The current weak state of the platinum market, as well as the large inventory of platinum group metals held by Russia, necessitates that the South African platinum mining industry must carefully evaluate the benefits and disadvantage of small-scale mining of shallow, open castable ore resources. Until the late 1980's, these resources were ignored due to the metallurgical complexities of treating oxidized ore, as well as the mind set that existed within the South African mining industry which militated against open cast mining in the Bushveld. During the latter part of the 1980's and early 1990's, advances in the metallurgical treatment of oxidized ore, specifically the UG2, as well as operational problems, created the impetus to begin the exploitation of these resources. Small-scale open cast mining has become viable due to the development of suitable mining methods that facilitate mining practices acceptable to the Department of Mineral and Energy Affairs, in terms of environmental legislation. Metallurgical advances and growing experience, especially with respect to the UG2, enables reasonable platinum group metals recovery from oxidized ore. The problems experienced in doing this can, and are being overcome. With growing public awareness of environmental issues, particularly related to the mining industry, the requirement to ensure that the small-scale open cast mine site is well managed is paramount. A methodology for the evaluation is presented along with a case study of a small-scale UG2 open cast pit. Evidence is presented that shows that these small-scale open cast mining operations are extremely profitable and require minimal capital expenditure. However, caution is advised when evaluating Merensky Reef open cast operations because of the problems that they present.

M.B.A. / The South African economy places great reliance on the gold mining sector, both for employment opportunities and revenue. Due to the increased price volatility of this precious metal in international markets, the economy has been placed under enormous pressure due to the loss of jobs and lower revenues generated, particularly from the country's marginal mines. Through discussions with representatives from the various facets of the mining industry, it has been noted that a large portion of the prospective and existing gold reserves are not being mined. This may be due to the high capital investment required to start-up such an operation and the resultant dividends are not appealing enough to attract the investment. Unrest amongst unionised labour has reduced productivity in the work force and this has further increased the cost of production, placing many South African gold mines in the "red". Historically, gold mines owned all of their own equipment and bore all of the risk. For all this investment, they took all of the profit, or loss from the operation, but this increased cost of capital and risk does not bring along an increased return on investment due to the volatility in both the gold price and the currency exchange rate. The aim of the research report is to establish a framework for conducting a technoeconomic due diligence in identifying a viable alternative to the traditional methods of mining gold in South Africa. The objectives of this dissertation are: To determine the viability of conducting an alternative approach to mining gold in South Africa; To determine if the proposed alternative approach would tolerate a lower gold selling price than the present methods and still remain profitable; To determine the barriers to entry and the pitfalls of mining gold in South Africa.

M.Phil. ( Energy Studies) / Please refer to full text to view abstract

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Submitted to: School of Mining Engineering, Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, South Africa September 2015 / Most coal seams in the Waterberg Coalfield contain medium to high levels of phosphorus in coal. Thermal coal, which has a lower value than metallurgical coal, is produced from these coal seams. Metallurgical coal used as feed for char production has especially stringent phosphorous content specifications. Phosphorous levels vary both laterally and vertically through the coal succession of the Vryheid Formation. If the coal horizons with elevated phosphorus could be identified and selectively removed, significant amounts coal could be saved and utilized as metallurgical coal through the life of the mine. Different mining horizons with regards to their phosphorus content have to be determined to increase the amount of char plant feed coal. Bench definitions and their techno-economic applications are therefore the main purpose of the current investigation. Bench 11 is currently the only source utilized for char plant feed coal. The char plant is therefore entirely dependent on coal supply from Bench 11. This poses a risk on the continual production of char at Grootegeluk Mine. It was determined that this bench is not suitable for char plant feed coal in certain areas of the resource. A high phosphorus coal horizon was identified in the upper portion of the bench. If this coal is removed separately, the phosphorus content of the coal in the remaining portion of the bench would be suitable for char plant feed coal. This alternative step is dependent on the phosphorus distribution in the resource and may therefore not always be effective. No changes to the other bench definitions could be established that would increase the amount of potential char plant feed coal. Three further aspects were investigated: The potential to reduce phosphorus in coal by means of coal beneficiation was determined. Results showed that phosphorus levels in coal cannot be lowered sufficiently by means of coal beneficiation. Secondly, the suitability of using different coal analyses to improve the estimation of phosphorus in coal was investigated. Results showed that phosphorus prediction and analyses cannot be enhanced nor replaced by other coal analyses. Lastly, the importance of Zone 1 as a source of low phosphorous coal was investigated. Zone 1 is currently not part of the mine plan, but if mined, it could be used as a source for blending; thereby increasing the amount of char plant feed coal from the reserves. In certain portions of the resource, utilizing Zone 1 may be the only feasible way of securing the continual supply of low phosphorus content coal. Analytical exploration borehole data of phosphorus in coal is limited in certain areas of the resource. Due to the variability of phosphorus in the coal horizons, more borehole data is required to increase the estimation accuracy of phosphorus in the coal. Based on such data, mining horizons might be changed in future to secure more char plant feed coal.

Dense media separation (DMS) plays an integral part in coal processing as well as in the upgrade of low grade ore bodies prior to further processing like flotation and leaching. Various separating vessels are used in DMS; of which the dense media (DM) cyclone is the most common. However, the limited materials of construction available for DM cyclones leave the industry with little choice. In addition, the DM cyclones available moved away from the basic principles of classification hydrocyclones which is to reduce the turbulence in the feed chamber in order to achieve improved efficiency. The ceramic tiled DM cyclones available in the market have ceramic tiles installed perpendicular to each other in the feed chamber, which increase the turbulence in the feed chamber at the expense of longer equipment life. For that reason, a research project was initiated to establish the current installed base of DM cyclones in Southern Africa and to develop and evaluate a DM cyclone with a laminar spiral feed chamber design to reduce the turbulence when feeding the cyclone, whilst achieving the same or superior wear properties. Because Cavex is well proven in hard rock mining and coal classification, it was used as basis for the development of a DM cyclone. Individual moulds were developed and produced in order to fabricate a Cavex DM cyclone with the exact laminar spiral feed chamber that exists when moulded out of rubber. Afterwards, the Cavex ceramic tiled (CVXT) cyclone was manufactured, installed and commissioned. Using the basic operating principles of hydrocyclones, the predicted results were achieved. The 650CVXT results confirmed that a DM cyclone and a classification cyclone are inherently the same piece of equipment; it is the selection criteria and material of construction that differ. There is a definite benefit in focussing on metallurgical efficiency in conjunction with wear properties, rather than equipment life (wear life) as the only parameter during equipment fabrication. A simple way to achieve improved performance is to reduce the turbulence in the feed chamber. Further work must include the evaluation of the Cavex CVXT DM cyclone in near gravity coal circuits and to investigate whether the same lower operating pressures (6D compared to conventional 9D) will result in improved coal yield, as was illustrated successfully in the separation of fluorspar by DMS, whilst achieving the desired ash contents. The work must include detailed studies on the effect of feed pressure vs. yield/recovery, when the turbulence the feed chamber is reduced. Overall energy savings should be quantified by reducing the cyclone feed pressure.

M.Sc. (Geology) / The study aims to provide a geometallurgical assessment, including an evaluation of the response of different facies types of the Merensky Reef to mineral processing, and the identification of critical characteristics that determine processing behaviour. This is accomplished by obtaining quantitative mineralogical information, combined with chemical assay, laboratory scale milling and flotation testing. Lonmin Platinum’s Marikana Mine is located on the Western Limb of the Bushveld Complex to the east of Rustenburg. Platinum group elements (PGE) occur in, and are mined from, a variety of facies types of the Merensky Reef, and the UG2. For the purpose of the present study, three facies types of Merensky Reef samples and one sample of UG2 were used. The Merensky facies samples comprise of the BK, RPM, and Western Platinum variants. The mineral assemblages of the various Merensky Reef facies types at this locality comprise varying amounts of orthopyroxene, clinopyroxene, plagioclase, olivine, talc, serpentine, chlorite, chromite, magnetite and sulphides (mainly pyrrhotite, pentlandite and chalcopyrite). Approximately 20 individual 10 cm channel samples were collected from each of the facies variants of the Merensky Reef, and the UG2. These are coarsely crushed, mineral modal abundances determined using the MLA, and then analysed for Co, Cr, Cu, Ni, S and 6 PGE. The samples were then combined per facies type, and each of these composites subjected to laboratory scale milling and flotation testing. Abundant sulphide typically occurs with (is associated with) thin chromitite stringers, as is commonly observed in the Merensky Reef throughout the whole of the Bushveld Complex. Chromitite stringers are characterized by high PGE concentrations. The milling behaviour of the various facies samples, as well as flotation behaviour, was observed to be a function of mineralogy. The influence of ore mineralogy on the various stages of flotation, the mineralogical makeup of the various flotation concentrates, and the level of recovery of the PGE’s during flotation, were also investigated. Ore facies having the most abundant anorthite required the longest milling time to achieve the target grind of 60wt.% passing 75μm; and the ore with the most abundant enstatite produced the largest mass pull on floating. The facies with higher PGE grade, modal abundance of base metal sulphides, higher degree of liberation of base metal sulphides and least enstatite abundance produced the most favourable set of characteristics for efficient PGE recovery.

This research focuses on three elements i.e. employment equity, employee engagement and generation theory and specifically where these elements intersect. The literature found that there were different perceptions of employment equity legislation. In addition, the literature found generational differences with respect to some elements of employee engagement. Limited empirical evidence was found on whether employment equity legislation had an impact on employee engagement. Consequently, three research questions were drawn from the literature reviewed. The research is a quantitative study based on a sample drawn from South African individuals who have completed grade 12 and are currently employed or have an employment history. The sample included employees of a financial services company based in Gauteng and GIBS MBA students. The results showed that there were differing perceptions of employment equity legislation and that the majority of respondents perceived the legislation to be affirmative action. There were no differences in the perception of employment equity legislation between generations. Additional findings were that the perception of employment equity legislation did not enhance employee engagement neither did the perception of the organisations implementation of employment equity legislation enhance employee engagement. Limited generational differences were found in terms of these findings. / Dissertation (MBA)--University of Pretoria, 2014. / zkgibs2015 / Gordon Institute of Business Science (GIBS) / MBA / Unrestricted

A thesis submitted to the Faculty of Engineering, University of the Witwatersrand, Johannesburg, in fulfilrMnt of the requirements for the degreel of Doctor of Philosophy. / This thesis has investigated ways of exerting control over coal breaking during blasting. Its ultimate objective has been to optimise the use of explosive energy in blasting so as to ensure reduced production of coal fines in the comminution process. The investigations reported were conducted on laboratory models at a scale of a controllable energy to enable the development of a theoretical background for the thesis, However, the bulk of the work was undertaken insitu in surface and underground coal operations. The research was conducted in three phases. The first phase dealt with the approach to modelling the primary crushing mechanism which generates the coal fines during the blasting operation. A laboratory apparatus to simulate blast-generated dynamic loading was devised. Dynamic coal crushing test conducted on a set of over 150 samples of coal showed an exponential relationship; between the comminution energy and the subsequent coal damage. A comminution index (Com ) characterising the ability of coal to generate fines was derived. The second phase of the research concerned the field investigations. This had the following double aim: validating the hypothesis of the influence of the dynamic loading of the shock waves and that of the inherent discontinuities imbedded in coal on fines generation; and quantifying the problem of fines in the blasting techniques currently used in the local mining industry. Three sites were used, namely Kleinkopje of AMCOAL, Greenside of Goldfields and ATC, Tavistock of JCI. The investigations undertaken at Kleinkopje (surface mining operation) involved the determination of discontinuities by logging inherent fractures appearing on 75 diamond drilled cores of coal and the monitoring of 76 blasts conducted on the sites sampled for discontinuities. These investigations indicated a good correlation between the fines observed in blasted piles and the fracture frequency of the pre" existing fractures per metre of coal. The work undertaken in underground collieries (Greenside and Tavistock) demonstrated the enormity of the fines' problem in the local mining operations. Approximately a third of the coal broken underground was observed, in 30 blasts sampled and analysed, to fall into the category of fragments of under 6 mm termed 'coal fines', Which generate low income. The third phase of the research dealt with the optimisation of coal breaking during blasting. A series of 100 trial blasts was undertaken with the aim of searching for a blasting technique that enables the generation of fewer coal fines. A number of options were investigated. Trial blasts carried out were evaluated and their results are discussed in this thesis. The results of the fieldwork undertaken confirmed that fines generation is site speolflc, However, the decoupling technique used with high VOD explosive products may be successfully employed to reduced coal fines generation in strong coals (few inherent fractures). / Andrew Chakane 2018

M.Phil. (Mineral Economics) / This work is an attempt to discover whether or not South Africa's gold reserves have been properly exploited - has the wealth that has been removed been used to the best advantage. It became apparent to the author whilst conducting feasibility studies on both projected and operating mines that scant attention is paid to the determination of an optimal time path of depletion for a mineral deposit by the planners. The main, if not sole, criterion is the maximising of returns on the capital invested. The thesis proposes a methodology to describe the actual depletion paths achieved by a selection of South African gold mines. The work of mineral economists, especially Harold Hotelling, is used to provide a theoretical base for the. proposals. The mines were selected to cover as wide a range of the exploitation cycle as possible from the planning stage to final abandonment.