Faculty of Engineering and the Built Environment (ETDs)

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Alternative Tenure Options as a Stepping Stone for Urban Land Reform: The Case of Kwa Mai Mai Muthi Market
(University of the Witwatersrand, Johannesburg, 2024-02) Mnguni, Thobeka; Maina, Miriam M.
This research uses qualitative methods to investigate the case of the Kwa Mai Mai muthi market located in the central business district of Johannesburg where over the decades informal traders have converted their trading units into residential homes. This case is used to respond to the research question, ‘To what extent is taking administrative action to improve land tenure by offering communities rights to occupy urban land feasible and necessary for advancing the urban land reform agenda?.’ The research acknowledges that popular approaches to improving tenure by converting insecure tenure rights to statutory ownership through the Deeds office has had limited success and resulted in efficiencies due to the high costs and the resources intensive nature of this approach. Instead, the research recommends a necessary transition to improving tenure in innovative, context-specific ways that work to build on existing settlements through taking low-cost and low LOE administrative action.
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.
Investigating the effect of size, density and shape of Iron ore particles on batch jig performance
(University of the Witwatersrand, Johannesburg, 2024-02) Dzaringa Kisembo, Daniel Elvis; Woollacott, Lorenzo
The gravity separation method is one of the oldest methods of mineral beneficiation that takes advantage of the difference in the specific gravity of particles that are being separated. The separation occurs in a fluid medium, usually water, and involves floating off lighter material to leave behind denser ones. There are several types of gravity separation techniques, and they vary according to the equipment that is used for the separation or the property of the medium that is being used; the main gravity separation methods that are widely used for the beneficiation of Iron ore are Jigging and Dense Medium Separation (DMS). In this research, the jigging method is selected to investigate the concentration of an Iron ore by using a batch laboratory Jig; the jigging method was preferred for its simplicity and availability, generally Jigging has several advantages, some of which include cost effectiveness and simplicity of operation and its minimum impact on the environment. During the beneficiation of minerals using the jigging method of ore concentration, several feed material characteristics affect the efficiency, such as the particle density, size and shape. The aim of this research was to investigate the effect of these feed properties on jig performance. Tests were conducted on a Hematite ore sample using a batch jig to gain a deeper understanding of how the density, the size and shape of particles affect segregation. The iron ore samples were screened and any extremely small particles were removed, maintaining a particle size range between 2.8 and 10 mm. The results showed that particles were stratified on the basis of their specific gravity, denser particles reported toward the bottom layer of the bed and separated more efficiently. Less denser particles reported more toward the upper layer of the bed and were less efficiently separated. Coarser particles tend to report to the bottom layer of the bed and finer particles to the top product layer. Particles that were flatter and more elongated tended to end up in the bottom layer of the bed more often, while more rounded particles were not as likely to be found in the bottom layer.
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.
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.
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.
The relevance of industrial development zones as prototyping hubs for the diffusion and scale-up of green hydrogen power fuels for South Africa: A case study of Atlantis in Western Cape
(University of the Witwatersrand, Johannesburg, 2024-02) Madhi, Fadheelah; Irurah, Daniel
In South Africa, provinces such as the Western Cape (WC) enjoy high levels of renewable energy (RE) resources such as solar and wind energy while also experiencing critical transmission and storage constraints. On the other hand, industrial development zones (IDZs) such as Atlantis in the WC, offer opportunities for adaptable infrastructure in support of green hydrogen (GH) technologies that can convert surplus RE to GH which is rapidly evolving as a globally flexible power fuel. Through a qualitative study approach, the study assessed the relevance of IDZs as prototyping hubs for addressing the challenges facing the prototyping and scale-up of GH from RE resources which are commonly associated with intermittency. Primary data were collected through interviews with senior engineers (electrical, mechanical, and industrial) in RE and GH while secondary data were extracted from relevant studies and industry reports as well as policy and regulatory frameworks covering RE, GH and IDZs. As one of the initial findings, in spite of rapid evolution in RE-technologies and policies in South Africa and globally, key barriers still exist in the adoption and diffusion of GH-technologies. Five key barriers identified are infrastructure, socio-economic, economic, water scarcity for GH from electrolysis, policy, and regulatory constraints. Secondary data further indicates that SA is in the roll-out stage of two key GH initiatives (Green Hydrogen Valley - GHV and Sasol-Toyota GH joint venture) aimed at tackling the identified barriers. However, further analyses indicates that such prototyping projects would still leave major gaps that need to be closed in order to expedite the scale-up of GH nationally. The study then interviewed one Atlantis IDZ official on the extent to which IDZs could facilitate in closing the adoption and scale-up gaps for GH in South Africa. As a hub specifically created for the testing, prototyping and production of green technologies in order to facilitate their scale-up and adoption, the study finds that Atlantis IDZ is uniquely positioned for mitigating the barrier-gaps identified. The IDZ is equipped with secure streams of capital investments which could be leveraged for GH-technologies as well as for addressing related constraints such as water scarcity through desalination technologies. Atlantis also holds unique learning opportunities, operates under entrepreneurship-friendly special policies, and enjoys access to infrastructure relevant for the adoption and scale-up of GH. Based on these findings, the study concludes that IDZs are not only relevant for the national adoption of GH but also critical for positioning South Africa as a leading GH economy globally.
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.
What are the Lessons that can be Drawn from International Experience on Sustainable Transport for Johannesburg? Case Study: Berlin, Germany
(University of the Witwatersrand, Johannesburg, 2024-02) Ngoma, Ralph Thabiso; Sihlongonyane, Mfaniseni
This study unravels the performance of sustainable transport in two vastly different and unique spatial contexts, which have developed from comparable historical landscapes. The transport performance in the city of Johannesburg, South Africa and the city of Berlin, Germany is assessed respectively, to note the effectiveness of the transport modes individually and collectively. It is not a comparative study, but rather a study seeking to understand the actualisation of the concept ‘sustainable transport’ in Johannesburg. The problem statement is asking how the nuanced applicability of sustainability in transport can inform transport plans. The nuanced applicability of sustainability must inform transport plans, so that the vision of sustainable transport is strategically applied in the Johannesburg city plans and those of the other cities in the global south. There is a set of criteria that was adapted to assess the performance of transport in the respective cities, thereby extracting valuable lessons for Johannesburg. The qualitative method of study was used to gather the required data, through case studies, desktop research and unstructured discussions. The report argues for innovative and context sensitive approaches to conceptualising sustainable transport in the cities of the global south, and this is informed by the growth strategy of the respective cities. It is noted that transport and land use are co-dependent, therefore sustainable cities are those that integrate all the elements of sustainability in development plans. The results speak to planners and policy makers to have a nuanced view of transport, thus developing forward-looking frameworks to address sustainability as postulated by UN Habitat goals. The goal is to improve mobility in the city and keep abreast with new innovative approaches to unpacking ‘sustainable transport’ in literature, to inform the ever-growing sustainable, resilient and inclusive cities of the global south.

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Browsing Faculty of Engineering and the Built Environment (ETDs) by SDG "SDG-17: Partnerships for the goals"

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