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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

Evaluation of the geochemical and mineralogical transformation at an old copper mine tailings dump in Musina, Limpopo Province, South Africa

Thobakgale, Rendani 18 September 2017 (has links)
MENVSC / Department of Ecology and Resource Management / Historically, mining activities have generated vast quantities of abandoned tailings dumps in several regions of South Africa and throughout the world. The management and disposal of huge volumes of tailings dumps has constituted a major challenge to the environment. The current study aims to establish the physicochemical properties and mineralogical characterization of the old copper tailings dump in Musina, to reveal the mobility patterns and attenuation dynamics of potentially toxic or heavy metal species as a function of depth, with a view of assessing their potential environmental impact with respect to surface and ground water systems. This information is crucial in the beneficial utilization of copper tailings in the development of sustainable construction materials as part of reuse approach management system. About twelve tailings samples were collected into polyethylene plastic bags from three established tailings profiles drilled by a hand auger. The collected tailings samples were characterized using standard analytical procedures i.e., X-ray fluorescence (XRF), X-ray diffraction (XRD) and scanning electron microscopy/energy dispersive spectroscopy (SEM-EDS). The transfer of potentially toxic or heavy metal species from tailings to water was evaluated using the standardized batch leaching test (EN 12457) and speciation-equilibrium calculations on the aqueous extracts performed by MINTEQA2. The leachate concentration of cations in the collected tailings samples was determined by inductively coupled mass spectrometry (ICP-MS) and the leachate concentration of anions was determined by ion chromatography (IC). A modified sequential extraction scheme was applied on the selected tailings samples of the drilled tailings profiles to further understand the mode of occurrence, the geochemical partitioning and distribution, real mobility, and environmental bioavailability of potentially toxic or heavy metal species in the tailings and tailings-soil interface. The extracted fractions or phases from sequential scheme were as follows: (F1) water-soluble fraction, (F2) exchangeable fraction, (F3) carbonate fraction, (F4) iron and manganese hydroxide associated fraction, (F5) organic matter and secondary sulphide associated fraction, (F6) primary sulphide bound fraction, and (F7) residual or silicate fraction. The results obtained from the seven steps sequential extraction scheme were validated by the determination vi of percentage recoveries from pseudo-total digestion or total metal content of the original sample. The distribution of major elements and potentially toxic or heavy metal species in different leachate fractions obtained after each step of sequential extraction of the selected tailings samples was determined by inductively coupled plasma mass spectrometry (ICP-MS). The appraised data was used to reveal the impact of atmospheric oxygen and infiltrating rain-water on the chemistry of copper tailings dump by depth profiles. Macroscopic properties revealed that the abandoned Musina copper tailings are fine to medium coarse grained, and range in color from light/dark gray at the upper or shallow depth of the tailings, to dark reddish-brown at the deeper zone where the tailings are mixed with the underlying soil or soil-interface. The drilled respective tailings profiles were uniform and slightly varied in both mineralogical and bulk chemical compositions with tailings depth. Mineralogical analysis showed the following order of mineralogical composition within the respective tailings profiles: quartz> epidote> chlorite> muscovite> calcite> hematite. Chalcopyrite was the only sulphide mineral observed by optical microscopy, although not identified or quantified by XRD and SEM-EDS analysis. The observed discrete chalcopyrite grains were attributed to the primary mined ore (i.e., chalcopyrite, chalcocite and bornite) during past copper mining activities in Musina. The tailings profiles were characterized by a medium alkaline pH (7.97-8.37) that corresponds very well with the tailings leachates or pore-water pH (8.36-8.46). This pH was constant and slightly varied with tailings depth in the respective tailings profiles. The high abundance of alumino-silicate minerals and traces of carbonates as calcite coupled with low sulphide mineral content, suggested a high neutralization capacity of the tailings which was in common agreement with an alkaline nature of the copper tailings dump. The chemical composition of major elements within the respective tailings profiles followed the order: Si>Al>Fe>Ca>Mg>K>Na, and corresponds very well with the mineralogical composition of the tailings, whereby alumino-silicates were the most abundant minerals in the tailings samples. Nevertheless, the solid-phase concentration of metals decreases with increasing tailings depth as Cu>Sr>Zr>Ni>Zn and was incongruent with the mineralogical composition within the respective tailings profiles. The main secondary minerals were calcite and hematite, and their proportion increased with increasing tailings vii depth. In addition, hematite formed coatings on the rims and corners of chlorite as observed from optical microscopy, and retained relatively high amounts of potentially toxic or heavy metals (up to 862 ppm of Cu, up to 36 ppm of Ni, and up to 25 ppm of Zn) at the upper and shallow depth of the respective tailings profiles, where bulk density was high and low porosity. Based on batch leaching tests, the amounts of potentially toxic or heavy metal species released into solution were low (0.27-0.34 μg/L Pb, 0.54-0.72 μg/L Ni, 0.88-1.80 μg/L Zn, and 20.21-47.9 μg/L Cu) and decreases with increasing tailings depth, indicating that, presently, the tailings have a minor impact on heavy metals load transported to the receiving surface and groundwater systems. The low concentration of potentially toxic or heavy metal species in solution is primarily due to their retention by secondary Fe oxide phases (i.e., hematite) and the prevailing medium alkaline pH condition of the tailings leachate or pore-water. The observations are consistent with MINTEQA2 speciation calculations, which predicted the precipitation of secondary phase cuprite (Cu2O) as the main solubility-controlling mineral phase for Cu, Zn, and Ni. Primary factors influencing aqueous chemistry at the site are neutralization and dissolution reactions as a function of pH, precipitation, and sorption into hydrous oxides (hematite and cuprite). Based on sequential extraction results, the leachable concentration of potentially toxic or heavy metal species in the water-soluble, exchangeable and carbonate fractions of the respective tailings profiles was relatively low, except for Cu and Mn. For instance, the leachable concentration of Cu and Mn reached 10.84 mg/kg and 321.7 mg/kg at the tailings-soil interface (3 m) in tailings profile C, respectively. The low concentration of potentially toxic or heavy metal species (Cr, Co, Ni, Zn, Cd, and Pb) in these fractions could be due to the low solubility of minerals bearing these trace elements caused by variations in pore-water pH in the respective tailings profiles. The high concentration of Cu and Mn in these fractions suggests their high mobility and therefore most available for uptake in the environment. Except for Cu>Mn>Cr, the contents of potentially toxic or heavy metal species in the Fe and Mn oxides and organic matter or sulphides bound fractions was low, due to the low viii quantity of these fractions in the tailings, despite their high affinity and sorption capacity for potentially toxic or heavy metal species. Likewise, the residual fraction of the respective tailings profiles contained the highest proportion of potentially toxic or heavy metal species. Although the highest potentially toxic or heavy metal species content was in fractions with limited mobility, care must be taken since any geochemical change or shift in the tailings pH or acidic conditions may cause them to be displaced to more mobile fractions, thereby increasing their mobility and environmental bioavailability. Therefore, physicochemical properties of the tailings including pH and mineralogical composition of the tailings samples were the main substrate controlling the geochemical partitioning and distribution, potential mobility, and environmental bioavailability of potentially toxic or heavy metal species by tailings depth. The knowledge of mobility and eco-toxicological significance of tailings is needed when considering tailings dump disposal or reuse in the environment. The addition of copper tailings at 3 and 28 days successfully improved the compressive strength of cement mortar mixtures incorporating tailings at C5 (5%) and C10 (10%) respectively, although with small margin relative to the control mixture (C0). The maximum strength was 31.15 Mpa attained after 28 curing days, and slightly varied when compared with other compressive strength on copper blended cement mortars mixtures in other countries, used for the development of sustainable construction materials. The chemical composition, physical properties and improved compressive strength on cement mortars mixtures incorporating copper tailings, implies that copper tailings are suitable for the development of sustainable construction materials, thereby ensuring job creation, availability of land for development usage, and the reduction of environmental pollution induced by the abandoned copper tailings dumps.
112

African worldviews : their impact on psychopathology and psychological couselling

Juma, James Onyango 10 1900 (has links)
This study investigates the role that African traditional beliefs and practices play in defining psychological problems, determines how these beliefs and practices manifest in a counselling relationship and explores how Western based forms of counselling manage these manifestations in counselling. This investigation is in the context of the on-going debate on the relevance of Western Psychological counselling in South Africa and the rest of Africa, including my experience during my internship to register as a Counsellor. It explores the impact of conducting counselling with clients whose worldviews are different from those of the counsellor and focuses on the impact of the client’s worldviews on psychological well-being, psychological ill health and the resolution of psychological problems. Psychological well-being, ill health and counselling were discussed from a Western perspective. The study found that the client participants defined their psychological problems in terms of their African traditional beliefs and practices. They communicated their presenting psychological problems in ways that created possibility of miscommunication between themselves and their counsellors, for example by using figurative language. There was also a clear distinction between how psychological problems are managed from an African traditional perspective (ritualistic) and a Western perspective (talking therapy). The study recommended the creation of specific departments in Universities to embark on research aimed at establishing foundational structures on which to build an African Indigenous Psychology as an alternative to Western Psychology. More comprehensive research on African people’s attitudes is, suggested, on what traditional Africans think of psychological counselling. Another recommendation accruing from the limitation on sampling in this study is that future studies should be conducted with larger and more diverse samples; moreover, data should be gathered on a wider variety of demographics and cultural belief systems and practices. To counter prejudice and ignorance, the counsellor ‘to be’ should study African culture and customs during their BA Honours studies. On-going training and workshops on cross-cultural issues from various cultures should be part of the counselling profession. More emphasis should be placed on prevention and therefore more mental health clinics in the rural areas need to be opened and general education on psychological issues and cultural integration be initiated. / Psychology / M.A. (Psychology)
113

A description of the process followed by Tshikondeni Coal Mine to ensure a competent workforce

Van der Merwe, J. O. 03 1900 (has links)
Thesis (MBA)--Stellenbosch University, 2001. / Some digitised pages may appear illegible due to the condition of the original hard copy / ENGLISH ABSTRACT: Successful organisations keep a well-balanced fit between their strategy, structure, processes, reward system and culture. Any significant change in any of the elements requires management to rethink and probably redesign the rest of the elements. Tshikondeni Coal Mine went through various changes the last few years. These changes were brought about by, amongst other things, a re-engineering project, production expansion and the appointment of new management A significant portion of the employees was newly appointed. Some of the older employees were appointed in other positions, or were required to do different work. Tshikondeni had to make sure that employees were equipped with the needed competency to do their job to the required standard and in a safe manner. The process started by ensuring that employees' medical profile fit that required by their jobs. They were also trained in identifying the hazards associated with their jobs and how to minimise exposure to risks. The gap between the competencies required for each job and that possessed by the job incumbent was identified. Training was designed to fill the identified gaps. Iscor management's annual salary increase is performance driven. The process of designing post profiles, competency documents and personal performance contracts is described. The link between the personal performance contract, the annual salary increase and the personal development plan is discussed. There is still no clear link between the annual salary increase of operational employees and their performance. Plans are in place to eventually reward all employees on a performance driven basis. The training section on Tshikondeni Mine was designed to support business objectives. It is also aligned with the trends experienced in modern training. The section, amongst other things, caters (through the use of an interactive multi media system) for the bulk of mining employees who can't read or write. All training information is kept on a central database. Employees must not only be able to do their job, but also willing or motivated to do it. Management created a work and home environment conducive towards motivated employees. A psychosocial study was done to. determine how employees and their families felt towards their environment. The results helped management to focus energy where problems were identified. Problems and pitfalls encountered during the process to ensure competency are discussed. The process followed by the mine is elucidated with modern trends, statements, remarks and suggestions found in literature. / AFRIKAANSE OPSOMMING: Hoë prestasie organisasies se strategië, strukture, prosesse, vergoedingstelsels en kultuur is in balans met dit wat sukses voorskryf. Enige wesenlike verandering in enige van die elemente kan veroorsaak dat die res van die elemente herbesoek en moontlik herontwerp moet word. Tshikondeni Steenkoolmyn het groot veranderinge oor die afgelope aantal jare beleef. Hierdie veranderinge was onder andere veroorsaak deur en proses herontwerp, produksie uitbreiding en die aanstelling van nuwe bestuur. en Beduidende hoeveelheid van wernemers was nuut aangestel. Van die ouer werknemers was aangestel in nuwe poste of was verwag om nuwe take te verrig. Tshikondeni moes verseker dat werknemers toegerus was met die nodige bevoegdheid om die werk te kan doen volgens die verlangde standaard en op en veilige manier. Die proses was begin deur te verseker dat werknemers se persoonlike mediese profiel pas by die profiel benodig deur hulle poste. Hulle was opgelei in die identifisering van gevaar in hulle werksomgewing en hoe om die risiko van blootstelling aan die gevaar te minimeer. Die gaping tussen werknemers se bevoegdhede en dié verlang deur hulle poste was geïdentifiseer. Opleiding was ontwikkel om die gapings aan te spreek. Iscor Bestuur ontvang jaarliks enprestasie gebasseerde salaris verhoging. Die proses wat gevolg is met die ontwerp van pos profiele, bevoegdheidsdokumente en persoonlike prestasiekontrakte word beskryf. me verhouding tussen die persoonlike prestasie kontrak, die jaarlikse salaris aanpassing en die persoonlike ontwikkelingsplan word bespreek. Daar is tans nie en duidelike ooreenkoms tussen die jaarlikse salaris aanpassing wat bedryfspersoneel ontvang en hulle prestasievlakke nie. Iscor het wel planne in plek om uiteindelik aan alle werknemers In prestasie gebasseerde vergoeding te betaal. Die opleidingseksie op Tshikondeni is ontwerp om besigheidsdoelwitte te ondersteun. Dit is ook belyn met moderne neigings met betrekking tot opleiding. Die seksie bedien, onder andere die grootste gedeelte van mynbou werknemers wat nie kan lees en skryf nie (met behulp van In interaktiewe multi media stelsel). Alle opleidings inligting word gestoor op In sentrale databasis. Werknemers moet nie net in staat wees om hul werk te kan doen nie, maar moet ook gemotiveerd wees om die werk te wil doen. Bestuur streef daarna om In werk- en huis omgewing te skep wat werknemers motiveer. In Psigososiale studie is gedoen om te bepaal hoe dat wememers en hulle gesinne voel ten opsigte van hulle omgewing. Die resultate het gehelp om bestuur se aandag en energie te fokus om probleme op te los. Probleme en slaggate ondervind tydens die bevoegdheidsproses word bespreek. Die proses gevolg word toegelig met moderne neigings, stellings, opmerkings en voorstelle soos wat gevind word in die literatuur.
114

The contribution of leadership behaviour in creating a safety conscious organisational culture : a case study of Anglo American mining operations

McLeod, Ashley 12 1900 (has links)
Thesis (MBA (Business Management))--Stellenbosch University, 2008. / ENGLISH ABSTRACT: In the 20th century, many employees in the South African mining industry were involved in occupational accidents which either resulted in personal injury or had fatal consequences. Despite the introduction of numerous industrial safety programmes to prevent fatal incidents and minor injuries, the South African mining industry death toll remains consistently high, at approximately 200 employees per annum. The trend of employee injury and death continues unabated into the new millennium. This safety performance has been met with growing dissatisfaction in the ranks of government, worker unions, employees and business stakeholders. This dissatisfaction is directed at chief executives who are being blamed for the occupational accidents on their mines. There is now growing focus on the leadership of mining companies and how it contributes to shaping an organisational culture for improved safety performance. The researcher examines whether leadership is a key component in creating a safety conscious organisational culture, and uses literature studies and the Anglo American mining company as a practical case study to support the investigation. Anglo American, listed on the Johannesburg and London stock exchanges is the largest mining company in South Africa and also one in which many fatal injuries have occurred; providing an abundance of safety information. The researcher reviews previous literature studies and explains the journey Anglo American undertook to improve its safety performance since listing on the London Stock Exchange in 1999. The concepts of organisational culture, safety culture, leadership and organisational performance, are discussed from a theoretical and practical perspective using literature studies. These are then examined with the ultimate view of understanding their practical impact on organisational safety as espoused in the literature. The literature provides a broad framework on which to assess Anglo American's safety journey from 1999 to the end of 2007. This journey details the safety programmes and efforts employed by Anglo American to eliminate fatalities and injuries and also highlights the impact of the organisation's leadership on the safety performance of the company. It is concluded that the contribution of leadership is pivotal to establishing a safety-conscious organisational culture and that specific behaviours from executives, senior managers, middle managers, supervisors and workers are needed to develop an organisations safety culture for improved safety performance. / AFRIKAANSE OPSOMMING: Gedurende die 20ste eeu was baie werkers in die Suid-Afrikaanse mynbedryf betrokke in beroepsverwante ongelukke wat tot persoonlike beserings of lewensverlies gelei het. Ten spyte van die instelling van veelvuldige beroeps-veiligheidsprogramme om noodlottige insidente en ander minder ernstige beserings te voorkom, bly die dodetal in die Suid-Afrikaanse mynbedryf konstant hoog, teen ongeveer 200 werkers per jaar. Hierdie tendens van dood en beserings onder werkers gaan ongetem voort tot in die nuwe millennium. Hierdie veiligheidsrekord word met toenemende ontevredenheid deur die regering, werkers-vakbonde, werkers en bedryfsinsethouers beskou. Hierdie ontevredenheid word gemik op uitvoerende bestuur, wie blameer word vir beroepsverwante ongelukke in hul myne. Daar word dus toenemend gefokus op die leierskap van mynmaatskappye en hoe dit bydra tot die skepping van 'n organisasiekultuur van verbeterde veiligheidsuitslae. Die navorser ondersoek die vraag of leierskap 'n kern komponent is in die daarstelling van 'n veiligheids-bewuste organisasiekultuur, en maak gebruik van literatuurstudies sowel as Anglo American mynmaatskappy as 'n praktiese gevallestudie om sy ondersoek te ondersteun. Anglo American is die grootste mynmaatskappy in Suid-Afrika en ook die een waar baie noodlottige ongelukke voorgekom het, en dus 'n groot bron van veiligheidsinligting kan voorsien. Die navorser hersien teoretiese literatuurstudies en verduidelik dan die optrede van Anglo American om sy veiligheidsrekords te verbeter sedert sy noteering op die Londonse Effektebeurs in 1999. Die konsep van organisasiekultuur, veiligheidskultuur, leierskap en organisasieprestasie, word bespreek vanuit 'n teoretiese en praktiese perspektief met behulp van literatuurstudies en hierdie word bestudeer met die uiteindelike doel om die praktiese impak daarvan in industrie te verstaan soos uiteengesit in die literatuur. Die literatuur voorsien 'n breë raamwerk waarteen Anglo American se veiligheidstog gemeet kan word vanaf 1999 tot einde 2007. Hierdie tog verskaf detail van hoe Anglo American veiligheidsprogramme gebruik het om noodlottigge ongelukke en beserings uit te skakel en beklemtoon ook die impak van die organisasie se leierskap op die veiligheidsrekord van die maatskappy. Die gevolgtrekking word gemaak dat die bydrae van leierskap kern is tot die daarstelling van 'n veiligheidsbewuste kultuur en dat spesifieke optredes van hoofbestuurders, seniorbestuurders, middelvlakbestuurders, opsieners en werkers nodig is om 'n veiligheidskultuur te bewerkstellig om veiligheid in maatskappye te verbeter.
115

Supply chain constraints in the South African coal mining industry

Mathu, Kenneth M. 11 1900 (has links)
Thesis. (D. Tech. - Business, Faculty of Management Sciences)--Vaal University of Technology, 2010. / The study explored the South African coal mining industry and it’s role players to establish the causes of the bottlenecks/constraints experienced in the coal mining industry supply chain. A qualitative research paradigm methodology was used. Both theoretical and philosophical assumptions were utilised with inferences from and references to works by other researchers to broaden the knowledge horizons for the study. Thirteen supply chain executives and professionals from the key role players in the coal mining industry were interviewed and provided invaluable input for the study. The study determined the presence of communication barriers between the industry role players in the public and private institutions that culminated in main themes and sub-themes being established from which the industry constraints were uncovered. The study identified six main constraints affecting the various role players within the coal mining supply chain and it culminated in the model that would enable the industry to minimise such constraints. To this end, the study proposes the development of an Integrated Strategy for the Development of Coal Mining (ISDCM).The model is based on the public and private partnership arrangement that would alleviate most of the prevailing constraints when implemented. The model would furthermore have the capacity to rectify most of the existing constraints. It would be funded from the commercial sector and would operate on triple bottom lines of economic, social and environmental factors, with equal weight. This is a desirable direction for the future in order to maintain sustainable development. Emanating from the study are policy and research recommendations for the South African coal mining industry, covering the coordination of the critical areas of the proposed integrated strategy for the development of the coal mining industry. Such recommendations include further research into new coal mines and power stations as well as perceptions and expectations of potential investors in the industry, among others.
116

Political consciousness and mobilisation amongst Afrikaner diggers on the Lichtenburg Diamond Fields, 1926-1929

Clynick, Timothy Paul 14 January 2015 (has links)
No description available.
117

The geology, geochemistry and silicate mineralogy of the upper criticial zone of the north-western Bushveld Complex, at Rustenburg Platinum Mines, Union Section

De Klerk, William Johan 20 March 2013 (has links)
Rustenburg Platinum Mines, Union Section, is located in the mafic phase of the north-western sector of the Bushveld Complex. This part of the Complex is characterised by transgressions of Upper zone ferrogabbros across the lower sequence of mafic rocks. These transgressions have effectively isolated a roughly triangular segment of Lower, Critical and Main zone rocks. It is in the upper part of the Critical zone that the Merensky Reef, with a strike length of 9,5 km, is found to suboutcrop below a 2-3 m black turf soil cover and it constitutes the orebody being mined at Union Section. Underground mining and development have exposed a stratigraphic succession from the Middle Group chromitites to within the lower part of the Main zone gabbros. A detailed investigation of a 100 m stratigraphic succession was undertaken in the upper part of the Critical zone, which includes the Bastard Reef, Merensky Reef, Pseudo Reef, UG 2 and UG 1 layers. Stratigraphic descriptions are presented for both a normal and potholed succession, as well as a description of pothole characteristics. The variations of Merensky Reef thickness, pothole distribution and structure of the are body are also discussed. Forty seven whole-rock major- and trace-element analyses were carried out on selected samples from both normal and potholed successions, although more emphasis was placed on the former. These samples were taken from just below the UG 1 to above the Bastard Reef. Trace elements determined included Sr, Rb, Y, Nb, Zr, Cr, Co, Ni, Cu and V. The cyclical nature of the layering is clearly defined by breaks in the trends of both the major- and trace element analyses, although some elements are strongly influenced by the modal proportions of the mai n mineral phases. Although major breaks are observed for individual elements , insignificant variation of the Mg/Mg+Fe 2 + ratio is observed throughout. New electron microprobe data are presented for the main silicate phases olivine , orthopyroxene, clinopyroxene and plagioclase , while only a limi ted number of analyses were carried out on the spine l phase. There would appear to be a reversal of the expected fractionation trend from the hanging wal l of the UG 2 to the Pseudo Marker layer. There is an upward increase of the Fo content of the olivine from F0₇₆ , ₇₋₈₁,₆ . A similar trend is observed for the orthopyroxene analyses . The Merensky unit, as a whole, exhibits a gradual decrease in the Mg end member of the Ca-poor pyroxenes from En ₇₈,₅₋₇₄ . was found to be markedly more calcic Cumulus plagioclase (An ₇₂, ₈-₈₁, ₇) than the intercumulus phase (An₅₆,₃₋₇₁, ₉) ' A further feature of the cumulus plagioclase is that strong zonation was observed with the cores of individual crystals being consistently lower in Ca relative to their margins . / KMBT_363 / Adobe Acrobat 9.53 Paper Capture Plug-in
118

An assessment of South Africa's coal mining sector response to climate change adaptation demands

Chavalala, Bongani 12 1900 (has links)
Climate change adaptation has received limited attention compared to mitigation across all spatial levels. This is besides the documented adverse impacts of climate change in different sectors of societies including mining in general and coal mining specifically. Against this background, the study set three objectives. The first objective was to identify current and possible future climate change impacts that may affect selected coal mines in South Africa. The second objective was to establish the nature and extent to which these mines were ready to address and implement adaptation measures. The last objective was to determine and document existing climate change adaptation practices in selected mines. Employing the mixed methods approach, the research engaged five coal mines located in Mpumalanga, Free State and Kwa Zulu-Natal, gathering both the qualitative and quantitative data. This data was analysed thematically. The research made three major findings. The first finding was that the climatic conditions in the research areas have been changing over the observed period. In general, rainfall has been declining and temperatures have been increasing, leading to increased cases of extreme fog, mist and heatwaves. The second finding was that there has been an increase in frequency and intensity of extreme weather events, most notably, floods and droughts. These changes in the climate and associated weather events have frequently affected mine operations particularly at the production sub-chain of the coal mining value chain. The third major finding was that despite this evidence of adverse impact of climate change on the production sub-chain of the South African coal mining value chain, adaption responses in all the studied mines showed reactive adaptation to extreme events instead of proactive adaptation planning and implementation. South Africa depends on coal-derived energy, electricity in particular and the coal mines are implicitly exposed and vulnerable to the adverse impacts of climate change. Reducing this exposure and vulnerability dictates the urgent need to implement anticipatory adaptation measures in all the sub-chains of the coal mining value chain. / Environmental Sciences / D. Litt. et Phil (Environmental management)
119

Geochemical characterisation of gold tailings footprints on the Central Rand Goldfield

Netshiongolwe, Khathutshelo Emmanuel 05 1900 (has links)
Gold mining in the Witwatersrand Basin of South Africa has resulted in soil contamination due to the lack of sufficient environmental management plans for the tailings dumps and remnant footprints. Tailings reclamation as a strategy of reducing pollution in the Central Rand, for instance, has resulted in contamination of water systems by acid mine drainage (AMD). After removal of the tailings dumps, remnant material is left over on the tailings footprints and these contain significant amounts of pollutants that were initially in the tailings. Heavy rainfall during summer dissolves primary minerals and later in the dry season, secondary minerals are precipitated as efflorescent crusts on and nearby tailings dumps as well as footprints due to high evaporation. The efflorescent crusts can redissolve when it rains and form acidic, metal and sulphate-rich solutions due to their soluble characteristics. This study aimed to characterise tailings footprints in areas targeted for human settlements and office spaces to assess their potential to release left over toxic elements such arsenic (As), lead (Pb), copper (Cu) and zinc (Zn). The approach to the study involved characterisation of oxidised and unoxidised tailings material and secondary precipitates on both tailings dumps and footprints. This involved determining the mineralogical composition using Powder X-ray Diffraction (PXRD). Dissolution and leaching studies were also conducted on the material followed by determination of constituent elements using inductively coupled plasma optical emission spectroscopy (ICP-OES) and sulphates using ion chromatography (IC). The leaching solutions used included rainwater; dilute sulphuric acid at pH of 3.0 (a common leachate in such acidic soils); as well as plant exudates such as oxalic and citric acids. The leachate solutions were used to correlate the mineralogical composition of secondary precipitates and tailings footprints. Potential implications on humans following any accidental ingestion of the tailings or contaminated soils were assessed using gastric juices. The ecological risk factors and risk index together with the model to evaluate daily intake and different pathways to humans were used to assess the toxicity caused by exposure to contaminants in the materials. The experimental work was augmented by computer simulations based on geochemical modelling (using the PHREEQC geochemical modelling code) to determine the speciation of elements (and thus their potential lability and bioavailability), dissolution and formation of secondary mineral precipitates in the tailings dumps and footprints. The findings of the PXRD study showed that the mineralogy of the tailings and footprints was dominated by quartz (SiO2) and some minor minerals such as pyrite (FeS2), pyrophyllite (Al2Si4O10(OH)2), chlorite (Mg,Fe)3(Si,Al)4O10), mica (K(Mg,Fe)3 AlSi3O10(F,OH)2) while that of secondary precipitates was dominated by jarosite (KFe3+ 3(OH)6 (SO4)2), goethite (FeOOH), melanterite (FeSO4.7H2O) and gypsum (CaSO4.2H2O). Minerals obtained for the secondary precipitates were corroborated by geochemical modelling. Leaching results using rainwater with pH ranges from 3.5 to 3.9 showed that trace elements are released very slowly from tailings dumps and footprints and in small concentrations during rainy seasons as follows: As (1.5 mg/L-4.5 mg/L), Pb (3.5 mg/L-5.5 mg/L), Cu (4 mg/L-4.8 mg/L) and Zn (23 mg/L-44 mg/L). The release and mobility of Cu, Pb, Zn and As occurs quite markedly when secondary precipitates dissolve, making the immediate impacted environment unfavourable for plant growth and any habits in the vicinity. This was substantiated by simulated dissolutions and assessment of the resulting elemental speciation that pointed to the elements being distributed in bioavailable forms, implying potential uptake by plants (such as vegetables that may be cultivated on such impacted soils). The model was used to evaluate the daily intake and different exposure pathways and the results showed that children may daily intake 48.4 mg kg-1 day-1 and adults‟ 32.8 mg kg-1 day-1 . After 5 years (1825 days) of exposure more harm may be experienced and findings shows that kids are the most victims on these contaminated sites compared to adults. Both children and adults may absorb low levels of these toxic elements daily and after long time of exposure it may cause disease like cancer in their body which may lead to death. Pathways may be through inhalation and accidentally ingesting tailings soil that contain toxic elements. Drawing from the above findings, it will be important that tailings footprints that have been earmarked as land for development (residential or office space) be thoroughly assessed for potential release of toxic elements and high levels of acidity. Further reclamation aimed at reducing these hazards can then be implemented. / College of Agriculture and Environmental Sciences / M. Sc. (Environmental Science)
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A stakeholder analysis of the Marikana mining incident : implications for HR management

Engelbrecht, Jennifer Esme-Louise 27 May 2015 (has links)
M.Com. (Leadership in Performance and Change) / In August 2012 the South African mining industry was the focus of attention due to an illegal strike at Lonmin Platinum mine that resulted in the police shooting striking employees on 16 August 2012. Thirty-four employees lost their lives on that day. An additional ten people died in violent protests in the build-up to the main shooting incident. This strike period has become widely known as ‘Marikana’. This historical incident illustrates how a single incident within an organisation can have an impact at various levels and affect multiple stakeholders. The main objective of this study was to identify the effect that the Marikana mining incident had on Lonmin (the organisation) and its main stakeholders as well as to identify the effect the stakeholders and Lonmin had on each other. In order to reach these objectives an historical timeline of the sequence of events surrounding the Marikana incident was constructed. The main stakeholders involved in the Marikana incident were then identified, and the relationships and the relative strengths between these stakeholders were mapped. The methodology used in the study was Quantitative Narrative Analysis (QNA) as applied by Franzosi (2010). In particular, the content from English newspaper articles sourced from South Africa and England relating to the Marikana mining incident for the period 1 to 24 August 2012 were reviewed, coded and analysed. All relevant data from the articles were recorded in a manual database, coded according to the semantic triplet of ‘actors’, ‘actions’ and ‘subjects’ (S-V-O) (Franzosi, 1989) and analysed based on QNA principles (Franzosi, 2010). First, a sequence analysis was conducted, identifying the roles (consequences) that the respective actors (stakeholders and subgroupings of stakeholders) enacted as well as the order in which they unfolded. The analysis was used to produce a series of network graphs to visually depict the sequence of events and the respective effects of the sequencing of these events. These graphs take the form of stake maps and visually tell the story of how events unfolded and the effects of these events on all the actors involved ...

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