Faculty of Engineering and the Built Environment (ETDs)

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Wear Reduction and Media Density Optimization for the Single Stage Pipe Densifier at Sishen Iron Ore’s Beneficiation Plants
(University of the Witwatersrand, Johannesburg, 0202-02) Botha, Simone; Kabezya, Kitungwa
The depleting high-grade iron ore mining supply at Sishen Mine in the Northern Cape, South Africa, has given rise to its beneficiation plants operating at higher media densities to upgrade lower-grade ore. In this study, densification was numerically modelled using an MPPIC model and experimentally tested using a 200-mm diameter centrifugal densifier from two local suppliers – Multotec and HMA. Shear stress, wear rate, separation efficiency and media losses were measured at increasing operating densities and differing vortex finder sizes. Optimum operating conditions were established. It was found that a feed density of 3.60 t/m3 and a shear stress of 9.70 e-3 N/m3 at the inlet using a vortex finder diameter size of 30 mm exhibited favourable performance in terms of media densification and downstream recovery. The practical significance of this is proven in terms of wear rate and its predictability to provide a consistent overflow of below 1.20 t/m3 media to the recovery circuit. Furthermore, information about ideal operating conditions in terms of inlet pressure and controls to identify premature failures were established.
Pegmatite investigations in the Karibib district, South West Africa
(University of the Witwatersrand, Johannesburg, 1963) Roering, Christian
The outer pegmatitie zone of variable thickness which is essentially a very coarse-grained granite consisting of larger perthite phenocrysts lying in a matrix of albite, quartz and muscovite. The inner portions of this zone may reveal a great enrichment of perthite, so much so, that it may grade into a giant perthite zone, e. g. Rubicon main ore-body; Karlsbrunn close to the Li-bearing ore zones. This outer portion of the pegmatite may also reveal a subdivision into two distinct units: an outermost zone of albite-quartz-muscovite and an inner zone of albite-perthite-quartz-muscovite. This sequence of essentially granitic crystallization is often abruptly broken by the appearance of a zone consisting essentially of cleavelandite with minor quartz and muscovite. This zone is characterized by the appearance of numerous accessory minerals often in economic quantities, e. g. beryl, columbite-tantalite-frondellite, topaz and apatite. The zone is generally of the order 1-5 feet depending on the original size of the pegmatitie and the degree of fractionation. That it is not a late replacement unit is confirmed by observations at Rubicon where corroded crystals of beryl belonging to this zone are found lying in a matrix of lepidolite and albite which is the next unit to form. The lepidolite-albite zone in fact replaces the beryl-bearing zone. The striking symmetry alone of the Rubicon body testifies to this zone preceeding in crystallization sequence the Li-ore zones. The significant fact about this zone is that it marks a distinct break in the crystallization history of the pegmatite, i. e. it marks the change from crystallization of essentially granitic components to the formation of late phase constituents, viz. Li-bearing and associated minerals. It possibly marks the break from magmatic crystallization to late-magmatic conditions when pneumatogenic and even hydrothermal processes begin to operate. The next group of minerals to form are noticeably rich in Li and are frequently associated with sugary albite. The major minerals are petalite, lepidolite and albite, while minor amounts of amblygonite also occur. There is a definite spacial relationship sequence in the formation of these minerals. Petalite crystallizes first and collects in the upper part of this unit generally forming a hood. Amblygonite, albite, quartz, may occur at the same time. Immediately below this petalite hood, and at a somewhat later stage, fine-grained lepidolite crystallizes together with albite and minor quartz. The final phase to form at this general stage is sugary albite which collects at the bottom of the still non-crystalline portion of the magma chamber. The sugary albite phase is able to behave diapirically and can intrude, brecciate, and replace any of the previously crystallized zonal constituents. Each successive stage here can assume corrosive relationships to previously consolidated units. No assessment is made as to the amount of replacement that may take place as the criterion commonly used for such diagnosis are somewhat subjective. During this entire process of complex diffusions and crystallization, silica is apparently being concentrated in the residual fractions of the pegmatite magma. The next zone to form is a cleavelandite-rich rock confined to the quartz core margin. This cleavelandite is able to vein and brecciate and corrode the immediately adjacent lying lepidolite and is often associated with minerals such as beryl, columbite, tantalite, tourmaline, topaz and apatitie. Amblygonite may also belong to this stage of mineralization though in general it tends to be associated close in time with the petalite stage of mineralization. The final stage of the crystallization sequence is the quartz core. Quartz veinlets emanating from the core have been observed to cut across adjacent lepidllite-rich and amblygonite-albite zones. Euhedral crystals of columbite and beryl at the core margin are completely surrounded by quartz. These observations may suggest that quartz, although concentrated in the centre of the dyke, probably existed in some unconsolidated state (e. g. a gel as Brotzen (1959) has suggested). The development of a gas phase at certain stages of the pegmatites consolidation history possibly accounts for the vertical fractionation found in these pegmatites. Finally details of the more important pegmatite minerals are given together with chemical analyses.
The Quantitative Hydrogeological Mapping of Zebediela Estates, Central Transvaal
(University of the Witwatersrand, Johannesburg, 1970-05) Pretorius, Desmond Aubrey
The groundwater system on zebediela Estates, situated along the northern edge of the Springbok Flats in the Central Transvaal, has been studied by physiographic, geologic , geophysical, geochemical, and hydrologic methods . Emphasis has been placed on the subsurface mapping of the spatial distribution patterns of a nvn1ber of hydrogeologic parameters, and computer-based polynomial trend surface analysis has been employed to facilitate the interpretation of the maps. The computer has also been used to determine the general statistics of the frequency distributions of the various parameters and to platform sequential multiple linear regression analysis in an attempt to determine the relationships between the variables . Data arrays of observations, computations, and interpretations have been disp layed in 38 tables in the text and 21 appendices to the text . The distr ibution patterns , in one and two dimensions, have been portrayed in 8 text figures and 117 maps, separate from the t ext. The area studied covers approximate ly 23 square mil es, in which 556, 000 orange trees have been planted on 5800 acres . An average annual amount of 2400 million gallons of water is required to maintain t he operation, and 560 million gallons of this quantity are withdrawn, on the average, each year from boreholes tapping the groundwater resources of the Estates . Up to April, 1969, 315 holes had been drilled, and 151 had become producers at one time or another. In 19 years of exploitation between 1950 and 1968, 10, 600 million gallons of groundwater were withdrawn, at an average rate of 13 million gallons per year per production borehole. The study has shown that the groundwater system supplying this substantial quantity of water consists of two main elements - a piedmont alluvial slope, in which stream channels and paleochannels on coalescing alluvial fans are acting as conduits for the transmistion of water from the intake areas; and an underlying bedrock storage reservoir composed of aquifers of the Transvaal and Karroo sequences . The Malmani dolomite aquifers and the Stormberg basalt aquifers are superior to those of the Wolkberg quartzites, shales, and lavas, and the Stormberg Cave sandstones. It has been possible to distinguish two cycles of Karoo basalts, each of which shows differentiation . The upper cycle is far more important as an aquifer than the lower cycle. The piedmont slope is composed of portions of three alluvial fans , the spines of which have a general southeasterly trend towards the junction of the Nkumpi and Olifant rivers in the valley-flat environment well to the south of the Estates . The upland areas above the apices of the fans embrace the mountain ranges which form the northern rim of the Transvaal Basin, and these uplands have suffered right-lateral movements along extensive east-northeast-trending transcurrent faults which must have continued to be active into recent times in order to displace the stream course on the fans. The fan-head section and portion of the midfan section of the Nkumpi fan, in which the Gompies River is situated, occur over the east-central, eastern, and southeastern parts of the property, and, where underlain by the upper basalt aquifers, constitute the most important source of groundwater on Zebediela Estates. The whole of the fan-head and mid-fan sections of the Mamukebe fan are located in the riorthern, west-central, western, and southwestern localities of the area studied. The fan is much smaller than either of the others, and is underlain by Wolkberg rocks, Cave sandstones, and lower basalts. Its overall groundwater potential is consequently lower than that of either of the other two components of the piedmont slope. Only a very restricted portion of the fan-head section of the Mogoto fan occurs in the extreme northwestern corner of the Estates, where it is underlain by the dolomite aquifer, Its groundwater parameters are consequently very favourable, but the true potential of this fan lies beyond the western boundary of the property. The average yield of boreholes in the upper basalt is 3600 gallons per hour; in the lower basalt, 2000 g.p.h.; in the sandstone, 1500 g.p.h.; in the dolomite, 11,200 g.p.h.; and in the quartzites, 1500 g.p.h. The average yield for all boreholes on the Estates is 4100 gallons per hour. All of these figures are appreciably higher than those for equivalent formations elsewhere in South Africa, testifying to the impoi,tance of the piedmont alluvial slope environment in the overall groundwater system at Zebediela. The average annual recharge of the groundwater reservoirs from all sources has been estimated at 700 million gallons. With the average annual withdrawal being of the order of 560 million gallons, the possibility exists that production from the aquifers can be increased by 25 per cent, without fear of serious, permanent deterioration in the performance of the groundwater system. However, excessive exploitation in times of low recharge might lead to the development of quality h.azards with respect to sodiuum, ehloride, and bicarbonate over the upperbasalts. This possibility does not exist for the remaining aquifers, particularly those in the dolomite, from which relatively pure water is drawn. An added problem in the recharge of the upper basalt aquifer is the contamination of t he groundwater in storage by lithium, brought into the Zebediela groundwater- system by the Nkumpi River, which transmits the element from the granite terrain to the north of the mountainous rim of the Springbok Flats. A new model of groundwater exploration has been devised, based on optimum drilling sites being located where coincidence takes place of piedmont stream channel conduits, dolomite or upper basalt aquifers, and transcurrent fault aquicludes, Results obtained from the employment of this model during two years of drilling subsequent to its development in a preliminary form produced an increase of 14 per cent in the average yield of all boreholes drilled.
Experimental heat transfer coefficients for the cooling of oil in horizontal internal forced convective transitional flow
(University of the Witwatersrand, Johannesburg, 1981) Rogers, Douglas Gordon; Van der Merwe, D.F.
The theory and practice of community participation in provision of urban structure
(University of the Witwatersrand, Johannesburg, 1993) Abbott, John; McCutcheon, Robert
The thesis develops a new approach to community participation, for application to infrastructure provision projects in developing countries, based upon social surveys and case studies of negotiations in five South African communities. Existing approaches to community participation are analysed and shown to be unsuitable for infrastructure provision. The thesis compares the characteristics of infrastructure projects with those of other types of development projects and demonstrates how these characteristics can be used to situate a given project within a project environment defined in terms of two variables: the openness of government to community involvement in decision-making, and project complexity. Social surveys carried out in Soweto and KwaThandeka showed the centrality of infrastructure to social change in South Africa. Existing urban management systems were unable to cope with the stresses placed upon them. Four facets of urban management were identified as being under stress: institutional capacity, legitimacy, affordability, and user convenience. These stresses change the nature of infrastructure provision from the supply of end products into a complex process. Central to this process are: an increased number of actors influencing decisions, the enhanced role of technical professionals, and the social implications of different levels of service. The case-study of KwaThandeka included a study of the negotiation process with the provincial administration. This research led to the development of a performance specification for comparing social, economic and technical measures of value. A new conceptual framework for community participation was derived, based upon the different actors involved in the decision-making process and the different needs of each of those actors. Three case studies from Natal identified different implementation strategies for community participation. Communities were found to have three distinct needs: involvement in the political process; involvement in technical decision-making; and representation as consumers of services. An analytical tool was developed to assist project managers in understanding the relationships between actors in a project. The thesis shows how technical project management can be integrated into the participation process. The success of community participation can be evaluated by assessing the degree of consensus achieved between actors, and the intensity of community involvement.
Comparative study of five country-specific labour-intensive infrastructure development programmes : implications for South Africa
(University of the Witwatersrand, Johannesburg, 2010) Quainoo, Harry Akyen; McCutcheon, R.T.
Unemployment and abject poverty in South Africa are widespread, persistent and disproportionately high. These problems are aggravated by inadequate capacity at all tiers of government and huge infrastructure backlogs in rural South Africa. Employment-intensive means of infrastructure delivery have been successfully implemented in several sub-Saharan African countries and elsewhere to generate employment and reduce poverty. It should be possible to replicate similar large-scale national programmes in South Africa. But South Africa has failed. Both prior to and since 1994, several supposedly employment-intensive programmes have been implemented in South Africa with poor results. In an endeavour to contribute to future South African policy and good practices regarding employment, this thesis describes and analyses in detail five major Sub-Saharan programmes and reaches conclusions regarding their achievements and shortcomings. Lessons derived bridge the knowledge gap between the large-scale programmes embarked upon in the sub-Saharan countries in the mid-1980s and the year 2007; these lessons should be applied to future endeavours in South Africa to generate significant employment per unit of expenditure and contribute to poverty alleviation. A major conclusion reached was that the success of employment-intensive infrastructure development programmes depends to a large extent on fundamental factors such as appropriate and implementable policy, government commitment, adequate and sustainable funding, adequate capacity and good preparation. Specifically, the thesis demonstrated that prior to implementation a sufficient timeframe is required for programme preparation in order to make significant contribution towards poverty reduction. Equally, national programme expansion requires a strategic balance between centralisation and decentralisation. In particular, for programme extension and decentralisation, due regard must be given to training and capability building and available resources. Deriving from the thesis’ major conclusions, the author developed three crucially important frameworks for anti-poverty infrastructure development programmes, namely; a four-phased model for evaluating the chances of success of infrastructure programmes, a five-phased result-oriented guidelines for testing the workability of infrastructure development policies, and a practical guideline for monitoring and evaluating employment-creation programmes that maximises the benefits thereof and pre-empts institutional memory loss through systematic knowledge management.
An analysis of public-private partnerships in housing in the Zimbabwe National Housing Delivery Programme: a case of Masvingo City
(2014-10-27) Chikomwe, Savory
Based on evidence of the performance of a public-private partnership (PPP) housing arrangement in Masvingo City, Zimbabwe, I argue that PPPs may not thrive in youthful democracies entrenched in informal approaches to project management. The PPP strategy which was meant to deliver about 10 000 housing units in Masvingo City has dismally failed to live to its expectation, save for an ignited spirit of cooperativism. This is in spite of what was dubbed as a potentially promising partnership strategy involving indigenous private developers and contractors. Yet the compulsory acquisition of urban and peri-urban farmland country-wide presented powerful launch pad for a promisingly successful housing delivery that is widely expected to wipe out serious housing deficits. Housing problems were recently further compounded by Operation Murambatsvina in 2005 which ruthlessly demolished all informal housing and left several hundreds of thousands homeless. Following an insightful in-depth interview methodology and several ground-truthing trips to the Victoria Ranch Housing Project site, I argue that Government of Zimbabwe (GOZ) arrangements in terms of legal, administrative and financial aspects were weak to enable successful implementation of a formal PPP strategy. The arrangements advertently or inadvertently promoted privatism instead of the mutually beneficial PPP arrangement. As such, there were no clear regulatory mechanisms and modalities to enable beneficiation of the targeted low-income people and other economically weaker sections of the Masvingo City Community. There are fears that undeserving better-offs could have hijacked the scheme. However, a commendable resilience has emerged through a resurgent self-help housing delivery approach resulting in many self-built houses in what is widely viewed as a “peculiar” parallel development. While it could be too early to meaningfully comment on the long-term performance of the PPP approach, it is clear that justice has not been done to low-income people in Masvingo who remain largely homeless.
A study of the finite element method, with reference to the Adina finite element package
(University of the Witwatersrand, Johannesburg, 2015-02-13) Constancon, Charles Peter
This dissertation presents a theoretical and practical study of the finite element met hod using the ADINA finite element program. The package was applied to the analysis of three different problems, namely: A nonlinear static analysis; a free vibration analysis and a themal analysis. The first two analyses were supplemented with experimental results for the purpose of comparison whilst the last was compared with a closed form analytic solution. The first problem consisted of a materially nonlinear static analysis of a cast iron sheave wheel. The sheave was physically loaded with a rope up to failure of the rim. Strain gauges monitored strain at twenty-four locations. In order to simulate the nonlinear properties of the east iron, a Drucker Prager yield criterion was utilised and accordingly, a subroutine describing the elasto-plastic constitutive laws was interfaced with the ADINA package. Owing to self-imposed limitations on computer resources, the sheave was modelled as a two-dimensional body. The results correlated well in the linear region but deviated when plastic deformation was pronounced. It is suspected that this was due to a combination of approximations in modelling the geometry and the material. In the free vibration analysis, a simple portal frame was built in order to compare its natural mode shapes and frequencies with those obtained from a finite element simulation. This comparison proved satisfactory. The thermal analysis was executed primarily to test and gain first hand experience with the ADINAT package. A two-dimensional flat plate subjected to a sinusoidal temperature load was simulated. Although the application was simple, the accuracy of the FEM results confirmed that the package was operating correctly. In all these exercises ADINA package performed satisfactorily. Experience show that the programme was not user-friendly, however this is not considered a drawback in a research environment.
Action volume ratio: a method to classify the danger of lightning in any given volume
(University of the Witwatersrand, Johannesburg, 2015-05-07) Dickson, Andrew Stuart
The annual number of injuries and fatalities from lightning has, over the last century, been on a steady decline. This is primarily due to urbanisation and movement away from agriculturally intensive activities. In countries with a high urban population, the incidence of lightning fatalities is below 1 death per million people per year. However, in countries with a larger rural population, this rate is significantly higher, ranging between 8 and 15 deaths per million people per year. There has been a large drive towards educating the general public about the dangers of lightning and methods to avoid being in a dangerous situation. However, fatal lightning events still occur on a regular basis. There are currently no methods to determine the risk of lightning to living beings in open spaces. The international standard (IEC 62305-2) provides a method for the assessment of risk to living beings within a structure, and up to three metres outside of it. Considering that the majority of deaths by lightning occur outdoors, a method of determining these risks is necessary. The Action Volume Ratio (AVR) is proposed as a new method for the analysis of the danger of lightning in any volume. It considers the dangers of all lightning injury mechanisms in relation to the objects in the space, which are assumed to be the preferential points of strike. A union of the dangerous volumes is then formed, and a ratio to the total volume is created. The AVR uses accepted electrical engineering equations to determine the dangerous areas, and places no reliance on probability theory, which can, in many cases, skew the results of a lightning risk analysis process. The AVR can be combined with lightning ground flash density data to indicate the incidence and frequency of dangerous events within a given volume.
Urbanism and sustainability in Daveyton: designing for the township main street :[an exploration of spatial transformation in previously marginalised townships, with a focus on the main street]
(University of the Witwatersrand, Johannesburg, 2016) Bham, Aadill; Van Der Westhuizan, Diaan
In township environments where pedestrian activity occurs out of necessity; and public transport prevails - the main street becomes a magnet for mobility, social encounters and economic exchange. It is the path that connects the settlement to the whole; it disperses and draws in; it collects and connects. It is the image of the township. Streets play an important role within townships as the primary form of public urban space. It is within these spaces that the residents make their own opportunities for a better quality of life. (Jacobs, 1993) explained that by designing the streets, one has largely designed the city.
Optimisation of fragmentation at south deep gold fields mine: a case study
(2020) Nong, Matsobane
A fundamental aspect of an efficient mining operation is the steady movement of material throughout the mine system; particularly the flow of ore from the upstream excavation point to the downstream processing or stockpile site(s). This can be achieved by attaining an optimal fragmentation size from drilling and blasting suitable for subsequent mining process such as loading, hauling and crushing. Drilling and blasting are the first fragmentation process and is currently the most economical technique of fragmenting hard and competent rock especially for deep-level mines where operational costs are high. The aim of this research is to analyse and optimise fragmentation to improve the oreflow efficiency at South Deep Mine in South Africa. The mine experiences coarse fragmentation that cannot pass through 300mm by 300mm grizzlies. As such, secondary blasting is often done to reduce the size of boulders either in the stopes or on top of the grizzly which leads to a reduction in productivity. Although coarse fragmentation is reported in the stopes and on top of grizzlies, the plant is reporting fine fragmentation that is not suitable for the ball mill. This results in reduced gold recoveries. To get a better understanding of the fragmentation size distribution achieved, fifty-one images of the muckpile from five stopes were analysed using the Split-Desktop software. The analysis showed an overall F80 passing of 287.48mm, which is less than the 300mm grizzly size implying that the fragmentation size achieved is adequate. However, looking at the overall particle size, the Rosin-Rammler distribution was found to be 0.80. This infers an inconsistent fragmentation where the mine produces both coarse and fine fragmentation size. The AEGIS Underground drill and blast software was used to analyse the drill and blast design patterns. The analysis showed that the design toe spacing varies from about 0.5m to 7.5m in the same blast. Due to the software’s limitations, the break model analysis was only run for toe spacing between 2m and 7.5m. This showed that there is no overlap between blastholes which may be the source of the coarse fragmentation size. Fine fragment size may be as a result of blastholes which are close together, i.e. 0.5m. Although not tested, the impact of blasting stresses emanating from primary stopes may result in fractures in secondary stopes which will have a greater impact on the propagation of the shock wave and high-pressure gases between the blastholes and consequently the fragmentation distribution size. It is recommended that the mine change their drill and blast pattern. The mine must change from 76mm blasthole diameters and introduce a larger blasthole diameter of 89mm blasthole diameter. Not only will this diameter improve drilling accuracies but will reduce the fragmentation size distribution. It is also recommended that the mine maintains a ring burden of 2m throughout despite an increase in the blasthole diameter. For the first design, the toe spacing must also be 2m followed by increments of 0.5m per blast until a suitable fragmentation distribution size is achieved. After which, the toe spacing must be kept constant. It is important that South Deep Mine continually evaluate the fragmentation size distribution achieved from each blast for optimisation purposes. Therefore, a blast management system is important.
Groundwater resource exploration within the inner-city of Johannesburg
(2020) Tywakadi, Ondela; Taigbenu, Akpofure E.
This study examined the hydrogeological characterisation of the Johannesburg inner-city. Residents reported a high water table that has resulted in groundwater seepage into building basements, posing a safety threat and limited functionality of these structures. Although this high groundwater table triggered this investigation, it took a deeper and broader approach by seeking to quantify the amount of groundwater resource that is available to be used to supplement the existing municipal supply. The study also aimed at establishing long-term sustainable abstraction rates and viable fit-for-purpose use of the available groundwater. The study then evaluated the abstraction rates against the water table response in order to achieve a safe water table level at which groundwater seepage into building basements does not occur. The methodology employed included assessing and verifying the number and distribution of buildings affected by groundwater seepage. Information was gathered by circulating a survey in the form of a questionnaire to a network database of property owners and managers. Field work, in the form of drilling and testing boreholes, and subsequent data processing were carried out to characterise the aquifers and establish the quantity of the resource. In order to determine possible uses of the groundwater, water chemistry testing was carried out. The characteristics and recharge dynamics of the aquifers that were established served as inputs into a numerical model which estimated the quantity of groundwater that can be sustainably abstracted for utilisation, while ensuring the water table is sufficiently suppressed. An estimated 2.47 million-m3 (or billion-litres) of groundwater is available as a total yield potential within the Johannesburg inner-city. This water can be sustainably withdrawn from the ground at a safe yield (abstraction rate) of over 56 million-litres per annum (56 902m3/a) from the nine drilled boreholes. The system response corresponding to this abstraction rate is predicted to cause a 2.3m decline in the water table level compared to the current scenario. This desired pumping scenario would suppress the water table level to be at an average of 8.6m below ground. The average basement depth in the Johannesburg inner-city is 8m below ground and hence, most building basements would consequently not be flooded under this scenario. Currently, 60% of building basements are subjected to the risk of flooding, and this would reduce to 30%, which is made up of those deeper than 9m. The current water demand in the Johannesburg inner-city is approximated to be 80Ml/day. Therefore, the estimated groundwater yield to supplement the municipal supply is insignificant (0.2%), and does not justify an investment into retrofitting the groundwater infrastructure into the bulk infrastructure system. Thus, developing a groundwater source infrastructure for bulk water supply purposes is not volumetrically viable in the case of Johannesburg inner-city, but can be beneficial for building strategic reserves and resilience into the system. It is recommended that in future, fine-tuning and continuous calibration of the numerical model should be carried out when the boreholes are in operation. Further research is also required to examine the aquifer geo-mechanics in order to assess the risk of land subsidence with decreasing water table levels, especially in a possible future scenario of over-exploitation of the aquifer.
Socio-economic Perspectives in the Redevelopment of Hostels in South Africa: A Case of Wolhuter Hostel, Jeppestown
(University of the Witwatersrand, Johannesburg, 2020-11) Madonsela, Thando Kwenza; Sihlongonyane, Mfaniseni
Hostels in the South Africa context are synonymous with the migrant labour system. The dominant feature of these pre-democratic hostels is that they catered for single-sex employees as opposed to worker families. This contributed to the destruction of the social fabric in terms of culture, traditions, and the destruction of the black families at large. In post-democratic South Africa, Hostel accommodation continues to paint a grim picture within our human settlement’s spaces. Socio-economic difficulties manifest themselves in mostly inadequate living conditions or poor housing circumstances that are largely conditioned by the unequal and distorted access to opportunities. To this day, most hostels that are not yet redeveloped or refurbished continue to present images of dirty menacing buildings associated with a public stigma of notoriety. This research study explores socio-economic perspectives in the redevelopment of hostels in South Africa. The study will consist of an interface between theoretical foundations, and empirical evidence. This research, data collection was sourced both from primary and secondary sources. Qualitative investigative methods were used to get an in-depth understanding of the subject. The research follows a case-study approach, that of Wolhuter Hostel, Jeppestown in Gauteng and undertook interviews of sixteen hostel dwellers plus a fucus group discussion. The study makes recommendations on policy reforms such introducing more responsive programmes in human settlements. It is also aimed at introducing an improved approach to the planning and redevelopment of the hostels by strengthening neighbourhood and precinct planning. The study contributes to the understanding and insight on hostels and their redevelopment and considering socio-economic perspectives in human settlements planning and development.
External change management: the revised policy of registered construction health and safety agents in South Africa
(2021) Khoza, Sepelong Rebecca
Purpose: South Africa’s construction industry continuously strives to improve its health and safety( H&S). Consequently, South Africa revised its Construction Regulations in 2014 to include the requirement for the application for construction permit to include a competent construction health and safety (CHS) agent. This research investigates how change management processes enable construction companies to effectively comply with the revised H&S policy requirement. Design/methodology/approach: Using a cross-sectional survey design, an online structured questionnaire was sent to SACPCMP-registered construction professionals and construction professionals of a state-owned enterprise in South Africa using purposive sampling. 170 construction professionals responded (85% response rate). Likert scale/ ordinal data were collected on the factors affecting the registration for the CHS agents (Objective 1), understanding of the implications of implementing the revised H&S policy (Objective 2), applicability of the different change management strategies (Objective 3), and the attitudes towards organizational changes for implementing the revised H&S policy (Objective 4). Findings: There was a strong agreement that H&S is best implemented in the early phases of construction project (Objective 1). Average understanding existed that any person who is interested in being an H&S agent can become one by going for an interview only(Objective 2). Also, there was a strong agreement that project participants’ need to comply with the changes as required by the law (Objective 3) and that the attitude of top management towards change is positive (Objective 4).Research limitations/implications: The construction professionals acknowledge that the revised H&S policy needs to be adhered to, as per the law, however there are hindrances to being registered because of factors that can be sorted out by management and how they roll out the change management within the companies. Originality/ Value: The Ingenuity of the research is based on the change management in the context of the revised H&S policy in South Africa
A bathhouse in Cyrildene - a phenomenological approach to the design of a bathhouse in Johannesburg
(2021) Kow, Alan
In Johannesburg, there is a lack of global bathhouse typologies. They either don’t exist or are in a form which caters to a niche subculture. Bathhouse culture has been around for hundreds of years and many people around the world take advantage of it as a form of communal bonding, relaxation and general hygiene. In addition to this, when done correctly, it has the effect of stripping away of social class and distinction as well as providing a safe and entertaining environment for those within its walls. This study aims to bring my personal experience of an East-Asian bathhouse into Cyrildene, a predominantly Chinese neighbourhood, that is slowly losing its cultural identity. Building on existing data on historic bathhouses from around the world, it asks: How can the concept of phenomenology be used to guide the design of an Asian style bathhouse in order to enhance the Asian/Chinese cultural experience and help in the revitalisation of Derrick street as a distinct cultural hub In Johannesburg? The main methodologies that will be used in this report will be from literature reviews on historical analysis of bathhouses around the world but more specifically in Eastern Asia. One on one interviews with the residents and shop owners living in Cyrildene as well as the owner/s of a spa. Observations based on mapping and photography will also be employed. The last will be the use of auto-ethnographic data from my own experiences. The main hypothesis of the report will be seeing if the bathhouse typology through the use of a variety of different programs that range from bathing to eating to sleeping in addition to the application of architectural phenomenological theories helps make it suitable for Cyrildene and thereby revitalise and strengthen the areas existing cultural identity.
A comparison of various modelling techniques to optimise production rate on a platinum mining project
(2021) Dreyer, Jaco
Every business aims to create an optimal economic value for its shareholders. The production rate is one of the critical drivers of value in the mining business. Several approaches have been developed to determine the production rate for mining operations. This study applied three approaches for determining production rate, namely the tonnage-based, microeconomic and marginal-analysis modelling methods. These methods were applied on a platinum project, and the production rate results from the three methods were used to determine the life of mine (LOM) production profiles, capital expenditure (CAPEX) and operational expenditure (OPEX). These results were then used as inputs into a discounted cash flow (DCF) model. The DCF model results were compared and analysed to determine a production rate determination method that results in an optimum production output rate for the project. The study revealed that the tonnage-based modelling technique resulted in the highest production rate of 410-kilo tonnes per month (ktpm), the highest CAPEX of USD957.24 million, the lowest OPEX of USD75.37 per mined tonne, the highest net present value (NPV) of USD63.12 million and the highest internal rate of return (IRR) of 12.85% over a 40-year LOM. The microeconomic modelling technique ranked second with a production rate of 270 ktpm, CAPEX of USD 726.24 million, OPEX of USD 76.68 per mined tonne, NPV of USD 3.46 million and IRR of 10.17%. The marginal-analysis modelling technique ranked last with a production rate of 230 ktpm, CAPEX of USD 658.76 million, OPEX of USD 77.83 per mined tonne, NPV of USD -10.69 million and the lowest IRR of 9.47%. Mineral Resource tonnage-based modelling may be further investigated in other commodities other than platinum or other multi-element/polymetallic mineral deposits in line with the South African mining industry. This will result in the formulation of industry-specific calibration in the South African mining industry
The polymorphic state and real estate: rethinking the relationship between the state and real estate through Johannesburg & Bangalore
(2022) Pillay, Sarita
This research seeks to expand understanding of the relationship between the state and real estate. It is guided by the impulse, from experience in urban land justice activism, to acknowledge multiplicity in the state, and to contextualise the nebulous boundary between the private and public. I argue that commonly adopted concepts in critical scholarship – in the strands of urban power, urban planning and historical materialism – do not adequately offer a means to do this. Thus, drawing from how these concepts have been stretched and refuted in critical scholarship, an analytical lens is assembled for this research. It is guided by three influences: a historical materialist analytic of the urban; non-normative approaches to a postcolonial state theorised in India; and insights on the amorphous boundary between the state and private sector in real estate The starting point for this research is Johannesburg. However, an expansive spectrum of Indian critical scholarship surfaced in reading the relationship between the state and real estate. This raised the methodological utility of bringing Johannesburg into empirical conversation with an Indian city. Emerging organically as this city was Bangalore. Rather than ‘cases’, Johannesburg and Bangalore are approached as ‘vantage points’ through which to explore the relationship between the ubiquitous, albeit socially constructed, state and real estate. This research was thus guided by the question: (How) can the relationship between the state and real estate be conceptualised through Johannesburg and Bangalore? To begin to explore this, I undertook in-depth interviews with 62 key informants in real estate and government, as well as observations in real estate conferences and as an intern in a real estate consultancy firm. Additional analysis was undertaken of news articles, industry reports and building statistics. Three lesser-seen relationships between the state and real estate emerged, grounded in each city but developed through each other: an enabling relationship between local government and real estate shaped by the post-apartheid transition in Johannesburg; central government’s incorporation of real estate in Bangalore; and the Government Employees Pension Fund’s (GEPF) embeddedness in Johannesburg real estate as an ‘investor state’. In a landscape of differentiated real estate, the state was shown to be central to financialised forms of real estate – but not only so. This contributes to conceptualising a polymorphic state and real estate. Empirically, this work expands critical scholarship to direct considered attention to non-corporate forms of real estate in India, and listed corporate real estate in South Afric
The underrepresentation of technical women in executive and board of directors’ roles in the ten largest listed mining companies in South Africa
(2022) Zulu, Noluthando
As with many technical industries, mining is dominated by men. It is well established that the industry has struggled with the attraction and retention of female talent. While women have made significant inroads in the industry, technical women (defined here as women who come from a geology, engineering, metallurgical, etc background) are underrepresented in the most senior decision-making roles of major mining companies. The purpose of the study was to explore this phenomenon, examining the executive committee and board composition of the 10 largest mining companies listed on the Johannesburg Stock Exchange and interviewing 30 technical women who have worked for, or currently work for, these organisations. The results demonstrate that technical women seldom advance from operations to the boardroom and, typically, play a support function while men make core mining and technical decisions. The study also finds that many technical women move into nontechnical roles for a number of reasons. Further, while attraction of women to the industry continues to rise, the studied companies are struggling to retain technical female talent. The study further highlights the significance of government intervention concerning the inclusion and advancement of women in mining. It also emphasises the need for continued policy development and concludes with recommendations on how mining companies can drive both the inclusion of women in mining as well as their corporate advancement.
Governance of infrastructure provision in informal settlements: the electrification of unproclaimed areas in the City of Johannesburg
(2022) Chikomwe, Savory
An increasing number of informal settlements in South Africa are receiving interim services for extended periods while awaiting permanent upgrading or housing solutions. This thesis explores the complex governance arrangements and challenges that arise around the provision of basic services using City of Johannesburg as a case study, with a focus on three ‘unproclaimed’ informal settlements that have undergone electrification. These are Stjwetla, Protea South and Slovo Park. The three cases shed light on the modes of infrastructure governance that characterize informal settlement upgrading as practiced in the City of Johannesburg and to some extent in South Africa more generally. Formal grid electrification in the case study settlements is juxtaposed by other temporary basic infrastructure provisioning in a complicated socio-political, institutional and governance context. The inquiry adopted a qualitative methodology. The case studies of the three settlements and the City of Johannesburg were compiled through an extensive literature and document review and indepth interviews with key informants. These spanned community leadership, political representatives, experts and officials in municipal, provincial and national departments and stateowned entities. The thesis finds ambivalence, disconnections, misalignments and contradictions in the basic infrastructure provision and upgrading processes within the City of Johannesburg and between the City and central government departments. This was accentuated by the role of the national state-owned electricity company Eskom in one of the three settlements. The thesis finds that the prolonged temporary status of the informal settlements promotes contestations at various levels, including ligation. In the absence of progress towards permanent upgrading, investment in grid electrification ambiguously signals permanence even where there is no state intention to upgrade in situ. Within communities, this confusion contributes to tension while also triggering consolidation and in-migration. Differing interpretations across entities of the state about the role of grid electrification in informal settlement trajectories open up space for temporary electrification ultimately to lead towards the pragmatic adoption of permanent in situ upgrading. This notwithstanding, literature reviewed for this thesis points instead toward the necessity for a turn to off-grid electrification technologies for informal settlements.
The Role of Chiefs in Land Management in Peri-Urban Customary Areas Of Blantyre, Malawi: The Case of Mpemba
(University of the Witwatersrand, Johannesburg, 2022-04) Magwede, Chimwemwe Edith; Williamson, Amanda
Peri-urbanisation is a new form of urbanisation and the peri-urban area is a new kind of multi-functional landscape for urban development. How peri-urban areas are managed matters because they are close to the city and due to high urbanisation rates in most developing countries, these areas will soon be part of the city. If urban peripheries are not well-managed, they will be a challenge for sustainable development. In Malawi, peri-urban areas fall under customary land and chiefs are the custodians of customary land. The study unpacks the role of chiefs in land management, how the National Land Policy and land-related legislation position customary leadership in the governance of land management and how municipal and customary land management systems interact with each other in the peri-urban areas. The study employed a qualitative approach. Semi-structured interviews were conducted and policy and legislation were reviewed. The 2002 National Land Policy of Malawi and land-related legislation were reviewed focusing on the role of chiefs in land management. Although the peri-urban areas fall under the jurisdiction of chiefs, the research reveals that this area is treated as no man's land as there exists an overlap of authorities in the peri-urban areas. The chiefs witness land transactions, advise their people on how to secure their land, and partially guide and manage land, although they are not aware of land regulations and standards. The findings also disclose that there is a lack of coordination within municipal land management systems and between municipal land management systems and customary land management systems. Although the legislation states that chiefs have to be incorporated in land management, these laws have not been fully implemented as there are still in the pilot phase.

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