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The 103rd Annual General Meeting of The South African Institute of Mining and Metallurgy was held in the Gold Room, Transvaal Automobile Club, 60 5th Street, Lower Houghton, Johannesburg on Wednesday, 16th August, 2000. Welcome The President extended a special welcome to the guests and representatives of our sister institutes and other associations. Also to recipients of awards, senior members of industry, Honorary Life Fellows, Past Presidents, our Members and other guests, among them the following: Reinie Meyer, President, The Geological Society of South Africa Dr Nielen van der Merwe, Chairman, The South African Institute of Rock Engineering Chris Fourie, President, Institute of Mine Surveyors of South Africa

Jan 1, 2001

By D. E. Ng?andu

The experience of Mufulira concentrator, of the Zambia Consolidated Copper Mines Limited, with underground mine drainage water, which is used in milling operations is discussed. It is shown that the underground mine water has a deleterious effect on flotation performance. The adverse effect of the underground water was successfully negated by adding lime into the primary ball mills and increasing the pH of the slurry, from a ?natural? pH of 8 to the flotation pH of 10.5. Traditionally, the pH modifier, quicklime, had been added downstream of the milling. Changing the lime addition point further reduced lime consumption by 50%,?a key issue as lime accounted for over 60% of the Mufulira flotation reagent costs. The nature of the effect of the underground water at Mufulira, particularly the sensitivity of the flotation to the pH at which the milling was conducted, characterized galvanic interaction. A large-scale plant situation is presented in which the desired electro-chemical response in the flotation was achieved, by a deliberate manipulation of the milling environment. The experience provides practical testimony of a more fundamental role for the milling process, other than the mere physical preparation, i.e. size reduction and liberation, of mineral particles prior to flotation.

Jan 1, 2001

By H. S. Marshall

Optimum Colliery is an opencast strip mine producing 18Mt of bituminous coal per annum for the export and inland markets as well as for domestic power generation at the Hendrina PowerStation. Coal is exposed by four 60m3 and four 11m3 walkingdraglines and transported from the open cuts to the processing plants by twelve 130 ton coal haulers. Overburden and interburden areas are drilled by nine 250mm-diameter rotary drill rigs. Until 1997 all surveying tasks were conducted by electronictotal stations requiring accurate control points from which line-of-sight XYZ readings could be taken. In 1997 a GPS system was introduced which consisted of a fixed base station and two rovers. The rovers were able to perform most of the survey tasks assigned to total stations. In addition, two overburden drills were equipped with blasthole drill navigation systems, which includes the drill monitoring and material (strata) recognitions system. The rest of the drilling fleet will also be equipped with GPS systems. Blasthole positions are designed in the office based on survey and geological/geophysical information and transmitted via radio link to an industrial PC on the drills. Together with GPS positional data, both the planned and actual drill positions are displayed on an LCD screen. This eliminates the need for surveyed hole positions to be staked before drilling, and for actual hole positions to be surveyed after drilling. As holes are drilled, performance and rock property data transmitted back to the office. Future applications will include GPS monitoring of dragline positions and pad elevations. GPS receivers on the draglines will utilize the existing base station to calculate and transmit XYZ co-ordinates. Another application will be locating of boreholes in the field prior to the pumping of specified explosive charges into the blastholes. Charging instructions for each blasthole will be loaded into the computer on the explosives truck which will be equipped with a GPS system for hole identification.

Jan 1, 1998

By M. D. Mwema

Copper oxide ores deposits in the Katanga province of the Democratic Republic of Congo (DRC) contain at variable level cobalt oxide minerals. In contrast to copper oxide minerals which readily dissolve in the sulphuric acid solution, the cobalt oxide bearings are difficult to dissolve, especially if cobalt is present in the third oxidation state (Co2O3). This species become soluble after reduction of Co+3in Co+2. In practice, the use of reducing agent is therefore necessary in order to transform the insoluble minerals into soluble cobalt sulphate species. The following reducing agents are currently used at the Shituru plant: ferrous ions, which are present in leach solutions, pulverised copper or sodium meta bisulphite (MBS). Due to the high consumption of reducing agents (0,8 t MBS/t of solubilized Co; 1,2 t Cu/t-Co), cobalt production is expensive. The use of sulphur dioxide as reducing agent was then investigated in order to reduce operating cost. This reagent also presents the advantage of sulphuric acid production during the leaching process. It has been added in the leaching vessel (tank). From the laboratory and industrial tests, selective leaching of cobalt (78%) has been performed. The cobalt leaching kinetic depend on sulphur dioxide dosage. Dissolution of copper, iron and manganese remained very low. No emanation of SO2 gas was observed during the process.

Jan 1, 2002

By C. C. Oosthuizen

Paper written on project work carried out in partial fulfilment of Technikon Practical Training Frank shaft is mining both Merensky reef and UG2 reef. The Merensky orebody is almost depleted and this was the reason for starting to mine the UG2 ore reserves. It was decided to mine the UG2 orebody with trackless equipment using a bord and pillar mining method. Frank shaft has been mining the UG2 orebody for nearly 5 years. The T-cut mining method was introduced to see if it could improve the grade of the run of mine (ROM) as well the extraction percentage.

Jan 1, 2005

By A. J. C. Paterson

High density slurry and paste tailings systems offer significant environmental benefits primarily related to reduced water consumption. However, these potential advantages need to be evaluated on a project-by-project basis. The successful design of a thickened or paste tailings system requires that the system is designed to accommodate the effect of the high density slurry on pumps, pipelines and the overall system operation. The transport system must be designed as an integrated unit and the interaction of all the components need to be considered. The transport system includes the slurry preparation plant, the pump station and the pipeline. This paper assesses the impact of increasing the slurry density in a platinum tailings system from conventional densities to thickened and paste tailings densities. As slurry density and rheology increase, there is a sharp increase in energy consumption for the additional water savings and this additional cost needs to be considered. A case study shows that there is a considerable benefit in increasing densities to the point at which tailings can be still be deposited in the standard manner. For existing systems, increasing density can result in an increased capacity at a marginal power cost, provided that the slurry is not too viscous. For a new system, a smaller pump and pipeline can result in lower capital costs and a marginally higher energy cost, if the optimum density is selected. Keywords: tailings, paste, pumping, slurry

Jan 1, 2004

By U. Singh, E. T. Brown, J. Coxon

The rapid fracturing and deformation that occurs around excavations during rock bursts demand that support and reinforcement systems have both deformability and damping capabilities. The energy demand and supply approach currently used in design is considered to be too simplified to represent adequately the rock burst process and the support and reinforcement system requirements. Momentum change may be a necessary second criterion for the analysis of dynamic loading situations. At the St Ives Gold Mining Company, DE plates made from conveyor belt rubber, and dynamic cables with sliding anchors have been developed and used to improve the dynamic performance of support and reinforcement systems. La fracturation rapide et la déformation qui se produisent autour des excavations lors de coups de terrain demandent que les systèmes d’armature et de support soient déformables et aient une capacité d’amortissement. L’approche basée sur l’énergie actuellement utilisée pour la conception est considérée être trop simplificatrice pour représenter adéquatement les coups de terrain et les paramètres de conception des systèmes d’armature et de support requis. Le changement de quantité de mouvement pourrait être un second critère nécessaire pour l’analyse des cas de charge dynamnique. St Ives Gold Mining Company a développé et utilisé des plaques « DE » constituées de caoutchouc de courroie de convoyeur et des câbles dynamiques avec ancrage coulissant afin d’améliorer la performance dynamique des systèmes d’armature et de support. Die ploetzliche Rissbildung und Verformung, die sich in Baugruben waehrend eines Felseinbruchs ereignet, verlangt Stuetz- und Verstaerkungssysteme, welche verformbare und mildernde Eigenschaften aufweisen. Die derzeitlich gebraeuchliche Methode den Entwurf auf den Energiebedarf und dessen Abdeckung zu basieren, wird als eine unannehmbare Vereinfachung betrachtet, da sie den Felseinbruch und die benoetigten Unterstuetzungs– und Verstaerkungssysteme unzulaenglich darstellt. Die Aenderung der Umstaende kann einen zweiten Ansatz fuer die Analyse der Lastsituation erforderlich machen. Die St.Ives Gold Mining Company hat DE Platten aus Foerderband-Gummi und elastischen Kabeln mit verschiebbaren Verankerung entwickelt und dazu verwendet, die dynamische Kapazitaet der Unterstuetzungs- und Verstaerkungssysteme zu verbessern.

Jan 1, 2003

To the members of The South African Institute of Mining and Metallurgy We have audited the annual financial statements of The South African Institute of Mining and Metallurgy set out on pages 483 to 496 for the year ended 30 June 2004. These financial statements are the responsibility of the Institute?s Council. Our responsibility is to express an opinion on these financial statements based on our audit. Scope We have conducted our audit in accordance with statements of South African Auditing Standards. Those standards require that we plan and perform the audit to obtain reasonable assurance that the financial statements are free of material misstatement. An audit includes: ?examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements, ?assessing the accounting principles used and significant estimates made by management, and ?evaluating the overall financial statement presentation. We believe that our audit provides a reasonable basis for our opinion. Audit opinion In our opinion, the financial statements fairly present, in all material respects, the financial position of the Institute at 30 June 2004 and the results of its operations and cash flows for the year then ended in accordance with South African Statements of Generally Accepted Accounting Practice. Auditors 30 July 2004 Council?s approval of the annual financial statements The annual financial statements for the year ended 30 June 2004 set out on pages 483 to 496 were approved by the Council on 30 July 2004 and are signed on its behalf by:

Jan 1, 2004

By Y. Guglielmi, V. Merrien-Soukatchoff, I. Kadiri

ABSTRACT: Hydraulic experiments have been conducted since 1997 within a small fractured calcareous rock mass in southeastern France, at a site called Coaraze. On this reduced-scale site closing a floodgate located on a downstream spring produces repeated hydraulic loadings. Simultaneous measurements of normal deformations and pressure in several joints have provided a better understanding of the hydromechanical behaviour of such a fractured rock mass. The present paper first describes both the site and conceptual interpretation of the measurements performed. We showed that accurate measurement reproduction requires incorporating certain features: a variable normal joint stiffness, the joint vicinity (through introducing a Z coefficient), and the initial stress state. The paper then develops an original analytical interpretation of the coupled pressure-displacement measurements carried out, which reveal the high level of measurement suitability to the non-linear behaviours examined. 2D modelling, using the discontinuous code (UDEC) was used to proceed with the calibration step. KEY WORDS: In situ test, methodology, hydromechanics, modelling, non linear behaviour ZUSAMMENFASSUNG : Hydromechanische Experimente werden seit 1997 in einer kleinen Kalksteinmasse, das sich im Südosten von Frankreich befindet durchgeführt. In diesem kleinen Standort, werden wiederholte Wasserdruck Erhöhungen durch das Schliessen eines Hahnes produziert. Gleichzeitiger Druck und normale Verformung Meßungen in mehreren Fugen haben erlaubt, das hydromechanische Verhalten einer solche gebrochene Felsenmasse besser zu verstehen. Der Artikel beschreibt zuerst den Standort und stellt die begrifflichen Interpretationen der Meßungen vor. Um die Meßungen gut zu reproduzieren ist es wesentlich, bestimmte Faktoren wie die veränderliche normale Steifheit der Fugen, die Nachbarschaft der Fugen (über einen Z-Koeffizient) und der Spannungstand zu berücksichtigen. Der Artikel erklärt die originale Methode für die Druck- und Verformungs-Meßungen Interpretation und zeigt die gute Korrelation der Meßungen mit dem nicht-linearen angenommen Verhaltens der Fugen. Die numerische 2D-Modellierung mit dem UDEC Software ist für die Verkeilung der Faktoren gebraucht worden. SCHLÜSSELWÖRTER: In-situ-test, Methodologie, Hydromechanik, Numerische Modellierung, nicht-lineares Verhalten RESUME : Des expérimentations hydromécaniques sont conduites depuis 1997 dans un petit massif calcaire fracturé situé dans le sud de la France. Dans ce site de taille réduite des mises en charge répétées sont produites par la fermeture d'une vanne située à l'aval du site. Des mesures simultanées de déformation normale et de pression dans plusieurs joints ont permis de mieux appréhender le comportement d'un tel massif fracturé. L'article décrit dans un premier temps le site et présente les interprétations conceptuelles des mesures. Pour bien reproduire les mesures, Il est essentiel de prendre en compte certains facteurs tels que la raideur normale variable du joint, le voisinage du joint (par l'intermédiaire d'un coefficient Z), l'état de contrainte initial. L'article précise la méthode originale d'interprétation des mesures pression-déplacements qui montre la bonne adéquation aux lois de comportement non linéaire proposées. La modélisation 2D, à l'aide d'un code discontinu (UDEC) a été employée pour le calage des facteurs. MOTS-CLEFS : In-situ, méthodologie, hydromécanique, modélisation, comportement non linéaire

Jan 1, 2003

Changes in reductant and energy inputs which are required to adjust the slag composition in anilmenite smelter to a higher or lower FeO content are calculated. The calculated changes are based on the assumption that solidification equilibrium with the freeze lining constrains the slag composition to follow a eutectic groove in the TiO2-FeO-TiO1.5phase diagram. Calculated equilibrium conditions along the eutectic groove are presented, and form the basis of the calculations. The inputs of energy and carbon need to deviate strongly from the steady-state values to adjust the slag composition. The inputs required at any given time depend on the desired rate of change of the slag composition, and the current slag composition. The steady-state relationship of a change in energy input of 5 kWh corresponding to a 1 kg change in carbon input does also hold for the changed inputs during transient changes in FeO content. Keywords: Ilmenite smelting, freeze lining, solidification, eutectic

Jan 1, 2003

By C. Erichsen, J. Werfling

ABSTRACT: A three-dimensional elastic constitutive model for rock salt is proposed. This stress strain law takes into account the three phases of creep (transient, steady state and accelerated creep), dilatancy, as well as the failure and post failure behaviour. The model was implemented into a finite element program and validated on the results of laboratory tests and in situ measurements. A good qualitative and quantitative agreement with the test and measurement results is achieved. A stability analysis for an underground repository in rock salt is presented. ZUSAMMENFASSUNG: Es wird ein dreidimensionales elastisch-viskoplastisches Stoffgesetz für Steinsalz vorgestellt. Mit diesem Stoffgesetz können die drei Kriechphasen (primäres, sekundäres und tertiäres Kriechen), Dilatanz sowie das Bruch- und Nachbruchverhalten erfaßt werden. Dieses Modell wurde in ein Rechenprogramm, das auf der Methode der finiten Elemente basiert, implementiert und an Ergebnissen von Laborversuchen und in-situ-Messungen validiert. Die Versuchs- und Meßergebnisse lassen sich mit diesem Stoffgesetz qualitativ und quantitativ gut nachvollziehen. Als Anwendungsbeispiel wird der Standsicherheitsnachweis für eine Untertagedeponie im Steinsalz erläutert. RÉSUMÉ: Cet article présente un modéle constitutive élastique/viscoplastique à trois dimensions pour sel gemme. Ce modéle comprend les trois stade de fluage (fluage primaire, secondaire et tertiaire), la dilatation, le comportement de défaillance et d'après défaillance. Il est implanté dans un programme de calcul aux éléments finis. À l'aide des essais laboratoire et des mésures in situ, le modéle a été validé. Les résultats des essais et des mesures concordent qualitatifs et quantitatifs aux résultats des calculations.

Jan 1, 2003

By J. L. Human, N. Fernandes

The rockfall hazard is the major contributing agency to fatal accidents in South African platinum mining operations. The majority of these accidents occur in close proximity to the working stope face. The collapse of fractured or blocky ground between individual temporary support units or the closest permanent support line to the stope face has not yet been adequately addressed. A large-scale stope support system testing facility funded by the Safety in Mines Research Advisory Committee (SIMRAC), has been designed and constructed to test support systems and stimulate innovative thinking by mining personnel, support manufacturers and suppliers by providing a facility where the interaction of stope support systems, a rigid stope face and a discontinuous hangingwall beam can be observed during quasi-static and dynamic conditions. Tests have been carried out on various types of stope support systems, focusing on the temporary support systems used in the immediate stope face area. The interlinking of the temporary support units with mesh or safety netting has been explored in the prevention of falls of ground between support units during gravity driven falls of ground. These tests illustrate the facility?s ability to be used to stimulate innovative thinking and provide a testing ground for the development of temporary support systems in order to reduce the risk off all of ground injury to mining personnel at the stope face.

Jan 1, 2004

By K. S. Rao, R. P. Tiwari, V. K. Shrivastava

ABSRACT: In this paper numerical simulation of jointed block mass behaviour obtained in an experimental study has been presented. Singh et al. (2002) conducted extensive tests on the jointed model materials with several joint configurations. The results of this experimental study were used to validate the strength behaviour of numerical block mass model developed using professionally available software. This software basically contains different kinds of material models. From the results of numerical simulation the existence of strength anisotropy was observed. The strength anisotropy so obtained has been compared with the experimental values reported by Singh et al. (2002). The anisotropic curves in both cases are U-shaped with flat base. They show good agreement in sliding mode of failure zone in which inclination ß (= 90° - ?) of joint set-I lie between 20° to 40° for all cases of interlocking. ZUSAMMENFASSUNG: In dieser numerischen Papiersimulation des verbundenen Blockmasse Verhaltens, das in einer experimentellen Studie erhalten wird, ist dargestellt worden. Singh et al. (2002) leiteten umfangreiche Tests auf den verbundenen vorbildlichen Materialien mit einigen gemeinsamen Konfigurationen. Die Resultate dieser experimentellen Studie wurden verwendet, um das Stärke Verhalten des numerischen Blockmasse Modells zu validieren, das mit professionell vorhandener Software entwickelt wurde. Diese Software enthält im Allgemeinen unterschiedliche Arten der materiellen Modelle. Von den Resultaten der numerischen Simulation wurde das Bestehen von Stärke Anisotrophie beobachtet. Die Stärke Anisotrophie also erreicht ist mit den experimentellen Werten verglichen worden, die von Singh et al. (2002) berichtet werden. Die anisotropen Kurven in beiden Fällen sind mit flacher Unterseite u-förmig. Sie zeigen gute Vereinbarung in gleitender Erscheinungsform des Ausfalls Zone, in der Neigung ß (= 90° - ?) von der Verbindung stellenSie Lüge zwischen 20° auf 40° für alle Fälle vom Ineinandergreifen ein. RESUME: Dans cette simulation numérique de papier du comportement joint de la masse de bloc obtenu en étude expérimentale a été présenté. Singh et autres (2002) ont effectué les essais étendus sur les matériaux modèles joints avec plusieurs configurations communes. Les résultats de cette étude expérimentale ont été employés pour valider le comportement de résistance du modèle numérique de la masse de bloc développé en utilisant le logiciel professionnellement disponible. Ce logiciel contient fondamentalement différents genres de modèles matériels. Des résultats de la simulation numérique on a observé l'existence de l'anisotropie de force. L'anisotropie de force ainsi obtenu a été comparée aux valeurs expérimentales rapportées par Singh et autres (2002). Les courbes anisotropes dans les deux cas sont en U avec la base plate. Elles montrent la bonne concordance dans le mode coulissant de la zone d'échec en lequel la inclination ß (= 90° - ?) du joint placez-Je le mensonge entre 20° à 40° pour tous les cas d'enclencher.

Jan 1, 2003

By S. M. Rupprecht

"SynopsisThis paper is intended to document recent personal thoughts, opinions, and debate around the South African Code for the Reporting of Exploration Results, Mineral Resources and Mineral Reserves (the SAMREC Code) (2009) and its current usage by Competent Persons. Admittedly, some debates are as old as the SAMREC Code itself and have been ‘parked’ as no consensus could be reached by members of the SAMREC Working Group.Some of the more critical issues currently under examination are the definition of Competent Person and the potential registration of Competent Persons, the current re-write of the Code, and the introduction of reporting of Exploration Results, Mineral Resources, and Mineral Reserves on an ‘If not – why not’ basis, noncompliance with the Code and discipline, the role of the Johannesburg Stock Exchange Readers Panel, and the valuation of mineral assets based on scoping studies.IntroductionThis paper is intended as a personal memoir of recent thoughts and debate around the South African Code for the Reporting of Exploration Results, Mineral Resources and Mineral Reserves (the SAMREC Code) (2009) (‘the Code’). Admittedly, some debates, such as reporting of Mineral Reserves inclusive or exclusive of the Mineral Resource, are as old as the SAMREC Code itself and have been ‘parked’ as no consensus could be reached by members of the South African Mineral Resource Committee (SAMREC) Working Group. The author, who has been involved with the SAMREC Working Group since 2007, offers observations in his personal capacity as a professional mining engineer with the intent of getting practitioners to contemplate the influence of the Code on the mineral industry. Current practices in the compilation and reporting of Exploration Results, Mineral Resources, and Mineral Reserves are often deficient in adhering to the Code and a conscious effort must be made by the mining sector to improve the standard of public reporting, in particular Competent Person Reports (CPRs) and Public Reports issued by listed mineral exploration and mining companies."

Jan 1, 2015

By R. L. Lawson

I?ve been asked to appraise the global role of coal and mining, and the best place I can think of to begin is with the World watch Institute, which purports to monitor all things global. Last fall the institute?s magazine, entitled World Watch, in a cover story called for a worldwide campaign to outlaw the use of coal before this century?s end. To my mind the article began the campaign. However, the institute had to admit that no such ban will be possible unless there is special help and heavy intervention?that is, novel policies and punitive taxes. I?ll quote directly from the magazine to underscore the point: ?without them the market will continue to deceive us into thinking coal is cheap, abundant and irreplaceable?.

Jan 1, 2001

By C. F. Strydom

Paper written on project work carried out in partial fulfilment of B. Eng (Mining Engineering) degree The Self-directed work team concept is the product of relentless performance pressure on American industries during the late eighties and early nineties from other world industrial leaders like Japan. The concept proved to be a successful vehicle by which the Americans could increase their production and improve their safety statistics. The aim of this study is to evaluate the concept as a means to improve the overall performance on South African goldmines. he study is directed by a historical research section, answering questions like: ?Why do we need to change? ?What is a Self-directed work team? ?What are the principle advantages of the concept? ?What are the essential requirements for the concept to succeed? The study also includes an empirical research section that focuses on the current Self-directed work team situation in the South African gold mining industry. The empirical research section is limited to three case studies within Anglogold due to a study period of only six weeks. The mines chosen for the case studies have been labelled Mine 1, Mine 2 and Mine 3. The latter being the base mine allowing for a more in depth study. This includes a perception analysis towards Self-directed work teams within the mine. The study proves the truth of the Latin proverb ?Tempora mutantur, nos et mutamur in illis? meaning ?The times are changing, and we are changing with them?. The chief change catalysts identified are a dwindling gold price and a projected labour crisis. From the study it is evident that the Self-directed work team concept disposes of the critical parameters required for a dramatic improvement in performance. The study also indicates that for the concept to succeed, certain factors like top-level commitment and management-employee trust have to be in place. Sadly, the concluding part of the study proves that very few of the identified critical success parameters are present in the South African gold mining industry. This can serve to explain why the industry only has success with the concept when monetary gain is the chief motivator. The study only focuses on the reasons why the concept is not performing to its full potential and does not wander into explaining the reasons for the current unsupportive milieu in the industry. Self-directed work teams could well rescue the South Africangold mining industry but currently we are driving a square pin into a round hole! [Terminology SDWT?Self-directed work teams AEL?Adventure Experiential Learning ISW?In-stope worker POLC?Plan, organize, lead and control TEC?Total employee costed Silo?The confinement of departments preventing networking JCI?Johannesburg Consolidated Investment Co. Ltd]

Jan 1, 2002

By J. R. Menasce

Mechanization in low-stope panels situated in hard rock infers roof support by tensile bolting to allow free passage of trackless mining equipment in the production areas. This is in sharp contrast to conventional mining, where compressive roof supports?such as timber and grout packs?have traditionally been used, up to 1.5 metres from the production face. Bolting is a hazardous operation because material is dislodged from the roof during the drilling activity. Even with temporary roof support installed, small pieces of rock are dislodged by the percussive action of the drifter. Operations with the man situated directly under the drill, during the drilling activity, are hazardous. The only way to remove the hazard is to move the man away from the machine for as much as possible throughout the complete cycle Costs associated with safety cannot be quantified, but need to form part of the decision-making process. Machine selections based on purchase and running costs alone do not justify the investment cost of mechanized bolters. The equipment selection process needs to take into account the total cost of mining as well as the human safety impact and loss of production costs from having to re-bolt roofs in a production panel to prevent falls of ground. Labour costs in mechanized low-stope bolting are between one-quarter and half the labour costs of non-mechanized bolting. This paper reviews the mechanized bolting option versus handheld bolting from a mining process and cost perspective in a hard rock, low-stope room-and-pillar mining operation in the platinum and chrome industries.

Jan 1, 2006

The paper reviews the results emanating from an experiment conducted in Bochum?Germany in which various international rope inspection authorities were requested to assess the conditions of a corroded rope sample as well as a rope sample containing internal fatigue breaks. Both samples were of the multi-layer low rotation construction.

Jan 1, 2000

By B. Kenny

The aim of this paper is to provide an overview of existing forms of subcontracting in the South African mining industry. A descriptive framework is developed to understand different subcontracting arrangements. We argue that, in order to do so, it is important to distinguish between labour broking and gang subcontracting. Data resulting from a research project (including an analysis of historical sources, interviews with contractors and focus group interviews with mineworkers) is presented to highlight the implications of changing formations of subcontracting for the South African mining industry in the late 1990s. Apart from the subcontracting of ?traditional? functions, such as shaft sinking, access development, catering and hostel maintenance, contractors are now used in ?core? mining activities. In some instances, whole shafts are ?outsourced? to outside agencies. It is argued that certain of the subcontracting arrangements have serious implications for the ability of the mining industry to improve health and safety standards. Some of the practices can potentially result in conflict between different categories of workers, and, as a result, instability in the industry.

Jan 1, 1999

By S. M. Rupprecht

"SynopsisOver the last decade in South Africa, there has been a significant increase in the number of mining operations, both open pit and underground, which use independent contractors to carry out mining activities. Often mine owners will choose the contractor option without fully understanding the consequences of undertaking this option. Traditionally, contract mining has come at a cost premium of about 15% to 20% compared to an owner mining scenario. However, due to the large number of junior mining companies entering the mining arena in South Africa contract mining rates have increased, with cost premiums as high as 50% being reported. This paper looks at the merits of owner mining versus contract mining and describes under what conditions it may be favourable to select the one option over the other. In addition, the methodology of entering into contract negotiations with the objective of establishing a fair and sustainable relationship is discussed.IntroductionOver the last decade in South Africa, there has been a significant increase in the number of mining operations, both open pit and underground, which use independent contractors to carry out mining activities. Surface mining, for example, may use contractors to conduct drilling and blasting operations or load and haul operations. Underground mining may contract out work such as shaft sinking, mining, support, construction work, cover drilling, sweeping and vampings. Common surface operations such as mineral beneficiation, waste disposal, security, and product transport may also be outsourced to contractors.Many companies have a business model that utilizes contractors for the entire mining cycle, maintaining a small head office to provide direction and control. The difficulty with this option is that often mining companies will choose the contractor option without fully understanding the implications."

Jan 1, 2015