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By deur A. P. van Wyk

Die Spesialistegroep, Materiaalingenieurswese van die Pretoria-gebied, het op 25 November 1981 'n baie geslaagde colloquium te Universiteit van Pretoria aangebied met die tema 'Oppervlaktebedekking van Metaalonderdele'. Die besprekings is ingelei deur mm. George Murray van Projects Expedited met sy lesing getiteld 'Surfacing by Welding'.

Jan 1, 1982

Rock engineering has now been practised as a discipline for about50 years, and many sophisticated methods of analysis for use in rock engineering design have been developed. However, analysis is only a tool for use in engineering design, and rock masses are often so complex that realistic modelling of them, even with sophisticated methods of analysis, is impossible. At the other end of the scale, rock mass classification methods have been developed to quantify the rock mass. These ?numbers? are now widely used for assessment of stability of underground and surface excavations in rock, for the determination of rock support requirements, and for the estimation of rock mass strength and deformation properties. In considering these areas, the two concepts?design, and prediction of behaviour?will be dealt with. The discussion will be introduced by a consideration of the characteristics of the rock mass, which will highlight the variability in its properties and hence the uncertainty in the behavioural parameters. Examples of real projects will be used to illustrate the discussion.

Jan 1, 2003

By H. Zhu, F. Xu, T. Wang

Abstract : The deformation monitoring data of the middle pier of the in permanent ship lock in Three Gorges revealed several interesting deformation phenomena. Conclusions and explanations are made concerning the phenomena in this paper, based on the finite element and engineering geology analyses. Firstly, the fluctuation of the horizontal transformations can be attributed to the alternate excavation of the two neighbouring ship lock rooms. Secondly, the rock mass discontinuities result in the displacement breaks. Lastly, the main reasons for the one-sided leaning phenomena are the natural stress, which is not evenly distributed, and the presence of discontinuities. This paper presents a valuable reference for studying the ‘individual phenomena’ in geotechnical engineering. ZUSAMMENFASSUNG: Die Beobachtungs claten an der Mittelpier deformation bezüglich Permannenter Schiffsschleuse in den Drei Schluchten offenbaren einige interessante Deformationsphänomene. Die Schlußforgerungen und Erklärungen dazu in dieser Arbeit basseren methodisch anf der ‚’ ‘Endlichen-Elemente-Analzse’ und der ‘Ingenieurnissen-Geograhnie-Analzse’. Erstens kann die Fluktuation der horiyontalen Transformation durch die ungleichzeitige Ausgrabung der zwei benachbarten Schiffsschleusenräume verursacht werden. Zweitens resultzert die Diskontinuität der Felsenmasse ans dem verlagerten Bruch. Drittens: Die Hauptgründe für das Zu-einer-Seite-Neigung-Phänomen in manchen Stellen sind der ungleich eigeteilte natürliche Druck und das vorhandersein der Diskontinuität. Diese Arbeit präsentiert eine wertvolle Referenz für die Untersuchung der Sonderfälle in geotechnischen Bau. Résumé: Cet article a analysé sérieusement et profondément , en utilisant des procèdes d’étude par exemple l’analyse d’éléments défini et celle de la condition géographique de traveaux , des règles typiques de la déformation montrées dans les données surveillantes à propos de la déformation des pierres centrales dans les écluses éternelles du Trois Gorges , on en a tiré une conclusion : 1) le changement des chiffres des déplacements horizontaux des pierres centrales est causé par les creusages séquentiels des cannelure voisines ; 2) l’inclinaison au Nord de toutes les pierres centrales entre les deuxième et troisième chambres d’écluse est causée par la différence de la gravitation entre les deux chambres d’écluse et par l’existence de la surface structurale ; 3) l’existence de la surface structurale cause le changement des chiffres des déplacements horizontaux des pierres centrales au niveau profond . Cet article donne une référence utile pour l’étude du ‘ problème d’indivudualité’( ou les situations anormaux) dans les données surveillantes de la déformation des pierres centrales de la génie civile.

Jan 1, 2003

The Annual General Meeting of the Branch was held in the Witbank Golf Club on Thursday, 28th August, 1969 at 5.00 p.m. Mr C. G. Sowry (Chairman) was in the Chair. There were also present: Ten Members: Messrs J. Meintjes (Vice-Chairman), J. E. van Aswegen, A. C. Hofmeyr, I. Botha, B. F. v. d. Merwe, C. H. Coxon, R. Canny, R. C. J. Goode, A. Bain, G. E. Carlyon. Six Associate Members: Messrs B. T. Hosking, R. E. Powell, W. Weber, T. Bulloch, E. J. Jackson, P. J. Muller. Fourteen Visitors. Total Present: 31. The Chairman declared the meeting open and extended a welcome to all visitors including Mr R. C. J. Goode, President of the Institute. MINUTES OF PREVIOUS GENERAL MEETING The Minutes of the General Meeting held on the 26th June, 1969, were read and adopted. CHAIRMAN'S REPORT The Chairman presented a report outlining the activities of the Branch during the past year. Membership of the local Branch had increased from 80 to 99 during the year. DECLARATIONOF OFFICEBEARERS The Chairman announced that owing to his transfer out of the Witbank area, he was unable to accept the nomination as Chairman for a further year of office. The outgoing committee had elected Mr J. Meintjes Chairman and Mr A. Bain Vice-Chairman for the ensuing year. Mr J. Meintjes then took the chair. Mr J. Meintjes thanked Mr C. G. Sowry for his successful steering of the Branch during its period of inauguration. ELECTION OF COMMITTEE MEMBERS The Chairman then read the Scrutineers' Report and declared the following eight members elected as Committee Members for the 1969-1970 year: Messrs I. Botha, A. W. Brereton, G. E. Carlyon, B. T. Hosking, E. J. Jackson, B. D. McNeice, P. J. Muller, B. F. van der Merwe. TALK The Chairman then called upon Mr A. Bain to present his talk and film show on 'Impressions of the mining and metallurgy congress tour to Australasia'. CLOSURE After thanking the speaker for an interesting talk, the Chairman declared the Meeting closed at 8.40 p.m.

2nd CONGRESS OF THE INTERNATIONAL SOCIETY FOR ROCK MECHANICS The 2nd Congress of the International Society for Rock Mechanics will be held in Belgrade, 21-26 September, 1970. The Congress will include: working sessions, study tours, receptions, excursions introduced in the working sessions and post-congress excursions and special programme for accompanying persons. Anyone interested in rock mechanics and its applicarion may take part in the 2nd Congress. Official languages of the Congress are: English, French and German. Simultaneous translation service will be provided during the Congress. All the correspondence concerning the 2nd Congress of the International Society for Rock Mechanics should be addressed to: Sekretarijat 2. kongresa Medjunarodnog drustva za mehaniku stena Institut za vodoprivredu "Jaroslav Cerni" Bulevar vojvode Misica 43, Postanski fah 530 Beograd - Jugoslavija NINTH INTERNATIONAL SYMPOSIUM TECHNIQUES FOR DECISION MAKING IN THE MINERAL INDUSTRY The Symposium which is to be held in Montreal during the week of June 14-19, 1970, follows the Computer Symposium held in Salt Lake City this year. The purpose of the Symposium is to define the role of decision making techniques within the mineral industry and to stimulate the development of specific applications. The subject of the Symposium-mathematics, operations research and computers as applied to the mineral industry-allows a complete picture of the mineral industry in its public policy, corporate, financial and technological environment to emerge. This is another of the series of symposia on this and related subjects started in the early 1960's at the University of Arizona. Sponsorship has included a number of Universities and the Society of Mining Engineers of the American Institute of Mining. This 1970 symposium is the first to be held outside of America, and is being sponsored by the Canadian Institute of Mining, McGill University and Ecole Polytechnique. A number of delegates from South Africa have participated in these symposia and several have already arranged to attend this symposium in Montreal. Enquiries should be directed to: Secretariat, The 9th International Symposium, Department of Mining Engineering, Ecole Polytechnique, P.O. Box 50l, Snowden, Montreal 248, Quebec, Canada. 24th INTERNATIONAL GEOLOGICAL CONGRESS This Congress is to be held in Montreal, Canada, from August 21 to 30, 1972. A very detailed and extensive programme has been proposed, and includes a number of excursions. Copies of the first circular are obtainable from: The Organizing Committee, 24th International Geological Congress, 601 Booth Street, Ottawa 4, Ontario, CANADA. SYMPOSIUM ON THE RECOVERY OF PYRITE The proceedings of the Symposium on the Recovery of Pyrite, held in Johannesburg on 12th to 13th June 1969 are now available. Copies may be ordered from the Secretary, S.A.I.M.M., P.O. Box 61019, Marshalltown, Transvaal at a cost of R10.00. Papers and addresses presented at the Symposium were: Opening Address by Mr J. K. E. Douglas (President). 'The world sulphur position,' by W. C. J. van Rensburg (Member). 'The South African sulphur position,' by D. L. Taylor (Member). 'The recovery of pyrite at Government Gold Mining Areas Limited,' by R. J. Westwood (Member), G. S. Stander (Affiliate) and H. R. Carlisle (Member). 'Recovery of pyrite concentrates from colliery-waste discards-A preliminary assessment,' by W. A. Gilbert (Visitor) and E. A. Nugent (Member). 'The role of pyrite in upgrading the uranium content of Witwatersrand conglomerate ores by means of the heavy-medium separation process,' by D. J. Tutt (Associate Member). 'Pyrite recovery by jigs at Durban Roodepoort Deep Limited,' by E. J. Dominy (Affiliate), F. Diamond (Affiliate) and A. D. Graham (Affiliate). 'The storage of pyrite concentrates,' by Joan C. Campkin (Visitor) and P. J. Lloyd (Member). 'The flotation plants of the Anglo- Transvaal Group,' by L. A. Bushell (Member). 'Pyrite flotation with amines and cyanidation of the products,' by E. H. D. Carman (Member). 'Gold recovery by cyanidation from mill products obtained after pyrite flotation,' by P. G. Mrkusic (Graduate), M. Sciarone (Visitor) and H. E. Simonsen (Visitor). 'The influence of sulphydral and cationic flotation reagents on cyanidation of native gold,' by K. G. Ashurst (Visitor) and W. P. Finkelstein (Member). 'Laboratory tests on the flotation of pyrite from Witwatersrand gold ores by cationic collector,' by J. Levin (Member), and M. L. Veitch (Visitor). Closing Address, by Dr R. E. Robinson (Director, National Institute for Metallurgy).

Council and Standing Committees-1984/85 President: J.D. Austin Vice Presidents: H.E. James and Dr H. Wagner Immediate Past President: Prof. R.P. King Honorary Treasurer: Prof. D.G. Krige Members of Council: B.C. Alberts, Prof. S. Budavari, E.B. Crocker, N.J. Devine, C.E. Fivaz, J.S. Freer, Prof. G.G. Garrett, J.J. Geldenhuys, Dr A.K. Haines, R.W.O. Kersten, Dr B.K. Loveday, I.D. Matthews, G. Maude, H.G. Mosenthal, B.E. Protheroe, Dr O.K.H. Steffen, Dr P.T. Wedepohl Chairman, Witbank/Middelburg Branch: W.C. Mather Chairman, Orange Free State/Klerksdorp Branch: Dr M.A. Orridge Past Presidents Serving on Council: Dr M.G. Atmore, Prof. A.N. Brown, Dr P.R. Jochens, G.Y. Nisbet, Prof. R.P. Plewman, Dr R.E. Robinson, Prof. M.D.G. Salamon, P.W.J. van Rensburg, D.A. Viljoen, P.A. von Wielligh Standing Committee Chairmen: Adjudication, Prof. R.P. King; Awards, Prof. R.P. King; Constitution, Rules and Policy, Prof. R.P. King; Excursions and Banquet, B.E. Protheroe; Journal, H.E. James; Membership, Dr H. Wagner; Phoenix National Committee, Dr M.G. Atmore; SAIMM School-Extractive Metallurgy, J.S. Freer; SAIMM School-Mining, Prof. S. Budavari; Special Publications, J.D. Austin; Technical Programme¬Extractive Metallurgy, Dr B.K. Loveday; Technical Programme-Mining, J.J. Geldenhuys; Technical Programme-Physical Metallurgy, Dr P.T. Wedepohl; Training, Career Guidance and Education, Prof. R.P. King; World Mining Congress-National Committee, Prof. R.P. Plewman; Working Group Physical Metallurgy, Prof. G. G. Garrett

Jan 1, 1985

By deur B. C. Alberts

Graduate engineers are a scarce and valuable resource. The situation is aggravated by the 2 years of national service, resulting in the elapse of 6 years after matriculation before a young engineer can start his practical training. After having started work, it is therefore imperative that employees in this category should be trained as effectively as possible in (1) the specialized activities of the employer and (2)the employer's specific work practices. Knowledge and experience of these two areas are vitally important for productive work performance by young engineers. Consequently, it is Iscor's primary objective to enable young graduates, in this case engineers, to obtain the knowledge and experience necessary for productive work in the shortest possible time. Iscor's training programme is therefore structured to enable the young engineer to - perform high-level engineering work and to make sound engineering decisions as soon as possible, - gain a thorough background of the employer's production processes, plant, and equipment, - become thoroughly acquainted with Iscor's work practices, policies, and procedures, - acquire a sound knowledge of Iscor's management techniques and philosophies, - do productive work during the training period, - obtain the following additional qualifications as soon as possible: . Government certificate of competency (legally required before appointment to certain positions) . registration as a professional engineer. Iscor's training programmes are no longer based on predetermined periods of time for each department and work practice. Neither is it a tour or visitors' programme. This contribution explains how Iscor, and more specifically its Mining Department, attempts to reach its objectives in this regard.

Jan 1, 1987

By J. W. van der Merwe, A. S. Bolokang, M. J. Phasha, V. J. Matjeke, C. Moopanar

"Excessive wear rates on railway wheels can result in rolling-stock derailments. If wear is detected early the possible derailments can be prevented by prematurely replacing wheelsets, although the inventory cost and maintenance downtime remain a challenge. In the current study, wheels were introduced and monitored in-service for two years to investigate the cause of excessive wear rates. The wear rates and stresses were calculated for the wheels suitable for a maximum load of 26 t per axle. Microstructural and mechanical properties were analysed. As expected, the general microstructure of all the wheels tested was pearlitic. Although all the wheels complied with the tensile strength requirements, stress calculations confirmed material distortion on excessively worn wheels whereas trial wheels revealed yield strength exceeding the yield criterion. High wear rates observed on the wheels were a result of low yield strength relative to the load per axle. The typical wear mechanism found was due to a combination of rolling contact fatigue and abrasive brake wear. Despite compliance of the wheels with existing requirements regarding material and mechanical properties (hardness, ultimate tensile strength), it is recommended that the yield strength must also be taken into consideration as a critical parameter.IntroductionRailway wheels are used to support the wagon mass and guide the wagon along the tracks (Park, 1974). The wheels and rails must be able to tolerate the applied tangential forces in order to effect wagon dynamic performance and reduce material deformation (Ghidini et al., 1994; RSE_TE_SPC_0045, 2011; AAR M107/M 208 Specification, 2011. Over the past ten years, the South African coal wagon maintenance depot has experienced excessive hollow wheel wear rates on the heavy haul line wheels. The maximum load of Jumbo wagons on the coal line is 104 t, or 26 t per axle. Although the maintenance intervention cycle for wheelsets was two years, between February 2011 and August 2012 some wheels experienced excessive hollow wear. Hollow wear is regarded as wear exceeding 2 mm on the central portion of the wheel tread (RSE_TE_SPC_0045, 2011). This happened despite the fact that these wheels were manufactured and certified according to the requirements of AAR M107/208 standard for carbon steel wheels (AAR M107/M 208 Specification,. 2011) and the local wheel RS/ME/SP 021 standard specification (RS / ME / SP / 021 REV 5 (2013). The AAR standard only specifies a minimum hardness as a required mechanical property and the local standard specifies hardness and minimum tensile strength only. In general, an increase in hardness will improve the rolling/sliding wear resistance of steel. This relationship of hardness and wear resistance was found to be true only in a situation where solid and similar alloys are in contact (Singh, Khatirkar and Sapate, 2015). The sliding wear resistance of a material is usually estimated using Archard’s equation (Liu and Li, 2001)."

Jan 1, 2016

By M. J. King, A. Weissenberger, W. G. Davenport

Keywords: Pyrometallurgy, sulphuric acid, sulphur dioxide The raw material for sulphuric acid manufacture is clean SO2 gas. It comes from (i) burning molten by-product sulphur; (ii) roasting or smelting metal sulphide concentrates, and (iii) decomposing contaminated organic chemical process sulphuric acid catalyst. Efficient gas cleaning is required for metallurgical and contaminated acid decomposition gases, especially the former. Sulphuric acid is made from SO2 gas by (i) oxidizing the SO2(g) to SO3(g) in contact with supported liquid-phase catalyst then (ii) reacting the resulting SO3(g) with the water component of 98.5 mass% H2SO4, 1.5 mass% H2O acid. This paper discusses the reasons for these process steps and indicates how acidmaking can be controlled and optimized. Special emphasis is placed on SO2(g) oxidation efficiency and how it is influenced by feed gas composition, feed gas temperature, catalyst composition, catalyst bed pressure, number of catalyst beds, and double versus single contact acidmaking. In addition, a review of various other treatment methods for SO2-bearing gases is provided. A brief description of each process is included along with commentary on their technical and economic applicability for use at metallurgical facilities.

Jan 1, 2006

By deur R. R. Mears

The expected curtailment of activities within the gold-mining industry by the closure of the more marginal mines, and the shortening of the life of the industry as a whole as a result of rising costs and/or an uncertain gold price, are factors that are bound to harm the South African economy in a number of ways. The industry has no option but to regard the gold price, which is determined on the world market, as a given quantity. The remaining ore reserves al tend to be of a lower grade and/or to be found at greater depth. Therefore tighter control of working costs would seem to be almost the only option open to the industry. Working costs can be divided into two broad categories: costs emanating from the environmental characteristics of the orebody, and costs emanating from the general inflationary environment in which the industry has to purchase its inputs. Working costs stemming from the physical environment also fall into two categories: those relating to the grade of the orebody, and those resulting from working at increasing depth and temperature, together with the need to pump increasing quantities of water. The industry is both capital- and labour-intensive in absolute terms, since it requires large inputs of labour as well as of capital. It is limited in its scope to adjust its production function by becoming more labour- or more capital intensive, and is dependent on a large labour force, which cannot easily be replaced by capital inputs. On the other hand, large amounts of capital are required for investment in shafts, development, machinery, and equipment. Since the early seventies, the working costs of the South African gold-mining industry have increased at an annual rate that was significantly higher than the general rate of inflation. This rapid rise in working costs has caused some mines to find themselves in a difficult profit position. At times, the gold-mining industry has even been compelled to restructure its cost/revenue relationship rather fundamentally by revising the grade of ore worked sharply upwards or downwards, as the case may be. The rise in the gold price since 1972 has made it possible for the industry to introduce significant changes in its Black wage policy. The main aim was to increase the permanency of the Black labour force and to encourage local Black workers to join the industry. At the same time, significant increases were also experienced in the cost of machinery and stores, as well as of capital, mainly as a result of inflation. In the study on which this paper is based, the author attempted to measure the influence of environmental factors on working costs, using the physical consumption of electricity as a criterion for measurement. He found that the usefulness of this criterion in relation to factors such as depth, temperature, and water quantities pumped was invariably more than neutralized by the effects of greater productivity and economies of scale. The effects of these environmental factors on the working costs of the industry could therefore not be determined to any degree of accuracy. It seems that good progress is being made with the development of capital-intensive forms of technology aimed at coping with rapidly rising working costs and other effects of increasing depth. Techniques are also being developed to improve rock-cutting procedures and to eliminate the use of explosives in order to introduce a continuous mining process. On the whole, the gold-mining industry seems to be more sensitive to general inflationary pressures than to the cost effects that are associated with depth, temperature, and water quantities pumped. Greater control is possible over physical environmental factors such as the grade of ore mined, temperature, rate and nature of development of a mine, and adaptation of the daily working cycle to a continuous mining process. Wolfe and others hold the view that the industry will lose control over labour costs as a result of the 'sharp increase in wages and the growth of Black trade unions. However, the use of more capital-intensive technology will allow the industry to reduce its labour force, and a smaller, better-trained, and more permanent labour force will enable the industry to cope with the increasingly difficult physical environment and higher wages.

Jan 1, 1987

By P. H. S. W. Kulatilake, B. Malama

To simulate brittle rocks, a mixture of glastone, sand and water was used as a model material. Thin galvanized sheets were used to create joints in blocks made out of the model material. To investigate the failure modes and strength, both the intact material blocks as well as jointed model material blocks of size 35.6 × 17.8 × 2.5 cm having different joint geometry configurations were subjected to uniaxial and biaxial compressive loadings. Results obtained from the intact model material blocks are used to validate a new intact rock failure criterion for biaxial loading. Results obtained from both the intact and jointed model material blocks are used to develop a strongly non-linear new rock mass failure criterion for biaxial loading. In this failure criterion, the fracture tensor component is used to incorporate the directional effect of fracture geometry system on jointed block strength. The failure criterion shows the important role the intermediate principal stress plays on rock mass strength. Zur Simulation spröder Gesteinsarten wurde ein Modellmaterial aus Dentalgips, Sand und Wasser hergestellt. Daraus wurden Blöcke gegossen, in denen mittels dünnen, galvanisierten Blechen Trennflächen erzeugt wurden. Die Blöcke mit Abmessungen von 35.6 × 17.8 × 2.5 cm wurden in einaxialen und biaxialen Druckversuchen belastet. Es wurde das Versagensverhalten und die Festigkeit von intakten Blöcken sowie durchtrennten Blöcken mit unterschiedlicher Trennflächengeometrie untersucht. Aus den Ergebnissen der Versuche an intaktem Material wurde ein neues Versagenskriterium für biaxiale Belastungen validiert. Die Ergebnisse der Versuche an intakten und durchtrennten Blöcken wurden verwendet, um ein neues stark nicht-lineares Versagenskriterium für geklüftetes Gebirge unter biaxialer Belastung abzuleiten. Darin wird der Bruchtensor verwendet, um den Einfluss der Trennflächengeometrie auf die Festigkeit zu erfassen. Das Versagenskriterium stellt heraus, welche Bedeutung die mittlere Hauptspannung für die Gebirgsfestigkeit hat. Un mélange de platre dentaire, de sable et d’eau a été utilisé pour développer un matériau analogue des roches fragiles. De fines feuilles galvanisées permettent de créer des discontinuités représentatives des discontinuités naturelles dans des bloques fabriqués avec ce matériau analogue. Les modes de rupture et la résistance, tant pour le matériau intact que pour le matériau avec ses discontinuités, ont été étudiés sur des blocs de 35.6 × 17.8 × 2.5 cm soumis à des efforts de compression uniaxiaux et biaxiaux. Différentes configurations de géométrie de discontinuités ont été considérées. Les résultats obtenus à partir des blocs intacts permettent de vérifier un nouveau critère de rupture pour les roches intactes soumises à des efforts biaxiaux. Les résultats obtenus, tant avec les blocs intacts qu’avec les blocs avec discontinuités, sont utilisés pour développer un nouveau critère de rupture, fortement non linéaire, pour les massifs rocheux soumis à des chargements biaxiaux. Dans ce critère de rupture, un tenseur de fractures est introduit pour caractériser les effets directionnels de la géométrie des systèmes de discontinuité sur la résistance des blocs avec discontinuités. Ce critère de rupture démontre le rôle important de la contrainte principale intermédiaire sur la résistance des massifs rocheux.

Jan 1, 2003

By J. Sikamo, A. Mwanza, C. Mweemba

"The Zambian copper mining industry as we know it today had its genesis in the 1920s. Consistent private sector-driven investment in the industry over a period of over 50 years in exploration, mine development and operation, development of minerals processing facilities, building of infrastructure for pyrometallurgical and hydrometallurgical processing, with attendant support facilities, including building of whole new towns, resulted in copper production rising to a peak of 769 000 t in 1969, providingover 62 000 direct jobs. The industry was nationalized in 1973 and remained in government hands for just over 24 years. During this period, the industry experienced a serious decline in production levels, reaching the lowest level in the year 2000 when production was 250 000 t. An average of just under 2000 jobs were lost every year in the 24-year period, reaching just over 22 000 direct jobs in 2000.Following the return of Zambian politics to pluralism and liberalized economic policies, the government decided to privatize the mining industry. The process started in 1996 and by the year 2000 all the mining assets had been privatized. The new investors embarked on serious investment to upgrade the assets and to develop greenfield mining projects. Fourteen years later and after more than US$12 billion investment, production levels increased year-on-year to a peak of 763 000 t in 2013 with direct jobs reaching 90 000.This paper discusses the impact of the mining industry in Zambia on the economy in areas such as employment, support for other industries, direct contribution to the national gross domestic product (GDP), foreign exchange earnings, and social amenities. The paper also focuses on the performance of the mines during these periods vis-à-vis mineral availability, mineral grades and complexity, new technologies, and human capital. This is looked at particularly in the light of current challenges the industry is facing. Suggestions are proposed on how the industry can be nurtured to continue being a major driver for the Zambian economy and a major player in the international copper mining business."

Jan 1, 2016

Notices THE FEDERATION OF SOCIETIES OF PROFESSIONAL ENGINEERS The following letter has been received from the Secretaries of the above Federation. Ref. EHvdL/MM/27 13/11/1973 TO THE SECRETARIES OF ALL MEMBER AND AFFILIATE SOCIETIES Dear Sir/Madam, ENTRIES IN TELEPHONE DIRECTORIES PAPERS OF INTEREST The following recently published papers may be of interest to memo bers. DIE FEDERASIE VAN VERENIGINGS VIR PROFESSIONELE INGENIEURS Die volgende brief is van die Sekretarisse van die bogenoemde Federasie ontvang. verw. EHvdL/MM/27 13/11/1973 AAN DIE SEKRETARISSE VAN ALLE LlD- EN GEAFFILIEERDE VERENI GIN GS Geagte heer/dame,

Jan 1, 1974

By T. F. Cho, B .. O. You, K. S. Yoon, K. S. Won

Discontinuity Orientation Measurement (DOM) drilling system capable of retrieving the reference line-marked core log, which can be used for determining the relative positions and orientations of discontinuity planes along the borehole axis, has been developed. Accuracy of the borehole joints data measured from the reference-lined core and, eventually, the significance and applicability of DOM drilling system for site exploration are verified by comparing with the spatial characteristics of joints investigated by implementing borehole image-taking instruments in the same borehole. Enhancement of boring efficiency has been also confirmed by performing twin drilling operations, one with DOM drilling system and the other with a conventional drilling machine equipped with D-3 core barrel, on two neighbouring sites of 5 m apart. Ein DOM(Diskontinuitätsorientierungsmessung)-Bohrsystem, das durch Grundlinien markierte Bohrprobelog extrahieren kann und die relativen Lagen und die Orientierungen der sich im Bohrloch verbreitenden Flächen bestimmen kann, ist entwickelt worden. Die Wichtigkeit des DOM-Bohrsystems und dessen Anwendbarkeit auf die Erforschung auf dem Bohrplatz werden dadurch bewiesen, dass man die Genauigkeit der Daten der Bohrlochsspalte, die durch die die Grundlinie zeichnende Bohrprobe gemessen werden, mit dem räumlichen Eigenschaften der Spalte vergleicht, die durch die Bildaufnahme des gleichen Bohrlochs nachgeforscht werden. Un system de sondage, Discontinuity Orientation Measurement (DOM), capable de récupérer des carottes markés en une ligne de référence a été dévelopé. Il peux être utilisé pour déterminer les positions relatives et les orientations des plans de discontinuité le long de l’axe de trou de sonde. Leur signification et applicabilité pour une caractérisation de site est verifiée par une comparaison de la précision des données a propos des joints mesurés a partir des carottes markés et les carac-téristigues spatiales des joints enquêtés par le camera de sondage

Jan 1, 2003

By P. Altounyan, K. Akermann, T. Van den Berg

Amandelbult Mine is currently undertaking a trial to mechanise the mining of the UG2 reef through the introduction of room and pillar mining. As part of the trial, a system of managing the control of the hanging wall has been introduced, based on systems and technology that are proving successful in the nearby coal mining industry. The principal features are the use of a high bond strength, stiff bolting system which can be easily installed to a high standard, and a range of in situ tests and measurements to optimise the level of support installed to control the movement of the hanging wall. The rock bolt system and the measurements and tests described are new to the platinum mining industry. The paper describes these systems and their adaptation and application to hard rock mining. La Mine d’Amandelbult est actuellement dans des essais en vue de mécaniser l’extraction dans la veine UG2 grâce à l’introduction d’une exploitation par chambres et piliers. Dans le cadre de ces essais, un système de gestion de la paroi suspendue a été introduit, base sur des systèmes et une technologie qui prouvent donner de bons résultats dans l’industrie voisine d’extraction de la houille. Les caractéristiques principales sont l’utilisation d’un système de verrouillage raide et à forte adhérence qui peut être installé à un haut niveau de qualité et une gamme d’essais et de mesures in situ pour optimiser le niveau de soutien installé pour contrôler le mouvement de la paroi suspendue. Le système de verrouillage de la roche ainsi que les mesures et les essais décrits sont une nouveauté dans l’industrie minière du platine. La communication décrit ces systèmes ainsi que leur adaptation et leur application à l’exploitation minière en roche dure. Amandelbult Mine unternimmt gegenwärtig einen Test um den Abbau des UG2 Riffs durchEinführung des Kammerpfeilbau zu mechanisieren. Als Teil dieses Tests wurde ein System zur Kontrolle der Stollenfirstes eingeführt, welches auf jenen Systemen und Technologien basiert, diesich im nahe gelegenen Kohlebergbau als erfolgreich erwiesen. Die prinzipiellen Charakteristikasind der Gebrauch von einem steifen Bolzensytem mit hohem Verbundwiderstand die leicht zueinem hohen Standard gebracht werden können, und eine Reihe von in-situ Tests und Messungenum das Niveau der installierten Unterstützung zu optimieren, und um die Bewegung desStollenfirstes zu kontrollieren. Das Gesteinsbolzensystem, die Messungen und die Tests, diebeschrieben werden, sind neu in der Platinbergbauindustrie. Diese Arbeit beschreibt diese Systeme, deren Anpassung und Anwendung im Hartgesteinsbergbau.

Jan 1, 2003

By B. H. Kim, S. K. Chung

RMR, Rock Mass Rating, is one of the famous rock classifications. However, RMR was proposed empirically and absolutely depends on the experience of engineer. Therefore, engineering verification is needed for RMR system itself. In this study, the factor analysis and the multiple regressions were performed in order to evaluate the validity of rating factor of RMR. Also numerical analysis was carried out using the FLAC based on Taguchi method, a kind of robust designs, in order to examine the support of tunnel corresponding to the revaluated RMR. As the result of the analysis new RMR was proposed with five minimized factors of intact rock strength, RQD, spacing, persistence and roughness of discontinuities. RMR est un des procédés de la classification du roc qui sont généralement utilisés. Mais RMR s'appuie sur l'expérience et se absolument soumet à l'expérience d'ingénieur. Il est donc nécessaire de vér- ifier techniquement sur le système de RMR. Dans cet étude, on met à exécution l'analyse du facteur et la régression multiple pour évaluer la convenance de la cause de classification de RMR. De même, pour évaluer le support du tunnel selon RMR réestimé, on a exécuté l'analyse de la valeur numérique par FLAC qui se base sur la lois de Taguchi, laquelle est une sorte de système du plan robuste. Selon le résultat de la régression multiple, il est proposé de nouvel RMR à partir de l’intensité de roc intact, RQD, l'espacement, la persistance et la rugosité RMR ist eine der weit benutzten klassifikationen fuer die felsenstuecke. Da aber RMR erfahrungs- maessig ist und ueberwiegend von der persoenlichen Erfahrung eines Ingenieurs entschieden ist, ist es mit Sicherheit notwendig, das RMR-system selbst technisch zu ueberpruefen. In diesem studium waren die faktorenanalyse und mehrfachregressionanalyse durchgefuehrt, um die gerechtigkeit der klassifikationenfaktoren von RMR zu bewerten. Ferner war noch eine numerische analyse mit ben- utzung von FLAC aufgrund der Taguchi-methode, eine art technik der robust design, eingefuehrt, um die tunnelstuetze infolge der neubewertung von RMR unterzusuchen. Gemaess der mehrfach regression analyse wurde eine neue RMR, die sich aus 5-eingeschraenkten faktoren wie intact rock strength, RQD, spacing, persistence und roughness von discontinuities zusammensetzen, in vorsch- lag gebracht

Jan 1, 2003

By L. Andrews

Mineralogy, traditionally associated with concentrator studies, is being increasingly applied to problems in pyrometallurgy. Such investigations commonly make use of a number of techniques, and the results are combined for a meaningful interpretation, which can lead to a successful solution for the problem. Mineralogical techniques are described for various pyrometallurgical operations. Examples are given of studies and investigations involving mineralogy in chemical-looping combustion, feed monitoring to platinum-smelting furnaces, and losses to slag in base metal and platinum smelting.

Jan 1, 2011

By R. Flatabø, K-E. Johansen, L. Hunsbedt, P. M. Cowx, J. A. Bustnes

Eramet and Tinfos are two producers of manganese alloys in Norway, which have worked hard for several decades to improve both the internal and external environment. Furnaces producing ferro- and silico- manganese alloys generate large amounts of off-gas that contains substantial amounts of dust, heavy metals and organic by-products. The dust is separated from the gas in venturi scrubbers by washing with water. The water is cleaned and recirculated, and the surplus water coming from moisture in the raw materials, is discharged to the adjacent fjords after further treatment. Emission figures show that the discharge of suspended solids, manganese, zinc and PAH (polycyclic aromatic hydrocarbons) have been reduced substantially over the last three decades as a result of process improvements and installation of state of the art environmental control measures. The two plants were the first world wide to install mercury cleaning of the off-gases from the furnaces. Mercury emission reduction has exceeded 90%. Concerning other environmental issues, such as utilisation of off-gases for energy recovery and chemical purposes, both plants have achieved good results. Major effort in the environmental work has come from the plants themselves, but other players like FFF, The Norwegian Ferroalloy Producers Research Association, and SFT, The Norwegian Pollution Control Authority, have contributed to the achieved results.

Jan 1, 2007

By Y. H. Hatzor

ABSTRACT: A fully dynamic, two dimensional, stability analysis of a highly discontinuous rock slope is demonstrated in this paper. The studied rock slope is the upper terrace of King Herod’s Palace in Masada, situated on the western margins of the seismically active Dead Sea Rift. The dynamic deformation of the slope is calculated using a fully dynamic version of DDA in which time dependent acceleration is used as input. The analytically determined failure modes of critical keyblocks in the jointed rock slope are clearly predicted by DDA at the end of the dynamic calculation. It is found however that for realistic displacement estimates some amount of energy dissipation must be introduced into the otherwise fully elastic, un-damped, DDA formulation. Comparison of predicted damage with actual slope performance over historic time span window of 2000 years allows us to conclude that introduction of 2% kinetic damping should suffice for realistic damage predictions. This conclusion is in agreement with recent results of Tsesarsky, Hatzor and Sitar (2002) who compared displacements of a single block on an inclined plane subjected to dynamic loading obtained by DDA and by shaking table experiments. Using dynamic DDA it is shown that introduction of a simple rock bolting pattern completely stabilizes the slope. RÉSUMÉ : On présente dans cet article une analyse bidimensionnelle complète de la stabilité d’une pente rocheuse très fracturée. La pente rocheuse étudiée est la terrasse supérieure du Palais du roi Hérode à Massada, située sur la rive Ouest du Rift sismiquement actif de la Mer Morte. La pente est constituée de blocs de dolomite raide présentant une stratification sub-horizontale et des joints sub-verticaux. La déformation dynamique de la pente est calculée en utilisant une version entièrement dynamique de l’Analyse de Déformation Discontinue (DDA) où l’accélération dépendant du temps est utilisée comme donnée. Les modes de rupture déterminés analytiquement des blocs clés dans la pente rocheuse fracturée sont clairement prévus par l’approche DDA à la fin du calcul dynamique. On trouve cependant, que pour obtenir des estimations réalistes du déplacement, il faut introduire un facteur de dissipation énergétique sans lequel la formulation DDA serait totalement élastique et sans amortissement. En comparant l’endommagement prévu avec les caractéristiques de la pente sur une période historique de 2000 ans, nous pouvons conclure que l’introduction d’un amortissement cinématique de 2% suffit pour obtenir de prévisions réalistes. Cette conclusion est conforme aux résultats récents de Tsesarsky, Hatzor and Sitar (2002) qui ont comparé les déplacements d’un bloc isolé sur un plan incliné sous chargement dynamique obtenus avec l’analyse DDA et à partir d’essais sur table vibrante. ZUSAMMENFASSUNG: En utilisant une modélisation DDA dynamique on montre que l’introduction d’un système simple de boulonnage stabilise la pente.In dieser Veroeffentlichung wird eine vollstaendig dynamische, zweidimensionale Stabilitaetsanalyse eines hoechst diskontinuierlichen Steinhangs dargestellt. Der untersuchte Hang ist die obere Terrasse des Herodespalastes in Massada, welche in den westlichen Randgebieten des seismisch aktiven Toten Meer Grabens liegt.Die dynamische Deformation des Berghangs wird mit Hilfe einer vollstaendig dynamischen DDA-Version berechnet, in welcher als Input die zeitabhaengige Beschleunigung eingegeben wird. Die analytisch bestimmten Versagensarten kritischer Schluesselbloecke in diesem zerkluefteten Steinhang werden durch Anwendung von DDA am Ende der dynamischen Berechnung klar vorausgesagt. Es zeigt sich jedoch, dass fuer realistische Dislozierungs-Abschaetzungen ein gewisses Mass an Energieverlust in der sonst vollstaendig elastischen, ungedaempften DDA-Fassung einbezogen werden muss. Der Vergleich des vorhergesagten Schadens mit dem aktuellen Verhalten des Berghangs waehrend einer historischen Zeitspanne von 2000 Jahren erlaubt uns zu schliessen, dass ein Zusatz von 2% kinetischer Daempfung fuer eine realistische Vorhersage des Schadens ausreichen sollte. Diese Schlussfolgerung steht im Einvernehmen mit neuen Ergebnissen von Tsesarsky, Hatzor und Sitar (2002), welche die Dislozierung eines einzelnen Blocks auf geneigter Ebene unter dynamischer Belastung – unter Anwendung von DDA und “shaking table”-Versuchen – verglichen. Mit Hilfe der dynamischen DDA wird gezeigt, dass der Steinhang durch Anwendung einer einfachen Steinschraubenstruktur vollkommen stabilisiert werden kann.

Jan 1, 2003

The January General Meeting was held at The Moth Hall, Witbank, on Thursday, 30th January, 1969. Mr C. G. Sowry (Chairman of the Witbank/Middelburg Branch) was in the chair. There were also present: Fourteen Members: Messrs A. Bain, A. W. L. Brereton, J. Meintjes, G. Langton, A. C. Hofmyer, J. H. Moore, T. S. Wilmot, B. F. van der Merwe, H. A. Williams, O. T. Wright, J. E. van Aswegen, P. J. Beukes, I. Botha. Six Associate Members: Messrs B. T. Hosking, R. E. Powell, J. B. Cornish, R. Ladner, W. Weber, P. J. Muller. Two Affiliates: Messrs P. B. Cass, W. K. C. Bremer. Nine Visitors. Apologies were received from Messrs G. R. Canny, E. J. Jackson. MINUTES OF THE PREVIOUS GENERAL MEETING It was proposed and accepted that these be taken as read. Proposer, J. Meintjies; seconded, A. W. L. Brereton. 75TH ANNIVERSARY CELEBRATIONS OF THE S.A.I.M.M. The Chairman reminded members of the functions arranged to mark this occasion. It was also mentioned that members desirous of forming parties to travel to Johannesburg should either make arrangements amongst themselves or inform the Secretary who would assist in arrangements. PAPER FOR PRESENTATION The Chairman then called upon Mr S. Selmer-Olsen to present his paper, 'Lectures on electro-smelting of ferro-alloys'. After Mr S. Selmer-Olsen had presented his paper, he answered questions arising from contributions from the floor. The Chairman then thanked Mr S. Selmer-Olsen for presenting his paper. CONTRIBUTIONS TO PREVIOUS PAPERS Contributions to the paper 'Photo-electric readings. Their significance for dust control on collieries,' presented by Messrs G. H. J. Kitson (Member) and Y. J. F. Haven (Visitor), were read by Messrs A. Bain and A. W. L. Brereton.