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By P. van Niekerk, V. J. Solomon

Improvements in the drilling and blasting techniques used in the stopes of narrow reefs have caused the clearing of broken rock to become the major cause of delay in the achievement of a regular cyclic operation. This paper discusses the development of a scoop in accordance with a predetermined set of performance parameters. The test results obtained to date have shown that the basic objectives have been achieved within tolerable limits of variation.

Jan 1, 1979

Measurements of the rates of penetration at various throttle air pressures are presented as a function of thrust for three different rockdrills when drilling quartzites with strengths of 45 000 lb/in2 and 39 000 lb/in2, The rate of penetration at optimum thrust is shown to agree well with the predictions of theory and curves of air consumption as a function of throttle air pressure are presented. Man-held machines are shown to be under-thrusted at throttle air pressures above 40 lb/in2g. Measurements of bit wear as a function of distance drilled are presented graphically and discussed in terms of the theory developed in Part 1.

By F. F. Roxborough, P. King, E. J. Pedroncelli

This paper describes tests on the performance of a continuous miner in cutting South African coal. Although coal cutting has been investigated extensively overseas, the results have not led to significant changes in machine design because these machines find little difficulty in cutting the softer overseas coals at a fast rate. In general, the results of the tests show that cutting efficiency improves markedly as the depth of cut per revolution of the drum increases, and that the best spacing of picks on the drum is twice the depth of cut. Pick shape is of secon¬dary importance in terms of cutting efficiency, only small differences having been found between the performances of conical- and chisel-shaped tools.

Jan 1, 1981

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.

I am a partner in a minerals' development company called A.B.F. Limited, that does minerals development in Africa and Asia. I have read your very fine magazine often at the Colorado School of Mines Library in Golden, Colorado. I would like to ask your assistance in trying to locate a South African smelter; preferably on the coast, but not totally necessary for the project, that can separate the first four metals (Au, Ag, Cu, and Pb).

Jan 1, 1980

An International Ferro-alloys Congress, arranged by the Ferro Alloy Producers' Association of South Africa, the South African Institute of Mining and Metallurgy, and the National Institute for Metallurgy, will be held in Johannesburg, South Africa, in April 1974. The technical programme, occupying five days, will cover the following topics in relation to all ferro-alloys: 1. Burden preparation, blending, pelletization, handling, reducing agents. 2. Electric smelting furnaces-design, operation, management,- smelting optimization, shop practice, refractories. 3. Mineralogy, reduction behaviour, smelting reactions, slags. 4. Automation, Pollution control. 5. Applications, trends in comsumption, trends in composition specifications. There will be no parallel sessions. Papers in the above topics are invited; review papers will also be welcome. Proposed titles and abstracts in not more than 200 words should be submitted before the 30th of November, 1972, to The Chairman, Programme Committee, INFACON 74, Private Bag 7, AUCKLAND PARK, South Africa. The abstracts will be considered during January 1973, and papers accepted for the Congress must be submitted in final form before the 31st of July, 1973. The proceedings of the Congress will be published as a special volume. There will be a series of post-Congress tours to ferroalloy plants and other places of both technical and scenic interest. A full ladies' programme will be arranged. The First Circular, giving further details, can be obtained from: The Secretary of the Organizing Committee, INFACON 74, Private Bag 7, AUCKLAND PARK, South Africa.

By E. Pothas, P. R. Jochens, L. B. McRae, D. D. Howat

SYNOPSIS The phase equilibria, viscosities and sulphur capacities of titaniferous slags were determined in the composition range of CaO = 30 to 0 per cent, MgO = 0 to 30 per cent, SiO2 = 19.69 per cent, AI.O. = 13.12 per cent and TiO2 = 37.19 per cent. The phase equilibria were determined by high temperature microscopy, the viscosities were measured using a rotating outer cylinder viscometer and the sulphur capacities were evaluated from the results obtained by equilibrating the slag in a gas stream of CO, CO2 and SO2. The behaviour of these titaniferous slags under reducing conditions was examined. Possible use of the slags for aggregate, or slag-cement, and the possibility of extracting the TiO2 are discussed. CONTENTS INTRODUCTION PHASE EQUILIBRIA VISCOSITIES DISCUSSION OF THE PHASE EQUILlBRIA AND THE VISCOSITY VALUES EFFECT OF REDUCING CONDITIONS SULPHUR CAPACITY DISCUSSION OF THE SULPHUR CAPACITY VALUES POSSIBLE USES CONCLUSIONS ACKNOWLEDGEMENTS REFERENCES INTRODUCTION The latest phase in the exploitation of the mineral wealth of the Bushveld Igneous Complex is the erection of a plant by the Highveld Steel and Vanadium Corporation Limited near Witbank to produce steel and vanadium-rich slag from the titaniferous magnetites occurring in this rock formation. These titaniferous magnetites occur as segregations in the gabbro body and the TiO2 is mainly present within the structure of other constituent minerals but also occurs in smaller amounts as ilmenite and ulvospinel. The vanadium is thought to be present in the iron oxide phase due to isomorphous replacement of the iron. Until very recently, it was feared that the high titania content of these titaniferous magnetites would militate against their value as useful iron ores. However, the design of an integrated plant to produce both steel and vanadium-rich slag, and in which the iron-making process is conducted in submerged arc furnaces instead of in

By L. J. Park, A. D. Thomas

Gladstone Pacific Nickel Limited (GPNL) is proposing to develop the Marlborough nickel deposit in central Queensland and the Yarwun Refinery in Gladstone, Australia. The project proposes to connect the two sites with a DN 500, single pump station slurry pipeline, transporting up to 4 Mtpa of nickel laterite ore as slurry 180 km from Marlborough to Gladstone. Slurry viscosity is a key parameter influencing pipeline design. Not only is the slurry viscosity relatively high, requiring pumping at low concentrations, around 30% by weight, but the viscosity (yield stress and plastic viscosity) increases with shearing or agitation. It is argued that the viscosity changes can be analysed in terms of total energy input, including energy input during grinding. The slurry viscosity is therefore expected to increase along the pipeline and the pumping concentration must be low enough such that the increase in yield stress does not cause transition to laminar flow towards the end of the pipeline. The base viscosity of two ore types is determined using a rotational viscometer for minus 212 micron slurries. Viscosity variations with ore particle sizes of d99 212, 425 and 600microns are investigated. For each of these particle sizes the expected increase in viscosity during pipeline transport is simulated on a laboratory scale by agitation with a turbine mixer in a baffled container to give the same equivalent unit energy input as will occur in the pipeline. Tests were also conducted on the d99425 micron slurry in a 2.7 metre diameter DN 200Wheelstand, rotated for the 23 hour transit time and at a similar relative velocity as in the pipeline. Based on the Wheel stand test results the yield stress is expected to increase by a factor of 3.1during pipeline transit. The preliminary design allows for a reduced pumping concentration to accommodate this increase in yield stress towards the end of the pipeline.

Jan 1, 2007

By D. J. Adams, R. G. Gürtunca

CONTRIBUTION BYJ.F. CURTlS The paper, which in an exemplary manner records the monitoring of backfill behaviour, falls short in the 'rock engineering' stated in the title. Just what the objective of the rock engineering was is obscure.

Jan 1, 1992

By B. N. Soutar

The design and operation of a double- V compartment vertical-flow settler by B. N. SOUTAR, B.Sc. (Mech. Eng.) Wits. (Visitor) This paper describes the development of a vertical-flow settler for underground pumping installations in the mines of Gold Fields of South Africa Ltd. The recommended settler employs the principle of 'dynamic filtration': the solids that are in suspension in mine water are filtered through a stable horizontal bed of flocculated particles, a technique that was established in about 1958.

Jan 3, 1977

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 E. Adlard

This paper sketches an expert system for use underground in pinpointing problem areas in the operation of machines. The system is typically a software 'shell' designed to accommodate a series of 'if-then' rules that are intertinked to systematically search for the cause of the problem. During the search, the system asks a series of questions that have to be answered by the operator and then, when necessary, by an artisan. The rules of the system are generated by a knowledge engineer whose function it is to gather the necessary diagnostic information and prepare it in the required format for the expert system. Much still requires to be done in the development of such systems and in the testing of hardware to withstand the mining environment.

Jan 1, 1990

By Zdenek Kunicky

Kovohute Pribram is a plant recycling lead wastes, lead acid batteries in particular. Relevant new recycling technologies are being gradually developed. Outdated technology of smelting lead plates has been replaced by a new technology based on processing of entire batteries in a blast furnace according to the process developed by know-how of German Varta company. The classical Harris refining has been substituted by the oxygen refining. New technologies aimed at utilization of related wastes arising from refining lead bullion in Kovohute Pribram are being developed in house. At present, a new technology of utilization of spent battery acid for extracting zinc from various wastes has been developed. Zinc oxide dross from alkaline refining of lead bullion, during which residual zinc from the preceding vacuum de-zincing is removed as well as waste zinc galvanic sludges (a product of neutralizing precipitation of metals from industrial wastewaters with lime) were treated. In this study, the new developed technology yielding basic zinc carbonate - a valuable raw material for zinc electrowinning, is described together with the first experience of applying the developed method to processing zinc wastes on a pilot scale. Most of the equipment used in the past to regenerate alkali solutions originating from Harris refinery was utilized in the practical realization of this new technology.

Jan 1, 2008

By M. D. G. Salamon

In view of an urgent need for a simple means of simulating the behaviour of stratified rock masses, a long-dormant linear model is revived, generalized, and discussed in some depth. The model is piecewise homogeneous, consisting of a pile of homogeneous isotropic laminae in which the interfaces between beds are parallel and free of shear stresses and cohesion. The continuity of stresses and normal displacements is assured across the bedding planes and, to maintain simplicity, the theory of thin plates is used as the kernel of the model. The paper covers the case where the rock mass consists of discrete beds in which the layers are arranged either heterogeneously or systematically. The stratification is regarded as uniform when all the layers are of the same thickness and their Young's modulus changes exponentially with depth; and as homogeneous when all the laminae have identical thickness and properties. The case of uniform stratification is also treated on the basis of an equivalent quasi-continuum derived from the basic model. Attention is focused on the derivation of influence functions. It is demonstrated that the quasi-continuous models, when they are available, can replace their distinct-layer counterparts. The homogeneous quasi-continuum, which permits the derivation of its influence functions in closed form, facilitates the determination of the roof and floor convergence. In the case of a significant class of problems, the convergence distribution is defined by a second-order differential equation in the xy plane, which simplifies to a Poisson's equation if the mining excavations are unsupported. With this result, the paper prepares for the solution of a host of practical problems. These solutions are presented in a series of papers that are in the course of publication.

Jan 1, 1991

Professor R. N. Pryor, AR.S.M., B.8c., C.Eng., F.I.C.E., F.I.Min.E., F.I.M.M., who died on 14th July, 1979, after a short illness, was President of the Institution of Mining and Metallurgy for the session 1978-1979. Weld pool metallurgy A high level of current interest in welding characteristics and behaviour and in the properties of welds was amply demonstrated by the large attendance at The Welding Institute's 1978 Conference on 'Trends in Steels and Consumables for Welding' and by the overwhelming number of papers offered for the International Conference on 'Arc Physics and Weld Pool Behaviour' in May 1979. Mine ventilation The First International Mine Ventilation Congress was held in September, 1975, in Johannesburg, South Africa, at the University of the Witwatersrand. It was organized by the Mine Ventilation Society of South Africa. Occupational accidents and diseases The IXth World Congress on the Prevention of Occupational Accidents and Diseases will be held in Amsterdam from 6th to 9th May, 1980. Rock mechanics The 21st U.S. Symposium on Rock Mechanics is to be held at Rolla, Missouri, from 27th to 30th May, 1980. Protection against noise An International Symposium on the Protection of Workers Against Noisewill be held in Dresden (German Democratic Republic) from 27th to 30th November, 1979. Management of mineral resources A joint meeting of the Institution of Mining and Metallurgy, the Society of Mining Engineers of AIME, and the Metallurgical Society of AIME is to be held in London from 27th to 30th May, 1980. INFACON 80 During 1970 various South African institutes and associations agreed to organize an international ferroalloys congress. It was recommended that this should be made a continuing forum, where ferroalloy people could meet and discuss matters of mutal interest.

Jan 1, 1979

Book review Pearson, J. S. Ocean floor mining. Park Ridge (New Jersey), Noyes Data Corporation, 1975. 201 pp. NIM reports Report no. 308 A mineralogical study of gold particles in pulp residues from the Bracken Gold Mine. (7th Mar.,1968. Re-issued Oct. 1975.) Report no. 377 Examination of pulp samples, treated with cyanide, for coated gold.(7th Aug., 1968. Reissued Oct.1975.) Report no. 385 The determination of the nature of coatings on gold particles. (2nd Aug., 1968. Reissued Oct. 1975.) Report no. 452 The Purlex Process - a description of the pilot plant leading to the use of the process in South Africa. (13th Jan., 1969. Re-issued Oct. 1975.) Report no. 482 Review of work on the treatment of pegmatites. (9th Apr., 1969. Reissued Sep. 1975.) Report no. 1443 Gravity concentration tests on four samples from Tantalite Valley,S. W.A. (5th Jul., 1972. Re-issued Sep. 1975.) Report no. 1489 The breakage of S oderberg electrodes. (10th Nov., 1972. Re-issued Nov. 1975.) Report no. 1545 A mineralogical investigation of leach residues from the Blyvooruitzicht Gold Mine. (22nd May, 1973. Re-issued Nov. 1975.) Report no. 1583 Preliminary tests on winnowing for the recovery of mica. (12th Nov., 1973. Re-issued Sep. 1975.) Report no. 1652 The identification of diamonds from Premier, Finsch, and Jagersfontein Mines by statistical analysis of data obtained from instrumental neutron-activation analysis. Report no. 1723 The determination of zirconium and aluminium in zirconiumaluminium alloys. Report no. 1739 The determination of trace amounts of noble metals in sulphate media. Report no. 1771 The determination of silver, selenium, tellurium, antimony, tin, lead, and arsenic in anode sludges. Report no. 1772 A study of copper recovery by lime roasting and leaching. Corrigendum The Special Issue of Volume 76 of the Journal ('Recent Advances in Mineral Dressing, October 1975) should be corrected as follows. The South African Institute Of Mining And Metallurgy - Information On Membershlp The Institute was founded in 1894 as the Chemical and Metallurgical Society of South Africa. In 1904 it was reconstituted as the Chemical, Metallurgical and Mining Society of South Africa and in 1956 it became the South African Institute of Mining and Metallurgy. Die Suid-Afrikaanse Instituut vir Mynbou en Metallurgie - Inligting Oor Lidmaatskap Die Instituut is in 1894 gestig as die Chemiese en MIetallurgiese Vereniging van ::!nid-Afrika. In 190-1is dit omvorm tot die Chemiese Metallurgiese en Mynbouvereniging van Sllid-Afrika en in 1956 het dit die Suid-Afrikaanse Instituut vir Mynbou en l\Ietallurgie geword.

Jan 2, 1976

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

Book reviews Fiftieth Annual Report (1971) of the Safety in Mines Research Establishment, published by H. M. Stationery Office, London on behalf of the Department of Trade and Industry. Advances in extractive metallurgy and refining. This excellent volume, published by the Institution of Mining and Metallurgy, contains all the thirty papers presented at the International Symposium held in London in October, 1971. Electric Melting Practice by A. G. E. Robiette, Charles Griffin and Co. 412 pp. In recent years the application of electric furnaces to melting processes has expanded to such an extent that it has become a topic in its own right, quite distinct from the related subject of electric smelting which is still limited, for the most part, to those areas where inexpensive electrical power is available. Optimum use of manpower by A. J. van Zyl. The sixties represented one of the longest periods of sustained economic growth South Africa has experienced. At the same time it caused a certain amount of inflation and an acute manpower shortage.

The Third International Conference on Coal Research was held in Sydney, Australia, in October 1976. The papers and proceedings of the Conference will be published in Australia on behalf of the International Committee for Coal Research in April 1977. The papers deal with the economics and practicability of coal conversion, coal winning, resources assessment, safety and dust, and coal and power generation, together with an appreciation of coal potential by the deputy chairman of the U.K. National Coal Board. Copies of the report are available to organizations within member countries of ICCR at a cost of 35 dollars (Australian), including postage, by application to the Executive Officer, Third ICCR, Box 3842 GPO Sydney, Australia 2001. Drafts should be in Australian currency payable to Third International Conference on Coal Research.

Jan 6, 1977

By J. E. Friant, R. P. H. Willis, J. Maaren

Considerable effort is currently directed towards the development of non-explosive mining methods with the potential to allow continuous mining in narrow reef conditions. Besides improving productivity, continuous mining results in concentrated mining which has a significant impact on reducing infrastructure costs. CSIR: Miningtek recognized the potential of mini-disc cutters in a long or short wall application for selective hard rock mining in 1999. EEA was chartered to build a 780 mm diameter by 800 mm deep drum cutter head. While EEA designed and built the head, CSIR designed and built the drive mechanism and chassis for the trial machine. After assembly and shop testing at CSIR’s facility, the machine was shipped to a platinum mine for trials. This paper traces the development of mini-disc cutters and their application in South Africa.

Sep 1, 2001