Electronic Theses and Dissertations (Masters)

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Browsing Electronic Theses and Dissertations (Masters) by SDG "SDG-17: Partnerships for the goals"

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    Benefits of using Internet of Things technology for fuel management at a mechanised underground platinum bord and pillar mine: A Bathopele mine case study
    (University of the Witwatersrand, Johannesburg, 2024-01) Thema, Sephela Makete; Cawood, Frederick; Feroze, Tariq
    The advent of the fourth industrial revolution, Environmental Social and Governance (ESG), and push for green energy transition has propelled mining companies to reconsider their strategies. Over the past two decades, mining companies along the Bushveld Igneous complex in South Africa have been shifting towards mechanized mining methods which are generally safer and provide for the generation of greater volumes of output. Sibanye Stillwater’s Bathopele mine, which has a fleet of over two hundred and fifty (250) trackless mobile machinery (TMM) and a daily fuel consumption of approximately ten thousand (10 000) liters per day. The introduction of Internet of Things (IOT) technology in the fuel management system at Bathopele mine achieved benefits such as fuel consumption tracking, effective inventory management, prevention of fuel theft, detection of fuel leaks, determination of maintenance requirements and readily available access to fuel use data. This access to data enabled the mine to effectively apply for fuel use rebates from the South African Revenue Services (SARS) with ease. To determine the impact of the increased distance to underground working places on the refueling of TMM, the Theory of Constraints (TOC) method, qualitative and quantitative techniques were applied. A bivariate analysis conducted indicated a linear relationship between fuel consumption and production output at Bathopele mine, which suggests that an effective fuel management system had a positive impact on production output at the mine. A real-time or near real time model for fuel management in underground trackless bord and pillar mines in proposed.
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    Pit Optimisation of Vondeling Quarry by Understanding Geotechnical Parameters Determined at Zoutkloof Quarry
    (University of the Witwatersrand, Johannesburg, 2023-11) Mukwevho, Tshinanne Matty; Pillay, Ohveshlan
    The purpose of the study was to investigate the geotechnical parameters at Zoutkloof quarry and how they affect stability and the mine planning process. The geological features of Zoutkloof and Vondeling are similar, hence the lessons learned while mining Zoutkloof quarry can be used when mining Vondeling quarry. Zoutkloof quarry has already reached its limits and is no longer operational. It is important that mine planning considers the critical geotechnical parameters. The main reason for this consideration is to keep slope walls stable, employees and equipment safe, and to continue mining the ore in an economical manner. The methodology of the research incorporated highlighting the literature in the public domain on geotechnical considerations in open pit mining. Evaluating geotechnical parameters such as groundwater, rock mass strength, slope angle and monitoring; and additionally, showed scheduling of mining blocks from 2007 to 2008 formed part of methodology in the research. The results analysis indicated that the strategies implemented to control groundwater were successful to keep the production benches dry and walls stable. Good understanding of the discontinuities and the rock mass strength enabled the quarry to be divided into ground control districts. Kinematics analysis for possible failures was done and the results showed that there was no probability of failure on planar mode. However, there were minor possibility that failure can occur on wedge and toppling mode. Yearly mining scheduling was completed, focusing on tonnage and quality requirements. During this period, Zoutkloof had minimum waste mined and the quarry had narrowed significantly which required the operational team to work within mine design specifications to maintain safety and slope angles. Some resources had to be compromised as it was not practical to exploit them safely. The research concluded its findings as successful because Zoutkloof quarry was mined completely with approximately 10 slope failures that resulted with no injuries to employees or damage to equipment. The factors of safety (FOS) were evaluated to be well above one and slopes remained stable until mining ceased. The research also made recommendations that can be implemented while the Pretoria Portland Cement (PPC) continue to mine Vondeling quarry to aid same success as Zoutkloof while being cost effective.
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    Selection of an Optimal Tunnel Development Method for an Underground Mine Travelling Way Using an Analytic Hierarchy Process
    (University of the Witwatersrand, Johannesburg, 2024-01) Meyer, Berto; Musingwini, Cuthbert; Tholana, Tinashe; Sihesenkosi, Nhleko
    This research study was conducted at the Marikana Operations (Marikana) which are situated within the Western Limb of the Bushveld Complex (BC) located in the North West province of South Africa. The Marikana Operations mine platinum group metals (PGM) using conventional underground mining methods. The Marikana Operations are owned by Sibanye-Stillwater. The PGM conventional underground mining entails extracting a shallow-dipping narrow reef horizon which is accessed via a network of development workings. Within this layout, a travelling way is an inclined tunnel that connects lateral development workings with the workings on the reef horizon. At Marikana the conventional hand-held mining method is used to excavate travelling ways. However, there was a trial process completed that proved the viability of the inverse drop raising method of excavating travelling ways at Marikana. With more than one viable tunnelling method being available for travelling way development, the need arose to select an optimal travelling way development method for Marikana. The selection is a multi-criteria decision making (MCDM) process because it requires the simultaneous consideration of several factors when evaluating the different alternatives or options. Commonly applied tunnelling techniques were reviewed leading to the selection of both the hand-held drill and blasting method and the inverse drop raising method as applicable to the conventional underground mining environment and specifically to travelling way development. Thereafter, Multi Criteria Decision Analysis (MCDA) techniques were reviewed, and the Analytic Hierarchy Process (AHP) was selected as the MCDA technique to be used as the selection tool for the research, due to its several advantages such as the ability to detect inconsistencies in judgements and provision to remedy the inconsistencies. After the application of AHP, the inverse drop raising method scored 7.2% higher than the hand-held method with a 53.6% versus 46.4% score. The inverse drop raising method was therefore selected as the optimal method to develop travelling ways at Marikana. With the approach that both these methods are currently being executed at Marikana, the inverse drop raising method is nearly twice as expensive as the conventional hand-held method. If PGM prices become a constraint, the method might not be sustainable if executed the way that it is done at the Marikana Operations from a cost perspective. It is suggested that further research should be done to see how the method can be executed more cost-effectively.
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    Slope Failure Prediction at Husab Open Pit Mine in Namibia
    (University of the Witwatersrand, Johannesburg, 2023-12) Thikusho, Christine Runguro; Watson, Bryan P.
    The study is focused on Domain D at Husab Mine in Namibia. The purpose of the study was to improve prediction of pending slope failures for planar and wedge configurations. Planar and wedge failures are similar in that little strain is required to initiate failure. Slope monitoring systems such as ground based radars, interferometric synthetic aperture radar and prisms were reviewed from the available literature. The data from the mine’s satellite monitoring data and the ground-based radar instruments was analysed. Slope prediction methods were used to back-analyse the failures, to determine if failure prediction times were possible. A case study was incorporated from the neighbouring Rössing Uranium mine, to supplement the data. The data utilised for the study was downloaded from the slope monitoring instruments on the mine i.e., the interferometric synthetic aperture radar, ground-based radar and tension crack data. The following slope failure predictive tools were investigated; the strain deformation approach; the inverse velocity method; the slope gradient method; the acceleration and velocity approach; and Displacement/Time plots. The back-analysis work done proves that the following slope failure predictive methods were able to predict failure at least 3 days before failure: velocity, cumulative displacement and inverse velocity. It appears that the Husab mine failure mechanism is not as brittle as previously assumed and failures are not necessarily instantaneous. Therefore, failures should be identified early, and the necessary risk mitigation measures implemented proactively. The ability of back analysing large volumes of stored data is important in the study of failure prediction.
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    Verifying the Quality and Performance of Grout Using Sensor Technology
    (University of the Witwatersrand, Johannesburg, 2023-10) Hadebe, Menzi Bright; Mitra, Rudrajit
    Underground mines systematically install ground support to stabilize excavations and provide safe working environments. Support units, such as rock bolts and cables, are commonly filled with cementitious grout to effectively prevent corrosion, maintain bonding behaviour between the support unit and grout, and enhance the load transfer between the grout and surrounding rock mass. The grouting process is however time consuming and labour-intensive, which leads to haphazard installations. These substandard grout installations are only observed after rock fall instabilities occur when the quality and extent of grouting inside a support hole are exposed and can be observed. The need to monitor grout installations increased (provide assurance) but remained a challenge due to the invisibility of grout inside the support hole. The invisibility of the grout column inside the support hole renders the routine quality control inspections of installed support units ineffective. This ineffectiveness of quality control inspections has led to a growing need to monitor grout installations with smart technologies to provide quality assurance of full-column grouting. In its current state, grout technology in the mining industry can only measure the extent of grout inside a support hole directly after installation (limited battery life). It cannot measure the loss of grouting material into near borehole fractures, shrinkage, quality of grout inside the support hole or its impact on support performance. These factors are critical to the success of an effective support system and pose a significant safety risk when overlooked. This research report will describe how grout sensor technology data was recorded and used to verify the extent and quality of cementitious grout inside support hole installations at laboratory and deep-level mine study sites. Grout sensor technology, in practice, utilizes several grout sensors placed at predetermined positions along a support unit with a receiver attached to the collar of the support hole. Electrical resistivity data from each sensor is collected using a grout detector. Depending on the position of each grout sensor, the extent of grout inside a support hole can be confirmed, hence eliminating the need for speculative and ineffective visual observations. The non-destructive verification and prediction of the quality and performance of grout inside support holes using sensor technology forms an invaluable strata control tool that can be used to identify sub-standard grouting operations and significantly improve safety at underground mines. This novel and innovative technology is a mining industry first.