no abstract provided by author / M.S.

Equipment availability is the most significant factor in the productivity of many mines and processing plants. Machine breakdowns are not only expensive in terms of production losses but also important in meeting production schedules. In a complex piece of machinery like a shearer or a powered support system in a highly automated longwall face, such breakdowns can be due to one of the large number of possible faults. A large proportion, up to 80% of the down time is spent in locating the fault. For this reason, a need for an automated diagnostic method to assist the operator in the diagnosis process is felt. In this study, a diagnostic system is developed by modeling the partially known or imprecise relations and poorly defined variables found in a diagnostic environment. Logic of fuzzy sets and systems theory finds an interesting application in this area. This study presents a diagnostic algorithm, which relates the possible causes of failure to their respective symptoms through fuzzy logic paths. Applications of the diagnostic method are illustrated through examples of a compressor and a shearer. / Master of Science

Master of Science

Deficiency of available nitrogen (N) is one of the major factors limiting the establishment of a long term self-sustaining vegetative community on mine soils. This investigation was conducted to study the nature of N form and dynamics in southwest Virginia mine soils. Fresh mine spoils contained a large amount of indigenous N, ranging from 650 to 2500 mg/kg soil, which complicated N studies. Most of the indigenous N was "geologic N" which was unavailable to plants. The geologic N came from either 2:1 silicate minerals (fixed NH₄⁺) or coal fragments (nonhydrolyzable organic N). Active N, consisting of hydrolyzable organic N and exchangeable N, comprised the minor fraction of indigenous N available to plants. / Ph. D.

In the San Dimas district, on the western flank of the Sierra Madre Occidental, near the small town of Tayoltita, Durango, gold and silver epithermal ore deposits are mined from the complex Arana fault system. The structural relationships of the Tayoltita system are well-mapped, but their kinematic relationship to ore deposition is unclear. In plan view and in cross-section, the Arana system has a horsetail or wedge-shaped geometry. Subsurface mapping of slickenside striae as movement indicators suggest that the N13°W-striking Arana fault, forming the eastern boundary of the system, is a normal slip fault with at least 250 m of throw. Subsidiary system faults display normal separation with varying degrees of dextral horizontal separation (which is a function of fault orientation). Experimental modeling of the Arana system indicated that the system formed under simple shear as the σ₂ and σ₃ stress axes rotated in a subhorizontal plane about σ₁. Rotational strain caused the developing fault strands to rotate and to be captured by the Arana fault, forming the typical wedge-shaped geometry. Later, a more complex rotation of the three major stress axes enabled hydrothermal fluids to progressively mineralize faults, which had more northerly strikes, by a process similar to progressive strain. This is documented by mineral assemblages that record the instants of fault opening and by the lack of mineralization along the high-angle, northwest- striking faults.

No description available.

Thesis (MSc)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: South Africa is one of the world's major coal producers, resulting in the second highest foreign exchange earner for South Africa. However, the mining industry contributes negatively to (ground) water pollution, due to the formation of acid mine drainage (AMD). AMD originates from the bacterial oxidation (Thiobacillus ferrooxidans) of pyrite (FeS) and contains high levels of sulphate and metals. Sulphate rich waters can be treated applying the biological sulphate removal technology. This study concentrated on biologically removing sulphate from synthetic feed- and mine water, using the single-stage completely-mixed reactor system. The advantage of using this reactor system is that except for removing sulphate from about 2000 to less than 200 mg/t', it can also partly biologically remove the formed sulphides. It was established that both ethanol and sugar can be used, as the carbon and energy source, however ethanol is more cost effective than sugar. Ethanol dosage and Hydraulic Retention Time (HRT) studies were undertaken to investigate at what concentration, the highest sulphate and sulphide removal rates were achieved. It was found that the highest sulphate reduction rates were obtained when using 1mf ethanol/f feed and that the removal rates were dependent on the HRT: the lower the HRT, the higher the sulphate reduction rate. The highest sulphide oxidation rate was achieved at the HRT of 6 h. It was, furthermore shown that the single stage completely-mixed reactor system could successfully be used to remove sulphate from Schoongezicht mine effluent, not only removing the sulphate, but also most of the metals, thereby increasing the mine effluent pH from 2.5 to 7. The conclusion of this study was that a completely-mixed reactor system, as described in this thesis, can successfully be applied to treating acid mine drainage using ethanol (1 m.e etanol/f feed water) as the carbon and energy source at a hydraulic retention time as low as 4 hours. This technology has great potential for pilot- and full-scale treatment of sulphate rich effluents such as acid mine drainage. / AFRIKAANSE OPSOMMING: Suid Afrika is een van die vemaamste steenkool produseerders in die wereld, terwyl die uitvoer van steenkool die land se tweede hoogste verdiener is van buitelandse valuta. Ongelukkig dra hierdie industrie ook by tot die besoedeling van (grond) water, veral vanwee die vorrning van suur myn afloop. Bakteriese oksidasie (deur Thiobacillus ferrooxidansy van piried (FeS) is hoofsaaklik verandwoordelik vir die vorrning van suur myn afloop bevattende hoe konsentrasies van sulfaat en metale. . Die toepassing van biologiese sulfaatverwyderingsprosesse vir die behandeling van sulfaatryke waters is vroeer gedemonstreer. Die doel van hierdie studie was om 'n enkel-stadium reaktor met volledige vermenging te evalueer en te optimiseer om toegepas te word vir die biologiese verwydering van sulfaat vanuit sinteties bereide, sowel as mynwater. Hierdie reaktor is in staat om sulfaat te verwyder vanaf vlakke van ~ 2000 tot minder as 200 mg/P. 'n Verdere voordeel gepaard met die gebruik van hierdie reaktor is dat die sulfied wat gevorm word tydens sulfaatreduksie, gedeeltelik verwyder word deur die oksidasie daarvan na So. Die resultate wat behaal is in hierdie studie het aangedui dat beide etanol en suiker gebruik kan word as die koolstof en energiebron, terwyl etanol meer koste-effektief aangewend kon word. In teenstelling was metanol nie 'n geskikte koolstofbron vir sulfaatverwydering nie. Eksperimente is daarvolgens uitgevoer om toestande van optimum etanoldosering en hidroliese retensietyd (HRT) vir maksimum sulfaat- en sulfiedverwydering te bepaaJ. Die hoogste reduksie tempo's was verkry met 'n toediening van 1 mP etanol/f invloei, en die effektiwiteit van verwydering was afhanklik van HRT. Hoe laer die HRT, hoe hoer die tempo van sulfaatverwydering. Die beste sulfaatverwyderingstempo was behaal teen 'n HRT van 6 uur. Die resultate het verder aangetoon dat die enkel-stadium reaktor met volledige vermenging in staat was om sulfaat effektief te verwyder, en die pH te verhoog vanaf na 2.5 tot 7, in mynuitvloeisels van 'n plaaslike steenkoolmyn. Die gevolgtrekking uit hierdie werk is dat 'n volledig-gemengde reaktorstelsel, soos beskryf in die huidige studie, geskik is vir die suksesvolle behandeling van suur mynafloopwater met die gebruik van etanol (l mflP toevoerwater) as koolstof- en energiebron by 'n hidrouliese retensietyd tot so laag as 4 uur. Die tegnologie het groot toepassingspotensiaal vir volskaalse behandeling van sulfaatryke afloopwaters soos by. suur mynafloop.

Thesis (MPhil (Sustainable Development Planning and Management))--University of Stellenbosch, 2007. / This is a technical and financial proposal for a large-scale and complex sustainable development project in Zambia. The sustainable development project is the Copperbelt Environment Project (CEP)1. This proposal aims at developing strategies for addressing sustainability problems of CEP. One objective of the proposed strategies is to raise additional funds to support its activities beyond CEP’s initial project-life. The other is to enhance public participation in CEP, especially of political and traditional leaders. CEP is a project of the Government of the Republic of Zambia (GRZ) created in 2002 to mitigate historical environmental and social liabilities caused by mining after the privatisation of stateowned mines. Furthermore, CEP is charged with the responsibility to improve compliance of ongoing mining operations through enhanced environmental and social regulation. CEP is faced with three key sustainability problems. The first problem relates to the cessation of CEP activities after the end of its conceptual project life span in 2008. If CEP activities cease without an exit strategy to take care of on-going CEP activities, serious environmental and socioeconomic problems are likely to arise in mining areas. The second sustainability problem relates to the financial deficit of CEP. Less than US $60 million of the US $200 million required has been sourced for CEP activities implying a deficit of about US $150 million. Unless the financial deficit is secured, it is unlikely that most historical environmental liabilities will be addressed. It is also unlikely that environmental and social regulation targets of CEP will be attained by the end of its initial life span. The third sustainability problem relates to inadequate public participation in CEP activities. Although public participation in development programmes is a policy and legal requirement in Zambia, it is however very low in CEP. Traditional and political leaders are not using their offices to advance CEP agenda. A hybrid of participatory research/action research, evaluation research, empowerment evaluation and literature reviews research methodologies is proposed to be used to develop the strategies that will address the above problems. In addition, multiple methods of data collection are proposed to be used, including structured and semi-structured individual and group interviews, questionnaires, documentary sources and analysis, plenary and focus group discussions, personal experience, commissioned expert inputs, websites and participation records. The long-term target of the proposed project is to generate in excess of US $900 million for CEP activities by 2025. The proposed project will also utilise the Community-Based Environmental Protection (CBEP) approach and draw on the South African experience on public participation to build the capacity of target groups to take stewardship of environmental problems in their areas. A detailed implementation plan will be developed to serve as the framework for operationalising the proposed strategies. Existing CEP monitoring and evaluation mechanisms will be used to track the implementation plan. A six-man team headed by a team leader is proposed to execute this project proposal. An activitybased budget including a logical framework, timescales for deliverables, coverage areas, target groups, action planning, project goals, stakeholder analysis, time plans for staff and activity schedules are proposed. Depending on the speed and efficiency with which the project proposal and its strategies are implemented, a sustainable solution to poor environmental management in mining areas of Zambia is possible.

Thesis (MPA)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: The aim of this research was to investigate the challenges to effective strategy implementation at the Zimbabwe Mining Development Corporation (ZMDC). Strategic planning is argued to have overshadowed the area of actual strategic implementation. Organisations put a lot of effort into drafting good plans, but do not put equal effort into their realisation. It was assumed that there is a big gap between strategic planning and implementation. This is what drove the researcher to go into the field and explore the situation at the ZMDC in greater depth in a bid to bridge the gap through research on the subject matter. Literature on strategy and strategy implementation was analysed critically. The research was guided by the post-positivism research philosophy. This research paradigm enabled the use of qualitative methods, which facilitated the interaction with respondents. The case study research design was adopted, as the research sought to discover the impediments to strategy implementation and the best way forward in turning the strategies on paper into action. The major findings were that there indeed were loopholes in strategy implementation at the ZMDC. The challenges to the strategy implementation process at the ZMDC were noted to be poor delegation, lack of training and development, poor ethical values, limited resources, low motivation of employees, poor communication and coordination, lack of control and poor teamwork. The organisation was noted to have deficient communication processes, which contributed to the challenges facing strategy implementation. The findings brought to light the fact that strategic planning starts with the executive management, hence the need for their commitment to owning the entire process of strategic planning and execution. The study revealed limited involvement of staff in the initial stages of developing strategy. In order to enhance the implementation of strategies, it was recommended that motivational leadership at the ZMDC had to be ensured. Leadership, ownership and drive are required to compete effectively and to deliver growth. Management should adopt the „Strategy into Action‟ planning approach, charting a course through performance factors, linking strategic thrusts to projects, as well as departmental and individual activity, with the ultimate goal being to enable the ZMDC to effectively translate strategic goals into results in a clear and inclusive process. To turn strategic desires into action that drives results, the ZMDC leaders need to develop strategic thrusts and broad-based action plans, putting the vision to light, and picturing to everyone what would be viewed as strategic success and what it takes to achieve and measure the desired outcomes. / AFRIKAANSE OPSOMMING: Die doel van hierdie navorsing was om ondersoek in te stel na die uitdagings vir doeltreffende strategie-implementering by die Zimbabwe Mining Development Corporation (ZMDC). Daar word aangevoer dat strategiese beplanning wesenlike strategiese implementering oorskadu. Organisasies werk hard aan die opstel van goeie planne, maar werk nie ewe hard aan die verwesenliking daarvan nie. Die aanname is gemaak dat daar ʼn groot gaping tussen strategiese beplanning en implementering is. Dit het die navorser aangemoedig om die situasie by ZMDC prakties en op diepgaande wyse te ondersoek ten einde hierdie gaping deur navorsing oor die onderwerp te oorbrug. Die literatuur oor strategie en strategie-implementering is krities ontleed. Die navorsing is gerig deur ʼn post-positivisme-navorsingsfilosofie. Hierdie navorsingsparadigma het die gebruik van kwalitatiewe metodes moontlik gemaak, wat interaksie met die respondente in die hand gewerk het. ʼn Gevallestudie-navorsingsontwerp is gebruik, aangesien die doel van die navorsing was om die struikelblokke tot strategie-implementering en die beste pad vorentoe om strategie op papier in aksie oor te skakel, te bepaal. Die vernaamste bevindings was dat daar wel skuiwergate in strategie-implementering by ZMDC is. Die uitdagings rakende die strategie-implementeringsproses by ZMDC is geïdentifiseer as swak delegering, gebrek aan opleiding en ontwikkeling, swak etiese waardes, beperkte hulpbronne, lae motivering van werknemers, swak kommunikasie en koördinering, gebrek aan beheer en swak spanwerk. Daar is gemerk dat die organisasie gebrekkige kommunikasieprosesse het, wat tot die uitdagings vir strategie-implementering bydra. Die bevindings het aan die lig gebring dat strategiese beplanning by die uitvoerende bestuur begin, en dus is hul toewyding tot eienaarskap van die algehele strategiese beplannings- en uitvoeringsproses noodsaaklik. Die studie het beperkte betrokkenheid van personeel by die aanvanklike fases van strategie-ontwikkeling getoon. Ten einde die implementering van strategieë te bevorder, is die aanbeveling om motiveringsleierskap by ZMDC te verseker. Leierskap, eienaarskap en dryfkrag is nodig om doeltreffend mee te ding en te groei. Die bestuur moet die beplanningsbenadering van „Strategie in Aksie‟ aanneem, wat die weg deur prestasiefaktore aantoon en strategiese dryfkragte aan projekte asook aan departementele en individuele aktiwiteit koppel. Die uiteindelike doelwit is om ZMDC in staat te stel om strategiese doelwitte doeltreffend in ʼn duidelike en insluitende proses in resultate om te skakel. Ten einde strategiese strewes in aksie wat resultate lewer om te skakel, moet ZMDC se leiers strategiese dryfkragte en breedgebaseerde aksieplanne ontwikkel, waardeur die visie duidelik gemaak word en almal duidelikheid het oor wat as strategiese sukses beskou word en wat dit verg om die gewenste uitkomste te bereik en te meet.

No description available.