To see the other types of publications on this topic, follow the link: Platinum mines.
Dissertations / Theses on the topic 'Platinum mines'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Platinum mines.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Xulu, Celiwe V. "Exploring the application of strategic foresight in South African Mines : focusing on the platinum mines." Diss., University of Pretoria, 2015. http://hdl.handle.net/2263/52353.
Full textAbstract:
The purpose of this research was to investigate the extent to which strategic foresight was used by business leaders with a focus on the South African Platinum Mining Industry. The motivation for the research was the reports of prevailing conditions in the mining sector, which brought into question the level at which strategic foresight was used in planning. This raised a further question of whether academic research of the past 50 years was perceived as valuable by organisational leaders.
Because strategic foresight is a managerial tool that, among other things, takes into consideration the value of employees and other stakeholders, the researcher interviewed corporate Heads of Strategy, Business Development and Sustainability, and Risk, Assurance and Sustainability. Finance, Risk and Operations Managers in the operations were also interviewed.
Conclusions reached in this research were that use of strategic foresight, as explained by Rohrbeck & Gemünden, (2008), Slaughter, (1995) and Godet, (2008), seemed to be limited in the area of focus which was the South African Platinum Mining sector. This was due to the fact that all participating organisations seemed to have an idea of what it was but, either had no resources to properly implement it; lacked the understanding of the concepts; or simply felt that parts of the process, rather than the whole process, would be sufficient to guarantee success.<br>Mini Dissertation (MBA)--University of Pretoria, 2015.<br>ms2016<br>Gordon Institute of Business Science (GIBS)<br>MBA<br>Unrestricted
2
Naidoo, Kumendrie. "Considerations for stope gully stability in gold and platinum mines in South Africa." Diss., Pretoria : [s.n.], 2001. http://upetd.up.ac.za/thesis/available/etd-11302005-123445/.
Full text
3
Carroll, Sandy. "The viability of the Kaplats Platinum group element deposit." Access, 2006. http://upetd.up.ac.za/thesis/available/etd-07102008-080330/.
Full text
4
Hlapho, Tseko. "Key drivers of employee engagement in the large platinum mines in South Africa." Diss., University of Pretoria, 2015. http://hdl.handle.net/2263/52407.
Full textAbstract:
The growing importance of managing employee relations and productivity in the platinum mining industry - one of South Africa s most significant employers - has made investigating employee engagement imperative, particularly in light of the 2014 platinum strike, the longest and most expensive in the country s history. As employee engagement is viewed as crucial for business success, this study aimed to ascertain the current levels of employee engagement in the large South African platinum mines, what the key drivers of engagement are, and whether these drivers differ between management and employees.
This was a cross-sectional study where a questionnaire was utilised. Data was collected from the two largest platinum companies with operations situated in North West province of South Africa. The questionnaire was based on the literature review, particularly the theoretical employee engagement model of Rana et al., (2014), to determine the drivers of engagement and to measure the degree of employee engagement. The study was based on 301 responses which equated to 75% response rate.
The study found that the majority of the respondents were engaged at work. Job design and characteristics, supervision, relationship with co-workers, workplace environment and human resource development (HRD) practices were confirmed as being the key drivers of employee engagement on the platinum mines. The study also revealed that drivers of engagement differ between the levels of employees. Operators and middle managers were found to share a similar view of drivers of engagement compared to supervisors and junior management. Female mineworkers were found to be less engaged than their male counterparts. These findings may benefit companies to better their understanding of employee engagement and consequently strengthening their employee engagement strategies.<br>Mini Dissertation (MBA)--University of Pretoria, 2015.<br>ms2016<br>Gordon Institute of Business Science (GIBS)<br>MBA<br>Unrestricted
5
Du, Pisani Petro. "The financial benefit of using borehole radar to delineate mining blocks in underground platinum mines." Diss., Pretoria : [s.n.], 2008. http://upetd.up.ac.za/thesis/available/etd-02092009-141519/.
Full text
6
Jali, Mthokozisi. "The impact of pay on productivity and motivation on general workers in South African platinum mines." Diss., University of Pretoria, 2015. http://hdl.handle.net/2263/52414.
Full textAbstract:
Pay is the main concern of employers, as it affects motivation and productivity. How well the firm motivates its workers is important in achieving the firm s set goals since motivation increases productivity. Motivated workers help make the company profitable. Pay is a powerful motivator for general workers, and no other motivation or motivational techniques is better than money. General workers performance is driven by the motivation to exert more effort in their job. South African companies are performing poorly in investigating and implementing motivational strategies that will drive productivity and very small number of studies has been carried out in labour intensive industries, such as the mining industry.
The aim of this research was to understand if pay does have an impact on general workers motivation and productivity. The result of this study will help South African platinum mine managers to understand what motivates general workers and can also be used by other firms in the mining industry to put together pay strategy that will motivate general workers to be more productive.
In line with qualitative research methodological principles, this study followed a non-empirical exploratory and adopted phenomenological approach in order to understand the impact of pay as a motivator for general workers. A total of 29 semi-structured interviews were held with general workers. Participants were selected from general workers that were working for the three biggest platinum mines in South Africa. These general workers were doing work that was linked with production. Permission for general workers to participate in the study was requested before commencing with the interviews and the participants were guaranteed confidentiality.
The finding of this study revealed that pay was an important and main motivator for general workers in South African platinum mine and it drives workers to be more productive. General workers will work hard if they are happy with their pay and if pay is increased regularly. The study proved that there is definitely a link between motivation and productivity. When general workers are motivated, they will work hard to achieve a set target. Good supervision and good relationships between general workers and their supervisors was found to be a second motivator for general workers.<br>Mini Dissertation (MBA)--University of Pretoria, 2015.<br>ms2016<br>Gordon Institute of Business Science (GIBS)<br>MBA<br>Unrestricted
7
Seke, Makunga Daudet. "The impact of the proposed nationalisation of South African mines on employment in the platinum sector." Diss., University of Pretoria, 2012. http://hdl.handle.net/2263/23050.
Full textAbstract:
Many forums have been recently organised in South Africa to discuss the level of State intervention in the minerals sector, the expropriation of private mining companies, and the transfer of mineral wealth to the people. The objective of this research was to explore the possible impact that the nationalisation and the introduction of a resource rent tax will have on the capability of platinum mining companies to create sustainable employment while remaining profitable in South Africa.The research was qualitative and exploratory in nature. The sampling frame included major platinum group metals companies, which constitute an industry concentration of more than 50 per cent. Semi-structured interviews were conducted with 13 senior managers and executives from the platinum mining industry.The results have shown that nationalisation of platinum mines, where the government has total ownership or majority control of the company, will not create sustainable employment in South Africa. In addition, nationalisation of mines will isolate South Africa from external capital because private investors have been reluctant to put their money where mining companies were nationalised, especially in Africa. Although the introduction of a resource rent tax may be viable in a short term, it is believed that the competitiveness of mining companies operating in South Africa will be compromised.<br>Dissertation (MBA)--University of Pretoria, 2012.<br>Gordon Institute of Business Science (GIBS)<br>unrestricted
8
Vos, Cornelius Francois. "The role of long-chain trithiocarbonates in the optimisation of Impala Platinum's flotation circuit." Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-10182007-103419/.
Full text
9
Zilibokwe, Nosibulelo Julie. "Characterization of the distribution of platinum group elements in sulphide ores within the Merensky Reef at Modikwa and Two Rivers Platinum Mines, Eastern Bushveld Complex, South Africa." Thesis, Rhodes University, 2017. http://hdl.handle.net/10962/7938.
Full textAbstract:
The distribution of the platinum group element (PGE), in the Merensky Reef was characterized by, first determining the occurrence of the platinum group minerals (PGM), then by establishing the PGE concentration in the base metal sulphides (BMS) associated with the PGE mineralization in the Merensky Reef from selected borehole intersections, at the Two Rivers (TRP) and Modikwa Platinum Mines in the Eastern Bushveld Complex. A mineral liberation analyser (MLA) was then used to identify the PGM phases; their silicate and base metal associations; and their grain size distribution. Electron microprobe quantitative analysis and mapping were then used to determine the compositional variation of the PGM and the PGE elemental distribution in the BMS, respectively. The study showed that the BMS including pyrrhotite, pentlandite, and chalcopyrite were the principal sulphides, where pyrrhotite was most prominent with minor quantities of pyrite. Orthopyroxene, clinopyroxene and plagioclase were the most abundant primary silicate minerals identified, while secondary silicates identified included talc, serpentine and amphibole. Platinum group minerals showed three distinct groups with respect to the mineralogical association with the PGE; (i) BMS association; (ii) chromite association; and (iii) silicate association. Of the BMS, chalcopyrite showed the most dominant association with the PGMs. All samples from both mines exhibited a wide range of PGMs, including maslovite, braggite, cooperate, laurite and PGE alloys such as ferroplatinum as well as other unidentified platinum and palladium sulphides, arsenides and bismuthides, while gold was present as electrum. The PGMs ranged in size from less than a micron to about 125 microns with an average of 20 microns. The close association of PGM with BMS along the margins of sulphides indicates that the PGMs were derived from the sulphide melt. PGE distribution in the sulphides at Modikwa showed pentlandite contained the highest concentrations of palladium (up to 379 ppm) and chalcopyrite hosting the highest rhodium concentrations (up to 793 ppm). Samples from Two Rivers revealed pentlandite as the principal host to both palladium and rhodium, with concentrations reaching up to 695 and 930 ppm, respectively. Magnetite at both Modikwa and Two Rivers showed significant rhodium content, reaching up to 982 and 930 ppm, respectively. The pyrrhotite compared to other sulphides contained all the elements found in the platinum group (PPGE), namely, platinum, palladium and rhodium, with all the platinum identified found in the pyrrhotite. The concentrations for the iridium group (IPGE) namely, iridium, osmium, and ruthenium were below the detection limit. The PGE mineralization in the stratigraphy varied within each mine. The mineralization revealed top loading in the central sector (Modikwa) and bottom loading in the southern sector (Two Rivers). The sequence of the Merensky Reef at the two sectors of the Eastern Bushveld Complex showed a remarkable similarity in their mineralogy suggesting that these two sectors were formed from the same liquid or formed simultaneously within a single magma chamber; however the PGE distribution within the stratigraphy may have been controlled by the presence of cumulate sulphides.
10
Tyira, Tshegofatso Windy. "An analysis of the operational value of the environmental management systems (ISO14001:2004) implemented at selected underground platinum mines in South Africa / cTshegofatso Windy Tyira." Thesis, North-West University, 2012. http://hdl.handle.net/10394/9848.
Full textAbstract:
ISO 14001 is the specification and guideline providing the framework for the establishment of the EMS. It was first published in September 1996 and updated in November 2004. It was developed by ISO, a Geneva-based NGO that promotes the development and implementation of international standards (Darnall, 2001:2). EMS is part of the organisation’s management system used to develop and implement its environmental policy and manage its environmental impacts (ISO 14001, 2004:2).
In South Africa there is no legal requirement for EMSs to be put into place, other than where it may have been made a condition of a permit or licence application. All Underground Platinum Mines are required to develop, document, implement, maintain and review their EMS, which should be certified toISO14001:2004 (AEW, 2009:13).
The problem is that the implementation of an EMS is associated with a number of shortcomings and may be seen as a paper exercise to satisfy the needs of external auditors during audits with no particular value accruing to the organisation.
The aim of the research was to determine the operational value of the ISO 14001 EMS at selected Underground Platinum Mines. A structured survey-based research study was conducted among employees in three different operations within Underground Platinum Mine. This included literature and case studies review, interviews with key EMS implementers and distribution of questionnaires to those employees involved with the EMS implementation.
The main aim of the research has been achieved and all the research sub-questions were answered. The study concludes that the ISO 14001 EMS as implemented at Underground Platinum Mine is not merely a paper exercise but has an operational value.<br>Thesis (M. Environmental Management)--North-West University, Potchefstroom Campus, 2013.
11
Mitchell, Andrew Alexander. "The petrology, mineralogy and geochemistry of the main zone of the Bushveld Complex at Rustenburg Platinum Mines, Union Section." Thesis, Rhodes University, 1988. http://hdl.handle.net/10962/d1001563.
Full textAbstract:
Union Section of Rustenburg Patinum Mines is situated in the northwestern part of the Bushveld Complex, some twenty kilometres north of the Pilanesberg Alkaline Complex. The mining lease area covers a roughly triangular segment of Lower, Critical and Main Zone rocks, transgressed to the north and south by magnetite-bearing ferrogabbro of the Upper Zone. The Main Zone at Union Section is the focus of this study. The prime source of sample material for the study is the deep exploration borehole SK2, but additional, supplementary samples were collected on surface and underground, as well as from a second surface exploration borehole, SK4. In line with the recommendations of SACS (1980), the top of the Critical Zone, and therefore the base of the Main Zone, is taken to be the top of the Bastard Cyclic Unit. Sharpe (1985) suggested that the succession from the base of the Main is an isotopically separate entity Zone up to the Pyroxenite Marker from the rest of the Bushveld layered succession. This is not strictly true, as there is evidence that more than one parental magma was involved in the formation of this interval. It is, however, true that there are fundamental differences, particularly in isotopic makeup, between the Main Zone rocks below the pyroxenite Marker and those above (the latter having been assigned by Molyneux (1970) to subzone C of the Main Zone). Kruger et al. (1986, in press) suggested that the Pyroxenite Marker marks the base of the Upper Zone, and this convention is adhered to here. The implication of this is that the rocks which formerly constituted subzone C of the Main Zone are now considered part of the Upper Zone. The Main Zone rocks below the pyroxenite Marker were originally subdivided by Molyneux (1970) into two subzones, A and B. The results of the present study indicate that this subdivision is not justified. Instead, eight units have been distinguished in the Main Zone on geochemical, petrological and mineralogical bases. Each of these units is characterized by a coherent set, or progression, of chemical and petrological characteristics. The specific assignment of genetic connotations to these units has been deliberately avoided , at least until further studies of the Main Zone prove this to be justified. The demarcation of the eight units is illustrated in the composite diagram (Fig. 34) in the back pocket of this work, and the reasons for the subdivisions are listed in Table 6 (at the end of chapter 7 of this thesis). Until the late 1970's, it was thought that most layered cumulates formed by crystal settling (Wager and Brown, 1968). More recently, there has been a fundamental conceptual change, and many workers now believe that most cumulate rocks formed by in situ crystallization at the floor and walls of the magma chamber (McBirney and Noyes, 1979, Irvine, 1980a; Campbell, 1987). There is, however, some evidence for the physical separation of phases undergoing cotectic crystallization, particularly in the Upper Critical Zone and lower part of the Main Zone (Eales et al., 1986). This process, which has been alluded to in the past by various authors (Ferguson and Botha, 1963; Vermaak, 1976) involves the flotation of early-formed plagioclase crystals due to their positive bouyancy in tholeiitic liquids. The result is an apparent decoupling of the chemistry of pyroxene and plagioclase, as in unit IV of the Main Zone, where plagioclase becomes more anorthitic upwards, whilst pyroxene becomes more iron-rich. There is some substantial evidence, particularly in reversals in the strontium isotope initial ratio and the orthopyroxene Mg/(Mg+Fe) ratio , for multiple intrusion in the Main Zone. Although the largest and most important magma influx in the Main Zone was a high-R₀ aluminous tholeiite, as suggested by Sharpe (1985), the intrusive history of the Main Zone is believed to be far more complex than Sharpe (op. cit.) suggested. Significantly, there is strong evidence for small influxes of Upper Zone-type (Fe-rich tholeiite) magma in the upper reaches of the Main Zone. These are believed to be precursors to the major influx of Upper Zone-type magma at the pyroxenite Marker (Kruger et al, 1986, in press). The fate of intercumulus liquids in cumulate rocks has recently recieved substantial attention (Sparks et al., 1985; Morse, 1986; Barnes, 1986: Campbell, 1987). It is believed that the migration, or at least redistribution, of intercumulus liquids has played a vital role in modifying fractionation trends in the Main Zone. More importantly, the accumulation of late-stage intercumulus liquids is believed to be responsible for the formation of the Fe-rich ultramafic pegmatite bodies that interrupt the layered cumulates in borehole SK2<br>Adobe Acrobat 9.53 Paper Capture Plug-in
12
Mooney, David G. "An evaluation of small scale open cast mining of UG2 in the Bushveld complex." Thesis, Rhodes University, 1997. http://hdl.handle.net/10962/d1005555.
Full textAbstract:
The current weak state of the platinum market, as well as the large inventory of platinum group metals held by Russia, necessitates that the South African platinum mining industry must carefully evaluate the benefits and disadvantage of small-scale mining of shallow, open castable ore resources. Until the late 1980's, these resources were ignored due to the metallurgical complexities of treating oxidized ore, as well as the mind set that existed within the South African mining industry which militated against open cast mining in the Bushveld. During the latter part of the 1980's and early 1990's, advances in the metallurgical treatment of oxidized ore, specifically the UG2, as well as operational problems, created the impetus to begin the exploitation of these resources. Small-scale open cast mining has become viable due to the development of suitable mining methods that facilitate mining practices acceptable to the Department of Mineral and Energy Affairs, in terms of environmental legislation. Metallurgical advances and growing experience, especially with respect to the UG2, enables reasonable platinum group metals recovery from oxidized ore. The problems experienced in doing this can, and are being overcome. With growing public awareness of environmental issues, particularly related to the mining industry, the requirement to ensure that the small-scale open cast mine site is well managed is paramount. A methodology for the evaluation is presented along with a case study of a small-scale UG2 open cast pit. Evidence is presented that shows that these small-scale open cast mining operations are extremely profitable and require minimal capital expenditure. However, caution is advised when evaluating Merensky Reef open cast operations because of the problems that they present.
13
Geldenhuys, Genna-Leigh. "Characterization of diesel emissions with respect to semi-volatile organic compounds in South African platinum mines and other confined environments." Diss., University of Pretoria, 2014. http://hdl.handle.net/2263/46248.
Full textAbstract:
Concentrations of diesel particulate matter (DPM) and polycyclic aromatic hydrocarbons (PAHs) in platinum mine environments are likely to be higher than in ambient air due to the use of diesel machinery in confined environments. PAHs may be present in gaseous or particulate phases each of which have different human health impacts due to their ultimate fate in the body. The sampling of both phases was made possible by means of small, portable denuder sampling devices consisting of two polydimethylsiloxane multi-channel traps connected in series and separated by a quartz fibre filter. Thermal desorption coupled with two dimensional gas chromatography with mass spectrometric detection (TD-GCxGC-ToFMS) was employed to analyse samples from three different platinum mines. The underground environments revealed that PAHs were predominantly found in the gaseous phase with naphthalene and mono-methylated derivatives being detected in the highest concentrations ranging from 0.15 – 8.73 μg.m-3. Similarly higher gas phase PAH loading was found in the Daspoort Tunnel. The particle bound PAHs underground were found in the highest concentrations at the Load Haul Dump (LHD) vehicle exhaust with dominance of fluoranthene and pyrene and concentrations ranged from 0.52-109.60 ng.m-3. This work highlighted the need to characterise both gaseous and particulate phases of PAHs in order to assess occupational exposure and demonstrated the successful application of these portable denuders in the mining environment.<br>Dissertation (MSc)--University of Pretoria, 2014.<br>tm2015<br>Chemistry<br>MSc<br>Unrestricted
14
Fischat, Herbert Robert James Falconer. "The criterion of justifiability as a ground for review following Sidumo v Rustenburg Platinum Mines (2007) 12 BLLR 1097 (CC)." Thesis, Nelson Mandela Metropolitan University, 2013. http://hdl.handle.net/10948/d1019792.
Full textAbstract:
This treatise will focus on the review of labour arbitration awards provided for under the oversight of the Commission for Conciliation, Mediation and Arbitration (CCMA), bargaining councils, statutory councils, accredited private agencies and approved private arbitration tribunals. The general grounds of review applicable to the arbitration awards of the different bodies are set out. Thereafter the case of Carephone (Pty) Limited v Marcus NO & others (1998) 19 ILJ 1452 (LAC) is analysed and the core principles pertaining to the justifiability test are clarified for the first time in the forum of the Labour Appeal Court. The judicial rationale for the relevance and applicability of the test to CCMA arbitration proceedings and criticisms of the test are examined. The justifiability tests are only applicable to review proceedings in CCMA matters and not available to private arbitration review matters. There are however three approaches which are being suggested for the application of the justifiability tests to private arbitration review. Firstly, it is suggested that the Arbitration Act could be interpreted to include the justifiability test under the statutory review grounds. Secondly, the arbitration agreements could be interpreted to include an implied term that the arbitrator is under a duty to give justifiable awards. Finally, it can be submitted that the law should be developed by reading into all arbitration agreements the ability to arbitrators to give justifiable awards. Since the judgment of Sidumo v Rustenburg Platinum Mines [2007] 12 BLLR 1097 (CC) various critical questions arose in relation to the interpretation and application for the purpose of dealing with subsequent review applications. Firstly, this research paper will seek to establish whether the courts in subsequent matters to the Sidumo judgment have interpreted reasonableness as a test or ground for review. Secondly the research paper will scrutinise case law whether the reviewing court is entitled to rely on and consider reasons other than those provided for by the commissioner in his award to determine inter alia, the reasonableness of his decision arrived at. The Constitutional Court in the Sidumo case rejected the so-called employer’s test, stating that ultimately the commissioner’s sense of fairness is what must prevail and not the employer’s view. Consequently an impartial determination whether or not a dismissal was fair is likely to promote labour peace amongst the labour force. The test arrived at by the Constitutional Court in the Sidumo case for determining whether a decision or arbitration award of a CCMA commissioner is reasonable, is a stringent test that will ensure that such awards are not easily interfered with. The question to be asked in determining whether there has been compliance with the standard is whether the decision of the commissioner is one which a reasonable decision maker could have reached. This approach will underpin the primary objectives of the Labour Relations Act which is the effective resolution of disputes. This finding will be apparent from important cases decided and discussed after the Sidumo landmark ruling.
15
Andrews, Lesley. "Base metal losses to furnace slag during processing of platinum-bearing concentrates." Diss., Pretoria : [s.n.], 2008. http://upetd.up.ac.za/thesis/available/etd-01222009-172643/.
Full text
16
Moore, Bronwyn Ann. "Investigation into the technical feasibility of biological treatment of precious metal refining wastewater." Thesis, Rhodes University, 2013. http://hdl.handle.net/10962/d1002013.
Full textAbstract:
The hydrometallurgical refining of platinum group metals results in large volumes of liquid waste that requires suitable treatment before any disposal can be contemplated. The wastewater streams are characterized by extremes of pH, high inorganic ion content (such as chloride), significant residual metal loads and small amounts of entrained organic compounds. Historically these effluents were housed in evaporation reservoirs, however lack of space and growing water demands have led Anglo Platinum to consider treatment of these effluents. The aim of this study was to investigate whether biological wastewater treatment could produce water suitable for onsite reuse. Bench-scale activated sludge and anaerobic digestion for co-treatment of an acidic refinery waste stream with domestic wastewater were used to give preliminary data. Activated sludge showed better water treatment at lab scale in terms of removal efficiencies of ammonia (approximately 25%, cf. 20% in anaerobic digestion) and COD (70% cf. 43% in digestion) and greater robustness when biomass health was compared. Activated sludge was consequently selected for a pilot plant trial. The pilot plant was operated on-site and performed comparably with the bench-scale system, however challenges in the clarifier design led to losses of biomass and poor effluent quality (suspended solids washout). The pilot plant was unable to alter the pH of the feed, but a two week maturation period resulted in the pH increasing from 5.3 to 7.0. Tests on algal treatment as an alternative or follow-on unit operation to activated sludge showed it not to be a viable process. The activated sludge effluent was assessed for onsite reuse in flotation and it was found that there was no significant difference between its flotation performance and that of the process water currently used, indicating the effluent generated by the biological treatment system can be used successfully for flotation. Flotation is the method whereby minerals refining operations recover minerals of interest from ore through the addition of chemicals and aeration of the ore slurry. Target minerals adhere to the bubbles and can be removed from the process.
17
Machumele, Nkateko Jones. "A geological, petrological and mineralogical study of the UG3 chromitite seam at Modikwa Platinum Mine : significance to exploration and PGE resources." Thesis, Rhodes University, 2014. http://hdl.handle.net/10962/d1013553.
Full textAbstract:
The UG3 at Modikwa Platinum Mine occurs as a platiniferous, planar chromitite seam. It is stratigraphically located in the Upper Critical Zone of the Eastern Bushveld Complex. Field work study comprise of underground mapping, sampling, surface mapping, borehole core logging, microprobing and microscopic investigations carried out at the Rhodes University. The UG3 at the Modikwa Platinum Mine is about 22cm thick chromitite seam underlain by a white fine grained anorthosite and overlain by a brown medium grained feldspathic pyroxenite. It is an incomplete cyclic unit consisting of chromite and feldspathic pyroxenite. The UG3 reef at the Modikwa Platinum Mine lease area represents a Platinum Group Metal resource of 300 million tons of ore at an in situ grade of 2.5g/t. Under the current market conditions the UG3 reef remains unprofitable to mine in an underground operation due to the operational cost involved. However, it has been illustrated that the UG3 chromitite seam can increase profit margins in an open pit operation provided it is mined together with the economic UG2 chromitite seam. The extraction of the UG3 as ore in the four Modikwa UG2 open pits would result in a combined operating cash profit of R330 million. The UG3 chromitite seam is platiniferous. The platinum-group minerals (PGM) range in size from less than 10μm to about 70μm. The PGMs are associated with sulphides and are both located in the interstitial silicates and are concentrated in the chromitite seam. The PGMs show a strong preference to contact boundaries of the silicate grains, the chromite grains and the sulphide phases. In some instances, they are enclosed within the chromite grains in association with sulphides. The general sulphide assemblage comprises pentlandite and chalcopyrite whereas, the PGMs assemblage comprises cooperite, ferroplatinum, laurite, FeRhS and PtRhS.
18
Van, Schoor Abraham Michael. "Using electrical resistance tomography (ERT) and induced polarisation (IP) tomography to map potholes and iron-rich ultramafic pegmatite bodies in South African platinum mines." Thesis, Lancaster University, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.539647.
Full text
19
Balakrishna, Manivasan. "An assessment of the economic viability of mining the UG2 Reef within the no. 12 Shaft lease area, Impala Platinum Limited." Diss., Pretoria: [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-06262008-113235.
Full text
20
Field, Matthew. "The petrology and geochemistry of the upper critical zone of the Bushveld complex at the Amandelbult section of Rustenberg Platinum Mines Limited, Northwestern Transvaal, South Africa." Thesis, Rhodes University, 1987. http://hdl.handle.net/10962/d1007499.
Full textAbstract:
A study of petrological and geochemical variations through the upper Critical Zone of the Bushveld Complex at Amandelbult section of R.P,M. was undertaken. The sequence at this locality may be divided into seven "units" two of which appear to be complete, possessing the sequence harzburgite-pyroxenite-norite-anorthosite. The other five Units lack basal, intermediate or upper members. Considerable lateral variations are apparent in this sequence, but these are restricted to the Lower Pseudo Reef-Merensky Reef interval, tne same portion of the succession which is affected by pothole structures. The single most important petrographic feature of genetic significance is the occurrence of annealed, recrystallized anorthosite immediately underlying ulstramafic layers. This, together with the undulatory nature of the contact between the two rock layers, suggests that the ultramafic layer was emplaced as a hot liquid over a pre-existing, crystalline anorthosite floor, and that some remelting of this layer occurred. Variations in the chemical make-up of constituent silicate minerals reveal a number of significant processes which may have been operative in the magma chamber prior to crystallization, Olivine grains, for instance, exhibit extremely wide chemical variations both within single layers and from one layer to the next. These variations are best explained by re-equilibration processes with spinel and base metal sulphides, rather than by wide variations in original liquidus compositions. It appears that the compositions of the initial liquids from which each basal olivine-bearing layer crystallized, were approximately similar. Variations in the iron-magnesium ratio of ortho-pyroxenes indicate well defined continuous fractionation trends in units which are considered to be complete. Magnesian compositions are recorded in ultramfic members, while increasingly iron-enriched values are recorded upwards through the sequence pyroxenite-norite-antorthosite. Plagioclase grains exhibit less well defined fractionation trends, but it is clear that an upward increase in An is encountered through indivitual Units. This is in direct contrast to the trend exhibited by orthopyroxene. A further feature of plagioclase grains is the considerable degree of chemical zonation exhibited by them. In cumulus grains this is commonly manifested as strongly reversed rims, while in intercululus grains normal zoning is ubiquitous. Whole-rock chemical variations through the succession indicate that cyclical variations occur through successive Units, but that these merely reflect changes in modal mineralogy and not liquid fractionation trends. Such trends can be shown for selected element ratios, where these elements are known to partition into a single mineral phase. Rations of pyroxene components such as the nickel/scandium ratio, exhibit a saw tooth pattern through successive Units, while ratios of plagioclase components such as the strontium/alumina ratio have unique, fairly constant values for each individual Unit but different values for successive Units. The latter type of cyclicity is not always strictly confined to lithologically recognized boundaries between Units, and a slight overlap into overlying ultramafic layers is apparent. An investigation of variations in trace element levels in a single layer in five widely separated boreholes revealed that there is some evidence for a lateral fractionation trend from the southwest (more primitive) to the northeast (more evolved), although the small number of data points available preclude definite conclusions. There exists in the data some evidence that the Giant Mottled Anorthosite differs chemically from the other anorthosites in the study section, and that it more closely resembles rocks of the Main Zone. This evidence is particularly apparent in variations of the chromium/aluminium ratio of orthoyroxene grains, and in the An content of plagioclase grains, both of whose trends exhibit distinct inflections at the base of this member. The features of the succession at Amandelbult are best explained by the model of Eales et al. (in press, a), which visualizes the input of a number of pulses of new, hot liquid into a magma chamber containing the fractionated residua of previous influxes. At a critical point in time, just prior to the mafic Merensky Reef input, a large input of gabboic liquid was intruded at high levels in the chamber. The lower portions of this liquid mixed with the residua of earlier mafic inputs, which in turn mixed with new inputs of mafic, typical Critical Zone liquids. Thus the lower portions of the study section represent mixtures of new Critical Zone liquids with the residua of previous such influxes, while the upper portions have the added complication of mixture with a Main Zone-type liquid. The unique chemical character of the Giant Mottled Anorthosite appears to be a direct manifestation of the influence of the Main Zone liquid.<br>KMBT_363<br>Adobe Acrobat 9.54 Paper Capture Plug-in
21
Williams, Stephen Bruce. "The effect of scale and shape on the strength of Merensky Reef samples." Diss., Pretoria: [s.n.], 2000. http://upetd.up.ac.za/thesis/available/etd-11092006-132936/.
Full text
22
Van, den Berg Mader J. "Western limb tailings reclamation project." Diss., Pretoria : [s.n.], 2004. http://upetd.up.ac.za/thesis/available/etd-07272005-100249.
Full text
23
De, Klerk William Johan. "Petrogenesis of the upper critical zone in the Western Bushveld Complex with emphasis on the UG1 Footwall and Bastard units." Thesis, Rhodes University, 1992. http://hdl.handle.net/10962/d1005598.
Full textAbstract:
This study is an account of the stratigraphic sequence, the petrography, mineralogy (microprobe investigations of orthopyroxene, clinopyroxene, olivine and plagioclase feldspar), and whole-rock major- and traceelement geochemistry of the silicate cumulates of the Upper Critical Zone in the western Bushveld Complex. Two parts of the study - an investigation of a 350m column incorporating the MG3 and UGI Footwall Units, and a comparison of two additional Upper Critical Zone profiles with a previously compiled profile between the UGI and Bastard Units - are focused on RPM Union Section in the northwestern sector of the Complex. The third part is a detailed vertical and lateral investigation of the Bastard Unit at the top of the Critical Zone, which draws on sampling and data compilation from seventeen profiles in the western limb of the Complex. The MG3 Unit (45m) is made up of a lower chromitite layer overlain by a norite-pyroxenite-anorthosite sequence while the UGlFW Unit (295m) is composed of a related series of lower chromitite layers (MG4) overlain by a pyroxenite-norite-anorthosite sequence capped by the UGI chromitite layer. These mafic cumulates display a distinctive pattern of oscillating cryptic variation in whole-rock Mg/(Mg+Fe), FeO/Ti0₂, Cr/Co and Ni/V ratios through the sequence. Sympathetic oscillations are recorded for compositions of orthopyroxene and plagioclase feldspar and eight subcycles are recognised through the UGlFW Unit. The entire sequence is characterised by the presence of small, spheroidal, embayed and irregularly shaped plagioclase grains which are poikilitically enclosed in cumulus orthopyroxene grains of both pyroxenites and norites. This texture is indicative of partial resorption of pre-existing feldspar primocrysts within the melt prior to their being incorporated into the host orthopyroxene grains. Textural, geochemical and isotopic data suggest that this sequence was built up by periodic additions of fresh, relatively primitive liquid into fractionated resident liquid, and subsequent mixing within the magma chamber. The Bastard Unit sequence, described in Chapter 4, is the last and most complete cyclic unit (c. 60m) of the Critical Zone, and its upper contact defines the boundary between the Critical and Main Zones of the Complex. This Unit can conveniently be sub-divided into a lower part, where orthopyroxene occurs as a cumulus phase, and the upper part which is composed entirely of anorthosite (Giant Mottled Anorthosite). The basal part of the Unit (≤ 18m) comprises a thin chromitite layer < O.5cm) overlain by a pyroxenite-melanorite-norite-leuconorite sequence. The basal pyroxenite is orthocumulate in character and rapidly gives way to norites and leuconorites. A distinct threefold subdivision emerges within the Giant Mottled Anorthosite which is predominantly an adcumulate which becomes orthocumulate in character at its top. Apart from minor deviations in thicknesses these lithologies are recorded over the entire strike-length covered in this study. Profiles of cryptic variation are compiled for orthopyroxene, plagioclase and whole-rock data and show that the Bastard Unit displays a characteristic pattern which is maintained throughout the western Bushveld Complex. A minor yet distinctive reversal in cryptic variation is revealed at a level which is stratigraphically variable within the lower Giant Mottled Anorthosite, and results in a double cuspate pattern. A remarkable feature of the basal Bastard pyroxenites is that although the modal proportion of mafic to felsic constituents varies systematically away from the northwestern sector, the Mg/(Mg+Fe) ratio of orthopyroxenes remains constant at 0.804 over a lateral strike distance of 171km. Within the upper part of the Unit the orthopyroxene is markedly Fe-rich and it is here that inverted primary pigeonite appears for the first time as a cumulus phase. In addition, K-feldspar, oscillatory zoned plagioclase grains and high levels of incompatible trace elements are noted at this level. On the basis of the data presented it is concluded that the Bastard Unit represents the crystallisation of a final, relatively large influx of hotter primitive liquid, with upper Critical Zone affinities, and subsequent mixing with a column of cooler (less dense) supernatant liquid which had in part hybridized with the overlying Main Zone magma. It is hypothesised that this new liquid was emplaced as a basal flow beneath supernatant liquid and that it initiated the deposition of mafic cumulates at its base. The supernatant liquid is interpreted as representing the fractionated residuum produced by crystallisation of earlier cyclic units, with plagioclase on the liquidus, and that it contained an abundance of small plagioclase primocrysts in suspension. Development of the Unit can be viewed as a two-stage process. In the lower half of the unit, chemical and physical parameters typical of the new magma dominated the crystallisation process, and resulted in cumulates very similar to other relatively complete Upper Critical Zone units. In the upper, leucocratic sequence, above a minor reversal, crystallisation was from a liquid which was the product of mixing of a minor pulse of primitive liquid with the reservoir of hybridized supernatant liquid. Although the Bastard Unit is not continuous around the entire Western limb of the Complex, it is concluded that it developed in a single, or connected, magma chamber and that its irruptive feeder zone was located in the proximal northwestern facies of the Complex.
24
Phillips, David. "Mineralogy and petrology of the Townlands iron-rich ultramafic pegmatite." Thesis, Rhodes University, 1985. http://hdl.handle.net/10962/d1007617.
Full textAbstract:
The Townlands iron-rich ultramafic pegmatite is a relatively large pipelike body situated in the western corner of Rustenburg Section, Rustenburg Platinum Mines. It is characterised by a strong negative magnetic signature and transgresses the noritic layered sequence of the upper critical zone of the Bushveld Complex. The layered rocks are downwarped in the vicinity of the pipe and are in sharp contact with the pegmatitic material. The pegmatite varies in composition between dunite and wehrlite, with the marginal zones being more wehrlitic in composition. Olivine (Fo₃₀ - Fo₅₂) and clinopyroxene (Wo₄₅En₃₀Fs₂₅ - Wo₄₅En₃₇Fs₁₈) are the dominant constituents and accessory phases include ilmenite, Ti -magnetite, apatite, amphiboles, chlorite-group minerals, biotite, ilvaite and a host of unusual ore minerals. The Fe-Ti oxides exhibit exsolution textures typically found in slowly cooled igneous rocks and temperatures of formati on are consi dered to be in excess of 800°C. The UG2 chromitite leader layers intersected by borehole TLP.l are enriched in Fe and Ti and exhibit compositions intermediate between chromite and Ti-magnetite. The ore mineral assemblage includes a primary sulphide assemblage consisting of troilite, chalcopyrite, cubanite and pentlandite, and an array of unusual phases formed by late-stage secondary processes. The unusual sulphides mooihoekite and haycockite, that occur in certain parts of the pegmatite, are considered to have formed by partial replacement of the primary assemblage and a possible paragenetic sequence is discussed. Mineral compositions and whole rock geochemical data are consistent with an origin for the pegmatite by crystallization from a fractionated melt. It is suggested that intercumulus fluids, trapped during the crystallization of the noritic layered sequence, accumulated in an area of structural weakness, in response to an increasing overburden pressure and/or tectonic activity. Evidence is also presented that indicates that the Townlands pegmatite may consist of at least two separate, but adjoining pegmatite bodies.<br>KMBT_363<br>Adobe Acrobat 9.54 Paper Capture Plug-in
25
Den, Boef Martinus. "Assessment of the national DSM potential in mine underground services / M. den Boef." Thesis, North-West University, 2003. http://hdl.handle.net/10394/111.
Full textAbstract:
ESKOM is moving towards a price structure for electricity which reflects, as far as
possible, the real cost of generation. It is called real time pricing (RTP). ESKOM
developed this cost structure to coax customers to use more electricity in off-peak
periods (low cost of generation) and less electricity in peak periods (high cost of
generation). However, many industries do not effectively use these price offerings
from ESKOM to the detriment of themselves and ESKOM.
In previous research improvements to this situation for the South African mining
industry were investigated. ESKOM funded research to find the potential for load
shifting on mines using RTP. The RTP investigation focused on the supply side
management (SSM) in the mining context of underground services on gold and
platinum mines. Elements investigated included the ventilation, cooling and pumping
(VCP) systems. (Except for pumps, these plants are generally installed
aboveground.)
Previous research showed a national RTP and SSM potential to shift 500 MW of
electrical load for a period of 5 hours. Through the previous research it became clear that the mines were previously able to
react partially to the price signals. However, it was proved by the research that the
full load shift potential can only be realised through the use of integrated dynamic
simulation and optimisation.
An even higher potential exists for load shift and electricity efficiency through demand
side management (DSM) on the underground services. Therefore, if underground
DSM strategies are combined with SSM strategies, a further and much bigger
potential can be exploited to the benefit of ESKOM and the mines. Due to these
factors this study was undertaken.
Three case study mines were identified for this study. They are Kopanang and
Target, both gold mines, and Amandelbult, a platinum mine. The DSM potential on
each of these mines was calculated using simulation, calibration, verification and
optimisation.
These results were presented to mine management to negotiate the implementation
of the proposed strategies on one of the mines. Kopanang's management agreed to
the implementation of these strategies for a trial period of 3 months after which the
success would be evaluated.
The results of the implementation, together with the case study results, were used to
calculate the national DSM potential in the mining sector through extrapolation. The
DSM potential amounts to 650 MW of load per day as well as 5% on electricity
consumption. This amounts to a potential saving of R72.1 million per year using
current tariffs. This means that ESKOM can save about R5000 million on the
building of a new power station to supply the equivalent load to the DSM potential.
Now that the national impact has been calculated and discussed, all these findings
must be used to motivate the implementation of these strategies throughout the
mining sector. A similar project can be undertaken to look at possible DSM
strategies in the industrial sector.
This might prove to be more difficult as the electricity intensive systems are mostly all
linked to the final production. In the mind of management this out-weighs the
possible cost savings that can be achieved.
ESKOM and the NER will have to rethink their strategy. Through DSM and load
shifting actions alone the pending electricity crisis will not be averted. The current tariff structures should be amended to not only reflect the true cost of electricity but
also provide incentive for DSM and load shifting.
Another problem that must be addressed to achieve the DSM targets set for 2007 is
the time that it takes to complete the study as well as the implementation time.
Software can easily be created to help in the speeding up of the case study itself, as
the process and steps followed, as well as models used, are very generic (at least in the gold and platinum mining sector).<br>Thesis (Ph.D. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2004.
26
Mnwana, Sonwabile Comfords. "Participation and paradoxes: community control of mineral wealth in South Africa's Royal Bafokeng and Bakgatla Ba Kgafela communities." Thesis, University of Fort Hare, 2012. http://hdl.handle.net/10353/526.
Full textAbstract:
Resource control as a form of community participation in the mineral economy has gained much recognition. One prevailing argument is that direct control of natural resources by local communities is an important precondition for equitable utilisation of the natural resource wealth, peaceful co-existence between mining corporations and indigenous communities, and congenial relations between local communities and the state. Studies have also shown that the absence of direct community control of mineral wealth remains a major factor in the communal resistance and socio-political conflict witnessed in the natural resource-endowed regions of countries such as Nigeria, Ecuador, Sierra Leone and the Democratic Republic of the Congo. However, little is known about mineral resource control at the community level. Does community control necessarily translate to equity? How does local involvement in the mobilisation of mining royalties benefit different segments of the community? Indeed, how do different segments of the community “control” the wealth? What is the specific model adopted to engender broad-based community participation in the utilisation of mineral wealth – and does it matter? These theoretical and practical questions were the impetus for undertaking this study in the Royal Bafokeng and Bakgatla Ba Kgafela – two platinum-rich ‘traditional’ communities in South Africa’s North West Province that have significant control over platinum resources in their territories. Utilising ethnographic data collected in the two study communities in 2008 and 2009, the thesis examines the character of community participation in platinum wealth utilisation; specifically, the conditions under which community participation promotes or hinders sustainable community development. The analysis uses a “three-dimensional participation ladder” conceptual scheme, based in part on Sherry Arnstein’s (1969) “ladder of citizen participation” and subsequent typologies of participation. Among the key findings of the thesis are that despite observed benefits, the interface of resource wealth and community development is fraught with tokenistic participation, elite-targeted grassroots anger, and local tensions – all linked to the contradictory nature of participation. The thesis further reveals that in some instances the challenge of platinum wealth-engendered community development tends to undermine existing customary and democratic spaces for participation, and that this is exacerbated by community-level issues such as poverty and inequality. The findings of the study compel a shift of analytical focus from conflict as an epiphenomenon of collective community exclusion and deprivation (as in the case of many natural-rich countries in Sub-Saharan Africa and elsewhere), to conflict as also resulting from collective community inclusion (in natural resource utilisation). At the policy level, the study generates insights that will, hopefully, assist mineral resource-endowed countries, such as South Africa, in dealing with the challenge of developing appropriate policy frameworks for regulating business and social partnerships between local communities and mining corporations, and within resource-rich communities themselves.
27
Maseko, Robert. "Being a black mine worker in South Africa: the case of Anglo Platinum Mine." Thesis, Rhodes University, 2016. http://hdl.handle.net/10962/651.
Full textAbstract:
This thesis presents a decolonial perspective on the experience of being a black mineworker in post-apartheid South Africa with specific reference to the Platinum Belt. It seeks to understand what it means to be a black mineworker by unmasking and analysing the existence and prevalence of coloniality in contemporary South Africa despite the end of formal colonialism (i.e. apartheid). As a world-wide system, coloniality has different dimensions which all speak to and highlight continuities between the period of colonialism and the post-colonial period. These dimensions are coloniality of power, coloniality of being and coloniality of knowledge. The power structure of coloniality produces and reproduces the identity of the black mineworker in present-day South Africa as a sub-ontological being devoid of an authentic humanity such that the mineworker is depicted as incapable of rational thought and knowledge. The existential condition of the black mineworker is symptomatic of the generic experience of being a racialised subject of colour in the current global power structure predicated on the dominance and hegemony of Western-centred modernity. The black mineworker exists on the darker side of Western-centred modernity, living a life of wretchedness and continuing to suffer the colonial wound in the absence of formal colonialism and apartheid. The mineworker is disposable and dispensable and lives and works in the shadow of death. In pursuing this course of reasoning, I deploy the epistemic method of ‘shifting the geography of reason’ in order to read the experience of mineworkers in South Africa from the locus of enunciation of the oppressed subject within the scheme of a colonial power differential based on a hierarchy of humanity. This method allows me to speak with and from the perspective of the black mineworkers in the Platinum Belt as opposed to speaking for and about them. I reach the conclusion that being a platinum mineworker in post-apartheid South Africa is a racial and market determined identity of colonialised subjectivity that relegates the dominated subject (the black mineworker) to the realm of the subhuman. In setting the context for this claim, I trace the origins and development of the black mineworker in South Africa with reference to historical processes such as dispossession and proletarianisation. Empirically, the thesis is rooted in a contemporary case study of mainly Anglo Platinum Mine, which involved comprehensive fieldwork focusing on the present lived realities of platinum mineworkers. The dignity and humanity of these black mineworkers has still not returned despite twenty years of democratic rule in South Africa, such that race remains a crucial organising principle in postapartheid South Africa.
28
Phale, Antoinette Sephiwe. "Work ethics of employees in the platinum mine industry / A.S. Phale." Thesis, North-West University, 2003. http://hdl.handle.net/10394/266.
Full textAbstract:
There are different factors that contribute to the development of work ethics. One such factor is
the individual in relation to the work, the organisation and the environment. Work ethics are
believed to be related to performance, productivity and the disciplining of extreme misconduct.
Work ethics are also associated with economic success. It is recommended that the organisation
should find out more about work ethics and how work ethics could be to the advantage of the
organisation.
The general aim of this research was to determine the work ethic of the employees in the
Platinum mine industry. Work ethics were defined in detail from the literature and the most
important factors that influence it were analysed.
A qualitative research design based on the phenomenological approach was used. The purpose of
this was to understand the individual in his or her totality and to make a qualitative analysis of a
person's conscious world. A questionnaire and interviews were used to determine employees'
experience of work ethics. Content analysis was done to define, examine, analyse, quantify and
interpret the research findings.
The results of the empirical study were discussed according to the themes of religion, culture,
individualism, group dynamics and organisational factors. It was found that factors influencing
work ethics have different effects on different people. Etiology, determinants and work-related
beliefs in different settings must also be taken into account. It was evident that people who
espouse work ethics are more productive, successful and satisfied.
Recommendations for future research were indicated.<br>Thesis (MA (Industrial Psychology))--North-West University, Potchefstroom Campus, 2004.
29
Marais, Laurette Marlize. "Characterization of bacteria isolated from a platinum mine tailings dam / Laurette Marais." Thesis, North-West University, 2012. http://hdl.handle.net/10394/8721.
Full textAbstract:
Contamination from various sources has a huge impact on soil health and microbial community composition. Metal contamination of soil in mining scenarios is of concern and is not adequately addressed, particularly with respect to the microbial community. The mining industry is one of the largest contributors to heavy metal contamination of soil in South Africa, especially since the country is one of the major mining countries in the world. Platinum mining is of special importance, since the largest percentage of the world’s reserves of platinum group metals are found and mined in South Africa. Metals from mining activities become irreversibly immobilized in soil systems because they cannot be degraded and has a huge impact on soil systems. In this study, bacteria was isolated from soil samples collected from a platinum mine tailings dam outside Rustenburg. During the warm sampling season (March 2006) most isolates were found, especially in sites 3 and 4. During the colder and drier season (May 2006) there were less isolates. Most of the isolated cultures also displayed a wide temperature growth range, mostly between 24°C - 37°C. Paenibacillus lautus and Bacillus subtilus DN-10 had a growth range between 5°C - 40°C. Culturable metal tolerant bacteria were isolated, purified and identified using 16S rDNA sequences. Nine different species were found namely Paenibacillus lautus strain DS19, Paenibacillus lautus, Paenibacillus sp. C15, uncultured Paenibacillaceae, Bacillus subtilis strain DN-10, Bacillus sp. KDNB5, Bacillus cereus, Stenotrophomonas maltophilia and Alcaligenes sp. DJWH 146-2. The ability of these strains to tolerate metal concentrations were explored by determining their minimum inhibitory concentrations for a selection of metals e.g. aluminum, barium, cobalt, chromium, cadmium, copper, iron, lead, manganese, nickel and mercury. Most isolates were able to tolerate >5mM of the Al\Ni alloy and cobalt. Transmission electron microscopy was used to determine the location of metals inside bacterial cells and electron dispersive X-ray analysis was used to determine the levels of metals inside microbial cells. Bacillus subtilis DN-10 (LDK0306) showed a high MIC (>5mM) for most metals used, except Hg. This strain also had a high percentage (10.26%) of Pb detected in its cells by EDX. This was the highest percentage detected. Plasmids were extracted from the identified strains and can help gain a better understanding of metal tolerance mechanisms used by these isolates.<br>Thesis(MSc (Environmental Sciences))--North-West University, Potchefstroom Campus, 2013
30
Schoonhoven, Martin. "Occupational exposure to radon in a South African platinum mine / M. Schoonhoven." Thesis, North-West University, 2012. http://hdl.handle.net/10394/9832.
Full textAbstract:
Background: The Platinum mining operations in South Africa mining platinum containing ore from areas where variable amounts of uranium are found, leading to the possibility of occupational exposure to the radioactive disintegration products of Uranium-238 and in particular the gas Radon-222. No scientific data is available for occupational exposure to Radon-222 in South African platinum mining operations. Objective: To determine the risk of occupational exposure to the radioactive disintegration products of naturally occurring Radon-222 gas in a South African platinum mine. Design: Quantitative sampling (personal and static) to establish baseline data on exposure to radioactive disintegration products of naturally occurring Radon-222 gas in a underground South African platinum mine. Setting: The Bafokeng Rasimone platinum mine located 30 km North West of Rustenburg in the Bushveld complex in the North West Province of South Africa. Study subjects: One hundred and seventy four potentially highest exposed underground employees and one hundred and twelve static underground samples were sampled. Method: Personal and area samples were taken on selected employees and in locations using RGM samplers using CR-39 plastic as a detection medium. Employees were selected to sample the highest exposed occupations and static samples were located to sample returning air from levels underneath the sampling point before it is exhausted to the above ground atmosphere. After analysis by an accredited laboratory, the results were converted to exposure following the National Council on Radiation Protection-78 methodology. Main outcome measures: Quantify the relative risks of potentially highest exposed employee`s exposure to the radioactive disintegration products of naturally occurring Radon-222 gas in underground working areas in milliSievert per year. Results: The mean reference background exposure averaged 0.6168 mSv/a with underground personal exposure averaging 0.6808 mSv/a, and underground static exposure averaging 0.8726 mSv/a. These values are substantially below the 50 mSv/a Occupational Exposure Limit, and only pose a slightly elevated risk for the development of lung cancer above the normal back-ground exposure. Mining Team leaders and rock drill operators were identified as the potentially highest exposed employees due to the close proximity to the working face, large amounts of time spent close to the working face and the lower ventilation volumes at the working face, with Team leaders having the highest exposure of the sampled occupations with a average of 1.16 mSv/a. Conclusions: Occupational exposure to radioactive disintegration products of naturally occurring Radon-222 gas in the underground air of a South African platinum mine does not pose a significant risk to the health of employees working in the platinum mine.<br>Thesis (MSc (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2013.
31
Jubileus, Mandy Theresa. "Assessment of platinum mine tailings storage facilities : an ecotoxicological perspective / Mandy T. Jubileus." Thesis, North-West University, 2008. http://hdl.handle.net/10394/3729.
Full textAbstract:
South Africa is one of the most important mining countries in the world, hosting the world's largest reserves of platinum group metals (PGMs). Even though mining is clearly an important activity in South Africa, contributing approximately US$ 7.4 billion annually to the countries' gross domestic product (GDP), the costs to the environment are not insignificant. One of the most severe environmental aspects associated with mining is the storage of mineral waste on tailings storage facilities due to their impacts on air quality, ground water quality, aesthetics and land use. It is also unknown whether the environmental effects of tailings storage facilities increase or decrease over time. The aim of this study was to determine the ecotoxicity of platinum tailings storage facilities of different ages by means of soil physical and chemical analysis, earthworm ecotoxicological studies, dehydrogenase activity and soil mesofauna studies. Samples were obtained from three platinum tailings storage facilities of different ages of which two were already rehabilitated while the third was still operational at the time this study was performed. The latter was used as a negative control for the purpose of the study. Soil samples were physically and chemically analysed. Earthworm ecotoxicological studies were conducted to determine changes in biomass, reproduction, mortality, neutral red retention times and tissue metal concentrations. Dehydrogenase activity was determined before the introduction of earthworms and manure, after introductions of manure and after introductions of earthworms and manure. Soil mesofauna were extracted and identified in order to determine species richness, diversity, abundance and functional grouping. Soil chemical analysis indicated that concentrations of certain heavy metals, especially chrome (Cr), present in platinum tailings materials could have a potential effect on microorganisms, microbial processes and earthworms. Earthworm ecotoxicological results indicated that earthworms that bioaccumulated higher levels of heavy metals showed poor hatchability of cocoons. Dehydrogenase activity indicated that earthworms play a significant role in increasing the number and biomass of soil microbes because significant increases in dehydrogenase activity were noticed after the addition of earthworms to platinum tailings materials. Results from the earthworm ecotoxicological studies, dehydrogenase activity, and soil mesofauna composition indicated that environmental impacts of tailings storage facilities did not increase with age, but is more likely to be an indication of the rehabilitation measures administered to the different tailings storage facilities.<br>Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2009.
32
Radloff, Carla. "Variables influencing the retention of designated employees in a platinum mine / Carla Radloff." Thesis, North-West University, 2005. http://hdl.handle.net/10394/642.
Full textAbstract:
Retention of key employees is becoming an increasingly important challenge faced by many
organisations. With every employee that leaves the company, cost of recruitment and
appointment, as well as training and development cost subsequent to that, are lost. The
situation is aggravated by the fact that it is usually the higher performing employee who is
more mobile from a career point of view, or the employee who has completed his/her training
and who is more marketable, that is lost to the organisation.
To effectively retain workers, employers must know which factors motivate their employees
to stay on and which factors cause them to leave. The general research objective was to
determine variables that influence the retention of designated employees within a platinum
mine.
A qualitative research design was used. Twenty four designated employees were selected
randomly from the following occupations in the mining career path, namely Crew Captain in
training, Crew Captain, Learner Official and Shift Supervisor. A qualitative measuring
instrument, based on the phenomenological paradigm, was used to determine employees'
perceptions of retention of designated employees. Content analysis was used to analyse,
quantify, and interpret the research data.
The results indicated that designated employees are poached by competitor companies; that
designated employees leave for better payment or benefits; that they value opportunities for
growth and development; that the Crew Captain title, job content and job category cause
employees to be unhappy; that designated employees leave after receiving training and
development; that they do not feel valued or listened to; that they are unhappy with
accommodation benefits and the bonus system; that they are managed by fear; that job
security makes designated employees to stay; that they leave due to poor benefits; that they
are in general dissatisfied with the company; that work and safety conditions are good; that
designated employees experience a lot of work pressure; that they value family responsibility;
that designated employees with limited education stay; and that they experience racial
discrimination.
Recommendations for future research are also made.<br>Thesis (M.A. (Industrial Psychology))--North-West University, Potchefstroom Campus, 2005.
33
Bonel, Kevin Anthony. "The mode of occurrence, recovery characteristics and petrogenesis of platinum-group and base metal sulphide minerals in the UG2 chromitite at Northam Platinum Mine, South Africa." Thesis, University of Exeter, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297790.
Full text
34
Wahl, Jurie Johannes. "Soil mesofauna as bioindicators to assess environmental disturbance at a platinum mine / Jurie J. Wahl." Thesis, North-West University, 2007. http://hdl.handle.net/10394/2042.
Full text
35
Rademeyer, Brian. "The influence of environmental impacts on tailings impoundment design." Thesis, Pretoria : [s.n.], 2007. http://upetd.up.ac.za/thesis/available/etd-01292008-172436.
Full text
36
Jordaan, Ilse. "Persistent organic pollutants (POPs) associated with a platinum mine in the Limpopo Province, South Africa / Ilse Jordaan." Thesis, North-West University, 2005. http://hdl.handle.net/10394/995.
Full textAbstract:
South Africa ratified the Stockholm Convention (SC), which became legally binding on 17
May 2004. This Convention targets 12 particularly toxic persistent organic pollutants (POPs)
for virtual elimination. The Convention also requires parties to reduce the release of
organochlorine pesticides and the intentionally- and unintentionally-produced POPs such as
dioxins, furans and polychlorinated biphenyls (PCBs) (referred to as dioxin-like chemicals).
Dioxins are a heterogeneous mixture of chlorinated dibenzo-p-dioxins and dibenzofurans
(PCDD/Fs) congeners. These substances were never intentionally produced but are produced
as by-products of industrial processes (such as metallurgical processes and bleaching of paper
pulp). They can also be formed during natural processes such as volcanic eruptions and forest
fires. The largest contributor to releases of PCDD/Fs in the environment is incomplete
combustion from waste incinerators leading to the unintentional production of these
compounds. Polychlorinated biphenyls (PCBs) are used in transformers and capacitors, but
can also be formed unintentionally during industrial and thermal processes. Dioxin-like
chemicals (PCDD/Fs and/or PCBs) are classified as persistent because of the following
characteristics: lipophilicity and hydrophobicity; resistance to photolytic, chemical and
biological degradation and they are able to travel long distances. As South Africa is a semiarid
region, POPs will be less prone to travel here because these substances favour colder
regions with high soil organic matter.
Fish, predatory birds, mammals (including humans) absorb high concentrations of POPs
through the process of bio-concentration, leading to bio-accumulation of these substances in
the fatty tissue. PCDD/Fs occur as unwanted trace contaminants in air, water, land, in
residues and products (such as consumer goods e.g. paper and textiles). The distribution of
these chemicals into various matrices is problematic since they cause damage to the
environment and human health. These chemicals pose a threat to human health when found
in high concentrations that may lead to acute hepatoxicity and dermal toxicity (chloracne).
Long-term exposure to low concentrations of these substances might lead to chronic effects
such as reproductive problems and carcinogenicity.
Since ferrous and non-ferrous metal production is a source of dioxin-like chemicals, a
platinum mine in the Limpopo Province, South Africa, was selected for this investigation.
The aim of the study was to determine if there are dioxin-like chemicals associated with
platinum mining and processing, and if the H4IIE reporter gene bio-assay could be used to
semi-quantify and assess the potencies of the complex environmental and process samples by
determining their Toxic Equivalency Quotients (TEQ). The implications of the sources to the
formation of dioxin-like chemicals regarding the SC were investigated and recommendations
were made to improve this study.
Samples were collected from tailings dams, woodchips, a dumpsite and slag from the smelter
at Union Section. Samples were extracted with the Soxhlet apparatus using hexane as
solvent. The percentage total organic carbon (%TOC) was determined for each sample to
normalise the data. The method used was the Walkley-Black method.
In determining the TEQ of each sample, the H4IIE luc cell line was used. The cells of the
H4IIE luc line are genetically modified rat hepatoma cells stably transfected with a luciferase
firefly gene. The luciferase gene is activated by the presence of dioxin-like compounds and
the concentration of the enzyme is measured as relative light units (RLUs). The amount of
RLUs is directly proportional to the dioxin load in the extract. This method is rapid, cost and
time-effective in determining the TEQ when compared to chemical analysis.
The TEQ2o-valuesin the various samples, as determined with the H4IIE luc cell line, ranged
from 0.007 ngTEQ/kg to 54.06 ngTEQ/kg. Thermal processes at the smelter, sorption of
hydrophobic organic compounds (HOCs) to soil and tailings, and external sources such as
anthropogenic activities contributed to high TEQ2o-values. Climatic conditions, wind,
precipitation, and solubility of HOCs into surfactants lead to low TEQ20. The smelter at
Union Section had a very high TEQ20of 44.62 ngTEQ/kg compared to Impala Platinum mine
(5.15 ngTEQ/kg). This implies that workers at Union Section are possibly exposed to low
and high concentrations of dioxin-like chemicals. Long-term exposure to these compounds
could lead to bio-accumulation in the fatty tissue of the mine workers, leading to chronic
effects such as reproductive problems and cancer. The air emission of the furnace at the
smelter was 0.03 gTEQ/annum and the release of the PCDD/Fs into the slag was 0.60
gTEQ/annum. By effectively managing the smelter it is possible to reduce the TEQ.
The TEQ of each sample increased due to normalising the data. The normalised TEQ20
ranged from 0.94 ng TEQ/kg to 42497.48 ngTEQ/kg.
Dioxin-like chemicals are present on a platinum mine, but at varying quantities and the effects
of these compounds might be detrimental to the environment and the workers at the platinum
mine. Further analyses of the health impacts associated with the platinum mine are needed.
The H4IIE reporter gene bio-assay could be used to effectively determine the TEQ of each
sample. Although this investigation has identified the formation and presence of dioxin-like
chemicals at certain stages of mining and processing, not all of the processes were
investigated. Some of these processes have the potential to add, and even destroy, these
chemicals, affecting potential human exposure and amounts released to the environment.
This, however, requires further investigation.
The financial assistance of the National Research Foundation (NRF) towards this
research is hereby acknowledged. Opinions expressed and conclusions arrived at, are
those of the author and are not necessarily to be attributed to the NRF.<br>Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2006.
37
Liebenberg, Marlize Maria Magdalena. "Establishing a baseline diesel particulate matter (DPM) exposure profile for an underground mechanized platinum mine / Liebenberg, M.M.M." Thesis, North-West University, 2011. http://hdl.handle.net/10394/7057.
Full textAbstract:
Background: Workers are daily exposed to diesel exhaust (DE) and DPM due to the
continuous increase of diesel–powered vehicles in the underground mining environment. The
National Institute for Occupational Safety and Health (NIOSH) recommends that DE be
regarded as a “potential occupational carcinogen”. A great concern in the South African mining
industry is that there is currently no existing occupational exposure limits (OEL) for DPM.
Aim: To quantify the exposure of workers to DPM (that consists out of total carbon (TC): which
is a combination of elemental carbon (EC) and organic carbon (OC)) in the ambient air of
underground working environments. Also to compare different occupations exposure levels to
an international standard (the Mine Safety and Health Administration’s (MSHA) OEL for TC) as
South Africa has no proposed guideline or standard for occupational exposure to DPM and
finally to determine whether or not occupations working at mines with different mining methods
have different exposure levels to DPM.
Methodology: Workers personal exposure to DPM was monitored using the NIOSH 5040
method. A DPM sampler that consisted of a cyclone, a pre–packed SKC filter cassette (37 mm)
with impactor, tubing, label clips and a sampling pump was used. The flow rate was calibrated
at 2.0 litres per minute (L/min) for the sampling of sub–micrometer particles. The personal
sampler device was attached to the employee’s breathing zone for the duration of the work shift
(normal eight–hour time–weighted average (TWA) standard). A high risk group (workers
operating diesel–powered vehicles), a low risk group (workers working in the same mine,
sharing the same supplied air, but not operating these vehicles) and a control group (workers
working at a different mine with a different mining method) was monitored. The exposure levels
were evaluated and compared with the specific OEL mentioned previously.
Results: For the purpose of this study, TC exposure results were evaluated and not EC or OC.
All the occupations within their specific exposure group was exposed to TC. When the control
group’s exposures were compared with the high and low risk group exposures, a significant
difference was recorded (p–value = 0.0001). However when the high and low risk exposures
were compared with each other, no difference was recorded (p–value = 0.4405). When the
results of the various groups were compared with the MSHA OEL all the occupations from the
high and low risk group’s results were above the OEL, but only one occupation from the control
group exceeded the OEL.
Conclusion: It should be noted that all the occupations no matter the mining method / mine
was exposed to TC. The high and low risk exposure groups was however much higher than the
control group and a continues monitoring programme should be implemented for these
exposure groups. Their results exceeded the OEL, where the control group had much lower
exposure levels and only one occupation exceeded the OEL. Greater focus should be given to
the mechanized mining occupations since diesel–powered vehicles are used to perform their
core mining needs whereas at the conventional mine the use of these vehicles are limited.
Recommendation: Depending on the different occupations sampled various engineering
controls can be considered. Some include diesel oxidation catalysts (DOC), diesel particulate
filters (DPF) and diesel disposable exhaust filters (DEF) or also known as disposable diesel
exhaust filters (DDEF) which is very effective in removing DPM from the exhaust of dieselpowered
equipment. Education and training are also critical components to the success of a
diesel emission management programme and the last resort to be considered is the appropriate
personal protective equipment (PPE). South Africa should consider the implementation of
national standards in order to monitor the progress and success of the diesel emission
management programme implemented.<br>Thesis (M.Sc. (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2012.
38
Bulou, Hervé. "Structure et croissance de films ultra-minces de platine sur co(0001)." Université Louis Pasteur (Strasbourg) (1971-2008), 1996. http://www.theses.fr/1996STR13135.
Full textAbstract:
Depuis quelques annees s'est developpee une nouvelle technique d'enregistrement magnetique dite perpendiculaire. La possibilite d'obtenir des densites de stockage cent fois superieures a celles de l'enregistrement traditionnel (longitudinal) font de ce nouveau type d'enregistrement une technique d'avenir. Les structures permettant de realiser de tels types d'enregistrements sont les multicouches et plus particulierement les multicouches platine-cobalt orientees 111. L'aimantation etant tres fortement dependante de la structure cristallographique des elements mis en jeu, une caracterisation de l'interface entre les differents constituants de la multicouches apparait primordiale. L'etude de la croissance et de la structure de films ultra-minces de platine deposes, a temperature ambiante et pour des flux d'evaporation faibles (une monocouche en quarante minutes), sur un monocristal de cobalt coupe selon une face (0001) a permis de mettre en evidence une interface abrupte entre le platine et le cobalt. Le film de platine est toutefois constitue de zones de platine de structure cubique a faces centrees, separees par des zones d'alliage ordonne. Par ailleurs, une faible augmentation de la temperature conduit a une reorganisation du film, qui depend de l'epaisseur initiale de platine deposee.
39
Zribi, Aymen. "Fluxmètre thermique : conception, modélisation, réalisation et caractérisation. Mesures de températures et de densités de flux thermiques." Thesis, Besançon, 2016. http://www.theses.fr/2016BESA2085/document.
Full textAbstract:
En vue d'applications futures dans le domaine de la récupération d'énergie à basse température à partir de microsystèmes, la connaissance des transferts thermiques aux parois est d'une grande importance. Ces mesures sont réalisées à l'aide de capteurs spécifiques qui permettent de connaître le flux thermique total échangé entre la paroi sur laquelle ils sont installés et le milieu environnant. Cette étude se situe dans le cadre du développement de fluxmètres thermiques a gradient répondant aux contraintes liées aux machines thermiques de type micro-moteur Stirling. Six types de fluxmètres thermiques à sondes à résistance ont été développés à partir de différents matériaux, géométries et formes de capteurs. Une étude électrothermique, prenant en compte l'effet d'auto-échauffement, a été menée et validée expérimentalement. Les techniques de fabrication et de caractérisation, opérés majoritairement en salle blanche, ont permis de réaliser de nombreux capteurs à couches minces. Des supports spécifiques pour ces capteurs ont été développés. Ces capteurs de flux thermique, dont les résistances ont été étalonnées par rapport à une sonde de référence de haute précision, permettent également la mesure de la température. Pour mesurer la densité de flux thermique, deux méthodes ont été testées. La première méthode est indirecte : elle consiste à mesurer le gradient de température à l'aide de deux sondes à résistance en platine. La deuxième méthode est directe : elle repose sur un étalonnage en flux. Enfin, l'influence de l'intrusion des capteurs sur le répartition des flux thermiques dans la pièce à mesurer, avec ou sans support spécifique, a été étudiée<br>For future applications in the field of low-temperature energy have sting in microsystems, knowledge of wall heat transfer is of great importance. These measurements are carried out using specific sensors which makes possible to know the total heat flux exchanged between walls and the surrounding environment. This study concerns the development of a gradient heat flux sensor compliant with their requirements associated with thermal machines such as micrometric Stirling engines. Six types of heat flux sensor with resistance temperature detector have been developed from different materials, with various geometries and shapes of sensing elements. An electro thermal study, taking into account the self-heating effect, was carried out and experimentally validated. The fabrication and characterization techniques, mainly carried out in clean rooms, allowed to produce numerous thin-film sensors. Specific housings for these sensors have been developed. These heat flux sensors, whose resistances have been calibrated with a highly accurate reference probe, also allow measuring the temperature. To measure the heat flux density, two methods were tested. The first method is indirect : it consists in measuring the temperature gradient using two platinum resistance probes. The second method is direct : it is based on heat flux calibration. The calibration and measurement benches have been modeled. Then, the experimental and numerical results have been compared. Finally, the influence of the sensor intrusion on the thermal fluxes distribution in the investigated sample, with or without a specific housing, has been studied
40
Mahlatsi, Tladi Abram. "Characterization of heavy metal tolerant bacterial plasmids isolated from a platinum mine tailings dam / by Tladi Abram Mahlatsi." Thesis, North-West University, 2012. http://hdl.handle.net/10394/9780.
Full textAbstract:
The development of metal-tolerance and antibiotic resistance in bacteria may be caused by metals polluting a particular environment. During mining and mineral processing activities, large quantities of metals are deposited into the soil. These high concentrations of metals are evolutionary pressures selecting for microorganisms tolerant to these metals. Metaltolerance maybe conferred to these organisms by mobile genetic elements such as plasmids. This study describes the characteristics of plasmids isolated from various bacteria that displayed an ability to withstand high metal concentrations. The isolated plasmids were individually transformed into Escherichia coli JM109. Transformants were then evaluated for metal-tolerant capabilities using a microdilution approach. Plasmids were then isolated from the transformants and the concentration of the plasmid DNA ranged between 11.75 – 118.06 ng/μl. These plasmids were of the same size as the original ones. This demonstrated that successful transformations with plasmid DNA were conducted. In order to determine the compatibility group, plasmids were subjected to PCR amplification using IncQ, IncP-9 and IncW specific primers. Only the IncW provided positive results. To demonstrate that the plasmids were free of genomic DNA, a 16S rDNA PCR test was included. The plasmids that were positive for IncW PCRs were all negative for the rDNA PCRs. Plasmids were stably inherited and at least three, isolated from three different Gram positive species, belonged to the Inc W group of plasmids. These were originally isolated from Paenibacillus ginsingari, Paenibacillus lautus and Bacillus cereus. Minimum inhibition concentrations (MICs) were carried out to determine the ability of transformed E. coli JM109 to tolerate metals at varying concentrations. Results indicated that transformed E. coli JM109 developed ability to grow in the presence of several heavy metals. Some strains were resistant to high concentrations (+10 mM) of Ni2+/Al3+, Pb2+ and Ba2+. The order of metal resistance was Ni/Al=Pb>Ba>Mn>Cr>Cu>Co=Hg. All the x transformants were sensitive to 1 mM of Co2+ and Hg2+. Moreover, protein profiling was used to determine the impact of plasmids on E. coli JM109. Proteins were extracted from both transformed and un-transformed E. coli JM109 using acetone-SDS protocol and subjected to one-dimensional (1D) and two-dimensional (2D) Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS- PAGE). Transformed E. coli JM109 were grown under the metal stress. One dimension SDS-PAGE illustrated general similarity of the profiles except for two banding positions in the 30 to 35 kDa region where bands were present in the transformants that were grown in the Ni/Al alloy containing media. Twodimensional electrophoresis PAGE analysis showed that some of the proteins were upregulated while others were down-regulated. The largest numbers of proteins were from 15 – 75 kDa. The majority of these proteins had isoelectric points (pI) between 5 and 6. It was concluded that plasmids isolated from various heavy metal-tolerant bacterial species were successfully transformed into E. coli JM109 rendering various new metal-tolerant E. coli JM109 strains. Furthermore, the study showed that metal resistance was due to the presence of the plasmids. Two-dimensional SDS-PAGE resolved more differences in the protein expression profiles. Since the plasmids rendered the E. coli JM109 tolerant to metals tested, it also can be concluded that the change in the protein profiles was due to the effects of the plasmids. Furthermore, plasmids were also re-isolated from the transformants and these plasmids were of the same size as the original ones.. All the plasmids in this study were also stably inherited, a feature associated with IncW plasmids. More detailed genetic characterization of these plasmids is required. Plasmids isolated and characterized in this study may hold biotechnology potential. Such features should be exploited in follow-up experiments.<br>Thesis (Master of Environmental Sciences)--North-West University, Potchefstroom Campus, 2013.
41
Piellard, Mickaël. "Etude de la liaison Platine – Alumine pour capteurs haute température." Poitiers, 2005. http://www.theses.fr/2005POIT2300.
Full textAbstract:
Ce mémoire est consacré à la création et caractérisation d'une liaison platine/alumine pouvant être utilisée pour la fabrication d'un capteur fonctionnant à haute température. La thermocompression est la technique étudiée et sa résistance est caractérisée par traction. La dispersion des résultats nécessite l'utilisation d'un outil adapté, la statistique de Weibull. Cette étude nous a permis de déterminer la très bonne résistance de l'assemblage ainsi que son excellente tenue à des cycles thermiques sévères. Des simulations de la diffusion à l'interface ainsi que de la déformation plastique du platine lors de la mise en forme ont été produites. Des couches minces épitaxiées de platine sur alumine monocristalline ont été également réalisées et étudiées. L'étude de leur adhérence en comparaison à la thermocompression, nous a permis de conclure à une grande similitude des deux techniques en matière de résistance d'assemblage, et donc à la validité industrielle de la thermocompression<br>This report is dedicated to the realization and the characterization of a platinum/alumina bonding designed for high temperature captor. An original fabrication method, thermocompression, was studied and a complete characterization of its resistance was driven by tensile test. An important variability with the tensile results has lead to use the Weibull statistics tool. That method has shown clearly the good strength of our bonding and its excellent resistance to severe thermal cycles. Simulations of interfacial diffusion and platinum‘s plastic deformation during thermocompression have been made to evaluate the process parameters influence. Epitaxial growth of platinum thin films on basal-plane sapphire has also been realized. The comparison of these films adhesion with that of the thermocompression one has shown very similar results. The thermocompression appear thus to be a very good solution for industrial applications
42
Karoum, Réda Billard Alain. "Utilisation de la pulvérisation cathodique magnétron pour la mise en oeuvre de la promotion électrochimique de la catalyse appliqué à la réduction catalytique sélective du monoxyde d'azote et à la combustion du propène." [S.l.] : [s.n.], 2008. http://artur.univ-fcomte.fr/ST/CHIORG/these/karoum.pdf.
Full textAbstract:
Thèse de doctoral : Sciences de l'ingénieur et microtechniques : Besançon : 2008. Thèse de doctoral : Sciences de l'ingénieur et microtechniques : Belfort-Montbéliard : 2008.<br>Bibliogr. à la fin de chaque chapitre. Glossaire.
43
"Experiences of women working on the mines: a case study from Rustenburg platinum mines." Thesis, 2007. http://hdl.handle.net/10210/134.
Full text
44
Mutasa, Francyn Chido. "Gender equality and corporate social responsibility in the workplace: a case study of Anglo American Platinum Mine and Impala Platinum Mines Rustenburg, South Africa." Thesis, 2017. https://hdl.handle.net/10539/24430.
Full textAbstract:
A research report submitted to the Faculty of Humanities, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Arts in Labour, Policy and Globalisation, 2017<br>This research presents an investigation of the role played by private corporations in promoting gender equality, using the platinum mining sector in the Rustenburg area as a case study. In evaluating this role the research uses The Mining Charter, a piece of legislation and Corporate Social Responsibility (CSR) to assess the efforts that have been made by Anglo American and Impala Platinum mines. This qualitative study uses an abductive approach and a Marxist feminist theoretical perspective to establish what constitutes the problem of inequality. Relying on data collected through document analysis, which included a review of the Mining Charter, and various company annual reports, coupled with data collected from conducting interviews from September to December 2016, the research has found companies to look at the problem of gender equality from a ‘female employees statistics’ point of view. As such, the problem of equality has ignored the indirect negative impacts mining has on women in the communities in which the mining companies operate. This research understands equality as having two sides, “formal and informal” equality. While efforts by the government, and mining companies have tried to address the part of formal equality through increasing the numbers of females in mining, and improving the general conditions in which they operate, this research finds that there exists a form of “informal equality.” This informal inequality looks at the outcomes of the efforts in reality, and goes beyond the company into society. Mining companies have the ability to address this type of equality through CSR, but this research notes that CSR programs are often not viewed through a gender lens. The study therefore concludes that there is a disjuncture between the perceived results of efforts made by corporations on paper and the outcomes in reality. While corporations can contribute to promoting equality in the workplace, their understanding of equality is skewed and one sided therefore inequality continues to persist. Perhaps if companies use the strategy of gender mainstreaming to address the goal of equality, which involves taking into account the particular problems of women in all facets, then equality can be achieved.<br>XL2018
45
Mauve, Anton Christopher. "The platinum market: fundamentals affecting supply and demand." Thesis, 2014.
Find full textAbstract:
The platinum market is best understood through a comprehensive
analysis of supply and demand. Supply is most significantly affected by
production constraints and the erratic draw-down in Russian stockpiles.
Total world supply of platinum for 1998 amounted to 5.915 Moz, 64% of
which was produced from the Bushveld Complex in South Africa. The
remainder emanated from Russia, Zimbabwe, the United States, Canada
and the recycling of autocatalysts. Supply is forecast to drop by
320 000 oz in 1999 due to a lower Russian export quota and reduced
Zimbabwean production.
Demand for platinum is unusual, in that it is sought after both as a store of
wealth, and has properties that make it irreplaceable in a host of industrial
applications. Current world demand for the metal is driven by a growing
Eastern jewelry market and increased use in autocatalysts due to vehicle
emissions legislation. Total world demand for 1998 amounted to
5.755 Moz. A predicted steady growth in the consumption of platinum for
jewelry and existing applications, together with development of new uses,
is expected to result in an annual 250 000 oz increase in demand for 1999
and 2000.
The derived supply and demand balance for 1998 shows a small excess
in supply relative to demand. This will be absorbed by inventories and is
likely to have little affect on price, A significant shortfall of 410 000 oz,
however, is predicted for 1999. This is likely to be followed by a further
shortfall in 2000 and will drive up prices, impel consumers towards
substitution and thriving and encourage producers to expand.
46
Erasmus, Andries Gustav. "Application of techno-economic modelling in the platinum mining industry of Southern Africa." Thesis, 2016. http://hdl.handle.net/10539/22601.
Full textAbstract:
A research report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, in fulfilment of the requirements for the degree of Masters of Science in Mining Engineering
2016/10/5<br>Management does not have an efficient mechanism to test strategic and operational alternatives and to assess the impact of these on the value and underlying trade-off variables of the business. Techno-economic models can be applied for this purpose as they provide a framework for undertaking advanced process simulation and business valuation. The purpose of the research report is to identify key components, principles and best practice as applied in techno-economic models, to improve techno-economic modelling for the purpose of decision-making and business optimization.
The integrated techno-economic model requires a mining model with production planning and scheduling abilities. The half-level system method can be applied to create production profiles for different mining options and only after optimisation the best option is taken forward for graphical design and detailed scheduling. A metallurgical model incorporates the logic and efficiencies of the treatment process into the techno-economic model from which the refined products are determined for revenue and costing purposes. The financial model integrates with the mining and metallurgical elements and uses detailed costing models and sound financial principles for operating and capital cost estimates. An accurate techno-economic model includes key cash flow components and applies rigorous valuation practice for investment analysis.
Techno-economic models are extensively applied in business planning, major project valuations and stay–in-business project valuations. Learnings from the review of these case studies suggest best practice, which allows the models to be applied to different types of business entities and contributes to the accuracy, consistency and efficiency of techno-economic modelling. Integrated techno-economic modelling is also applicable in strategic planning and mine design optimization as it provides a powerful instrument for decision-making and business optimization. The future of the mining business depends on it as an invaluable direction steering tool.<br>MT2017
47
Vos, Cornelius Francois. "The role of long-chain trithiocarbonates in the optimisation of Impala Platinum's flotation circuit." Diss., 2007. http://hdl.handle.net/2263/28821.
Full textAbstract:
Trithiocarbonates (TTCs) with less than six carbon atoms per molecule historically have proved to be better bulk sulphide mineral collectors than conventional dithiocarbonates (DTCs). However, high vapor pressures of the short-chain mercaptan decomposition products prevented them from general industrial use. Impala’s commitment in TTC development changed in 2002 when the nC12-trithiocarbonate indicated strong synergism when added to their existing flotation suite. A concerted research effort at the University of Utah followed, and in particular on their surface chemistry. To compliment current research and development at Impala, fundamental work regarding the surface hydrophobicity of pyrrhotite under electrochemically controlled conditions was undertaken at Utah University. Controlled contact angle measurements showed that the surface hydrophobicity of pyrrhotite can be increased by small additions of nC12-trithiocarbonate to SIBX. It was also found that this improvement in the surface hydrophobicity with the SIBX-TTC mixture was more significant at lower oxidation potentials. Work at Utah University further showed that a C12 decomposition product may or may not be present with an adsorbed TTC molecule. External reflectance infrared spectroscopy in the mid infrared region suggested a “crowding” of the collectors at the surface when SIBX and TTC are combined. This was based on an increase in the absorbance of the -CH2- peaks in the mixed collector system. In bench scale flotation tests on PGM bearing samples from the Merensky reef, it was found that a 5 molar percent replacement of SIBX with nC12-trithiocarbonate improved the flotation activity relative to the standard SIBX-DTP mixture. Improvements were in the recoveries of PGMs, copper and nickel. The addition of TTC also increased the flotation rates of both slow and fast floating valuables as is predicted by the Kelsall equation. The optimum mixture for the pilot plant trials was thus a 5 molar percent replacement of the current collector suite with nC12-TTC. Based on the bench flotation results, research was extended to a pilot plant trial. At a depressant dosage of 100g/ton, the PGM concentrate grades from the first rougher cell improved from 120g/ton to 175g/ton when the TTC was introduced. This was achieved without any effect on the recovery from the first cell. This increase in concentrate grade is believed to arise from the nature of both: <ul> <li>The mineral-collector surface state, and</li> <li>The bubble surface interaction.</li> </ul> Overall, the standard SIBX-DTP collector combination and the new SIBX-DTP-TTC collector combination (both at 100g/ton depressant) was also compared to pilot plant tests with SIBX-DTP at high (350g/ton) depressant dosages. The latter suite forms the currents reagent suite at Impala Platinum. When comparing the first two trials, at 100g/ton depressant, the addition of TTC as a ternary collector resulted in a recovery improvement of approximately 2.2% with a simultaneous increase in final concentrate grade from 57g/ton to 73g/ton. The result was a reduction in solids recovery from 5.3% to 4.1%. When comparing the TTC trial to the standard collector suite at high depressant dosages, only a small reduction (3.6% vs. 4.1%) in solids recovery was achieved with a final concentrate grade of 85g/ton. The PGM recoveries were very similar. Based on current Merensky milling rates, depressant and TTC costs, and calculated replacements based on the pilot plant tests, a projected cost saving on chemicals is R9.6 million per annum. Financial impacts on processing, grade and kinetics have not been made. It was also concluded that the detrimental effect of mild steel milling on the flotation activity of SIBX-DTP was diminished with the addition of the long-chain TTC with SIBX and DTP. As part to this research, a preliminary plant trial on UG-2 underground material showed a reduced primary rougher chromite grade as well as a significant increase in PGM concentrate grade for the first two primary rougher cells. This is an important finding, especially for the melting process. In this final study a partial (5 molar percent) replacement of the standard collector used was also made. What was further realised was a significant increase in the final concentrate grade when compared to the standard conditions.<br>Dissertation (MEng (Metallurgical Engineering))--University of Pretoria, 2007.<br>Materials Science and Metallurgical Engineering<br>MEng<br>unrestricted
48
Tshisekedi, Jean Rene Ngalamulume. "Energy consumption standards and costs in South African gold and platinum mines." Thesis, 2009. http://hdl.handle.net/10539/7043.
Full textAbstract:
Benchmarking of selected energy use indicators and related best practices definition
are helpful tools in establishing an effective energy reduction and energy efficiency
strategy. The current energy scarcity exposed by electricity supply shortage in South
Africa is an opportunity to assess and determine consumption limits for major
consumers, including the mining sector for which gold and platinum producers are
among the highest consumers. This dissertation develops, using a survey
questionnaire, visits on mine sites and interviews for data collection and analysis, a
range of energy consumption indicators and related costs. These indicators are related
to mining depth, mechanization and production. These are the most energy intensive
parameters for underground mines and influence the growth rate of energy
consumption. A relationship between these parameters and the energy consumption
data constitute the main findings of this work. The acceptable limits and averages of
energy consumption can be used to compare different and specific energy intensive
activities involved in the mining process, costs of mines operating in similar conditions,
to develop energy efficiency improvement plans and saving targets and to forecast mine
unit demand of power in short and mid–term for gold and platinum mines.
49
Deysel, Jan Adriaan. "DSM strategies to reduce electricity costs on platinum mines / Jan Adriaan Deysel." Thesis, 2015. http://hdl.handle.net/10394/15179.
Full textAbstract:
Labour disruptions, operational cost increases, mineral price decreases and nationalisation are only a few of the financial risks faced by mining companies in South Africa. These risks are not only impacting the mining companies but have a rippling effect on the surrounding communities and the country’s economy.
With the South African Platinum Group Metals (PGM) largely affected, platinum mining companies are reviewing all possible cost savings strategies. Together with the help of Eskom’s Integrated Demand Management (IDM) programmes, various electricity cost savings strategies are being investigated. To date implemented DSM strategies have deemed themselves successful on numerous mines.
These DSM strategies range from replacing basic equipment to maintenance schedules. However, there is a need to evaluate DSM strategies specifically applicable to standard underground platinum mines. Therefore this study reviews several plausible DSM strategies for the largest service systems including compressed air, refrigeration, ventilation, water reticulation and dewatering systems on platinum mines.
The first step in the investigation evaluated each DSM strategy according to existing system operations and infrastructure. The second step determined the feasibility of each DSM strategies for specific platinum mine case studies. This was done by simulating the electrical energy impact and investigating the required infrastructure for each strategy. With the predicted results and required infrastructure, an estimated payback period and a five year financial prospect was calculated to determine the feasibility.
Three strategies were selected and successfully implemented on the platinum mine case study. With the delivered electrical energy impact the annual electricity cost savings was calculated at an average R14.5 million with the implementation of the three DSM electrical cost saving strategies. The study provides insight into selecting the best proven electricity cost savings strategy according to the layout and design of a platinum mine.<br>MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2015
50
"The safe mindset of managers, shiftbosses and miners on a platinum mine in South Africa." Thesis, 2010. http://hdl.handle.net/10210/3451.
Full textAbstract:
M.Phil.<br>The mining industry in South Africa is in a process of transformation, which can be ascribed to various influences. First and foremost is the process of the conversion of mineral rights, employment equity and black economic empowerment. The ethnic distribution of mining employees at the time of the study reflected that Managers were predominantly white, the majority of Shift bosses were white and Miners were predominantly black. Central to the transformation process is maintaining and improving production output in a safe manner. Leadership in addition also impacts on health and safety in the workplace and the process to transform the organisation to world- class status commences with leadership. Transforming health and safety in the organisation to world-class status is a leadership imperative. The fatality rates in South African mines are continuously being addressed not only through initiatives from the Chamber of Mines of South Africa, but also through the various mining houses. The introduction of the Mine Health and Safety Act and Regulations 29 of 1996 made a profound impact on health and safety management on South African Mines. The introduction of blasting certificate holders replaced the scheduled person (contract miner). Various mining houses grasped the opportunity and trained their own miners from previously disadvantaged communities. This also assisted in achieving transformation objectives. The fatalities on platinum mines in South Africa since 1995 have remained constant up to 2007 although a slight decrease is reported. Nevertheless, injuries and fatalities in South African mines are attracting negative attention from society and the investment community. This is not in the interest of the mining industry. Research indicates that unsafe behaviour contributes 87% and more to incidents and injuries (including fatalities) on mines. The study of behaviour as a contributing factor in organisational safety is a relatively young science since the first reported studies in the 1980's. Research in this domain strives to develop an understanding of behaviour as a contributing factor in organisational safety.