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By Pamela Binstead

The Institute's ninetieth anniversary was celebrated in grand style with a banquet and dance in the ballroom of the Carlton Hotel in Johannesburg, on 22nd March. Some six hundred and thirty members and guests filled the room to capacity, and many remained to enjoy the festivities until well past midnight.

Jan 1, 1985

By M. P. Mohring

A School on the Total Utilization of Coal Resources, which was organized by the Technical Programme Commitee of The South African Institute of Mining and Metallurgy in conjunction with the South African Coal Processing Society, was held in the Civic Theatre at Witbank from 30th October to 2nd November, 1989.

Jan 1, 1990

Arthur Robert Owen Wiliams died on 18th May, 1989, at the age of 84. ARO, as he was known, was educated at Malvern in England, and graduated from the Royal School of Mines in 1926. He went to South Africa as a Learner Miner with Consolidated Gold Fields at Robinson Deep.

Jan 1, 1989

By J. M. Musadaidzwa

Skorpion Zinc is located 25 km north-west of the small settlement of Rosh Pinah in southern Namibia. Commissioned in early 2003, Skorpion Zinc became the first mine-to-metal operation to commercially apply a purely hydrometallurgical process route to exploit a zinc oxide orebody. The novel technology, known as The Modified ZincexTM Process patented by Tecnicas Reunidas, comprises sulphuric acid atmospheric leaching, zinc solvent extraction (SX) and electrowinning (EW) to produce London metal exchange (LME) Special high grade (SHG) zinc. Forming the core of the process, the SX step has thrived in its role as a barrier to impurities and also in the upgrading of the pregnant liquor solution (PLS), converting it into a loaded electrolyte (LE) sufficiently rich and pure for EW. Against this successful run, a number of challenges have, however, been encountered in SX due the emergence of upset conditions largely emanating from upstream processes. This paper outlines some of the major deviations that have beset the SX process in its first five years of continuous operation. Impurity excursions, temperature depressions, changes in phase continuity, excess aqueous entrainment, the effect of colloidal silica and the accumulation of rare earth elements on the organic phase will be discussed in detail. Keywords: skorpion zinc, solvent extraction, the Modified ZincexTM Process (MZP) DE2HPA, aqueous entrainment (AE), loaded electrolyte (LE), standard liquid validation (SLV) test, organic continuity, aqueous continuity (AC), electrowinning, colloidal silica, phase disengagement time (PDT), rare earth elements (REE).

Jan 1, 2009

By Colin M. Spence

The Federation of Societies of Professional Engineers (FSPE), in collaboration with the Habitat Council and the Environmental Planning Professions Interdisciplinary Committee (EPPIC), held a Symposium on 'Engineering our Environment' at the Rand Afrikaans University on 5th June, 1984, under the chairmanship of Mr Colin M. Spence, Vice-President, to commemorate World Environment Day.

Jan 1, 1984

By J. H. Fourie

This paper highlights modern practices in ore-treatment plants, with particular reference to the flotation of P2O5 at the plants of the Phosphate Development Corporation (Foskor) at Phalaborwa in the northern Transvaal. The following aspects are covered: design criteria, equipment and personnel, production standards and control. cost control, maintenance, and process development.

Jan 1, 1981

The Registrar has requested us to publish the following notices: COUNCIL'S POLICY REGARDING LATE APPLICATIONS IN TERMS OF SECTION 18(4) (b) OF THE PROFESSIONAL ENGINEERS' ACT, 1968 (ACT NO. 81 OF 1968) Laat aansoeke om registrasie as Professionele Ingenieurs Die Suid-Afrikaanse Raad vir Professionele Ingenieurs (SARPI) vestig die aandag daarop dat daar 'n mistasting bestaan oor die vraag of 'n persoon sonder erkende ingenieurskwalifikasies wat nie in 1969 aansoek gedoen het om registrasie as professionele ingenieur nie, nie meer aansoek mag doen nie. Diegene wat voor 14 Februarie 1969 minstens 3 jaar aanvaarbare ingenieurswerk gedoen het kan nog oorweeg word. Die werk moet egter voldoen aan die standaarde deur SARPI neergele: dit Suid-Afrikaanse Road vir Professionele Ingenieurs DIE WET OP PROFESSIONELE INGENIEURS, 1968 (WET NO. 81 VAN 1968): JAARGELD: 1972/73 BOEKJAAR Kragtens die bepalings van Artikel 18(9) (b) van die Wet verval die Registrasie van 'n persoon wat as 'n ingenieur of ingenieur-in-opleiding geregistreer is as sodanige persoon versuim om die voorgeskrewe jaargeld binne ses maande nadat dit betaalbaar word, te betaal. Aandag word ook vriendelik daarop gevestig dat persone wat kragtens Artikel 18(4) (b) van die Wet geregistreer is (dit wil se persone wat nie oor 'n erkende akademiese kwalifikasie beskik nie) en wat toelaat dat hulle registrasie verval, moontlik nie weer vir registrasie in aanmerking sal kan kom nie. Vir persone in hierdie kategorie is dit dus van kardinale belang om toe te sien dat hulle jaargeld binne die voorgeskrewe tydperk betaal word.

By A. N. Brown

Underground rock boring was the topic of the mining vacation school held at the University of the Witwatersrand in the week 4th to 8th February, 1980. The School, which dealt with the management and economics of the subject, attracted 75 delegates from all sectors of the South African mining industry, in addition to two delegates from Germany and one from Zambia.

Jan 1, 1980

By U. S. Kusel

Extractive metallurgy in Iron Age South Africa U. S. KUSEL, B.A. Hons. (Pta) (Visitor) The finds relating to the metal-working of Iron Age Bantu tribes are reviewed, the following metals or alloys being considered: gold, tin, copper, bronze, brass, and iron. Most is known about copper- and iron-working, but even this is very little, and no one has successfully been able to demonstrate how iron was smelted in the primitive furnaces that have been found.

Jan 1, 1974

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

By S. Duma

The main sulphide zone (MSZ) of the Great Dyke is cryptic and without obvious stratigraphic markers. Although there are trends in the dimensions of the PGE and base metal profiles across the Hartley Complex, the profiles are invariant within a particular mining area. Ratios derived from these profiles are used to interpret diamond drill cores drilled ahead of underground development. Detailed logging of oriented core shows the exact position and attitude of intersected faults. Metal ratios are used to estimate fault throw to within 25 cm. It is possible to draw detailed sections showing the extent of ground disturbance well ahead of mining. The method has been confirmed by mining and by drilling inclined holes through the fault blocks. Keywords: main sulphide zone, Hartley Complex, Great Dyke, Zimbabwe, platinum, Palladium, Nickel.

Jan 1, 2004

GENERAL Invitation to attend O.F.S. Branch Meeting: Members of the Witbank/Middelburg Branch were invited to attend a branch meeting of the O.F.S. Branch on the 15th November. The subject of the meeting would be a talk on the Hendrik Verwoerd Dam Project and up to 25 members could be accommodated on the nights of the 14th and 15th November by kind invitation of members of the O.F.S. Branch. A questionnaire would be issued at a later date, to obtain the names of those interested in attending the meeting. PAPER FOR PRESENTATION The Chairman called upon Mr G. H. J. Kitson to present his joint paper, entitled: 'Photoelectric readings; their significance for dust control on collieries.' G. H. J. Kitson (Member) and Y. J. F. Haven (Visitor). After Mr Kitson had presented his paper, both he and Mr Haven answered questions from the floor. The Chairman then thanked Mr G. H. J. Kitson for presenting the paper, and the meeting closed at 6.15 p.m.

By G. Panopoulos, R. P. King, A. H. Juckes

The flotation characteristics of two South African coals were investigated: one from the Dumacol Colliery in Natal, and the other from Landau Colliery in the WitbankCoal Field. Samples of fine coal (smaller than 1 mm)were studied, the Dumacol coal showing significantly better ash-liberation characteristics than the Landau coal. Neither coal was found to produce satisfactory flotation concentrates, except at very fine sizes. The poor flotation performance can be ascribed to the non-selective flotation of unliberated particles that may contain considerable quantities of ash. Flotation recoveries were greatest for particles between 100 and 200 µ m, and fell of rapidly as the size increased above 200 µ m. Very fine particles were found to float adequately, and acceptable concentrates can be made at comparatively high yields from materials smaller than 75 µ m. The flotation of ultrafine coal was demonstrated successfully in a continuous pilot plant. This result opens the way to a potentially viable industrial process for the beneficiation of ultrafines from the Witbank No. 2 seam, which for decades has been regarded as non-floatable.

Jan 1, 1986

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

By G. Rebel

Owing to the helical construction of the wires and strands in a triangular-strand rope, a torque is generated when the rope is restrained and tensioned. When a rope is suspended vertically, there is a load differential along its length due to the self weight of the rope. This load differential gives rise to an initial torque differential m the rope. Since the rope is constrained only at the conveyance and sheave wheel, the torque along its length must be constant ID order to maintain equilibrium, a variation in lay length occurs so that the lay length at the conveyance end decreases, and the lay length at the sheave end increases, from the manufactured state. The tension-torsion testing of steel-wire ropes is discussed, and it is shown how the results of the tests can be used to predict static in-shaft torsional behaviour. The expected changes in strand lay length in very deep shafts (deeper than 2500 m) are calculated, and the associated problems and of severe changes m lay length on rope endurance and safety are discussed. Examples of current in-service rope distortions such as kinks and corkscrews are shown.

Jan 1, 1996

By M. A. Ford

This paper reviews the history, sources, mineralogy, extraction metallurgy, conversion, and enrichment of uranium in South Africa. Over the past 40 years extraction plants were built at 27 sites, an9.over 140 kt of uranium have been produced. Older plants have had to adapt to changing market conditions, no single technology has had the opportunity to become entrenched, and costs have been reduced to a third of those of the original flowsheet. The research efforts aimed at developing the country s nuclear raw materials have been particularly rewarding, as they have enabled South Africa to become a world leader in the extraction of uranium from low-grade ores and to develop methods for uranium enrichment and the production of nuclear fuels.

Jan 1, 1993

By C. H. Wyndham, N. B. Strydom, S. Benade

A group of 23 underweight men weighing less than 50 kg were subjected to an acclimatization procedure in which the work rate was gradually increased from 35Watts on the first day to 70Watts on the eighth day. Excessively high body temperatures and heart rates were observed on these subjects throughout the acclimatization period and on their performance they must be rated as heat-intolerant. It can be concluded that such underweight men should not be subjected to acclimatization at such high work rates and that they should not be allocated to tasks involving these rates in a hot environment. The fact that their body surface areas are inadequate to enable them to get rid of the internal heat produced during strenuous work plus their low work capacities are the major reasons for their inability to tolerate heat.

By R. M. Morris, G. A. Matthesius, M. J. Desai

Slow pyrolysis experiments were caried out on samples of coal from north em Natal having a volatile mater content ranging between 10 and 25 per cent by mass and a constant particle-size distribution. The tests were conducted at atmospheric pressure in a helium atmosphere, and ata heating rate of 10 KImin and a final temperature of 1220 K. The pyrolysis products were taken as coke and volatile mater (tar and eight other species), and tMir respective yields were measured. The experimental results were used in the modification of an existing mathematical model and in the derivation of new corelations for some of the parameters of the model, so that the volatile products of a coal can be predicted from ultimate and proximate analyses of the coal. The pyrolysis tests showed good agreement between the model predictions and the experimental results.

Jan 1, 1987

The addition of binder to full plant tailings significantly affects the rheology of a backfill mixture and, consequently, the pressure gradients in the pipeline. The binder increases the yield stress and apparent viscosity of the mixture, and the transition velocity between the laminar and turbulent flow regimes. In a test conducted at a slurry relative density of 1,72 with binder addition, the mixture also exhibited time-dependent behaviour owing to the hydration of the binder.

Jan 1, 1993

By R. T. Rudd

The impact of slimes-dam formation on water quality and pollution by R. T. RUDD*, B.Sc., AMI (S.A.) CE (Visitor) This paper discusses the mechanics of pollution by slimes dams in the gold- and fluorspar-mining industry, as well as that caused by coal dumps and slurry dams. The effect of coal mining on two typical rivers in Natal is shown and the implications discussed. The implications and trends of sulphates pollution on the Rand Water Barrage in the Vaal River are discussed. The spread of pollutants (sulphates and fluorides) from the Reef and elsewhere, and the impact on urban use and agriculture downstream of the barrage, are illustrated. Conclusions and future policy are outlined.

Jan 12, 1973