fuelling technique Consolidated Metallurgical Industries Limited - the Lydenburg-based ferrochromium producer in the J.C.I. group - was one of the five recipients of the 1981 National Productivity Institute annual award.

Jan 1, 1981