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By A. K. Haines

Hydrometalurgy, particularly leaching, is a highly topical subject and always generates great interest in the mineral industry. This was evident right from the start of the organization of the SAIMM Colloquium on Leaching, which was held at Mintek on the 8th and 9th November, 1988. The response to the cal for papers was so good that the Colloquium was extended to two days, instead of the usual one day.

Jan 1, 1988

"Chairman: Dr DeV. HarrisRapporteur: Mr A.H. MunroPapers:Corporate exploration strategies by MacKenzie, B.W.The Engel Simulator and the search for uranium by Griffiths, J.C. and Singer, D.A.The Chairman opened the session by tracing the changes which have taken place in the exploration field since the days of the lone prospector who relied upon his individual skills and to a large extent on luck. The deposits which now remain to be discovered are better covered and are of lower grade. A much greater team effort, involving geoscientists and engineers, is required. The gamble is thus much greater -not only are the probabilities of failure still significant but the consequences are more severe. A recent Canadian survey indicated that expenditures of between two and nine million dollars on regional exploration programs are required to locate one significant deposit.The Chairman went on to say that these facts have led companies to regard exploration as another form of investment and to treat it accordingly. This had placed exploration in the context of corporate strategics and structures, which was the subject of the first paper of the session.In introducing his paper, Dr B. W. MacKenzie said that the paper suggested a decision framework for exploration planning. Initially the environment is analyzed to define observable and relevant economic characteristics. The terms of reference for exploration planning and the appropriate allocation of capital and skills are then established in the light of corporate objectives and growth alternatives. With the aid of this information and in the light of profit and corporate risk criteria, exploration strategies can be selected.Dr MacKenzie went on to say that the usefulness of the concept and criteria outlined in his paper depended critically upon three characteristics of any particular economic environment, namely, the return resulting from an economic discovery, the unit discovery Cost and the probability of making an economic discovery. He then showed by means of a case history relative to the Canadian Shield and Cordilleran areas that these three characteristics could, in fact, be evaluated for regions with reasonable histories of mineral activity.The first contributor to the discussion of the paper, Mr Alfred Weiss, mentioned that his group had been involved in exploration modelling for some ten years and were thus particularly interested in the paper. He went on to say that they had experienced greatest difficulty with reconnaissance programs and that he sensed that these difficulties were also present with the methodology which had been outlined. Mr Weiss asked Dr MacKenzie how he would deal with such situations when no information was available but where there was the potential for both exploration and discovery. Dr Mackenzie agreed that the lack of information was a very severe limitation and said that at the present time his methodology probably did not provide a basis for breaking down the broad geological regions he considered into areas for further assessment."

Jan 1, 2014

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

Jan 1, 1992

By S. Carter

this paper describes an innovation in computer software that permits mining professionals to collaborate on exploration and mining projects regardless of geographic location. Growth of mining companies through merger and acquisition has created a greater need for mining professionals to collaborate, especially as projects and project participants are becoming geographically remote. Surpac NetVision, the name given to this new collaboration technology, satisfies this need by deploying interactive 3D graphics sessions across computer networks. It achieves this by using common web browser technology as the deployment medium. A plug-in architecture that supports diverse file formats permits transparent read and write of foreign data to further enhance the collaboration process. Surpac NetVision supports any number of connections from web browsers on remote computers using existing networks. Software components required to enable the collaboration session are deployed to the remote computer as required and cached for future sessions. The collaboration session at each computer is characterized by a fully functional replica of the user interface for Surpac NetVision from which any function can be executed by any client, at the owners discretion. All geometry and display attributes deployed to remote clients to render 3Dgraphics are highly compressed to reduce bandwidth requirements. The key benefits of this collaboration technology is improved communication in regard to exploration and mining projects leading to: •More informed decision making •Improved deployment of project objectives and plans beyond the technical planning group to project management and operations staff •Improved technical support for software users. Keywords: 3D graphics, project collaboration, interactive graphics, internet 3D graphics, mining software

Jan 1, 2003

By M. A. de Ruijter

Bracken Gold Mine ceased mining operations during February 1993. The clean-up of the gold plant, which had already commenced in September 1992, was completed in January 1994. The mine had been in production since early in 1962 but, because of a decreasing ore reserve, increasing working costs, and a relatively low gold price, closure had become inevitable. The closure had been under consideration since August 1983, when the first estimate was made regarding the amount of gold that could be recovered from the clean-up operations. Until that stage, it had been accepted that Bracken would conform to the commonly accepted idea that 0.25% of the total gold produced by the plant would be recovered during the clean-up operation. This idea was dispelled when the initial estimates indicated that the gold recovery would vary between 0.049 and 0.095%. The actual figure realized was 0.036%, showing that there is no generalforl1ula for the calculation of the amount of gold to be recovered from such clean-up operations. During the clean-up operation, Bracken became an unexpected contributor to the State's Reconstruction and Development Programme by having al the mine and plant buildings purchased and converted into a community development centre. This shortene4 the time available for the clean-up, and several of the buildings remained intact. However, the foundations and sub-soils had been sampled extensively, and it is considered that no recoverable gold was left behind.

Jan 1, 1996

By D. F. Malan, T. E. Oates

A recent experimental pillar extraction project at a UG2 bord-and-pillar mine presented a unique opportunity to compile a new pillar database. Currently, the South African hard rock bordand- pillar mines are designed using the Hedley and Grant formula with a modified K-value. This empirically derived formula was developed for uranium mines in the Elliot Lake district of Canada. The use of this formula for the design of pillars in South Africa is questionable. Very few pillar failures have nevertheless been observed and its current calibrations for the various reef types are possibly too conservative. A new UG2 pillar database of 66 pillars, of which seven are classified as failed, was compiled by the authors. This enabled a revised ‘first-order’ calibration of the K-value for the Hedley and Grant formula. The new estimated value for the UG2 is K = 75 MPa. This gives a pillar strength that is more conservative than the PlatMine formula. This work should nevertheless be considered as only a preliminary calibration as the database was small. Further work is also required to determine whether the exponents in the formula for the width and height parameters are appropriate for UG2 pillars.

May 3, 2023

By W. J. Whiten

Models of cone crushers and vibrating screens are described. These models have been constructed from actual plant data using a systematic model-building technique. Included in this technique is regression analysis using multi-dimensional spline functions. The models have been used too simulate complete crushing plants and hence to design and evaluate a control system for crushing plants.

Bougainville Copper Limited (BCL) operates a 50 Mtpy copper/gold/silver mine and concentrator on Bougainville Island, Papua New Guinea. BCL has installed an in-house developed data logging and supervisory process control system using a DEC PDP 11/73 mini-computer in the mill and has recently installed a similar system in the crushing plant. Together with the central DEC VAX 11/780 computer, they form part of a high speed, fibre optic, local area network in the concentrator. The in-house developed software, known as BIAS (Bougainville Copper Information and Automation System), was developed as a low cost option to interface to a number of different existing plant input/output systems while providing the capability to make maximum use of computer networking facilities. The package includes the more usual control system colour displays and data logging features, but also makes provision for two novel features: (a) Any user connected to the computer network can access the system displays. This allows metallurgists and management to monitor (but not control) plant operation from their offices. (b) Specialized application programs for performing advisory and supervisory control, dynamic simulation, and data analysis are easily incorporated into the system. The mill process system currently runs rougher/scavenger flotation stabilizing control and general data logging. The crushing plant system currently performs data logging only; however it will soon be augmented with the facility to run dynamic crushing plant simulations. Future developments will concentrate on making greater use of the detailed information available from the mine's fully automatic truck dispatch system which runs on a VAX 11/780 computer. Milling process control will be expanded to examine possible economic control of the operation of regrind and cleaner flotation circuits. An advisory water management system to optimize water supply within powerhouse generating capacity constraint will also be investigated.

Jan 1, 1987

By G. T. G. Emère

The Harmony Gold Mining Company Limited employs approximately 29 500 people, including 27000 Black workers recruited from areas both within and beyond the boundaries of the Republic of South Africa. The problems arising from the control of this diverse and complex labour force have led to the need for a fully computerized labour control system. This paper describes how, with the aid of an extensive interrelated network of satellite minicomputers, together with ancillary peripheral user terminals and printers, the management of Harmony Gold Mine intends to meet these problems.

Jan 1, 1983

By C. Chongo, F. X. Paquot, C. Ngulube

"Over the last six years, the Kansanshi copper-gold mine has continued to process significant quantities of complex transitional mixed ores. Initially, the ore treated came predominantly from accumulated stockpiles. Subsequently, the feed source shifted primarily to freshly mined ore that generally showed less tarnish with better flotation kinetics, but with the downside of lower concentrate grades. A number of changes were made to improve the efficiency of the rougher circuit and quality of concentrate produced. These changes were as a result of initial mineralogical studies and laboratory flotation test work that were discussed at length in a previous paper1. Salient among the recommendations adopted as a result of previous work were increased circuit capacity and a modified configuration to increase the residence time and the number of sulphidization stages. These modifications were completed and commissioned in 2011. This, however, resulted in significantly low rougher concentrate grades and a below-specification final concentrate product. This was due primarily to higher mass pulls from the extended rougher bank with multiple concentrate discharge streams, and which necessitated an enlarged cleaning capability. The extra cleaning capacity came on stream in 2014. Of note was the development of a recovery model, based on the strong correlation between the total copper and acid-soluble copper ratio, as a tool for monitoring plant performance. IntroductionThe Kansanshi mine, the largest copper mine in Africa, is 80% owned by Kansanshi Mining plc, a subsidiary of First Quantum Minerals. The remaining 20% is owned by the state through the parastatal Zambia Consolidated Copper Mines Ltd (ZCCM). The mine is located approximately 10 km north of the town of Solwezi and 180 km to the northwest of the Copperbelt town of Chingola. The mine has been in commercial operation since 2005."

Jan 1, 2016

By V-P. Takalo, M. Natsvlishvili, M. Hicks, S. Khizanishvili

"The complexity of copper-gold ores leads to large variations in recoveries and concentrate grades in the processing plant. Detailed chemical and mineralogical studies revealed considerable variation in the ratios of chalcopyrite, chalcocite, and oxidized copper minerals in the ore types studied. The end-member ore types are chalcopyrite-dominated and chalcocite-dominated, while most of the ore types plot between these end-members. In addition, increasing amounts of copper oxide and sulphate minerals result in a decreased response to flotation. Good recoveries and concentrate grades can be achieved from the chalcopyritedominated ore type, while the more altered chalcocite-dominated ore type is more challenging to enrich. IntroductionRich Metals Group (RMG) Copper in Georgia (Figure 1) produces copper-gold concentrates from two open pit mines, Madneuli and Sakdrisi, both located in the Bolnisi mining district in South Georgia. RMG and Outotec began a cooperative project with the aim of improving the recoveries and metal grades in concentrate by gaining an increased understanding of the ore variability and developing more efficient procedures for ore blending, grinding, and flotation. This type of mineralogy-led approach has already been used for other complex ores such as iron oxide copper-gold ores (Hunt, Berry, and Bradshaw, 2011), for iron ores (Lund, Lamberg, and Lindberg, 2013), and for Kupferschiefer ore deposits (Rahfeld et al., 2018).The project started with process audits and mineralogical and chemical characterization of process samples, followed by detailed chemical and mineralogical characterization of six different ore types with simultaneous flotation test work on the same samples. Since neither the recoveries nor the concentrate grades correlate with the head grades of the ores, the modal mineralogical composition, together with the ore hardness, proved to be the most promising approach in developing the geometallurgical classification of these ore types."

Apr 1, 2019

By S. Potgieter-Vermaak

The main mineral components of the so-called heavy sands (or black sand) are the titanium, zirconium and iron-bearing minerals, rutile, zircon and illmenite, accompanied by various minor and trace amounts of silicates or phosphates, often present together with the rare earth elements. The investigated samples originated from Richards Bay Minerals (RBM) in South Africa, which is jointly owned by BHP Billiton and Rio Tinto, the largest titanium slag producer in the world. The present study focused on the characteristics of samples originating from various points in the separation plant. The heavy-mineral fractions and concentrates of a representative suite of samples were investigated using various analytical techniques to establish the differences in morphological and elemental compositions at the different points in the plant. These techniques included: reflected light microscopy, micro-raman spectrometry (MRS), scanning electron microscopy coupled with energy dispersive X-ray analysis (SEM/EDX) and structural and chemical analyser (SCA). All samples comprised a heterogeneous population of zircon and rutile grains with diverse physico-chemical properties, expressed by large differences in colour and trace element chemistry of single grains. The elemental composition proved the presence of the rare earth elements that appeared to coexist with both Ti and Zr minerals. The percentage of grains hosting inclusions, such as anatase, monazite, quartz, spessartine, augite, epidote and actinolite, varied for each sample and could be uniquely characterized by Raman investigations. Keywords: heavy mineral sands, micro-ram an spectrometry, elemental analysis

By G. Chisakuta, P. Bwando, G. Mitshabu

By the end of 2022, the south-eastern Copper Belt region of the Democratic Republic of Congo was host to more than 40 small, medium, and relatively large sized copper solvent extraction sites. To date, solvent extraction reagents supplied in this region have never exceeded 50% of ketoxime content. We generated laboratory extraction and strip isotherms and used these with the BASF IsocalcTM modelling software to assess the benefit of using higher ketoxime blends on the main metallurgical performance indicators such as copper recovery and net transfer. Pure ketoxime extractants combine a relatively low strip point and a decent loading capacity, which are most effective as the pH of the pregnant leach solution gets closer to 2.

Jan 1, 2023

By W. Valderrama, D. G. Almond

Operation of large SAG mills requires a change in the conceptual approach to grinding processes. The traditional energy consumption criteria are now enhanced with new criteria derived from the mechanical dynamics of the mill load. This new approach demands instrumentation capable of providing accurate information about the load movement and the ratio of balls and ore inside the mill. This paper discusses two new performance enhancing tools available to meet these needs.

Jan 1, 2004

By W. K. Brisden

The SAG Milling Seminar, which was held at Murdoch University in Perth on 30th November and 1st December, 1989, was a very successful technical seminar. Organizer Dr Norm Stockton reported a total attendance of 130, which was higher than the 70 expected: 20 delegates came from the eastern States and the remainder were from Western Australia.

Jan 1, 1990

By H. Xuchun, H. Nailian, L. Guoqing

With the accession to WTO and the establishment of Shanghai Gold Exchange, gold mines in China are facing more severe competition from both home and abroad. Supply Chain Management (SCM), a new management idea gradually accepted all over the world, provides the gold mines in China with a new management mode. In this thesis, under the guidance of SCM theory, based on the analyzing to the actualities of Jiaojia Gold Mine, the Jiaojia supply chain framework is constructed, the function system for Jiaojia SCM is configured, and function modules are described in detail. Keywords: Supply Chain Management, Gold mine, Informatization

Jan 1, 2003

By deur J. V. D. M. Grimes

Sishen Iron Ore Mine is one of the largest open-pit mines in the world, and loading and hauling constitutes one of the major cost items on the mine. Because high productivity in loading and hauling results in large financial benefits, the following projects to improve productivity were implemented at Sishen: - a computerized truck-allocation system, - an overhead power-supply system for the dieselelectric driven rear-dump trucks, - an in-pit crusher and a belt-conveyor system. This paper concentrates on the truck-allocation system, with special reference to the improved productivity of loading and hauling resulting from the implementation of this system.

Jan 1, 1984

Statistical summary of the mineral industry world production, exports and imports 1964-1969 Published by Her Majesty's Stationery Office, London, on behalf of the Institute of Geological Sciences (1971) The Statistical Summary contains a wealth of care fully garnered information on the production, exports and imports of the principal minerals and mineral products throughout the world for the period 1964-1969, and it should therefore be of particular interest to economic geologists and others concerned with marketing and selling minerals. In view of the intractable nature of the source data it is quite an achievement to have published figures for 1969 so expeditiously. On picking up the Summary this reviewer instinctively compared it with the Annual Yearbook published by the United States Department of the Interior. The Yearbooks have been issued annually since 1882, and today each consists of a set of three separate books containing five volumes. Apart from abundant statistics on the domestic and international mineral industries, the Yearbooks are known for their perspicacious reviews and articles on a host of different facets of the world's minerals industry. Physically the Summary is a much slimmer publication than the Yearbook, and it contains no commentary whatsoever other than occasional footnotes. The principal contents are a series of tables showing production, exports and imports of fifty-nine of the world's more important minerals and mineral products. Each table shows the weight of the material produced or traded, by countries, with figures for each of the six years in adjoining columns. In some cases (e.g. diamonds) values in British currency are quoted in addition to weights. Most of the data have been abstracted from national reports and returns, although in some instances estimates are quoted where national sources are silent--as for example the production of platinum in South Africa. One wonders in passing if any useful purpose is served by the continued suppression of this particular figure. The four South African producers must surely be able to estimate each other's production fairly accurately by now, and one imagines that the national export figures can likewise be synthesised. This reviewer has two minor criticisms of an otherwise praiseworthy publication. Firstly it seems an unnecessary anachronism to perpetuate the split between 'Commonwealth' and 'Other' countries-the split can have little practical significance today. Secondly, what is one to make of the statement that the 1966-1969 figures for exports from Rhodesia of chrome ore and copper, to take two examples only, are 'not available'? It seems improbable that no estimates of these figures have been made since the imposition of sanctions, and inevitably one suspects that the figures have been excluded on policy grounds. Hopefully this problem will have been solved when the next Summary is published. M.J.M. South Africa, land of Challenge by Maurice Tyack France Interpresse, 323 pages, price R18-00. Is South Africa God's richest acre? In its mineral wealth it certainly is, but what of the many other complex overlays of emotions, traditions and racial problems? South Africa, Land of Challenge, provides the background. This is reported to be the first comprehensive documentary work of its kind on South Africa. It is a handsome volume measuring 12ft by 9f', is illustrated by at least 600 photographs of South Africa, more than half of which are in colour, and contains 21 original maps and charts. The book covers the full spectrum of South Africa's very existence, its geography, pre-history, its customs, countryside, natural resources and its cities. The more controversial categories are thoroughly discussed, the people, their policies and politics. Mr Tyack is eminently qualified to write on South Africa, being the author of over 20 books on other African countries and having spent more than three years of research, in the field, in South African archives and also in various libraries and museums, in preparation for this book. The book claims to be free of any party political bias and appears to be an honest attempt at a factual survey. However, a work of this magnitude will undoubtedly leave an impression on the reader and the tone of this book is decidedly patriotic. This is a useful reference work on South Africa that most South Africans will be proud to own. J.P.H. Ergonomics and physical environmental factors This publication by I.L.O. of a symposium in Rome in September 1968 has much useful information for the mining industry in regard to the health and productivity of its labour force. The first subject dealt with is mechanical vibrations. From this section it is clear that men who drive, for many hours each day, vehicles which vibrate in the 6 Hz range are subject to serious physiological and psychological effects. The former may show as changes to the vertebral column (which has a resonance in the 4-5 Hz range). The circulatory system is adversely effected by values in the 6-10 Hz range and the vision is impaired at between 40-100 Hz. Less definite knowledge exists of the effects of vibration on the hand-arm system from mechanical drills etc, although Raynauds disease of the blood vessels of the hand and degenerative diseases of the elbow and shoulder joints occur in men using drills which vibrate, respectively, in the higher and low frequency ranges. Industrial noise is extremely well dealt with and the latest knowledge is summarized. Clear information is given on the relationship between time of exposure to

By D. G. Millenbruch

An account is given of a four-phase system for the appraisal of a mineral project while it is still in the exploration stage, and for continual consideration of a favourable appraisal until the production stage is reached. There are ten stages from the idea of a likely project to the production stage, and all the staff that are eventually to be concerned with the development of the project are involved at an early stage.

Jan 1, 1979

By J. A. C. Diering

The determination of stresses and displacements close to tabular excavations is of considerable importance in the planning of tunnels and of remnant and pillar layouts. This paper gives a description of a simple yet effective method for the achievement of improved values from an analogue or MINSIM type of analysis. Essentially, closures and rides (the movement of hanging-wall relative to footwall) in mined-out areas are assumed to vary in a piecewise linear fashion as opposed to a piecewise constant fashion. As the former fashion more closely resembles the true variation, it is possible for the stresses and displacements at points close to the excavations to be calculated with much better accuracy.

Jan 1, 1980