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By A. Peake

Background The CSIR Division of Mining Technology assumed responsibility for the operations of the Hoist Rope and Mechanical Test Laboratories at Cottesloe in April 1999. The laboratories were previously the responsibility of the CSIR’s Division of Manufacturing and Materials Technology, before which they fell under the National Mechanical Engineering Research Institute (also of CSIR). As the focus of this conference is on safety in mines research institutes, it was thought appropriate that this paper should review some of the activities at Cottesloe and its role in supporting mine safety strategies.

Jan 1, 2003

By Sylvie Poirier

Researchers at Natural Resources Canada (NRCan) CANMET Mining and Mineral Sciences Laboratories (CANMET-MMSL) and Mining Technologies International (MTI) have designed and built a hybrid diesel-electric mining loader that is the first of its kind to be developed for underground mines. Diesel equipment is popular because of its mobility and most mining operations are reluctant to replace it with tethered electrical equipment despite the obvious elimination of diesel contaminants and significantly lower heat generation (? 35% of an equivalent diesel). However, a diesel-electric vehicle, being currently evaluated by CANMET-MMSL, could be beneficial. In this unit, a constant load diesel generator feeds batteries which, in turn, powers electrical motors that drive the equipment. In a hybrid diesel-electric unit, the constant load diesel generator can be optimized for minimal emissions and hence lower dilution air requirements. This paper will present the project status and the anticipated benefits for mining operations through the application of this technology.

Jan 1, 2008

By X. B. Zhao, J. G. Cai

When stress wave propagates through fractured rock masses, the wave will be slowed and attenuated due to the presence of these fractures. If the amplitude of stress wave is large enough to mobilize nonlinear deformation of these fractures, they will present different effects on one-dimensional P-wave propagation compared with those of linear deformational fractures. The static BB model is adopted to describe the nonlinear deformational behavior. Method of characteristics combined with displacement discontinuity theory is used to build analytical solutions of wave particle velocities and wave stresses. These equations are numerically solved with sufficient accuracy.

Jan 1, 2003

By S. L. Bell

Most Australian longwall coal mines are currently working coal faces up to nine kilometres from the surface. In the event of a mine emergency walking this sort of distance wearing breathing apparatus becomes very difficult if not impossible. Self-rescue continues to remain the focus of mines rescue in Australian coal mines and this paper describes a vehicle modification which will improve the chances of a miner rescuing himself. Existing mine personnel transport vehicles are not designed to operate in some types of atmospheres that may be present following a mine fire or explosion event. An Australian Coal Association Research program (ACARP) funded research project recently completed in Australia has developed a specification for a vehicle that is able to operate safely in some types of post emergency atmospheres. During the course of this investigation, diesel and electric vehicles were examined prior to making a final decision on vehicle suitability. Based on the fact that there are already some 1500 diesel vehicles in use in underground coal mines in Australia it was decided that modifications to existing diesel engines would be the best option. This presentation will outline the proposed specification for the vehicle and the reasons behind the decisions that were made with respect to the specification.

Jan 1, 2003

By J. -C. Tricket, W. A. Düweke, S. Kock

The high-resolution three-dimensional (3-D) seismic reflection data acquired for Impala Platinum between 1998 and 2002 in the western Bushveld Igneous Complex form an integral part of Impala?s mine planning and development programme. These data are of sufficiently high quality to provide unprecedented 3-D models of the geological structure of the Merensky Reef and UG2Chromitite Reef, from which the mine deduces the size, geometry and distribution of mineable blocks. Conversely, the seismic data details zones of un-mineable ground caused by structural disturbances in the form of potholes, fault zones and pegmatoid intrusions. Furthermore, variations in dip and strike are well imaged, allowing the mine planners to optimize the mine design and layout. Current interpretation work is focused on enhancing the accuracy of these geological model seven further through the analysis of ?seismic trace attributes.? Preliminary testing on the Impala Platinum 3-D seismic volume has shown that attribute analysis has the potential to illuminate a number of geological reef disturbances that are otherwise ?invisible? in the original seismic time volume. Potential areas of improvement include inter alia: ?Improved definition of major fault zones ?Improved definition of zones of reef depression (?slumping?) ?Identification of reef terracing and/or reverse dip.. Keywords: 3D reflection seismics; Impala Platinum Ltd; seismic attribute analysis; Seismic Micro Technology (SMT); rock solid attributes; dip-azimuth; instantaneous phase and similarity.

Jan 1, 2004

By W. Zhu

ABSTRACT: This paper presents further developments of the principle of Construction Process Mechanics of rockmasses, The principle of loading variations analyses in space-time is systematically described. To demonstrate the applicability of the theory and method, the effect of the construction process of two practical engineering cases are analysed. ZUSAMMENFASSUNG: Das Mechaniksprinzip vom Konstruktionsprozess des Massenfels wird in diesem Aufsatz weiter Entwickelt.. Das Prinzip von Variationsladungsanalyse mit dem Zeit-Raumseffekt wird systematisch erklaert. Um die Anwendungsmoeglichkeit der Theorie und der Methode zu anschaulich darstellen, das Mechanikseffekt des Konstruktionsprozess wird fuer zwei praktische Anwendungsbeispielen zergliedert. : RESUME: Dans ce papier le development se fait pour principles de la mechanique de process de construction . Le principle de variable analyse considerant effet de temps et de Space est present ´e . Pour demonstrer l´appilicabilite de le theorie et la methode , l´èffect de processe de construction pour ce deax examples sont analysés .

Jan 1, 2003

By D. Botha, J. F. Cronjé

"SynopsisAlthough women all over the world have been involved in mining activities for centuries, mining has always been considered a very masculine industry due to its heavily male-dominated workforce as well as the physicality of mining work. The mining industry has not been an obvious career choice and preferred place of employment for women; women were mainly employed in administrative and advisory positions. Until 1994, women were legislatively prohibited from being employed in underground operations in South Africa, but the Mines Health and Safety Act, No. 29 of 1996, removed these restrictions. In addition, new mining legislation (the Mineral and Petroleum Resources Development Act, No. 28 of 2002) and the accompanying Mining Charter make specific provisions for the inclusion of women in core mining activities and require 10% of core positions to be filled by women.This article voices perceptions of the physical ability of women employed in core mining positions. Findings are drawn from empirical work undertaken at platinum, phosphate, and copper mines. Quantitative and qualitative research paradigms are used. It is evident that women find it extremely difficult to perform mine work that requires physical strength and stamina. Practical recommendations, informed by the literature review and empirical findings, are made with the objective of contributing to the sustainable deployment of women in the mining industry.IntroductionFor many years, mining has been considered the foundation of the South African economy. Although the mining industry in South Africa is currently under considerable pressure and experiences various challenges, including escalating operational costs, electricity tariff increases, safety-related issues and associated production stoppages, poor productivity, labour unrest, and reduced demand both globally and domestically, it remains a key contributor to the national economy and development of the country (IDC, 2013, p. 9).Until 1994, women were legislatively prohibited from meaningful participation in the mining industry and were denied access to skills and jobs, self-employment, and entrepreneurship. The newly elected democratic government in 1994 initiated substantial socio-political and economic transformation in South Africa. Nearly every sector in the country was transformed and re-shaped, primarily through sector-specific legislation, but also through negotiations between government, industry, and labour unions to create and refine the so-called sector charters, which included the Mining Charter. The vision of the new regime, the African National Congress (ANC), was to ‘transfer power to the people and transform society into a non-racial, non-sexist, united, democratic one, and change the manner in which wealth is shared, in order to benefit all the people’ (ANC, 2007)."

Jan 1, 2015

By F. Crundwell, A. J. Lathwood

A number of base-metal operations would like to increase production to take advantage of the higher metals prices. In general, this higher production should not be achieved with major operating changes. In hydrometallurgical facilities, leaching and pressure leaching represents one area where upfront limitations may be a bottleneck to the capacity of the entire plant. An assessment of the capacity of the leaching tanks and autoclaves was performed using a predictive model within the AweSym flowsheet simulator. The model is described, and the results of the application of the model to a number of different leaching reactors are presented. It is argued that the leaching number, which relates the residence time, particle size and the leaching rate, is of prime importance. Finally it is shown that there are some unexpected catastrophic events in increasing production capacity without a thorough understanding of the leaching operation.

Jan 1, 2007

By M. Wong-Kian, L. A. Cornish, A. van Bennekom

Samples of four different satellite materials were prepared by either hot isostatic pressing (HIP) of the powder or tungsten inert-gas welding of rod onto a 316 L stainless-steel substrate. The samples were subjected to a series of comparative erosion corrosion tests, and generally the Hipped samples experienced between 13 and 24 per cent less loss in mass than the equivalent welded alloys. Resistance to erosion corrosion increased with increasing carbon, chromium, and tungsten contents. Metallographic studies indicated the differences in carbide content between the different satellite materials, and the differences in morphology between the Hipped and welded samples. Finer and more homogeneous microstructures were

Jan 1, 1995

By W. V. Mutler

Present day capital costs are analyzed for a 2,000 metric tonne per day (MTPD) pyrite burning plant and compared with a sulphur burning plant of the same capacity. Power, raw material and steam production rates are then compared for the two facility types. A sensitivity analysis is conducted to highlight the impact changing sulphur, pyrite, capital and operating costs have on the relative economics of these feeds. Technological improvement effects on capital cost and energy recovery are also discussed. Besides the steam produced from the burning of pure sulphur or pyrite, plants using an advanced form of heat recovery can produce up to 10 bar steam using heat from acid formation. The quantity depends on the overall water balance which is influenced by such factors as gas strength and product acid concentration. Modern materials and innovative process design also improve the ability to increase the high pressure steam from the roaster boiler in pyrite plants above the traditional 1.25 kg of superheated steam per kg of acid produced.

Jan 1, 2009

By P. Sun

Abstract: From the viewpoint of interaction mechanics of solid and gas, a coupled mathematical model is presented for coal/rock mass deformation and gas leak flow in parallel deformable coal seams. Numerical simulations for the prediction of the safety range of mining of protection layer are performed with experimental data from a mine with potential danger of coal/gas outbursts. Analyses show that the numerical simulation results are consistent with the measured data on the spot. Therefore, the coupled model shows a positive future for applications in a wide range. ZUSAMMENFASSUNG:Von der Veranschaulichung der Abhängigkeit Mechaniker für Körper und Gas, wird ein verbundenes mathematisches Modell für festen coal/rock Deformation und Gasleckstelle Fluß in parallele deformable Kohlenähte dargestellt. Numerische Simulationen für die Vorhersage der Sicherheit Strecke, die Schutzschichtbergbau verwendet, werden mit experimentellen Daten von einer Grube mit möglicher Gefahr der coal/gas Ausbrüche durchgeführt. Analysen zeigen, daß die numerischen Simulation Resultate mit den gemessenen Daten bezüglich des Punktes gleichbleibend sind. Folglich zeigt das verbundene Modell eine positive Zukunft für Anwendungen in einer breiten Strecke. RÉSUMÉ: Du point de vue de la mécanique d'interaction pour le solide et le gaz, un modèle mathématique couplé est présenté pour l'écoulement plein de déformation de coal/rock et de fuite de gaz dans les filons houillers deformable parallèles. Des simulations numériques pour la prévision de la gamme de sûreté employant l'exploitation de couche de protection sont effectuées avec des données expérimentales d'une mine avec le danger potentiel des accès de coal/gas. Les analyses prouvent que les résultats numériques de simulation sont conformés aux données mesurées sur place. Par conséquent, le modèle couplé montre un futur positif pour des applications dans un éventail.

Jan 1, 2003

By M. G. Wimberger

The Merensky Reef zone, as developed on Impala Platinum?s Rustenburg Operations, displays a gradational mineralized zone, with grades decreasing from the Merensky Pegmatoid Unit into the footwall and hanging wall. A system of identifying a manageable method of defining the mining cut is introduced, termed the grade profile attenuation cut-off grade. Although horizontal grade selectivity is not applied in the mining of the Merensky Reef zone, low extraction of the orebody, due to manageable and non-manageable factors, can contribute to a reduction in revenue, even losses, due to fixed cost contributions in the mining and beneficiation of the ore. A model is proposed that integrates all variables affecting the revenue of the mining operation, including the grade profile attenuation cut-off grade, the extraction factors, commodity prices and exchange rates, utilizing numerical simulation techniques in a PC-based environment. A breakeven extraction factor for a specific cut-off grade is delivered for a range of market conditions. The breakeven extraction factor is a useful guide when designing mining layouts in structurally complex and low metal content areas. Incorporating distribution functions for individual commodity prices and exchange rates into the model provides mineral resource managers with a risk profile for individual mining areas. Shaft areas have varying grade profiles and each area should have individual models run, to prevent generalizations being made about acceptable risk levels on mining areas.

Jan 1, 2004

By S. J. Thomas, P. A. Lilly, J. A. L. Napier

An industry research project has been established to examine the issue of rock mass failure in large open pit slopes. The approach began with numerically modelling failure at the laboratory scale with a displacement discontinuity program. The interim results from the program suggest the output failure mode is dependent upon the input parameter cohesion weakening. Es wurde ein Forschungsproject mit unterstützung von Bergbauindustrie bearbeitet. Die Zielsetzung der vorliegenden Arbeit war die Analysierung des Böschungsgefähr im größen Festgesteinstagebauen. Das Verfahren besteht aus der numerischer Modelierung mit Ansatz einen sonderen Rechnerprogram. Die erste Ergebnis zeigt, daß die Aufgabe am Angabendaten (cohesion) abhängig sein wird. Un project de recherche industriel fût conduit avec le but d’examiner les éboulements de roche dans les mines a ciel ouvert. La premiere étape a été de modelliser numériquement les éboulements dans un laboratoire en utilisant un programme de déplacement discontinu. Les resultants préliminaires du programme indiquent que la prédiction des ébouliements est directement reliée à la magnitude de la cohesion.

Jan 1, 2003

By W. V. Mutler

Present day capital costs are analyzed for a 2,000 metric tonne per day (MTPD) pyrite burning plant and compared with a sulphur burning plant of the same capacity. Power, raw material and steam production rates are then compared for the two facility types. A sensitivity analysis is conducted to highlight the impact changing sulphur, pyrite, capital and operating costs have on the relative economics of these feeds. Technological improvement effects on capital cost and energy recovery are also discussed. Besides the steam produced from the burning of pure sulphur or pyrite, plants using an advanced form of heat recovery can produce up to 10 bar steam using heat from acid formation. The quantity depends on the overall water balance which is influenced by such factors as gas strength and product acid concentration. Modern materials and innovative process design also improve the ability to increase the high pressure steam from the roaster boiler in pyrite plants above the traditional 1.25 kg of superheated steam per kg of acid produced.

Jan 1, 2009

By D. Nyembe, B. Mamba, Antoine F. Mulaba-Bafubiandi

Copper and cobalt are generally electro-won from their aqueous sulphate solutions. After optimised leaching of their ores, concentrates or calcine bearing minerals, the leachate is clarified and suitably purified prior to the electrolytic extraction of the metal of pursuit (Pearcy, 2006). Solvent extraction (SX) using appropriate organic solvents and ion exchange (IX) with relevant resins are known purification processes used for copper and cobalt recovery (Stanely, 1970).As zeolites in general and natural zeolites in particular, demonstrate ion exchange properties (Korkuna et al., 2005), an attempt has been made to use Southern African natural clinoptilolite in the recovery of copper and cobalt from their aqueous sulphate solutions. Initially, synthetic Co and Cu solutions were prepared. Preceded by laboratory ore leachate, plant solutions are to be used. AAS, XRF, XRD, Mossbauer spectroscopy and BET were characterization techniques used. Natural clinoptilolite was used as-received as well as acid activated; and cobalt and copper extractions were performed at room temperature.

Jan 1, 2007

By B. R. Broekman, D. W. Penman

Discussion by P.J Lloydt Broekman and Penman describe (J.S. Afr. Inst. Min. Metal., vol. 91, Aug. 1991, p. 261) the addition of sodium cyanide and zinc sulphate to the flotation feed at Prieska. They note that for 'safety sake, lime was added to the rod mil to raise the pH to 9,5', and that 'personnel working in the vicinity of the rod mil were required to wear gas masks'. Author reply to P.J. Lloyd We thank Dr Lloyd for his interesting contribution. As he correctly points out, the Prieska float had run with cyanide solutions at pH values of 6,4. In fact, it ran safely for extended period with the pH slightly below 6.

Jan 1, 1991

By B. Dias, P. C. Schutte

Work-related musculoskeletal disorders (WMSDs) affect the wellbeing of workers and result in poor quality work, lower work performance and decreased motivation. In contrast to ‘occupational’ diseases where there is a direct cause-and-effect relationship between hazard and disease (e.g., asbestos and asbestosis, lead and lead poisoning), ‘work-related’ diseases are multifactorial, where the work environment and the type of work that is performed contribute significantly to musculoskeletal disorders. WMSD is the term used to describe disorders and diseases of the musculoskeletal system (i.e. muscles, joints, ligaments, tendons and nerves). WMSDs are by definition a work-related phenomenon. The literature shows inarguably that certain jobs and certain work-related factors are associated with a significant risk of contracting a WMSD. It is assumed that repeated movements and postures, static work, continuous loading of the tissue structures or lack of recovery time, trigger or cause a pathological process that then manifests itself as a WMSD. This paper looks at the prevalence of the WMSD condition at three mines in South Africa: a coal, a gold and a platinum mine. Predisposing factors that include work factors, presentation of symptoms and psychological factors will be discussed in the paper.

Jan 1, 2003

By A. R. Leach

Anomalous mining conditions can be described where the level of hazard is increased relative to normal conditions within a mining area. Normal conditions would be those defined as a Ground Control District in a mine’s code of practice, and for which mine standard support layouts are generally developed. It has been found that up to 80% of fall of ground accidents occur where anomalous mining conditions exists, typically in the vicinity of geological weaknesses. These areas require specific attention to ensure they are readily anticipated and identified and that appropriate strategies are used to reduce the hazards associated with them. As part of SIMRAC project GAP 607 checklists to aid identification and best practice mining methods were identified for a range of geotechnically anomalous conditions.

Jan 1, 2003

Most processing plants use automatic samplers to extract ore aliquots along a producing shift. These aliquots are combined into a sample normally sent to lab analysis. The sampler used in the extraction of an aliquot from a continuous flow of ore, i.e. a belt conveyor is required to be both precise and accurate. Surprisingly, not all commercial automatic samplers exhibit these two mandatory properties. Consequently, it is recommended the development of a procedure able to check sample assays reproducibility obtained using a given sampling protocol. This paper uses the Gy’s sampling theory to evaluate coal quality control practices at a washing plant using an automatic sampler extracting coal increments from the ROM feeding belt conveyor. Gy’s theory provides the means to establish the precision limits for a given sampling protocol. Various ore properties are required to be determined in combination with sample mass and mass of the lot sampled. All this information leads to the definition of the precision limit. The precision limit obtained was checked via an experiment mimicking what happens in situations where both miner and consumer use the same and appropriate sampling practices. The experiment demonstrates that sampling theory precision limits were valid if unbiased samplers are used by both parties, i.e. miner and consumer. Keywords: sampling, quality control, coal

Jan 1, 2003

Bateman Engineering managed the establishment of a second diamond treatment plant at the Letseng Mine in the Mokhotlong District of northern Lesotho, about 100 km from the town of Buthe Buthe. Letseng Diamonds Proprietary Limited, is owned 70 % by Gem Diamonds and 30 % by the Government of the Kingdom of Lesotho. The second plant, which commenced construction in late 2006, doubled Letseng Mines' hard rock processing capacity from 2.6 million t/yr to 5.2 million t/yr, making it the worlds' seventh largest diamond mine by throughput. Bateman Engineering provided the engineering design, procurement and construction management of the new plant.

Jan 1, 2010