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

No description available.

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.

References appear at the end of each chapter / The importance of gold in the development of South Africa as an industrialised economy cannot be over - emphasised. Towards the end of the 19th century the economy depended almost entirely on the production of gold and diamonds which laid the foundation for a highly - developed national economy. With gold still continuing to play an important role coupled with the recent price increases, a need was felt to investigate the potential effect of higher prices on gold production in South Africa. For reasons set out in the study, it was decided to compare potential out put for five different gold prices. A gold price received by the mines of 050 per ounce was used as abase. Further calculations were made at 060, 070, 0100 and 0150 per ounce. The calculations for all the cases were done duri ng the period when the Rand was floating with the Pound Sterling and a Rand : Dollar parity of 1:1, 2 4 was used. Since then two parity changes occured : the Rand was pegged to the Dollar on the 25th October, 1972 to give a Rand : Dollar parity of 1:1,27732, and the Dollar was devalued on the 13th February, 1973 by 1 1,1 % to give the present Rand : Dollar parity of 1:1, 4192. The e ffect of the above two parity changes is that revenue in Dollar terms is overstated by 14,45 5%. It is suggested that for purposes of this study the Rand figures be accepted and wherever Dollars are used in future estimates these be increased by the afore-mentioned 14, 455%. In Dollar terms the five Cases analised will change as follows: Case A : 5350 becomes 057, 23 per ounce Case B : 260 becomes 068, 67 per ounce Case C : 270 becomes 080,12 per ounce Case D : 0100 becomes 0114 ,46 per ounce Case E : 0150 becomes 0171, 68 per ounce To do an in-depth investigation into the effects of higher gold prices on each individual mine, it was necessary to analyse the various parameters required in the determination of gold p r oduction, revenue, lease and tax payments , and dividends. For each mine the pay limits at the various gold prices and at estimated working cost levels, were determined . Graphs of the estimated tonnages at various pay limits as well as the average grade of ore mineable at these limits were determined. From these graphs it is possible to obtain the total tonnage mi neable at various pay limits. Once the foregoing parameters were obtained for each mine, it was possible to determine annual gold production, revenue, lease and tax payments and amounts available to share holders which are then summarised in tables and illustrated in graphs. For ease of reference the mines were divided up into geographica l areas. Gold production revenue, lease and tax payments to the State and the amounts available to shareholders are summarised and compared for the various gold prices. The summaries show bold production remaining fairly constant at or just below the present level of about 900 000 kilograms per year until 1978 for Case A, 1979 for Cases B and C, 1983 for Case D, and 1984 for Case E. before declining progressively thereafter. Revenue following the same pattern as gold production for Case A , as is to be expected, but increasing to a peak of R1 466 million in 1977 for Case B before progressively declining, increasing to a peak of R2 434 million in 1982 for Case D before progressively declining, increasing to a peak of R3 478 million in 1983 for Case E but remaining above the 1973 level of R1 254 million until the year 2005. Lease and tax payments and amounts available to share-holders following the same pattern as that indicated by revenue reaching peaks of respectively R390 million and R268 million for Case B R485 million and R339 million for Case C R756 million and R536 million for Case D R1 000 million and R779 million for Case E. Following the recent monetary unrest, gold prices assumed for 1973 are too conservative. Should the present gold price of about $80 and the 1972 level of production of 909 000 kilograms continue for the remainder of 1973, then gold production, revenue, lease and tax payments and dividends as shown for Case C for the year 1975 will be applicable for 1973. This shams gold production of 919 520 kilograms, gold revenue of R 1690 million, lease and tax payments of R465 million, and dividends of R339 million. The effect of the higher gold price can be clearly seen when the fore-going figures are compared with the 1971 totals of gold production of 97 6,600 kilogr ams , revenue of R396 million from gold, lease and tax payments of approximately R139 million, and dividends of R142 million . Despite a decline in gold production, revenue is expected to be up by 8 9 % whilst lease and tax payments increase by 2 35% compared with a dividend increase of 139%. Finally certain tax concessions to increase productivity and the rebuy alleviate the labour shortage, prolong the li ves of the mines by mining lower grade ore, and encourage exploration was investigated and suggestions made. / Business Management / D. Com.