In general, as the uniaxial compressive strength of rock samples is tested, the uniaxial strength of the rock decreases with increasing sample size until a strength is reached beyond which no further decrease in strength is observed for further increases in size. The size at which this occurs was termed the critical size by Bieniawski (1968) and the corresponding strength the critical strength. Once these values are obtained no significant changes in strength may be expected as a result of further volume changes. For the purposes of pillar design, this strength should be adjusted to account for other factors that affect pillar strength, the main factors being the width to height ratio (w/h) effect, jointing and contact conditions. Further test work on Merensky Reef was required to clarify the: 1. Values of it’s critical size and strength 2. Effect of the w/h on it’s strength 3. Effect of the frictional contacts between the reef and the surrounding rock on the reefs uniaxial strength. These results could then be integrated into a holistic pillar design methodology to improve current pillar designing practices. These effects were examined through the laboratory testing of samples originating from Amandelbult Platinum mine. A critical strength of approximately 110 MPa was obtained for samples with diameters, 130 - 250 mm (w/h =1). Increasing the frictional contacts between sample and loading platens was found to increase the sample's strength. A marked difference was found between the insitu and laboratory contact friction angles for Merensky Reef. The insitu contact friction angle was found to be approximately 2.5 times larger then the laboratory contact friction angle. The uniaxial strength increased linearly with increasing w/h ratios up to a w/h ratio of 6. For w/h ratios greater then 6 the strength continued to increased with increasing w/h ratios, but no curve could be acceptably fitted to the data to describe this trend. The results of this study can be applied to mine pillar design in the Bushveld Igneous complex. / Dissertation (MEng (Mining Engineering))--University of Pretoria, 2007. / Mining Engineering / unrestricted

This study investigates the impact of violence and intimidation, especially the extent to which these have an effect on the behaviour of union joining and leaving in the platinum mining site located in the North-West Province. Accepting the premise that unions have substantial leverage, both in terms of legislative provisions of the Labour Relations Act for bargaining for wage increases and the capacity for organized industrial action, the study zoned in on the localized offshoots of the experience of union domination as intimidation This has particular value in understanding the often-ignored reasons why employees behave in ways that express solidarity, on the one hand, and rivalry, on the other—both of which articulate to a propensity to behave in ways that mask or avoid vulnerability. One of these ways is union-joining behaviour. Framed on a qualitative methodology, this study measured the aforesaid behaviour through research questions and hypothesis that scale intentions to join through normative beliefs above organizational justice. In order to provide a logical link between its independent variables of violence/intimidation and the union-joining dependent variable, it marshalled scientific constructs gleaned from Icek Azjen’s Theory of Planned Behaviour. Accordingly, it used convenient sampling to manage the data gathered from the Theory of Planned Behaviour Questionnaire, which was apt to accurately and validly score the values of research constructs—such as they were ranged against moderators and mediators. The study arrived at the following significant findings: the propensity to join unions is as much prompted by an urgent sense of threat to job security and personal safety as it is by the need to leverage organizational justice. On the basis of these findings, the study makes bold recommendations to all concerned stakeholders. / Dissertation (MBA)--University of Pretoria, 2014. / lmgibs2015 / Gordon Institute of Business Science (GIBS) / Unrestricted

A dissertation 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. Johannesburg, 2017 / The primary objective of any mining business unit is to make profit by extracting, processing and selling minerals from a particular mineral deposit. It is important to optimise the extraction of the mineral resource given time, space and resource constraints. The mineral extraction process is often associated with uncertainty due to variable technical and human factors. Technical factors such as grade distribution, ground conditions and equipment reliability influence the performance of the mining production system (MPS). The performance of the MPS is also impacted by human factors such as employee skills, health and attendance. Uncertainty associated with technical and human factors often leads to planned output being different to actuals obtained. Therefore an in-depth analysis of the significant causes of deviations from the planned outcomes becomes a very important exercise. This research investigated the empirical relationships between inputs and outputs in a MPS in order assist management in directing efforts at key production drivers. A literature review revealed that production output is an end result of a chain of processes dependent and directly linked to each other, often referred to as the Mining Value Chain. The processes can be seen as milestones to be achieved within a production project. The process requires technical and human factors as resources. The literature review also highlighted that the production stage is the most obvious stage for investors to realise their return on investment. The production stage which constitutes a MPS was chosen as a relevant research area for the reason mentioned. Once a MPS has been empirically characterised, more effort and resources can be focused on the key decision making variables (DMVs) in order to meet the planned outcomes. A production function was developed accordingly, based on the production logic and historical data. The research concludes that for a typical platinum mine the face advance, face length mined, number of teams, and team size (independent variables) have a statistically significant relationship with the centares (m²) (dependent variable / response variable) produced which is a key performance indicator (KPI) for a platinum mine. A statistically significant regression equation with a coefficient of determination R2 = 0.99835 was obtained for the MPS. The production function can be used to align the physical, technical and human factors together to predict the optimal output level. The production function also highlights that the most significant production lever of the MPS is the face advance, contrary to a commonly held sentiment that lost blasts are the most significant. / MT 2017

Please read the abstract in the 00front part of this document / Dissertation (MSc (Mining Engineering))--University of Pretoria, 2007. / Mining Engineering / unrestricted

M.Phil. / The mining industry in South Africa is in a process of transformation, which can be ascribed to various influences. First and foremost is the process of the conversion of mineral rights, employment equity and black economic empowerment. The ethnic distribution of mining employees at the time of the study reflected that Managers were predominantly white, the majority of Shift bosses were white and Miners were predominantly black. Central to the transformation process is maintaining and improving production output in a safe manner. Leadership in addition also impacts on health and safety in the workplace and the process to transform the organisation to world- class status commences with leadership. Transforming health and safety in the organisation to world-class status is a leadership imperative. The fatality rates in South African mines are continuously being addressed not only through initiatives from the Chamber of Mines of South Africa, but also through the various mining houses. The introduction of the Mine Health and Safety Act and Regulations 29 of 1996 made a profound impact on health and safety management on South African Mines. The introduction of blasting certificate holders replaced the scheduled person (contract miner). Various mining houses grasped the opportunity and trained their own miners from previously disadvantaged communities. This also assisted in achieving transformation objectives. The fatalities on platinum mines in South Africa since 1995 have remained constant up to 2007 although a slight decrease is reported. Nevertheless, injuries and fatalities in South African mines are attracting negative attention from society and the investment community. This is not in the interest of the mining industry. Research indicates that unsafe behaviour contributes 87% and more to incidents and injuries (including fatalities) on mines. The study of behaviour as a contributing factor in organisational safety is a relatively young science since the first reported studies in the 1980's. Research in this domain strives to develop an understanding of behaviour as a contributing factor in organisational safety.

M. Tech. Human Resources Management / The purpose of the research was to develop a list of priority training needs for engineers in the platinum mining industry. In the current skills shortage, it is imperative to reconsider engineering disciplines or qualifications in relation to the engineering skills in the mining industry, taking cognisance of the list of training priorities in the platinum mining sector. The study intended to achieve the following objectives: to develop a list of priority training needs of the engineers in the platinum mining industry; and to determine if there is correlation between the training needs of engineers in the platinum mining industry.

M. Tech. Business Administration / The aim of this research it to investigate factors that can sustain T1 category small and medium enterprises (SMEs) that provides service at Impala Platinum Mine in Rustenburg. The population for the study was 53 SMEs owners/directors, convenient sampling was used and a sample of 26 percent responded to the questionnaire.

Detailed geological knowledge is often a major unknown factor in open pit mining and design, and therefore poses a significant risk in the mining venture. As the knowledge of the geology improves so the risk of unforeseen conditions reduces and therefore safety and productivity can be increased. Historically, geotechnical methods and information have predominantly been used exclusively for pit slope optimisation. This research documents the procedures and developments undertaken to compile a comprehensive geotechnical database, and the application of the geotechnical data to open pit mining, beneficiation and planning. The utilisation of the geotechnical information has been enhanced through the novel development and application of a computerised, 3D geotechnical model. Sandsloot open pit was developed to extract the Platreef pyroxenite orebody, which is hosted within the Northern Limb of the Bushveld Complex. Sandsloot is currently the world's largest open pit exploiting Platinum Group Metals. Interaction of the basic magma with the footwall sediments of the Transvaal Supergroup and varying degrees of assimilation has resulted in a unique suite of hybrid rock types. These various rock types provide significant engineering geological challenges. Geology and the detailed understanding of its properties are fundamental to the optimal design and successful operation of any mine. Extensive fieldwork was conducted to collect geotechnical information, both from exploration boreholes and in-pit mining faces. Over a 5-year period, geotechnical data were collected from 29,213 m of exploration core and 6,873 m of exposed mining faces. Extensive field and laboratory testing was undertaken in order to define the complete set of geotechnical properties for each rock type in the Sandsloot mining area. The geotechnical information relating to each borehole and facemap was stored in the Datamine® software package. The information was collected in the form of rock mass rating (RMR), uniaxial compressive strength (DCS), fracture frequency (FF/m) and rock quality designation (RQD). The architecture of the database was developed along the principals used for generating an ore reserve model. One of the novel applications was the development of a computerized 3D, geotechnical model in Datamine®. The geotechnical parameters, namely RMR, DCS, FF/m and RQD, were modelled for each rock type, using geostatistics, to generate a 3D model. The data were interpolated between exploration boreholes and exposed mining faces and the modelling was constrained using wireframes separated by rock type. The result is a 3D model containing 15 m3 model blocks populated with interpolated geotechnical information. The dimensions of the model blocks are linked to the mining bench height of 15 m. The model can be queried to give predictions on rock mass conditions for any planned mining area, as is the case with the ore reserve model, which provides predictions on platinum grades. The crux of the innovative research is the practical application of the 3D geotechnical model. This was achieved through the development of both a fragmentation and a slope design model, which read the interpolated geotechnical information. These models provided an engineering tool to optimise mining and milling perfonnance. Rather than viewing the drill and blast department as an isolated cost centre and focussing on minimising drill and blast costs, the application of the model concentrated on the fragmentation requirements of the milling and mining business areas. Two hundred and thirty-eight blasts were assessed to detennine the optimum fragmentation requirements for ore and waste. Based on the study a mean fragmentation target of 150 mm was set for delivery to the crushing circuit and a mean fragmentation of 230 mm was set for waste loading from the pit. The mine operates autogenous mills, which are sensitive to the fragmentation profile delivered. The harder zones occurring in the ore zone have a major impact on the plant's perfonnance. The geotechnical parameters in the model were related to Lilly's Blastability Index, and in turn to required explosive volumes and the associated drill and blast costs. Having defmed the fragmentation targets, the Kuz-Ram equation was used in the fragmentation model to predict the explosive volumes required to ensure consistent mining and milling perfonnance. The geotechnical model is used to predict changes in geotechnical conditions and therefore the blasting parameters can be adjusted in advance to ensure the milling and mining fragmentation requirements are met. Through the application of the fragmentation model over an eighteen-month period the loading and milling efficiencies improved by 8.5% and 8.8% respectively, resulting in additional revenue ofR29 million for PPL. Based on the mining rock mass rating (MRMR) values within the geotechnical model a stable slope design model was created in order to calculate optimum inter-ramp angles. From a slope design perspective the model was used to target data-deficient zones and highlight potentially weak rock mass areas. As this can be viewed in 3D, the open pit slopes were designed to accommodate the poor quality areas before they are excavated. It also follows that competent geotechnical zones can be readily identified and the slope optimised accordingly. Due to the detailed geotechnical infonnation being available in three dimensions, the open pit slopes were designed based on a risk versus reward profile. As a significant geotechnical database was available, more accurate and reliable designs were generated resulting in the overall slope angle increasing by 3 degrees. This optimisation process will result in a revenue gain of R900 million over the life of the mine. The revenue and safety benefits associated with this design methodology are substantial and have potential application to all open pit mining operations. The research has enabled detailed geotechnical infonnation to be available in three dimensions. This information can be readily accessed and interpreted, thus providing a powerful planning and financial tool from which production optimisations, feasibility studies and planning initiatives can be implemented. The development and application of a 3D geotechnical model has added a new dimension to the constant strive for business improvement and reflects a novel and successful approach towards the application of engineering geology at the Sandsloot mining operation. / Thesis (Ph.D.)-University of Natal, Durban, 2003.

Thesis (M.Sc.(Applied Science-Metallurgy))--University of Pretoria, 2008. / Abstract in English. Includes bibliographical references (leaves 136-145).

Union Section of Rustenburg Patinum Mines is situated in the northwestern part of the Bushveld Complex, some twenty kilometres north of the Pilanesberg Alkaline Complex. The mining lease area covers a roughly triangular segment of Lower, Critical and Main Zone rocks, transgressed to the north and south by magnetite-bearing ferrogabbro of the Upper Zone. The Main Zone at Union Section is the focus of this study. The prime source of sample material for the study is the deep exploration borehole SK2, but additional, supplementary samples were collected on surface and underground, as well as from a second surface exploration borehole, SK4. In line with the recommendations of SACS (1980), the top of the Critical Zone, and therefore the base of the Main Zone, is taken to be the top of the Bastard Cyclic Unit. Sharpe (1985) suggested that the succession from the base of the Main is an isotopically separate entity Zone up to the Pyroxenite Marker from the rest of the Bushveld layered succession. This is not strictly true, as there is evidence that more than one parental magma was involved in the formation of this interval. It is, however, true that there are fundamental differences, particularly in isotopic makeup, between the Main Zone rocks below the pyroxenite Marker and those above (the latter having been assigned by Molyneux (1970) to subzone C of the Main Zone). Kruger et al. (1986, in press) suggested that the Pyroxenite Marker marks the base of the Upper Zone, and this convention is adhered to here. The implication of this is that the rocks which formerly constituted subzone C of the Main Zone are now considered part of the Upper Zone. The Main Zone rocks below the pyroxenite Marker were originally subdivided by Molyneux (1970) into two subzones, A and B. The results of the present study indicate that this subdivision is not justified. Instead, eight units have been distinguished in the Main Zone on geochemical, petrological and mineralogical bases. Each of these units is characterized by a coherent set, or progression, of chemical and petrological characteristics. The specific assignment of genetic connotations to these units has been deliberately avoided , at least until further studies of the Main Zone prove this to be justified. The demarcation of the eight units is illustrated in the composite diagram (Fig. 34) in the back pocket of this work, and the reasons for the subdivisions are listed in Table 6 (at the end of chapter 7 of this thesis). Until the late 1970's, it was thought that most layered cumulates formed by crystal settling (Wager and Brown, 1968). More recently, there has been a fundamental conceptual change, and many workers now believe that most cumulate rocks formed by in situ crystallization at the floor and walls of the magma chamber (McBirney and Noyes, 1979, Irvine, 1980a; Campbell, 1987). There is, however, some evidence for the physical separation of phases undergoing cotectic crystallization, particularly in the Upper Critical Zone and lower part of the Main Zone (Eales et al., 1986). This process, which has been alluded to in the past by various authors (Ferguson and Botha, 1963; Vermaak, 1976) involves the flotation of early-formed plagioclase crystals due to their positive bouyancy in tholeiitic liquids. The result is an apparent decoupling of the chemistry of pyroxene and plagioclase, as in unit IV of the Main Zone, where plagioclase becomes more anorthitic upwards, whilst pyroxene becomes more iron-rich. There is some substantial evidence, particularly in reversals in the strontium isotope initial ratio and the orthopyroxene Mg/(Mg+Fe) ratio , for multiple intrusion in the Main Zone. Although the largest and most important magma influx in the Main Zone was a high-R₀ aluminous tholeiite, as suggested by Sharpe (1985), the intrusive history of the Main Zone is believed to be far more complex than Sharpe (op. cit.) suggested. Significantly, there is strong evidence for small influxes of Upper Zone-type (Fe-rich tholeiite) magma in the upper reaches of the Main Zone. These are believed to be precursors to the major influx of Upper Zone-type magma at the pyroxenite Marker (Kruger et al, 1986, in press). The fate of intercumulus liquids in cumulate rocks has recently recieved substantial attention (Sparks et al., 1985; Morse, 1986; Barnes, 1986: Campbell, 1987). It is believed that the migration, or at least redistribution, of intercumulus liquids has played a vital role in modifying fractionation trends in the Main Zone. More importantly, the accumulation of late-stage intercumulus liquids is believed to be responsible for the formation of the Fe-rich ultramafic pegmatite bodies that interrupt the layered cumulates in borehole SK2 / Adobe Acrobat 9.53 Paper Capture Plug-in