M.Phil. / The study was undertaken at Bosjesspruit, one of the Sasol Collieries, to investigate aspects that contribute to the degradation of coal. Bosjesspruit is penalised with more than nine million rands per year for fine coal that exceeds the set limits. Compliance to quality is the main reason. The cost is directly deducted from the profit. The quality of coal is of importance for the effectiveness of the gasifying process. A feasibility study has indicated that this study is viable. Various factors in the process were studied to identify the system deviations such as: coal bunkers, section and main conveyor belts, geology, production section activities and coal production equipment. A literature study was done and time was spent to become conversant with the coal transport system. The process is described from where the coal is mined, through the handling action up to where it is fed into the Sasol plant gasifiers. Several coal samples of the identified bottleneck areas were taken and analysed. The four main areas that were studied are: Loading actions at East 700 bunker. Incline shaft transfer chute. The horizontal bunker on surface. The South section conveyor chutes. The free-flow technology was researched and developed for an acceptable chute design. The design is now computerised and in use at Sasol Collieries. The current design and its restrictions are compared with the proposed designs to indicate the improvements. A detailed cost analysis was done to determine the expenditures such as: Penalties for fine coal. The cost of adaptability and redesign. - Forecast cost savings after the redesigns are implemented. - Cost to produce coal as well as the income for Bosjesspruit. An economical evaluation indicates that all the suggested solutions are economically justifiable. The results of the study indicate several suggested solutions to overcome the identified bottlenecks. It is further suggested that results of this study are also implemented at the other Sasol mines as well as the mines that are being developed.

Thesis submitted for the degree MAGISTER SCIENTIAE to the Faculty of Science, Department of Geology, University of the Witwatersrand, Johannesburg / The Koperberg Suite intrusion at Jubilee, Namaqualand varies in composition from anorthosite, through mica diorite to pyroxene leucodiorite and pyroxene diorite. Detailed mapping and petrological studies of these rocks indicate that they were sequentially emplaced into the Concordia Granite country rocks, and that each of the rock types represent discrete magmatic events. The sequence of intrusion is from more acidic to more basic. Whole-rock geochemical analyses indicate that these rocks represent cumulates involving variable proportions of plagioclase, orthopyroxene, mica, quartz, oxides and immiscible sulphides. These cumulate phases intruded into the Concordia Granite at the time of peak of metamorphism and deformation in the Okiep Copper District, i.e, about 1030Ma ago, At the time of intrusion, the country rocks were under going partial melting under high grade (granulite facies) metamorphic conditions. and granitic anatects were present in the crust. Hybridisation of basic magma and granitic melts occurred within the shear zones along which the basic magmas ascended. The En content of orthopyroxene in the Koperberg Suite exceeds the An content of plagioclase. This is atypical of basic intrusions and is a consequence of this mixing. Mixing calculations based on the initial 87Sr/86Srratio (Ru) of the Jubilee samples at 1030Ma, imply high levels of assimilation (as much as 80% assimilation in the case of anorthositic rocks) between a granitic component, similar in composition to the Nababeep Gneiss and a mantle-derived basic magma. Sulphide mineralisation was initiated by the assimilation process, which caused the separation of immiscible sulphides from the hybridised magma. Subsequent oxidation of the original sulphide assemblage produced bornite, chalcopyrite and Ti-poor magnetite. / Andrew Chakane 2019

A research report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science in Engineering, 2016 / Spontaneous combustion of coal may occur when coal is mined, stored or transported and is influenced by a combination of intrinsic and /or extrinsic factors. While it is unusual for intact seams to burn in the highwall, the most common occurrence is when surface mines extract seams previously partially mined by underground bord and pillar operations. The aim of the study is to provide a predictive model (matrix) of the spontaneous combustion potential of remnant pillars at Colliery X. A number of different thermal, chemical and petrographic tests (coal factors) will be undertaken to determine their individual and collective impacts on the sponcom predictive model. The primary geology at the mine is conformable with that of the Witbank Coalfield. Battacharyya (1982) described 3 main factors in the spontaneous combustion of coal, mining factor, coal factor and geological factor which have an aggregate effect. Some of the main historical and present theories of sponcom are the pyrite theory, the bacterial theory, the oxidation theory and the humidity theory. It is important to note that no single factor is responsible for spontaneous combustion. The oxidation of coal occurs constantly. The temperature of the coal is a function of the rate of heat generation versus the rate of heat loss. Fires can start at outcrops and move through interconnected workings with heat transfer by conduction (into the overburden) or convection (between panels).The overburden can also insulate the burning coal seam. Geological factors such as depth of overburden, the degree of fracturing, and the nature of the overlying strata vary between coalfields. A coal seam fire or mine fire is the underground smouldering of a coal deposit, often in a coal mine. Such fires have economic, social and ecological impacts In order to extinguish a fire, one of three elements, fuel, oxygen, or energy, must be removed. The components of the fire triangle can be further subdivided into conventional mine control techniques and more or less unconventional or unproven mine fire control techniques. The thermal techniques discussed include the crossing point temperature, thermogravimetric analyses and oxygen absorption. Macerals, the microscopically identifiable organic constituents of coal, are one of the three basic parameters that define coal. The other two parameters are the coal rank and the mineral matter Vitrinite is the principal maceral group of the No.5 seam and inertinite dominates the No.2 and No.4 seams. The results obtained from the 22 drill-core samples and 2 ROM samples were matched to the existing borehole dataset (2296 boreholes) based on similarity of heat value (figure 3.11). A total of 24 test results (thermal, chemical and petrographic) from borehole A and borehole B were thus assigned to the borehole database which has approximately 1500 samples for each seam. By linking the laboratory datasets (borehole A and B) and the existing borehole database used for resource modelling, the sponcom variables could be modelled in a similar way to the coal resources. The overall risk matrix was calculated on a full seam basis by combining 15 variable scores, each variable having a score of 0, 1 or 2 (low-mod-high probability). The overall results from this research produced clear and unambiguous contour plans of different factors effecting sponcom of coal using single variable and combined variable datasets. In conclusion, it appears that the acceptability of a method for determining spontaneous heating characteristics of coal mainly depends upon how closely it predicts the spontaneous heating behaviour in the field conditions / CK2018

Three hybrid moment tensor inversion methods were developed for seismic sources originating from a small source region. These techniques attempt to compensate for various types of systematic error (or noise) that influence seismograms recorded in the underground environment in order to achieve an accurate and robust measure of the seismic moment tensor. The term 'hybrid' was used to distinguish between the relative method proposed by Dahm (1995) and the methods developed in this thesis. The hybrid methods were essentially weighting schemes designed to enhance the accuracy of the computed moment tensors by decreasing the influence of any low quality observations, to damp (or amplify) any signals that have been overestimated (or underestimated) due to local site effects, and to correct for raypath focussing or defocussing that results from inhomogeneities in the rockmass. The weighting or correction applied to a particular observation was derived from the residuals determined when observed data were compared with corresponding theoretical data (for a particular geophone site, sensor orientation and wave phase) and were calculated using a cluster of events rather than a single event. The first and second weighting schemes were indirectly related to the mean and the median of the residuals where the residuals were defined as the ratio of the theoretical to observed data. In the third scheme, the residuals were defined as the difference between the observed and theoretical data and the weights were based on the distance of a data point (measured in standard deviations) from the mean residual. In each of the weighting schemes, the correction was applied iteratively until the standard error of the least-squares solution (normalised to the scalar seismic moment) was a minimum. The schemes were non-linear because new weights were calculated for each iteration. A number of stability tests using synthetic data were carried out to quantify the source resolving capabilities of the hybrid methods under various extreme conditions. The synthetic events were pure double-couple sources having identical fault-plane orientations, and differing only in rake. This similarity in the mechanisms was chosen because the waveforms of tightly grouped events recorded underground often show high degrees of similarity. For each test, the results computed using the three hybrid methods were compared with one another and with those computed using the single event, absolute method and two relative methods (with and without a reference mechanism). In the noise-free situation, it was found that the relative method without reference mechanism showed the highest resolution of mechanisms, provided that the coverage of the focal sphere was not too sparse (> 3 stations). The hybrid method using a median correction was found to be the most robust of all the methods tested in the most extreme case of poor coverage (2 stations) of the focal sphere. When increasing levels of pseudo-random noise were applied to the data, the absolute moment tensor inversion method, the hybrid method using a median correction, and the hybrid method using a weighted mean correction all showed similar robustness and stability in extreme configurations concerning network coverage of the focal sphere and noise level. When increasing levels of systematic noise were added to the data, the hybrid methods using a median correction and weighted mean correction were found to exhibit similar robustness and stability in extreme configurations concerning network coverage of the focal sphere and systematic noise. In all situations investigated, these two hybrid methods outperformed the relative and absolute methods. The hybrid moment tensor inversion methods using a median and weighted mean correction were applied to a cluster of 14 events, having remarkably similar waveforms, recorded at Oryx Gold Mine. For comparative purposes, the absolute method was also applied. The inputs to the inversion methods consisted of the spectral plateaus of both P- and S-waves at frequencies below the comer frequency of the time-integrated displacement traces. The polarities of dominant motion were used as an additional constraint and were determined from cross-correlation of observed with synthetic P- or S-waves. The solutions computed using the hybrid moment tensor inversion using a median correction displayed a distinct improvement after the iterative residual correction procedure was applied. The radiation patterns and faultplane solutions showed a high degree of similarity, and are probably more accurate reflections of reality than those computed using the absolute moment tensor inversion methods. These observations are very encouraging and point towards the method's potential for use as a standard processing tool for mine seismicity. The implications of this work are a better understanding of the focal mechanisms of seismic events induced by mining activities, ultimately leading to improved safety underground.

A research report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Engineering Johannesburg 2017 / The study assesses the drilling, loading and trucking stages of the mining cycle of an iron ore mine situated in the Northern Cape province of South Africa for the period of 1 January to 30 June 2011. The purpose of this study is to investigate the effect of increasing reliability and maintainability of mining equipment in an effort to increase throughput of iron ore. The data processing indicated that both availability and utilisation are contributing to the sub-optimal performance of the mine. Data regarding reliability (MTBF), maintainability (MTTR), planned and unplanned maintenance was analysed, and this provided input for the simulation model. The intention of the simulation model is to simulate scenarios of proposed improvement in MTBF and MTTR through increasing planned maintenance activities. A simulation model provides insight regarding where to invest in interventions. It is determined that the drilling equipment is the problem area. / MT2018

This study explores the potential extension of occupational health and safety to informal small scale miners in South Africa. It was motivated by an understanding of the integral but much neglected relationship between the quality of work and the goals of poverty reduction and economic development. The study recognises that poor working conditions can reduce productivity and that work-related injury or illness is an unaffordable risk for those working without access to adequate social protection. Further, the protection of labour standards, including work health and safety, is an established basic right in those countries where relevant LLO Conventions have been ratified. Conventional occupational health and safety (OHS) regulation operates through formal employment structures and therefore offers limited or no protection to informal workers. In a country where increasing policy attention is being paid at national and local level to the employment and economic growth potential of the informal economy, this study practically explores within one sector - mining - how the institutional positions of both conventional and identified non-conventional OHS stakeholders work to constrain, or provide opportunities for, the extension of health and safety protection to those working informally. The focus on one kaolin and one clay/coal informal small scale mine site within KwaZulu-Natal and the use of in-depth interviews with workers and a range of identified stakeholders enabled a structured qualitative investigation into the health and safety challenges faced by informal miners; the nature of the support provided to small scale mining by the Department of Minerals and Energy (DME); and the institutional processes acting through national, provincial and local structures that do or could influence workers' access to OHS. The threats presented by each mine to worker and public, as well as environmental health and safety were found to be numerous and severe. There was also evidence of a negative impact of poor working conditions on both the health and economic security of the workers. Despite this, the study identified a vacuum of accountability for the labour protection of informal miners. Conventional mining OHS mechanisms are vertically driven, resource intensive and technocratic. They are both inappropriate for and inflexible towards meeting the challenges presented by informal work. In a minority of cases interdependent links between the responsibil ities of non-conventional OHS stakeholders and work health and safety are understood, but the lack of a worker focus, the institutional boundaries within which people work, their limited OHS knowledge, and the major financial and human resource constraints they face, appear to present significant barriers to any actual OHS intervention. Through the research process it became clear that the management and nature of the DME's small scale mining support strategy itself present fundamental barriers to the extension of OHS. The strategy is a product of a narrow conceptual isation of what is needed to achieve formalisation. This, and the lack of genuine worker representation and accountability within it, means that not only does the strategy fail to attend to OHS and a variety of other worker needs, but that the DME continues unchallenged in its neglect of such issues. With an understanding of the real constraints faced by both workers and the range of identified OHS stakeholders, and in view of the future plans to overhaul the existing national OHS framework in South Africa, the study concludes by outlining some practical opportunities and recommendations that could help to break down existing barriers to the OHS protection of informal workers. Conventional OHS mechanisms could be reoriented to take advantage of cheaper, simpler and more appropriate workerled approaches which could potentially achieve substantial improvements for large numbers of informal workers. Realistic opportunities also exist to more firmly secure the participation of promising non-conventional OHS stakeholders including, in this case, formal mining companies and local government. Finally, there are ways to bridge existing deep divides between social and economic institutional responsibilities that currently serve to obscure potential resource sharing and multiplier impact opportunities of working more collaboratively to improve OHS for the benefit of informal workers. / Thesis (M.Dev. Studies)-University of KwaZulu-Natal, Durban, 2006.

Thesis (MScEng (Industrial Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: the potential to serve as a strategic economic driver for the country if a local processing and production industry could be successfully established. According to the US Geological Survey, conducted in January 2009, South Africa has approximately 14% of the world’s reserves in ilmenite and rutile, the two most important titanium-containing minerals, but no metal producing abilities. The only role players, Exxaro and Richards Bay Minerals, have smelting operations and produce an enriched titania slag, but all the slag is exported. The processing steps between titanium-containing minerals and the metal represent a significant portion of the total production costs and this study is chiefly concerned with recommending a more cost-effective alternative for these steps. The existing industrial process is archaic, cost and energy intensive, batch operated with unfavourable economics. A large number of internationally research initiatives are actively trying to address the problem of high production costs by searching for and developing alternative, more costeffective, processes. It was the purpose of this study to provide the decision making authorities with a ranking and evaluation of these alternatives to produce titanium metal. A 2-Phase Filtering System, based on both qualitative and quantitative techniques, was designed to assess, evaluate and formulate a final ranking. This evaluation was followed by a detailed sensitivity analysis of both local and global parameters. A total of 26 process alternatives were selected to be evaluated in this techno-economic evaluation. The complete ranking is given in Table 8.8, and the four leading process alternatives, based on this evaluation and the findings of the sensitivity analysis, are as follows: 1. CardQIT: The Canadian affiliate of Rio Tinto, QIT, developed a high-temperature titanium extraction process based on an electrolysis reaction, where molten titania slag is the cathode. 2. ArmITP: The Armstrong process is a continuous process that produces titanium in a very similar fashion as with the Hunter process, by the reduction of TiCl4 with sodium. TiCl4 vapour is injected into a stream of molten sodium to form titanium powder as the reaction product. 3. Kroll: This process was developed in the 1950s and the reduction step remains very much similar to the original process used by the USBM (United States Bureau of Mines). Two criteria played a big part in the unexpected high ranking of the Kroll process, and that were academic coverage, with almost 60 years of research, and the commercial readiness of an industrial process. 4. FFC: Solid pre-forms are pressed and sintered from pigment grade TiO2, to be directly electrochemically reduced to metallic titanium in a molten electrolyte of CaCl2. For future work, it is recommended that an additional filtering stage, a detailed profitability analysis, be added to the decision model. The top 4 alternatives, as mentioned above, should be used to estimate the cost-reduction potential as well as the capital investment and production costs based on process, industrial and economic engineering fundamentals. / AFRIKAANSE OPSOMMING: Titaan is deur die Suid Afrikaanse regering geidentifiseer as 'n mineraalhulpbron met die potensiaal om te dien as 'n strategiese ekonomiese drywer, indien 'n plaaslike verwerkingen verwaardingsbedryf suksesvol op die been gebring kan word. Volgens die US Geological Survey, wat in Januarie 2009 gedoen is, het Suid Afrika ongeveer 14% van die wêreld se reserwes in ilmeniet en rutiel, die twee belangrikste titaanhoudende minerale. Suid Afrika het egter geen metaal-vervaardigingsaanlegte nie. Die enigste twee rolspelers, Exxaro en Richards Bay Minerals, het smelteraanlegte en vervaardig 'n verrykte titaandioksiedkonsentraat, wat alles uitgevoer word. Die waardetoevoegingsaktiwiteite tussen die titaanhoudende minerale en die metaal verteenwoordig ‘n groot gedeelte van die produksiekoste van titaanmetaal en hierdie studie is hoofsaaklik daarmee gemoeid om ‘n meer koste-effektiewe aanbeveling te maak, m.b.t. dié stappe. Die bestaande bedryfsproses is argaïes, koste- en energieintensief, en is ontwerp as ‘n lot proses met ongunstige ekonomiese eienskappe. 'n Groot aantal internasionale navorsingsinstansies is aktief besig om oplossings te soek vir die probleem van hoë verwerking- en vervaardigingkostes, deur alternatiewe opsies te ondersoek en te ontwikkel. Die doel van hierdie studie was om vir die besluitnemingsgesag 'n rangorde en vergelyking van die alternatiewe opsies om titaniummetaal te vervaardig, te gee. 'n Tweeledige Filter Stelsel, gebaseer op beide kwalitatiewe- en kwantitatiewe tegnieke, is ontwerp om die rangorde te vorm, te bereken en te formuleer. 'n Sensitiwiteitsanalise is gedoen om die besluitnemingsparameters se invloed op die finale rangorde en uitslag te toets. 'n Totaal van 26 prosesse is geidentifiseer en gekies om aan hierdie tegno-ekonomiese evaluasie, te onderwerp. Die volledige rangorde word in Table 8.8 getoon, en die vier leidende prosesalternatiewe, gebaseer op die uitkomste van dié evaluering en die bevindinge van die sensitiwiteitsanaliese, is as volg: 1. CardQIT: Die Kanadese filiaal van Rio Tinto, QIT, het ‘n hoë-temperatuur titaan ontginningsproses ontwikkel, gebaseer op ‘n elektrolitiese reaksie, waarin gesmelte titaandioksiedkonsentraat die katode vorm. 2. ArmITP: Die Armstrong proses is ‘n kontinue opsie wat titaan produseer op ‘n baie soortgelyke wyse as die Hunter proses, deur die reduksie van TiCl4 met natrium, Na. TiCl4 damp word in ‘n gesmelte stroom natrium ingespuit om titaanmetaalpoeier te vorm as die reaksie produk. 3. Kroll: Die proses is ontwikkel in die 1950s en die reduksie stap wat vandag gebruik word is steeds soortgelyk soos die oorspronklike proses, aan gebruik deur die USBM. Veral twee besluitnemingskriteria het ‘n belangrike rol gespeel om tot die onverwagte hoë plasing van die Kroll proses te lei. Eerstens, akademiese dekking en die feit dat omtrent 60 jaar se navorsing in hierdie opsie ingepomp is en tweedens, die kommersiële gereedheid van hierdie prosesalternatief as ‘n volskaalse bedryfsproses. 4. FFC: Gegoe vorms van pigmentgehalte TiO2, word gepers en gesinter om die katodes te vorm wat dan direk elektrochemies gereduseer word tot titaanmetaal in ‘n gesmelte bad van CaCl2, as die elektroliet. Vir toekomstige werk word aanbeveel dat ‘n addisionele filtervlak, ‘n winsgewendheidsanalise, by die besluitnemingsmodel gevoeg word. Die vier prosesalternatiewe, soos hierbo genoem, kan gebruik word en vir elk moet die kostebesparingspotensiaal, die kapitaal insetkoste en die produksiekostes bereken word. Hierdie berekeninge kan gebaseer word op proses-, bedryfs- en ekonomiese ingenieurswese beginsels.

Behind the fortunes in diamonds, the great open mines and the teeming town that was early Kimberley, were African labourers. Diggers seemed scarcely to care about them unless they were "in short supply", and many historians have been interested only in the guns they carried home with them. This study is concerned with these men: where they came from, why and how they came, and their treatment while they worked in Kimberley. The initial inspiration for the study came from the chapter on diamond production in Sheila van der Horst's Native Labour in South Africa, a remarkable contribution to the history of the Diamond Fields. The later studies by G.V. Doxey and more recently by John Smalberger which have expanded on aspects of Van der Horst's work, have led me to delve more deeply into other areas upon which they have not touched. One potentially fruitful line of study which was beyond the scope of this work was an investigation into the degree to which the Griqualand West labour question affected the attempts at South African federation in the 1870's. The main sources for the work have been the Griqualand West archives in the Cape Archives, for the period 1872-1880, and the various Kimberley newspapers. Labour returns were printed monthly in the Griqualand West Government Gazette for most years, till 1880. Cape Blue Books were useful sources for the period after 1880. De Beers Consolidated Mines Ltd. hold very little material relating to the pre-amalgamation period, though the extant minute books of the De Beers and Kimberley Central Diamond Mining Companies provided valuable information. A considerable number of contemporary published works were also consulted but, though most made some reference to African labour, few contained anything worthy of mention.

The skills shortages in mining and mineral sector had existed for a decade and had a widespread effect on South Africa economy. It affects the level of economic productivity and reduces the country’s capacity to develop a knowledge society. This, in turn, affects the country’s functioning in the global economy. Despite the sector’s best efforts, the shortages continue to grow and threaten the delivery of projects and growth plans. Some researchers contend with the view that the persistence of skills shortages in mining and mineral sector is largely due to entrenched attitudes among both the industry and the community. They claim that employers have the means to change the educational profile of the subsectors by appointing recruits with higher levels of schooling. However, owing to the limited number of higher educated people living in the communities surrounding the mining operations and lack of interest in mining of people with higher levels of education, to name but few, employers are perceived to have a habit of employing people with little skills. The current study was aimed at investigating the impact of skills shortage on organisational performance, propensity to leave, competitive advantage and sustainability, from the management perceptive. The main objective of this study was to incorporate and embed previous research findings and theories into a comprehensive hypothetical model. A hypothetical model showed various factors that may influence skills shortage. Four independent variables (working environment, employment conditions, resources and education and training) were identified as variables that may influence skills shortage; and mediating variable (skills shortage) was also identified as a variable that have potential to affect dependent variables (organisational performance, propensity to leave, competitive advantage and sustainability) of gold mining sector. Furthermore, eight hypotheses were developed to test the relationship between independent, mediating and dependent variables. All these variables were clearly defined and operationalized with various items obtained from measuring instruments used in other similar studies. A purposive sample of 343 respondents was drawn from the population. A seven-point Likert scale and structured questionnaire were administered in person to the respondents and of which 300 were usable and subjected further to several statistical analyses. The validity and reliability of the measuring instrument was evaluated using significant effect p< = 0.001 and Pearson’s correlation test (α = 0.05). Data gathered were fed to and analysed by STATISTICA (version 10) and factor analysis and regression analyses were the statistical procedures used to test the significance of the relationships between the various independent and dependent variables. Consequently, working environment, resources and education and training were three independent variables that were identified as having ability to predict propensity to leave, competitive advantage and sustainability. An attempt was made to establish whether various demographic variables have an influence on mediating and dependent variables through the introduction of gender and position in the organisation while conducting an Analysis of Variance and Multiple linear regressions, but they obtained negative values. The conclusion is that demographic variables do not have over mediating and depended variables. The findings of this study states that with conducive working environment, availability of resources, the high levels of education and training, the country could produce skills that would reduce propensity to leave, drive competitive advantage and sustainability, innovation and entrepreneurship, create competitive advantages and boost employment sustainability.

Department of Mining and Environmental Geology / MESMEG