Search Documents

By K. Shin

Determining the anisotropy of rocks has in the past been difficult and rarely attempted in engineering practice. Here we have developed a new practical methodology for measuring orthotropic anisotropy that requires only one hollow cylinder specimen to determine the anisotropy of a set, even when the directions of the anisotropic axes are unknown. Autrefois, la détermination de l’anisotropie des roches était difficile et elle a été rarement essayée dans la pratique de l’ingénierie. Voilà c’est nous qui avons mis au point une nouvelle méthodologie pratique pour mesurer le coefficient de conductibilité thermique de l’anisotropie qui exige un seul spécimen du cylindre creux afin de déterminer l’anisotropie d’une série, même si les directions des axes anisotropiques sont inconnues. Früher war die Bestimmung der Anisotropie von Gesteinen ein schwieriges Verfahren, das in der technologischen Praxis nur selten in Angriff genommen wurde. Wir haben hier eine neue praktische Methodik zur Messung der orthotropen Anisotropie entwickelt, bei der nur ein Hohlzylinder an Gesteinsproben benötigt wird, um die Anisotropie einer Reihe von Steinen zu bestimmen, selbst wenn die Richtungen der Anisotropieachsen unbekannt sind.

Jan 1, 2003

By P. Horrell, K. Rhodes, G. Harrison, J. Dean, D. Sammons, M. Stander

Anglo Platinum have perceived a need to increase the rate of reef development both for new mechanised stoping technology and on conventional new developing mines. The Research and Development Division of Anglo Platinum therefore initiated an experimental reef raise project with a tunnel boring machine (TBM) at Bafokeng Rasimone Platinum Mine (BRPM). The scope of the trial was for the boring of a reef raise 340 metres in length on the Merensky Reef. The boring phase of the trial took place over six months and the average rate of penetration of the TBM was 0,47 metres/hour. TBM utilisation was 22%. The TBM used in the trial was a Jarva MK6 manufactured in 1972 and its design with its backup system was not considered to be an ideal machine for reef development. However it was the intention of the trial to prove the concept of developing with a TBM on reef. In this respect the trial was unequivocally a success. There were many problems and long delays did occur during the boring phase. Nevertheless there is every confidence that a new TBM can be designed specifically for this type of work that will achieve high rates of advance up to (say) 400metres/month and with a more flexible steering system in order to negotiate reef changes. It can therefore be expected that TBMs will be used in the future for reef development on South African platinum mines.

Sep 1, 2001

By H. Scott-Russell

Much of the technology and methodology extensively employed in current mining operations is in the mature phase of its lifecycle and, consequently, subject to the principle of diminishing returns. It is probable that future gains in productivity and safety of the magnitude essential for the sustained economic viability of the industry will be derived only from a determined technological development programme. The history of trackless mechanized mining, which represented a radical change in methodology in deep-level gold mines, is reviewed. The benefits and obstacles to the realization of the full potential are highlighted. Similarly, an overview is given of alternative mechanization developments in South Africa. In addition to the development and application of advanced technology, an envelope of operating parameters relevant to each methodology must be engineered to facilitate the site-specific selection of the most appropriate. Furthermore, a mechanism for the evaluation of cost effectiveness is essential to the decision-making process. The narrow, tabular orebodies of relatively low dip that are encountered in the South African hard-rock mining industry make the design and manufacture of a comprehensive range of stoping equipment extremely difficult. The machinery that has been available to date has demonstrated only limited site-specific success. The development of suitable machinery must necessarily be initiated and driven by the South African mining industry in collaboration with the major equipment manufacturers in the world.

Jan 1, 1993

By C. S. Oteo, H. Suárez, P. de la Fuente

ABSTRACT: In the south of the Island of Gran Canaria (Spain) there appear layers of swelling clays inside volcanic formations of a fonolitic type, down to depths as low as 500 m, with thicknesses of 1 to 3 m. Two tunnels (each of length 1,500 m) have been built in these zones (ignimbrites and swelling clays), work on which started in the ‘70s. The construction has been influenced by phenomena of expansivity and decompression. Presented below are the problems that arose, the field and indoor studies conducted and the numerical optimisation of the lining. ZUSAMMENFASSUNG: Im Süden der Insel Gran Canaria (Spanien) kommen im Inneren vulkanischer Formationen phonolithischen Typs in Tiefen von bis zu 500 Metern 1 bis 3 Meter dicke Blähtonschichten vor. In diesem Gelände aus Schmelztuff und Blähton begann man zu Beginn der siebziger Jahre, zwei Tunnel von jeweils 1.500 Metern Länge anzulegen. Die Bauarbeiten standen unter dem Einfluss von Dehnungs- und Dekompressionserscheinungen. Der folgende Text enthält eine Darstellung der aufgetretenen Probleme, der durchgeführten Feld- und Laborstudien und der numerischen Optimierung der Tunnelauskleidung. RESUME: Dans le sud de l’Ille du Gran Canaria (Espagne) on a détecté des couches d’argile gonflante dans l’intérieur des formations de roches volcaniques fonolitiques, à la profondeur autom des 500 m, avec épaisseur de 1 à 3 m. On a perforé deux tunnels (de longueur 1.500 m chaque un) dans cettes zones (igniumbrités et argiles gonflantes), chantier qui comenza pendant les 70’. La construction on a influencé pour des phénomènes d’expansivité et de décompression. Dans cette communication on présente les problèmes presentes, les études de chantier et théoriques realicés et l’optimisation numérique développé pour dimensionner le revêtement.

Jan 1, 2003

This paper summarises some observations regarding the way SAG and AG mills work based on the last ten years of pilot plant operation, grinding circuit design and operational reviews for various projects in Australia and overseas. The main purpose is to promote discussion on key factors influencing breakage in a SAG mill. The focus of the paper is on two questions: ? How do mill lifters and liners really work and have an effect on grinding? ? How does the mill charge composition impact on grinding performance? The focus of the paper is on observations of mill behaviour in both pilot plant trials and plant operation, particularly on Cadia ore. DEM, by others, and JKSimMet modelling of SAG mill performance have greatly assisted in forming the ideas expressed in the paper and both are valuable tools in developing our understanding of the comminution process. Put in the `extreme' form the major observations and conclusions expressed in this paper are that: ? the main purpose of mill lifters is to reduce mill liner wear and not to promote rock breakage; ? the often promoted theory that balls impacting the ?toe of the charge? is a dominant form of breakage is incorrect; and ? fines production in a SAG mill is primarily a function of the rock load mass, with a secondary dependence on ball load for any given circuit configuration.

Jan 1, 2007

By N. R. Shoko, J. Chirasha

Refractory design remains the most fundamental factor in furnace construction. Refractory design details and proven technology consideration is of paramount importance to come up with an optimum furnace life and to maintain productivity in the life span of the furnace lining. The failure to produce a technically or operationally durable refractory design lining could give rise to pre-mature deterioration of the refractory lining and furnace shell. The premature failure of the furnace lining will lead to extensive heat losses, furnace bath shift, change in taphole orientation and alteration of the Pitch Circle Diameter. A combination of these were experienced at Zimbabwe Alloys? new high carbon ferrochrome furnace. The Zimbabwe Alloys experience has shown an excellent furnace performance in the first two years of operation although signs of an anomaly showed within the first six months of the new furnace. Production slowed down due to induced problems from refractory failure causing furnace distortions impacting on the availability of the furnace and smelting capacity. This paper presents the lessons learnt, measures taken to deal with the premature failure and constraints within which the situation was managed.

Jan 1, 2007

By M. Pelser, J. Hagemann

"The Anglo American Platinum Rustenburg Base Metals Refiners (RBMR) is the largest producer of nickel cathode in South Africa. It treats slow-cooled matte to recover a platinum group metal-containing magnetic fraction for downstream processing and a nonmagnetic fraction to produce nickel and copper cathode, cobalt sulphate, and sodium sulphate. The refinery was recently expanded from 21 to 33 kt/a nickel. During the ramp-up phase, the sulphur removal section was found to be a constraint to throughput. Nickel hydroxide is precipitated from nickel spent electrolyte by addition of sodium hydroxide, and filtration of the nickel precipitate allows sulphur to be removed from the circuit as aqueous sodium sulphate in the filtrate. The filtration fluxes were found to be limiting the circuit’s capacity. An obvious solution would have been to install additional filtration capacity at significant capital cost and long lead times. RBMR chose rather to first initiate a collaborative project with Anglo American Technical Solutions to better understand the impact of process conditions on filtration characteristics and to evaluate whether the filtration flux could be increased by improving the quality of the nickel precipitate.A deeper understanding of nickel hydroxide precipitation chemistry and kinetics in the context of high nickel and sodium hydroxide concentrations was developed, guided by precipitation theory and confirmed by laboratory tests and plant observations. It was found that the filtration rate could be significantly improved by modifying the precipitate characteristics. A new precipitation process was engineered and retrofitted into the existing plant. Since start-up of the new precipitation system, the available capacity of the sulphur removal section has more than doubled, and control of the process has improved with the better agitation. This paper describes the theory and results used to design the new agitation system, as well as the impact of the change on capital investment, operability, and process efficiency."

Jan 1, 2016

By F. Pinto, J. V. Lemos, A. Sousa, L. Ribeiro e Sousa

The Rossio railway tunnel was built in 1890 crossing several formations involving limestones, basalts and also sandy and clayey formations. Due to the fact that it is an old underground structure rehabilitation and repair works were performed, namely at Km 0,900 and in a zone crossed by a new tunnel from the Lisbon Metro. Reinforcement support systems were designed in the Rossio tunnel in order to prevent its stability. In this paper, repair works and anchor tests performed at km 0,900 are presented, as well as the monitoring system implemented in order to observe the structural effects induced by the construction of the works. For the interpretation of the obtained information complex 3D models was built, permitting the simulation of the sequential excavation scheme used, non-linear behaviour of the different formations, and the support systems used. Der 1890 erbaute Rossio Eisenbahntunnel durchoertert mehrere Formationen, einschliesslich einer Kalkstein-, Basalt- sowie einer sandigen und tonigen Formation. Auf Grund des Alters des unterirdischen Bauwerks wurden Instandsetzungs- und Reparaturarbeiten im Bereich km 0,900 sowie im Kreuzungsbereich mit einem neuen Tunnel der Lissabonner U-Bahn durchgeführt. Aussteifungssysteme wurden entworfen, um die Stabilität des Rossio Tunnels zu gewährleisten. Im Folgenden werden die Instandsetzungsarbeiten und Anker Tests im Bereich km 0,900 sowie das Messystem zur Ueberwachung der strukturellen Auswirkungen der Bauarbeiten dargestellt. Zur Interpretation der gewonnenen Informationen wurden komplexe 3D Modelle entwickelt, die eine Simulation des Bauablaufs und die Anwendung nichtlinearer Stoffgesetze fuer die verschiedenen Formationen und Aussteifungssysteme ermöglichten. Le Tunnel ferroviaire du Rossio a été construit en 1890, traversant des différents terrains comme des calcaires, des basaltes et aussi des formations limoneuses et sableuses. Dû à l’ancienneté de l’ouvrage, des travaux de réhabilitation et réparation ont été faits, nomment au km 0,900 et dans la zone traversée par le nouveau tunnel du Metro de Lisbonne. Des systèmes de support renforcé ont été conçus pour le Tunnel du Rossio de façon à rassurer sa stabilité. Dans ce papier, on présente les travaux de réparation et les essais d’ancrage réalisés au km 0,900, et aussi, le système d’auscultation mise au point pour l’observation des effets structuraux induits par les travaux. De façon à interpréter l’information résultant de l’observation, des modèles 3D complexes ont été utilisés, permettant la simulation de la méthode séquentielle de l’excavation, du comportement non - linéaire du terrain et, aussi les systèmes de support utilisés.

Jan 1, 2003

By H. A. D. Kirsten

The skills differential between manpower supply and demand is due to deeply rooted socio- and politico-educational misconceptions that can be remedied only by a concerted cooperative effort on the part of the general public, the State, organized industry, organized engineering, and engineering education. This will require the general public to recognize that the reasons for the shortages in engineering manpower should be regarded as critical. Public perceptions of engineering, of the vocational and educational prospects in engineering, and of the skills required are poor. The spectrum of engineering vocations, the corresponding function profiles, the interaction between the vocations and the relative proportions of the vocations in the engineering team are in general not adequately appreciated. The recruitment and training of students and teaching staff, teaching facilities, educational curricula, practical training, qualifications, professional registration, and financing are aspects of engineering education that should be brought to the attention of all concerned. . In addition, the educational curricula for the various vocations need to be specified clearly and definitively if the overall mission of engineering education is to be properly appreciated. The uncertainties between university and technikon education and the pursuant vocations need to be resolved. This can be done only by defining the respective curricula in terms of the mental skills and scientific techniques required. The remedial actions with regard to the rationalization of engineering education comprise informing of the public; establishment of an active political lobby; revision of existing education policy; rationalization of existing educational infrastructure; promotion, development, and guidance of engineering student intake; financing of engineering education; accelerated creation of new employment opportunities; and monitoring of the supply and demand of high-level manpower. The parties required to nitiate these remedial actions are various State departments and corporations involved in engineering and industry, various departments of education, the Directorate of Technology of the Department of Trade and Industry, organized engineering education, organized engineering, organized industry, and the Human Sciences Research Council. Only if these interest groups actively initiate the various actions under the coordinated guidance of organized engineering wil the required results be achieved. The South African Engineering Association has proposed a comprehensive programme as strategy to solving the problem, and has obtained broad consensus from various State departments, organized engineering education and research, and the private sector. A joint venture between the Foundation for Research Development, the South African Engineering Association, and organized industry has been charged by the State President with the task of launching the programme.

Jan 1, 1991

By Y. Sagawa

The Hishikari Gold Mine consists of epithermal vein type Au-Ag deposits, each of which has several veins standing almost in parallel each other and inclining 70 to 90 degrees. The veins have 1 to 3m widths and are extracted mainly by drifting and bench stoping with waste rock fill. The Hishikari has tried to optimise the stope dimensions by the Potvin’s Stability Graph Method, which is well known as an easy and effective tool to design appropriate stope dimensions. The method, however, has some limitations of application due to its simplicity so that it has been used only in limited cases. The authors developed a new numerical approach, based on 2D FEM solu-tion for the stability analysis. As a result, it has been possible to solve the Hishikari situation. The authors also introduce the concept of the design approach and compare the results obtained by us-ing the approach with the database of the Stability Graph Method for validation. La mine d’or Hishikari se compose de gisements d'Au-AG avec des types de filons épither-maux dont chacun a plusieurs veines qui sont presque parallèle les unes par rapport aux autres et sont inclinées de 70 à 90 degrés. Les veines ont de 1 à 3 m de largueur et elles sont principalement extraites en creusant et en abattant des bancs de roches encaissantes. Hishikari a essayé d’optimiser les dimensions du chantier d’exploitation avec la méthode de graphique de stabilité de Potvin, bien connue comme un outil facile et efficace pour avoir des dimensions de chantier d’exploitation appropriées. Toutefois, la méthode a certaines limites d’application dues à sa sim-plicité de sorte qu’elle a été utilisée seulement dans des cas limités. Les auteurs ont développé une nouvelle approche numérique, basée sur la solution 2D FEM, pour l’analyse de stabilité. Par conséquent, il a été possible d'expliquer la situation de Hishikari. Les auteurs présentent le concept de l'approche et ils comparent les résultats donnés en l'employant avec la base de données de la méthode de graphique de stabilité pour la validation. Die Hishikari-Goldmine besteht aus Au-Ag-Ablagerungen mit epithermalen Adern, die jeweils mehrere Adern aufweisen, die mit einer Neigung zwischen 70 und 90 Grad nahezu parallel zueinander verlaufen. Die Adern haben eine Breite von 1 bis 3 Metern und werden überwiegend durch Vortrieb von Stollen und Bergversatz abgebaut. Hishikari hat versucht, die Abmessungen des Abbauorts durch das Potvins Stabilitätskurvenverfahren zu optimieren, das als einfaches und effizientes Mittel für die Erzielung angemessener Abmessungen des Abbauorts bekannt ist. Das Verfahren weist jedoch aufgrund seiner Einfachheit einige Anwendungsbeschränkungen auf, so dass es nur in einigen Fällen benutzt worden ist. Vor diesem Hintergrund haben die Autoren einen neuen numerischen Ansatz entwickelt, der hinsichtlich der Stabilitätsanalyse auf der 2D-FEM-Lösung beruht. Dadurch wurde es möglich, das Problem von Hishikari zu lösen. In diesem Dokument stellen die Autoren die Grundlagen des Ansatzes vor und vergleichen die erzielten Resultate durch Benutzung der Datenbank des Stabilitätskurvenverfahrens zur Validierung.

Jan 1, 2003

By G. du T. Judeel

An investigation was carried out to determine whether a numerical model could be constructed that would produce results that realistically represent actual ground deformations in and around a vertical shaft. The ground deformation was brought about by the partial extraction of the shaft pillar. A special characteristic of the rock masses, affected by the shaft pillar extraction, was that the shaft was located in poor quality rock masses. After the extraction of a portion of the shaft pillar, excessive deformations occurred at the shaft/reef intersection. Therefore, a decision was taken to extract the entire shaft pillar protecting the shaft by a proposed waste-cut across the shaft. The effects of stress and displacement on the shaft were investigated by using inelastic numerical modelling in different stages. A calibrated numerical model was constructed producing modelled results comparable to the actual displacements along the shaft. Des recherches ont été poursuivies pour déterminer si on pouvait construire un modèle numérique qui donnerait des résultats représentant avec réalisme les déformations réelles du terrain à l’intérieur et autour d’un puits vertical. La déformation du terrain était entraînée par l’extraction partielle du massif de protection. Une caractéristique spéciale des masses rocheuses, affectées par l’extraction du massif de protection, était que le puits était situé dans des masses rocheuses de qualité inférieure. Après l’extraction d’une portion du massif de protection, des déformations excessives se sont produites à l’intersection du puits avec le filon. Par conséquent, la décision a été prise d’extraire le massif de protection en entier par une coupe de déblais à travers le puits. Les effets de contraintes et décalage furent étudiés en utilisant une modélisation numérique inélastique à des stages différents. Un modèle numérique calibré fut construit, donnant des résultats modelés comparables aux décalages réels le long du puits. Eine Untersuchung wurde durchgeführt um festzustellen, ob ein numerisches Modell konstruiert werden könnte, das Resultate produzieren würde, welche realistisch aktuelle Bodendeformationen in und um einen vertikale Schacht darstellen. Die Bodendeformation resultierte teilweise aus der Extraktion des Schachtpfeiler. Eine spezielle Eigenschaft der Gesteinsmassen, beeinflußt durch die Schachtpfeilerextraktion, war, daß der Schacht in Gesteinsmassen geringer Qualität situiert war. Nach der Extraktion eines Teils der Schachtpfeiler, traten übermäßige Deformationen am Schacht/Riff Kreuzungspunkt auf. Folglich wurde die Entscheidung getroffen, die gesamten Schachtpfosten zu extrahieren und den Schacht mittels eines geplanten Verlustschnittes quer zum Schacht zu schützen. Die Auswirkungen des Druckes und der Versetzung auf den Schacht wurden unter Anwendung unelastischer numerischer Modelle in unterschiedlichen Stadien untersucht. Ein kalibriertes numerisches Modell wurde konstruiert, welches berechenete Ergebnisse mit den tatsächlichen Versetzungen entlang des Schachtes vergleicht.

Jan 1, 2003

By R. E. Phillips, L. A. Cramer, R. T. Jones

Atomaer (Pty) Ltd is a technology-driven company with interests in Western Australian nickel. Atomaer (RSA) Pty Ltd is a process technology company operating in Southern Africa. It is a subsidiary of Atomaer Holdings Pty Limited (Atomaer), which has operating companies in Australia, Africa, South America, and Europe. In addition, Atomaer has substantial shareholdings in Braemore Resources Plc, a nickel company with interests in sulphide nickel projects in Western Australia and Southern Africa listed on the Alternative Investment Market of London Stock Exchange (AIM); Mintails Limited, a gold company with interests in gold operations in South Africa listed on the Australia Stock Exchange; and Brinkley Mining Plc, a uranium company with interests in Southern Africa listed on the AIM. Independence Platinum Limited (IPt) has been formed by Atomaer to undertake the commercial development and exploitation of Mintek's ConRoast technology with the strategic objective of providing independent smelting and refining facilities with lower capital and operating costs for the treatment and processing of platinum concentrates, including those with high chrome and/or nickel and/or low platinum group metal values, for the development of platinum projects by junior resource companies in South Africa. The platinum mines of South Africa have traditionally exploited the Merensky Reef of the Bushveld Complex for platinum production. However, the mining of this reef is reaching depths that require significant vertical shaft systems and costly refrigeration for access to the ore bodies at deeper levels. In the past decade, all of the platinum producers have begun to mine the UG2 reef because of its cheaper mining costs. UG2 ore usually has lower platinum group metal contents and higher chrome values. The new junior resource companies have gained access primarily to UG2 reefs. Consequently, platinum mining is becoming more UG2-based and the resulting concentrates contain high levels of chromitite. UG2 concentrates are difficult to smelt in the current six-in-line submerged arc furnaces, and this leads to increased capital and operating costs for those smelting operations. The platinum mines of South Africa produce the majority of the world's platinum metal used in automotive catalysts and jewellery. As the platinum market is forecast to grow at a healthy rate into the future, the SA producers Anglo Platinum, Impala, Lonmin, and Northam are planning to expand mining operations in the next decade. Furthermore, a number of smaller new producers who are accessing other mineral resources are entering the buoyant market and will produce platinum concentrates for purchase or toll treatment. Hence, a shortage in both smelting and refining capacities is anticipated. Further smelting and refining facilities independent of the major platinum producers will be required in South Africa by 2010. Mintek's ConRoast technology is best suited to fill the need to treat a high proportion of UG2 concentrates in a cost-effective and technically efficient manner. Atomaer base metals technology has been developed for rapid leaching of nickel and other base metals from alloy. Significant reductions in capital and operating costs are expected from the combination of the two advances in process technology compared with that installed at the existing smelters and refineries that were established over 20 years ago. Independence Platinum will be listed on AIM and the Johannesburg Stock Exchange (JSE) in 2007, and developed as an independent, vertically-integrated platinum company using its independent smelting and base metals refining facilities as a strategic platform to promote the development and mining of platinum projects by junior resource companies in South Africa through technical co-operation, strategic alliances, joint ventures, off-take, toll-refining, and marketing agreements.

Jan 1, 2006

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. The objects of the Institute are to advance the science and practice of mining and metallurgy, to afford opportunities for the interchange and recording of knowledge of mining and metallurgy and to ensure high standards of professional conduct and competence. Membership benefits include monthly issues of the Journal of the Institute, monthly General Meetings at which papers are read, symposia, excursions to mining and industrial concerns and the use of club facilities at Kelvin House. Technical journals received on an exchange basis are available to members at the Johannesburg Public Library. The current membership of the Institute is over 1,400. Membership applications are accepted from suitably qualified persons and the requirements for entrance to the various grades of membership are summarised below. Members shall be not be less than 30 years of age, shall be university graduates in pure or applied science or shall produce evidence to the satisfaction of the Council that they have successfully completed a co-ordinated course of study in pure or applied science of at least three years' duration at an approved university or institution deemed by the Council to be of equivalent status. Members shall have been employed in senior technical positions in important mining or metallurgical undertakings for at least five years or they shall have practised as mining or metallurgical consultants for at least five years. They shall be practising their profession at the time of application. Entrance fee R4.00; Annual subscription R14.00 (town), R12.00 (country). Letters of designation: M.S.A.INST.M.M. Associate Members shall be not less than 25 years of age and shall be university graduates in pure or applied science, or shall have successfully completed co-ordinated courses of study in pure or applied science of at least three years' duration. They shall have been engaged in work of an approved technical character in the mining or metallurgical industries, of which not less than two years shall have been in positions of responsibility. A candidate shall be practising his profession at the time of his application. Entrance fee R2.00; Annual subscription R12.00 (town), R10.00(country). Letters of designation: A.M.S.INST.M.M. Affiliates shall be not less than twenty-five years of age, and shall have been engaged in positions of responsibility in, or associated with, the mining or metallurgical industries for periods of not less than three years. If, however, the candidate for admission to the higher grade of Affiliate, is at the time of his application, already a Student member, he need satisfy the Council only that he is, at the time of his application, engaged in a position of responsibility in or associated with the mining or metallurgical industries. In all cases the applicants shall satisfy the Council that they are fit and proper persons to become Affiliates. Entrance fee R2.00; Annual subscription R12.00 (town), R10.00(country). Graduate Members shall be not less than 21 years of age and shall be university graduates in pure or applied science, or have completed co-ordinated courses of study in pure or applied science of at least three years' duration at an approved university or institution. They shall not remain Graduate members after attaining the age of 30 years without the permission of Council. Entrance fee R1.00; Annual subscription R7.00 (town), R6.00 (country). Students shall be persons not less than 18 years of age who are being educated or trained in a manner approved by the Council, to occupy a technical position in or associated with the mining or metallurgical industries and who, furthermore, shall not have attained the qualification required for a higher grade of membership. They may remain Students until they have obtained the necessary qualifications for transfer to a higher grade of membership, but not after the end of the Institute's financial year in which they attain the age of 28 (twenty-eight) years. They shall then transfer to a higher grade to retain membership of the Institute. The Council may relax the provisions of this clause in such cases as it considers appropriate. Entrance fee nil; Annual subscription R3.00 (town), R3.00 (country). Other. The Council has the power to elect to the grade of Member or Associate Member candidates who may not fulfil all the requirements for entrance to these grades but whose status, professional achievements and practical experience in mining or metallurgy justify such election. Applications. Requests for membership application forms should be addressed to the Secretary: South African Institute of Mining and Metallurgy, P.D. Box 1183, Johannesburg.

Your Council has pleasure in submitting its report for the year ended 30th June, 1970. COUNCIL The following served as Office Bearers during the year under review: Messrs J. K. E. Douglas (President), V. C. Robinson and Prof D. D. Howat (Vice-Presidents), R. C. J. Goode (Immediate Past President) and D. G. Maxwell (Honorary Treasurer). Members of Council: Mr. R. J. Adamson, Dr. M. G. Atmore, Mr M. Barcza, Dr J. M. Bereza, Messrs H. Britten, H. E. Cross, A. R. C. Fowler, G. W. Holl, Dr J. P. Hugo, Messrs N. A. Honnet, P. Lambooy, Prof J. de V. Lambrechts, Mr C. E. Mavrocordatos, Dr J. T. McIntyre, Messrs J. Meintjies, T. C. A. Meyer, J. A. Nixon, Prof R. P. Plewman, Dr R. E. Robinson, Messrs J. F. Reid, H. Simon and P. W. J. van Rensburg. Ten Council meetings were held during the year with an average attendance of seventeen and the standing committees held 45 meetings. FINANCE The annual accounts, which are attached to this report, show an excess of expenditure over income of R4,608 compared with R2,124 last year. This deterioration can be attributed largely to two important factors, namely an increase in secretarial fees of RI, 789 and an increase in the loss on the Journal from R2,343 to R3,508. In addition, our contribution to the expenses of the Federation of Societies of Professional Engineers increased by R607 from R549 to R1,156. The increase in secretarial fees is partly due to our increased demand for services and partly to increased salaries. In order to maintain its essential services it has been necessary for the A.S. & T.S. to increase salaries in order to keep pace with commerce and industry. With regard to the Journal, we did not expect immediate dramatic results from the changes that were effected as from the beginning of last year in the arrangements for publication. However, the improvement has been even slower in materialising than we expected. This situation is being watched carefully and we will not hesitate to make further changes if necessary. It became clear early in the year that the financial position was deteriorating and your Council decided that it was essential to meet the situation by raising subscriptions and entrance fees. At the same time it was decided that there are no grounds for a distinction between Town and Country members and that in future the scale for the compounding of subscriptions should be based on anticipated future membership, rather than past membership. These changes have had only a minor effect on the accounts under consideration. The MacArthur Forrest Memorial Fund shows an excess of income over expenditure of R132 and the total fund was, therefore, increased by this amount to R4,338. The balance sheet shows that the market value of quoted shares and debentures decreased during the year from R13,059 to R6,567, while accumulated funds now amount to R17,959 compared with R22,567 last year. It will also be noted that we are holding R25,844 on behalf of the Symposium on Opencast Mining. MEMBERSHIP Twenty-eight Fellows, twenty-four Members, seventeen Graduates, twenty-five Associates and twenty-seven Students were elected during the year. Four Members were admitted to Life Membership; Five Members were transferred to the grade of Fellow; one Student was transferred to the grade of Member; two Graduates and one Student were transferred to the grade of Member; six Students were transferred to the grade of Graduate; One Associate was transferred to the grade of Fellow; One Associate was transferred to the grade of Graduate. One Fellow, one Member, six Graduates, four Affiliates and ten Students were removed from the Membership Roll in terms of by-law 7.7.1. Your Council records with deep regret the death during the year, of the following: R. A. H. Flugge-de-Smidt, C. S. McLean, Dr H. J. van Eck, (Honorary Life Fellows), J. C. Humphreys, O. Lazar (Life Fellows), D. G. Beadle, J. G. Craig, P. U. Fisher, R. G. McConnell, J. H. Moore, S. Sterling, L. R. Ulyate (Fellows), H. H. Burger, E. A C. Dickson, R. Jack, S. Ring (Members), M. J. Worrall (Graduate). A comparative statement of the membership as at 30th June, 1970, and the end of the previous year is shown in the following tabulation: 30th June 30th June Honorary Life Fellows 10 8 Honorary Fellows 6 6 Life Fellows 189 191 Fellows 514 530 Members 448 465 Graduates 68 80 Associates 155 172 Students 162 161 1,552 1,613 RECLASSIFICATION OF MEMBERSHIP The designations of grades of membership were altered to accord with the practice in professional institutes both here and overseas and members were advised of the new classifications. MEMBERSHIP DRIVE A committee was established to organise a drive for membership as it was felt that there are numbers of persons in our mining and metallurgical industries who are not yet members but who qualify for membership. Members of the committee were allocated responsibility for campaigning in sections of industry and for publicising the aims, objectives and advantages of belonging to the Institute.

By JOURNAL SAIMM

SYMPOSIUM ON PELLETS AND GRANULES During October 1974, the Newcastle branch of the Australasian Institute of Mining and Metallurgy is to hold a symposium on pelletizing and granulation, with particular reference to the iron ore, fertilizer, and cement industries.

Jan 12, 1973

By K. L. Morton

This technical note reviews the status quo of mud rushes and flooding, which have claimed them lives of many people in underground mines in South Africa and globally. Given that the causes are well known and can be managed, the note calls for the development of a national and global standard on flood and mud rush prevention in order to save lives.

Mar 30, 2026

By A. S. Macfarlane

"SynopsisMetal accounting and reconciliation is an increasingly important governance issue in all mining operations, in that it is required, from a risk management perspective, that the company is in control of its product throughout the whole mining value chain. Reconciliation is a grossly misunderstood term. It means different things to different people, and therefore one of the purposes of this paper is to ensure a holistic and integrated understanding of ‘reconciliation’.Previously, where reconciliation was done, it was often for internal control purposes and loosely applied, sometimes with a low degree of confidence and understanding of the underlying parameters and their natural variability.In most mining operations, issues such as dilution, stope performance, and recovery are critical to profitability and long-term value, and thus understanding and control of these key value drivers is essential, not only from the governance perspective, but also from the perspective of maximizing shareholder returns. In order to implement a system for metal accounting and reconciliation, it is important that the cause and effect of these value drivers is understood, and that a systematic control system be established.While a number of off-the-shelf solutions exist for this work, it is the contention of this paper that a full understanding of the metal flow, its variability, its underlying loss potential, and its control points is necessary before a systematic approach to reconciliation can be undertaken.The paper also advocates that this approach should ensure that the reconciliation system clearly addresses the reconciliation needs, within a consistent framework. Such a framework has been developed by AMIRA, in terms of a metal accounting code. However, up until now, this code has been aimed at plant processes, whereas this paper shows how the concept can be extended to cover the full reconciliation requirements for a base metal mine.IntroductionReconciliation is defined as ‘the process of finding a way to make two different ideas, facts, etc., exist or be true at the same time’. In terms of a mining process, this refers to the comparison of measures and estimates along the value chain, and at different points in time, in order to track and optimize metal recovery. This leads to the notion of having a system in place for accounting for the metal. The University of Cape Town defines metal accounting as ‘… the estimation of (saleable) metal in a mine and subsequent process streams over a defined time period. Comparisons of estimates, from different sources over a specific time period, are called reconciliation.’Traditionally, metal accounting has consisted of geological reconciliations of mineral resource to mineral reserve conversion, mine planning reconciliation related to the reconciliation of long-term plans to short-term plans, grade control reconciliation of head grades to sampled or block grades, and mine survey reconciliation of tonnage discrepancies and mine call factors. In addition, metallurgical reconciliation has tended to be based on metal balancing, followed by some commercial metal accounting that links dispatched product to sales quality, quantities, and revenues. Miners disparagingly refer to this plant process as ‘millmatics’."

Jan 1, 2015

By S. F. Burks

"This paper develops themes explained at two SAIMM platinum conferences. Optimization techniques can be used to significantly increase the value of mining businesses by enabling better long-term planning decisions. Open pit and underground mine design, mine scheduling, cut-off grade and blending, stockpiling, and the linking of these to flexible elements of the metallurgical recovery processes are all evaluated together. Transport or sale of intermediate products and the requirements of the product metal markets can also be considered. Experience shows that net present value (NPV) can be increased significantly, usually even before the expenditure of significant amounts of project capital. Recent studies of NPV have aimed to simultaneously evaluate the impact of the optimized financial solution on the non-financial features of a project or operation.The case study presented comprised a commercially orientated review of the prefeasibility study designs and cost estimates of a platinum group metal (PGM) project in South Africa, followed by value chain optimization and sustainability studies of the project carried out simultaneously to identify potential value uplifts to be gained and guide the owners’ team going forward into the feasibility study phase. Some of the major aspects of the project that were found to have significant potential to add value included enhancement of the business model by the application of activitybased costing and theory of constraints, focus on the highest net value portions of the orebody in the early years of production, enhanced and optimized scheduling of the underground mining operation, application of dynamic grind and percentage mass recovery from ore to flotation concentrate (also known as percentage mass pull) to optimize revenue, application of elevated cut-off grades early in the life of mine, matching of the mining and processing capacity, expansion of the operation subject to capital availability, and installation of downstream processing facilities subject to regional third-party capacities.The investigation of non-financial project features focused on demonstrating that a financially optimized solution could also have a number of other benefits. These are mentioned briefly in the paper, which aims to present the status of the project at an early stage of its development."

Jan 1, 2016

Jan 1, 1981

The confusion caused by the different numerical representations of time in the ever-increasing international exchange of information has underlined the need for a world-wide uniform representation of time.

Jan 1, 1989