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, 2016 / Since mining platinum started at Unki Mine in 2005, large and small geologically controlled falls of ground (FOG) have been problematic especially in 2011 where a FOG caused a fatality. This study is about determining the rock properties at Unki Mine and then using the results to design and recommend robust support to reduce the FOG problems that are continuously happening. The study analysed all the FOG data from the mine database from 2010 to 2015 using statistical methods. Rock properties of the hangingwall, ore zone and footwall were determined from the laboratory tests. The geological structures were also mapped carefully. The results were then used as input data to the numerical modelling softwares Phase2 and J-Block. The J-Block program was used to determine the number of keyblocks that were stable, unstable and failed with support in designated and specified bords. A probabilistic approach was used to evaluate the stable span with special reference from small to large hangingwall instabilities for different mining scenarios. It was found out using Phase2 that large spans at Unki Mine are possible provided appropriate and robust support system is adopted. To fully address the issue of FOG problem at Unki Mine, a probabilistic approach is recommended as this is considered to be more appropriate than a deterministic approach that has been the traditional design approach so far. / MT2017

Sandsloot open pit mine extracts platinum, copper and nickel from the Platreef orebody in the Northern Limb of the Bushveld Complex. At present, it is the world's largest open pit platinum mine, but it is one of the smaller of six pits to be mined in this area by Potgietersrust Platinums Limited (PPRust). As mining progresses and the mine operations expand, sound knowledge of the subsurface ground, the orebody properties and their performance in the processing plant is imperative. An accurately characterised orebody, in terms of its geotechnical, geochemical and metallurgical properties, will facilitate the development of appropriate and cost effective mining practices and processing plant design. It will improve the prediction and performance of materials in each of the steps involved in converting the orebody rock mass into a concentrate /marketable product, which ultimately leads to mine-to-mill optimisation. This dissertation has focused on the geotechnical and metallurgical strength properties of the Platreef orebody at Sandsloot; the geochemical properties of the various lithologies and defined for each orebody rock type the associations and correlations within and between these properties. The petrography of the orebody material was studied to identify and classify the rock types. A rigorous testing programme was conducted and an extensive database of petrographic, geotechnical, geochemical and metallurgical information was assembled. The corresponding results within and across the different studies were grouped together and statistical analysis and interrogation of the data sets were performed. The research identified diverse rock types with contrasting physical properties in the Sandsloot open pit orebody. For each of the rock types the distinguishing characteristics and the variations in properties were identified. Significant differences and relationships between rock types for each property were assessed for predictability in mining. Statistical associations and correlations between the properties of each study were defined and models for predicting strength and rock type were developed. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2008.

Thesis (M.Sc.(Earth Science Management and Practice))--University of Pretoria, 2007. / Abstract in English. Includes bibliographical references (leaves 95-99).

Thesis (M.Sc.(Mining))--University of Pretoria, 2001. / Includes abstract in English. Includes bibliographical references.

Thesis (M.L.(Prof.))--University of Pretoria, 2004. / Includes summary. Includes bibliographical references.

M.B.A. / To develop four Strategic Scenario's for Lonmin Western Platinum Mine ( WPM ) based on investigation into outsourcing, financial, productivity and technological aspects to enable Lonmin Western Platinum Mine management to refocus their operating strategies. 1.7 Objective of research 1.7.1 To analyse the current external and internal environment 1.7.2 To evaluate Lonmin Western Platinum Mines current situation 1.7.3 To utilize an appropriate research methodology 1.7.4 To provide strategic scenarios to top management 1.7.5 To evaluate the strategic scenario's and provide a recommendation to management

M.Sc. (Geology) / Please refer to full text to view abstract

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.

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