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By B. G. Meyburgh

E. H. D. Carman: The results achieved at Buffelsfontein Gold Mining Company Limited are very encouraging and it seems certain that as far as the conventional uranium recovery process is concerned solvent extraction must entirely supplant the old resin ion exchange process. The operational costs given by Mr Meyburgh indicate that the chief cost items in solvent extraction are reagents. In other words 38.4 per cent of the operational cost at Buffelsfontein is due to the replacement of the organics lost from the plant. It is reported from a wide field of experience that loss, particularly of amine, is a direct function both of the quantity and nature of finely divided suspended solids in the pregnant solution and the extent to which the design of the mixers causes the formation of secondary dispersions which do not easily separate in the settler. There is in addition the unavoidable loss of amine due to its solubility in the aqueous solution which is thought to be about 4 p.p.m. In order to minimise solvent losses therefore, efficient clarification at the head of the solvent extraction plant would appear to be a most important requirement. For this reason the newly erected plant at West Driefontein Gold Mining Company Limited has two Funda Pressure Filters each with a filtering area of 540 sq. ft. which are together designed to handle up to 440 g.p.m. of filtrate. This plant has not yet been commissioned but preliminary testing indicates that suspended solids in the sub micron size range which do not settle even on protracted standing of the solution, will rapidly blind the clarifiers. This should not affect solution clarity but frequent backwashing adds to the cost of precoating. The difficulty was countered in the laboratory with continuous additions of filter aid in addition to the precoat but, as Table 11shows, cost of filter aid is high and its use will have to be optimized against organic losses due to less efficient clarification. This will need much careful observation over a relatively long period of time. Costs shown in Table 11 are based on Mr Meyburgh's figures adjusted to probable conditions at West Driefontein Gold Mining Company Limited. The assumption based on small scale testing is that it will cost 5.2c/ton in filter aid to clarify filtrate to a level of about 5 p.p.m. of suspended solids, in order to restrict the amine loss to 10 p.p.m. which is likely to be equivalent to an entrained organic loss worth approximately only 2.6 cents per ton. Of course poor clarification as mentioned earlier is only one of two or even more causes of organic losses and it seems obvious on the above basis that the operation and economics of pressure clarification will need close investigation. A second important consideration at West Driefontein has been the design of the pump-mixers which must perform the dual function of phase mixing and providing the necessary hydraulic gradient for counter current flow of the two phases. The arrangement is shown in Fig. 1.

Jan 10, 1970

By H. C. Van Der Merwe

In the 21st century, dynamic, accurate digital 3-D geological models are essential to the pursuit of safe, efficient and profitable mining. This is particularly true for the deep-level underground mines in South Africa. The Sirovision® solution is a collaboration project between the Australian CSIRO (Commonwealth Scientific and Industrial Research Organisation), Datamine Software Ltd. and AngloGold Ashanti Ltd (AGA). The purpose of the project is to provide a fully integrated digital rock face imaging, geological mapping and modelling system for the AGA gold mining operations. The CSIRO-developed Sirovision® Stereo Camera Rig (SCR) consists of two digital cameras, alighting system, a laser guidance system and image processing software. The imaging system works on the principles of photogrammetry, i.e. overlaying of two 2-D images with a central focus point, with mathematical algorithms extracting 3-D information from the 2-D image pair. The output from matching several image pairs is a computer-generated, full 3-D, virtual copy of the mining excavation. The image resolution and relief ares of sufficient quality to distinguish different rock types and structural contacts. Functionality within Datamine Studio3 is used to add geological intelligence to the 3-D images provided by Sirovision®. The geologist identifies and ?draws? lines representing geological features directly onto the image. By utilizing the inherent ?topography? of the 3-D image, the software is able to convert the lines into 3-D surfaces, ready for use in the 3-D geological model. Subsequent to promising underground test results from AGA?s Sunrise Dam Gold Mine (SDGM) in Australia and other mining operations worldwide, it was decided to test the Sirovision® system in the South African deep-level gold mines. The first underground tests at Moab Khotsong Mine began in January 2009. The objectives of these tests entailed the capturing of 3-D images of selected development ends, mapping of geological features onto the 3-D images and integration of the mapping data with the 3-D geological model. Some downsides have cropped up during the feasibility testing, related to practicality of the SCR for acquisition of 3-Dimagery in the deep-level underground operating environment. These constraints will have to be addressed prior to operational implementation. Facing such difficulties is not unusual when attempting to implement new technology in such a challenging working environment and testwork is still in progress at the mine in order to prove the concept of using this technology in a Witwatersrand underground gold mine. The great advantage of the Sirovision® solution is that it offers the geologist the opportunity to work remotely on a 3-D virtual copy of a mining excavation, without the heat, humidity, hazards and time constraints associated with physical mapping in an underground workplace.

Jan 1, 2009

By E. Vascotto, S. M. Rupprecht, H. C. Grobler

Shaft sinking survey practices in Southern African mining operations have been refined over many decades to meet the stringent accuracy, safety, and productivity demands of deep vertical excavation. However, much of this specialised knowledge remains poorly documented, and the decline in new shaft sinking projects presents a risk that these proven practices may be lost to future generations of mine surveyors. This paper reviews and synthesises current survey control methodologies employed during shaft sinking operations, with particular emphasis on the establishment and maintenance of surface and underground control networks, shaft verticality control, and elevation transfer. Traditional techniques, such as plumb-wire plumbing systems, steady brackets, and calibrated steel shaft tapes, are discussed in detail, alongside quality control principles and common sources of error affecting coordinate transfer. The paper further examines the integration of modern technologies, including total station resections and LiDARbased laser scanning, highlighting their benefits, limitations, and practical constraints in active shaft environments. By documenting both established and emerging practices, this review aimsto preserve critical institutional knowledge, support consistent survey standards, and provide guidance for accurate spatial control throughout the shaft sinking lifecycle.

Mar 30, 2026

By D. Mesa, J. Karvonenb, A. López, P. R. Brito-Parada, R. Grau, D. Davoise

The froth zone in flotation cells plays an important role in determining metallurgical performance. This is even more critical as cell sizes increase, since larger bursting surface areas can easily result in poor froth transport and even stagnant froth zones, which are detrimental to recovery. Generating additional overflowing lip length by adding internal launders and reducing surface area (while also directing the froth to the overflow) by adding crowders are well established design strategies to enhance froth mobility. However, comparative experimental studies of froth zone design modifications at industrial scale are scarce and often lack detailed froth characterisation. In this work, we present the results of two experimental campaigns that were carried out at Atalaya’s Riotinto concentrator in order to determine the effect of a new froth zone design on the flotation performance of a TankCell® e300 cell that operates as the first cell of the rougher bank. These campaigns provided a unique opportunity to assess froth phase phenomena and metallurgical performance before and after changes in design. The original cell design had an internal peripherical launder and a froth cone, while the new concentrate launder technology adds a centre launder and an adjustable froth crowder to the existing launder design. The new concentrate launder arrangement reduces significantly the froth area as well as the froth transport requirements, aiming to improve froth recovery and, consequently, enhance flotation performance, allowing copper recoveries in the TankCell® e300 cell to increase dramatically. In addition, radial profiles of froth height and froth velocity at the surface were determined, which provide valuable insight into the effect of design changes on froth stability and mobility. Keywords: Flotation performance, enhanced recovery, launder, crowder, froth stability

Jan 1, 2020

By A. R. Javadi

Pyrite (FeS2), chalcopyrite (CuFeS2), sphalerite (ZnS) and galena (PbS) generate hydrogen peroxide (H2O2) when placed in water, with pyrite generating the most amount of H2O2. The order of these minerals for generating H2O2 in water is: pyrite > chalcopyrite > sphalerite > galena. In previous research, the methods of generation of H2O2 in the grinding mill were studied. In this study, data from experiments were included by using MODDE 9 software for six parameters composed of water, grinding media, particle size; adding collector to the grinding, and adding depressant and pH. Finally the optimal condition was achieved. According to the results, most of the recovery is related to the particle 75 μ size and when using processed water, adding 100% collector and without depressant and pH 10. The most recovery of lead in the case of the use of fresh water is in the case of 100% collector, without depressant, pH 10 and 150 μ particle size. Maximum recovery in fraction size 45 μ in the case of water process is 100% collector, without depressant and pH 10. Maximum depressant of pyrite will be the fraction size 75 μ, distilled water, without collector, 100 depressant. Keywords: Sulfide mineral, hydrogen peroxide, flotation, oxidation

Jan 1, 2020

By R. C. J. Goode, W. S. Rapson, W. R. Lawrie, L. W. P. Van Der Bosch

W. R. Lawrie (Member): As all the Institute members present are aware, the Ninth Commonwealth Mining and Metallurgical Congress was held in Great Britain from 3rd to 24th May, 1969. The Congress opened in London and the first week was devoted to technical sessions. Several receptions and other forms of entertainment were held in the evenings. The Congress was attended by some 1 200 delegates, many of whom were accompanied by their wives. As can be imagined a large organisation was needed to cater for all the whims of these delegates, to arrange accommodation and to provide transport for the technical trips, for the receptions and for the sight-seeing tours. Papers presented at the technical sessions proved of great interest. It was stimulating to hear of the developments taking place in the various branches of mining and metallurgy. The discussions which developed between men from so many different countries were thought provoking, led to new friendships and most of us made valuable contacts for the future. There were 141 papers presented in the one week. They were given in four separate halls with two, three and sometimes four papers coming up for discussion in each of the three sessions per day in each hall. Among the more interesting subjects were those concerning off-shore drilling and the facilities for production of petroleum and natural gas. Beach mining at Consolidated Diamond Mines drew a large audience. Automation, mechanization and other technical developments were well described and we were brought up to date with modern techniques of mineral prospecting. There was general discussion on the future of the mineral industries together with comments on the consumption and price trends of these metals and minerals. The future of uranium, of vital interest to us in South Africa, came in for much debate. During the first week, besides attending the technical sessions and seeing some of the sights of London, we were royally entertained. There was a banquet, attended by some I 400 people, where we were welcomed by Princess Alexandra, a reception by H.M. Government in the Banqueting House, and we were entertained at the House of Lords on a terrace overlooking the bustling and rather muddy river Thames. Then there was the visit to the Glyndebourne Opera. It is only in London that at 3 o'clock of an afternoon, nearly 1 000 people all togged up in dress suits and long dresses and carrying packets of sandwiches for supper could arrive at a station to catch a train, and not even cause a stir of interest or a raised eyebrow! This is the way we travelled 60 miles to the opera from London. Surely there can be no more picturesque or romantic a setting for an opera than this large 400-year old red brick manor house nestling in the green valleys of the unspoilt Sussex countryside. It was a glorious evening and though we returned somewhat late and tired, not one of us would have missed this experience. After the first week in London there was a choice of tours of one week to London and the Home Counties, Cornwall, a Geological tour to Scotland, South Wales, and North England. These were followed by further one week tours to Yorkshire and Lancashire, Scotland, West Country and Midlands, a Geological tour of Wales, and a Mining and Geological tour to Jurassic Iron Mines. We then returned to London for the final session and closing banquet. Post-congress tours were arranged to Europe and to Ireland. It was a wonderful Congress, a great experience, we made many friends and may there be many more congresses! . L. W. P. van den Bosch (Member): Much has already been said in appreciation of the excellent organisation and arrangements made for the delegates who attended this Congress. This report is confined to a brief discussion of the personal impressions gained from the papers presented and the technical visits attended. The papers covered a wide variety of subjects ranging from highly theoretical observations to practical descriptions of operations. There were three main themes, VIZ: 1. The attention given to research and its forceful application to practical operation. 2. A steady development in mechanization and automation leading to savings in manpower. 3. Improvization, modernization and adaptation of exisitng facilities. Thoughts on these themes can best be illustrated by comments on some of the industries visited. COAL The National Coal Board (N.C.B.) has been most progressive and all of us have heard of the Bevercotes Colliery with its completely automatic mining and coal handling equipment. This was not, unfortunately, on show but there is no doubt that this is one of the greatest advances in coal mining leading towards continuous production. Coal in Britain is fighting for its life against oil, North Sea gas, imported gases and nuclear power. Output is dropping, the less efficient collieries are closing down and efficiencies are steadily rising as the following tabulation indicates: In 1931: 1 million men produced 300 million tons of coal In 1947: 0.7 million men produced 230 million tons of coal In 1968: 0.4 million men produced 160 million tons of coal

By I. Mc Dougall

Water-cooled copper tap-hole blocks provide an effective means of extending the life of tap-hole refractories, as the lower temperature of the refractory material inhibits wear and other damage and promotes the formation of a protective frozen slag layer. This is particularly beneficial during prolonged tapping cycles. The copper block forms an integral part of the lining, and provides mechanical support to the refractory, facilitating rapid replacement of tapping channel bricks without disturbing the surrounding lining. Safety considerations are an important design factor, and the positioning of the water channels is optimized to prevent leaks although the copper is not in direct contact with the molten fluids during normal operation. Water-cooled copper blocks designed by Tenova Pyromet have successfully been utilized on metal, matte, and slag tap-holes for a number of processes, including nickel, platinum group metals, and mineral wool.

Jan 1, 2014

The June General Meeting of the Institute was held in Kelvin House, Johannesburg, on 18th June, 1969, at 4.30 p.m. Mr J. K. E. Douglas (Vice-President) was in the Chair. There were also present fourteen Members, Messrs R. J. Adamson, F. P. Bath, D. M. Jamieson, D. G. Maxwell, Dr J. T. McIntyre, and Mr P. W. J. van Rensburg (Council Members), Messrs B. F. Berry, A. F. Lee, J. E. van Leeuwen, G. G. Nicolson, N. F. Peverett, Dr A. G. Raper, Messrs E. R. Rudolph and H. R. Reid. Five Associate Members, Messrs T. D. Brown, M. R. Fuller-Good, J. S. Freer, Dr P. R. Jochens and Mr D. A. Viljoen. One Graduate, Mr P. G. Mrkusic. Five Students, Messrs N. A. Barcza, J. A. Cruise, R. P. W. Henrard, D. I. Ossin and J. C. M. Wethmar. Nine Visitors, Messrs M. Badenhorst, N. J. Bovey, H. H. Herold, Dr H. J. S. Kriek, Messrs M. S. Rennie, B. B. Segal, S. Selmer-Olsen, O. A. W. Strydom and B. Yates. Secretary, Mr D. C. Visser. Total present: Thirty-six. MINUTES The Vice-President: "May we confirm the minutes of the Monthly General Meetings held on 24th March, 16th April and 21st May, 1969 as published in the Journal?" Agreed. MEMBERSHIP The Vice-President: "I have much pleasure in announcing that the names of the undermentioned candidates having been published in accordance with By-Law 5.2.2, Council has elected them to membership of the Institute in the following grades: Members: Wilfred Desmond Morgan, Abraham Kriek. Associate Members: Rodger Neville Hampson, Robert Richard Booth Lodge. Graduates: Beverley Hugh Waiters, Gwynne Hugh Johnston. Students: Colin Edward Alvery, Peter Marthinus Haikes, Charles Aubrey Husband, John Nowell Randell, Frederick Johannes Jacobus Blaauw, Johannes Andries Breytenbach, Peter Vos, Frederik Hendrik Coetzee, Petrus Nicolaas Jacobus Smit, Patrick Alien Boardman, Robert Nelson Guest. "May I welcome the newly elected members to the Institute." (Applause.) ELECTION OF SCRUTINEERS FOR THE 1969-70 BALLOT FOR COUNCIL The Vice-President: "In terms of By-Law 9.4, I now call for nominations for scrutineers for the 1969-70 ballot for CounciL" P. W. J. van Rensborg: "I wish to nominate Messrs R. C. J. Goode, V. C. Robinson, J. K. E. Douglas, P. Lambooy, D. G. Maxwell, H. Britten and H. Simon as scrutineers."

By Z. Gxowa, L. H. Chown, U. Curle, G. Govender

This work evaluates the deformation behaviour, at warm working temperatures, of green particle-reinforced aluminium composites produced by powder blending in a high-energy ball mill. The work focuses on metal matrix composites (MMCs) based on the 2124-Al alloy, reinforced with 10 or 15 vol.% SiC and metal matrix nanocomposites (MMNCs) based on the 2124-Al alloy, reinforced with 5 or 10 vol.% Al2O3. Three batches for each powder were blended and powder properties such as particle size distribution (PSD) and shape were consistent after blending. It was observed that a more uniform distribution of the reinforcement phase in the aluminium alloy matrix was achieved in 2124-Al/Al2O3 than in 2124- Al/SiC composites. The powders (unreinforced 2124-Al and blended) were initially over-aged at 350°C for 2 hours to reverse any natural ageing that may have occurred prior to use. The over-ageing was incorporated to improve compressibility of the powders with the aim of achieving green compacts with higher integrity. Uniaxial compression tests performed at ambient temperature on a Gleeble® 3500 thermomechanical simulator were unsuccessful as the green compacts fragmented. Engineering stress-strain curves showed that green compacts of unreinforced 2124-Al, 10%SiC MMC and 5%Al2O3 MMNC deformed in a similar manner at ambient temperature and had the same compressive fracture stress of approximately 170 MPa. When the deformation temperature was increased from ambient to warm working temperatures (170–280°C) it was observed that electrical resistance heating (the heating mode of the Gleeble®) of unreinforced Al alloy, MMC and MMNC green compacts did not occur. This was attributed to the high electrical conductivity of aluminium, which resulted in poor heat generation due to the low electrical resistance in the samples. It was presumed that the small sample size (d=8 mm, h=12 mm) also caused rapid heat loss. After further experimentation, the green compacts were heated successfully by insulating the samples to retain heat. It was found that at 280°C, increasing the soaking time from 6 to 20 minutes decreased flow stress and improved plastic flow in the 2124-Al/10%SiC green compact.

Jan 1, 2016

By Y. Fu, C. Aldrich

This study investigates the use of dense convolutional neural networks to estimate bubble size distributions in flotation froths. 20 videographically captured images of froths from an industrial platinum flotation plant in South Africa were labelled semantically with an image annotation tool, LabelMe (https://github.com/wkentaro/labelme). As a result, pixels in the images could be categorized into three classes, namely ‘bubbles’ (class 0), ‘bubble boundaries’ (class 1) and ‘background’ (class 2). A U-net architecture with a ResNet34 backbone was trained to segment the images via classification of the pixels in the images. 5 of the 20 images were used to validate the performance of the neural network. Explicit inclusion of the bubble boundaries as a class proved to be significantly more effective than training the network with two classes only (i.e. bubbles and background). However, the thickness of the boundary layer regions were critical. If too thin, it was difficult to distinguish between some contiguous bubbles and if too thick, some fine bubbles may not be identified. The results were promising, although there is still significant scope for improvement, among other by making use of more images for training and validation. Keywords: Flotation Froths, Convolutional Neural Networks, Deep Learning, Bubble size Analysis

Jan 1, 2020

By A. C. Johnstone

The aim of the study is to determine if pit lakes are a sustainable coal mine closure option in South African. The water balance, chemistry, limnology, and bacterial population of three selected pit lakes were investigated. The lakes are in the three major coal basins of South Africa and are associated with different lithologies and mining methods. The major factors driving the water balance of the pit lakes are direct rainfall, runoff, inflow from old mine workings, and groundwater infiltration, with the major losses being evaporation or discharge onto surface. The study indicated that pit lakes can be designed as ’terminal sinks’ to provide a sustainable mine closure option. The pit lakes sampled have an alkaline pH, and mostly a sodium/calcium sulphate water with total dissolved solids content of less than 3000 mg/l. The phytoplankton and microbiological data indicates that the pit lakes support aquatic life. The study shows that correctly designed pit lakes can be an environmentally sustainable closure option for South Africa’s coal mines. A suggested design manual has been developed to assist mine owners and regulators in developing sustainable coal mine pit lakes as a closure option.

Oct 1, 2021

By S-J. Park

When evaluating mining investment opportunities, one should consider the risks associated with mineral exploration and development. These are commonly classified as technical, economic, and political risks, and are accounted for in the investment decision by changing the discount rate. Thus, a company may use different discount rates associated with varying risks in order to compensate for the variability of success. The discount rate has a tremendous effect on the economic evaluation of mineral projects. Even when all other factors used as inputs for calculating the NPV (net present value) are equal, the project under consideration may be accepted or rejected depending upon the discount rate. Determining a realistic discount rate for a given project is therefore the most difficult and important aspect of cash flow analysis. It should be determined with the consideration of proper technical, economic, and political conditions surrounding the specific project undergoing economic evaluation. One key problem for determining the appropriate discount rate is that it typically depends more on subjective perception of the degree of risk or other experience factors than on a systematic approach. Thus, this study aims to identify, analyse, and document the type, role, and impact of risk factors influencing the determination of discount rates, and then to determine discount rate by using the aforementioned factors.

Jan 1, 2011

By P. Saayman

The mining industry has much potential for automation. A great deal of work has been done on this subject and is still ongoing. With automation comes the possibility for optimization, because more information is available and actions can be repeated with more accuracy. This paper looks at possible solutions to the problem of optimizing the autonomous vehicle dispatch system in an underground mine. Possible optimization strategies are evaluated using a simulated environment. The majority of the results indicate that improvements on current methods are possible. Keywords: mining automation, simulation, vehicles, dispatching strategy, optimization.

Jan 1, 2006

By A. Tello

Variography was introduced by Dr. Pierre Gy to monitor a process, in the sixties. Later on, Francis Pitard extended this concept, building a complete system of variographic controls for different applications. Nevertheless, the existence of information about its use as a way to effectively control plants has been limited. There are infinite areas where variography and chronostatistics can be used. In this paper, two different cases related to gold and silver recovery, through well known but complex metallurgical routes are studied. The use of effective management of process variability software (EMPV) has shown to be a suitable solution to clarify problems at the plant and, consequently, a solution to the encountered problems has been proposed. Chronostatistics is like opening a new world to the metallurgist, making the process variability speak in a more comprehensive and in depth way. Once the ore has been extracted from the mine, sampling is necessary at each sequence of the metallurgical process involved. As a first example, leaching of the ore with cyanide in agitated tanks is another case of a complex metallurgy. The aim of the process is to know about residual values in the tailings in order to optimize process. As a second example, leaching of gold and silver in ore heaps, has to be optimized in terms of time, reagents consumption and, of course, in predicting a reasonable recovery. This last issue appears to be crucial. After cyanide leaching at the heaps, a carbon in columns process is involved, where there are a series of carbon loaded columns that are submitted to a dynamic process of load and unload, to finally deliver an enriched solution to the precious metal electrowinning plant. In both cases, variography has been a good approach to show metallurgists ways to improve the operation.

Jan 1, 2009

By E. Öğretici, S. Kahraman

The indirect estimation of intact rock properties is particularly useful for preliminary investigations in engineering projects. In this paper we examine the usability of electrical resistivity, a nondestructive measurement, for the prediction of physical and mechanical rock characteristics. Physico-mechanical tests (uniaxial compression, Brazilian tensile, density, and porosity tests) and electrical resistivity measurements were performed on specimens of 36 rock types. Before the resistivity tests, the specimens were completely saturated with saline solution. Evaluation of the test results showed that there are medium or strong correlations between resistivity and rock properties. There are also strong or stronger correlations between the two parameters for the rock classes. The regression equations developed were statistically tested, and their validity was confirmed. The results were also compared with previous studies. The conclusion is that electrical resistivity measurement can be used for reliably estimating physical and mechanical rock characteristics.

Aug 8, 2024

METRICATION In order to bring South Africa into line with metric countries the world over and in view of the indisputable advantages of using the comma as a decimal sign, the Metrication Advisory Board has decided to recommend that the comma be used consistently as decimal sign as from April 1, 1971. Numbers consisting of more than three figures are separated by spaces into groups of three to the left and right of the comma, and not by commas, e.g... 2 734 671,512 73 A quantity such as 12,41 kg is read as "twelve comma four one kilograms" and 31,34 km as "thirty-one comma three four kilometres." A motor-car previously described as a 3.8 litre model now becomes a 3,8 litre model. THE BRITISH COUNCIL AWARDS 1972-1973 The British Council invites applications from permanent residents of all races in the Republic of South Africa and South West Africa, for the following awards:- SCHOLARSHIPS Scholarships are available to such residents who hold University degrees or comparable professional qualifications. The scholarships are tenable for post-graduate study at Universities and other educational establishments in Britain for the academic year of approximately ten months beginning 1st October 1972. All arrangements will be made by the British Council and the scholarships will include tuition fees, a maintenance allowance, approved travel in Britain, return fares to Britain, a books grant and a clothing grant. The closing date for applications is 31st July, 1971. BURSARIES Bursaries are available to such permanent residents who hold University degrees or who, being already established in their professions or trades, hold other qualifications. The bursaries are tenable at British educational in-institutions or other suitable establishments in Britain for a course of training, study or research lasting not less than two months or more than six. The British Council will arrange full programmes and professional contacts, and the bursaries will include a maintenance grant, a books grant, authorised course fees and certain other expenses. The British Council may, at its discretion, bear the cost of single or return fares to Britain. The closing date for application is 31st July, 1971. TRAVEL GRANTS Travel grants each of £300 are available in respect of journeys to Britain undertaken between 1st April, 1972, and 31st March, 1973, and are provided to facilitate visits to British Universities by persons holding staff appointments or graduate research posts at South African Universities. Visits must normally be of at least six months duration though grants are occasionally made for visits lasting for one complete term. Grant holders will make their own arrangements with the universities which they wish to visit and will be responsible for finding their own accommodation. The British Council's assistance is limited to the contribution towards cost of fares. The closing date for applications is 31st October, 1971. For further particulars and the relevant application forms please write stating the type of award you wish to apply to: THE CULTURAL ATTACHE BRITISH EMBASSY PRETORIA

By A. E. Voigt

Iron ore samples representing the input and output of several jigging experiments were analysed to determine the effect of particle size, shape, and density on jigging performance. Traditionally, the manual measurement of the size and shape of individual particles is very tedious and prone to inaccuracies and inconsistencies. Using a novel multi-view imaging technique the 3-dimensional representations of each particle in the sample was determined. From this representation several size and shape measurements were extracted, and these were correlated with the individual particle density measurements. A rigorous investigation into the confidence associated with density and the size and shape features as a function of sample size was conducted, thus allowing the significance of correlations in the data to be determined. The jig?s performance was seen to be clearly sensitive to density and markedly so to particle size, while the results for shape indicated the need for continued work in the definition of particle shape.

Jan 1, 2012

By K. Naidoo, M. Pelser, J. Hagemann, K. C. Sole

The copper tankhouse at Rustenburg Base Metals Refinery is an essential component of the Anglo American Platinum value chain. The tankhouse uses starter-sheet technology that was adopted in the 1980s, so dependence on manually intensive labour and overall operational excellence has a significant impact on process performance. An efficient, stable, and sustainable electrowinning process contributes to minimising energy consumption and reducing operational costs, and enables improved product quality and increased throughput. Historic performance of this tankhouse has often been suboptimum over prolonged periods. An in-depth operational review of performance from 2018–2024 was carried out to understand challenges, risks, and high-impact factors that contribute to poor performance. Implementation of adherence to fundamental operational basics identified from global best practice, such as the frequency and quality of cell cleaning and maintenance, preventing backlogged harvesting or maintenance, preserving cell-top furniture conditions and integrity of electrodes, preventing short circuits and poor current distribution, and maintaining a high level of operational discipline, has since contributed to an era of exceptional performance. Root-cause analysis fault trees pertaining to poor current efficiency and high scrap rate are summarised. Current efficiency has significantly improved since 2021, now consistently exceeding 88%. The copper scrap rate, previously believed to be limited to a minimum of 4%, achieved a historic monthly low record of 2.06% in 2023. Chemical and physical quality has considerably improved, and cathodes exhibit minimal morphological defects.

Jun 27, 2025

By A. M. Croll

The efforts to mechanize narrow reef tabular orebodies unique to this country, are not new. They began in the early 1900s and have over the last century seen varied rates of progress and success. Efforts to mechanize with the use of scraper winches can be regarded as a success. The scraper winch replaced the hand lashing of ore and development waste into hoppers. The initiatives by Anglo Gold and the then JCI to implement trackless mining equipment into these environments had limited success but in general were looked upon as a failure?at least this is the perception. The Chamber of Mines Research Organization (COMRO) in conjunction with various mining houses tried to make a success of the impact ripper. Diamond wire cutting of the stope face is another, which has been tried and tested. The use of high-pressure water to cut rock has also been trialed. These attempts, amongst others, are just a few of the efforts that have not been successful in the quest to make life at the face safer, more productive and easier for our employees. Against the backdrop of an emerging South Africa, the associated high expectations of historically disadvantaged people within the country, a strong rand, demands for better safety, lower cost of production and more efficient operations, mechanization has the chance to make a difference to Anglo Platinum?s business. Mechanization has certainly changed the way other commodities such as coal, base metals and diamonds are won from the earth. Mining?s image is still one of people crawling around in stopes?a dirty, ?low-tech? business. Anglo Platinum?s latest journey to mechanize its underground operations began in earnest in1998 and has enjoyed some successes and failures. The opportunity to change the way mining is done within the company is there. Technologies are evolving, and the implementation of mechanization can certainly assist with the achievement of the goals referred to above. When mechanization commenced, targets were set for the company to achieve but these have been revised in the light of recent events relating to the strengthening rand and a slow-down in expansion plans. However, the intent to mechanize appropriately in Anglo Platinum still exists.

Jan 1, 2004

By M. Rossouw

The paper sets out the strategic importance of South Africa?s mining and minerals sector to the national economy. It relates how inexorable and accelerating urbanization and industrialization in emerging markets, especially in China and India, will translate into sustained demand for the minerals that South and southern Africa have in abundance. It warns that while countries buying raw materials from South Africa use these inputs as the basis on which to build value-added, employment-creating industries, South Africa is failing to exploit the economic benefits inherent in its mineral wealth, exacerbating its shortage of skills.

Jan 1, 2011