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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Die optimale benutting van steenkool met verwysing na grootte by Bosjesspruit Steenkoolmyn

04 September 2012 (has links)
M.Phil. / The study was undertaken at Bosjesspruit, one of the Sasol Collieries, to investigate aspects that contribute to the degradation of coal. Bosjesspruit is penalised with more than nine million rands per year for fine coal that exceeds the set limits. Compliance to quality is the main reason. The cost is directly deducted from the profit. The quality of coal is of importance for the effectiveness of the gasifying process. A feasibility study has indicated that this study is viable. Various factors in the process were studied to identify the system deviations such as: coal bunkers, section and main conveyor belts, geology, production section activities and coal production equipment. A literature study was done and time was spent to become conversant with the coal transport system. The process is described from where the coal is mined, through the handling action up to where it is fed into the Sasol plant gasifiers. Several coal samples of the identified bottleneck areas were taken and analysed. The four main areas that were studied are: Loading actions at East 700 bunker. Incline shaft transfer chute. The horizontal bunker on surface. The South section conveyor chutes. The free-flow technology was researched and developed for an acceptable chute design. The design is now computerised and in use at Sasol Collieries. The current design and its restrictions are compared with the proposed designs to indicate the improvements. A detailed cost analysis was done to determine the expenditures such as: Penalties for fine coal. The cost of adaptability and redesign. - Forecast cost savings after the redesigns are implemented. - Cost to produce coal as well as the income for Bosjesspruit. An economical evaluation indicates that all the suggested solutions are economically justifiable. The results of the study indicate several suggested solutions to overcome the identified bottlenecks. It is further suggested that results of this study are also implemented at the other Sasol mines as well as the mines that are being developed.
12

The effect of organisational restructuring at Xstrata Coal South Africa and its impact on the business culture at the Tweefontein division

Alberts, Rasmus Stephanus 12 1900 (has links)
Thesis (MBA (Business Management))--Stellenbosch University, 2008. / ENGLISH ABSTRACT: Xstrata Coal South Africa (XCSA) embarked on a restructuring exercise towards the end of 2005 to enable the organisation and its management to adapt to the pressures and requirements of an ever-changing South African coal industry. The executive team of XCSA felt that some of the business units were too large to be effectively managed by one general manager and his/her management team. The Tweefontein and Impunzi business units fell into this category. Further, the executive team felt that the existing organisational structures on the mines were unable to effectively manage the demands coming from an ever-changing coal industry. Most such demands emanated from sustainable development issues: workplace safety, environmental management, health-related concerns to do with the employees and community development around the mines. The restructuring took place towards the end of 2005, not long after the restructuring of the business performance went into decline. The author of this thesis, as the General Manager of the Tweefontein Complex from the beginning of 2006 until mid-2008, was responsible for the day-to-day management of the division at the time. After explaining the need for restructuring, as well as how the structure was changed, the author will describe a comprehensive literature research study. The aim of such a study is to create a common understanding with the reader of the principles relating to culture, leadership and change management. The author then compares the two climate assessments of the organisational culture of the Boschmans Colliery undertaken during 2005 prior to embarking on the restructuring exercise, and of the Tweefontein Complex undertaken during 2007, on completion of the restructuring. Boschmans Colliery employees now constitute most of the underground and surface operations areas of the Tweefontein Complex. The organisational culture of the Tweefontein Complex was found to have been influenced by the restructuring exercise. The author concludes with recommendations on how the organisational culture of XCSA as a whole could be aligned. Chief among the recommendations are that: • A cultural alignment programme should be implemented to create a common organisational culture across XCSA. • A leadership development programme should be implemented to promote the desired organisational culture. • A communication strategy should be implemented to support the cultural alignment programme. • A branding campaign should be launched to strengthen the image of XCSA within the surrounding community. / AFRIKAANSE OPSOMMING: Xstrata Coal South Africa (XCSA) het aan die einde van 2005 besluit om die besigheid te herstruktureer om aan te pas by die veranderende aard van die Suid-Afrikaanse steenkoolindustrie. Die gevoel van die uitvoerende komitee was dat sekere van die besigheidseenhede te groot was om effektief deur een algemene bestuurder, bestuur te word. Die Tweefontein- en Impunzi-besigheidseenhede het in die kategorie geval. Verder het die uitvoerende kommitee gevoel dat die bestaande bestuurstruktuur per myn nie voldoende was om al die verwagtinge vanuit 'n vinnig veranderende steenkoolindustrie effektief te kan bestuur nie. Die vernaamste verwagtinge van die vinnig veranderende industrie was die vanuit die veld van Volhoubaarheid, naamlik veiligheid op myne, omgewingsbewustheid, gesondheid van die werknemers, sowel as die opbou van die gemeenskap. Die herstrukturering het aan die einde van 2005 plaasgevind en nie lank na die herstrukturering nie het die prestasie van die besigheid drasties afgeneem. Die skrywer was die Algemene Bestuurder van die Tweefontein Complex vanaf die begin van 2006 tot die middel van 2008, en was verantwoordelik vir die dag-tot-dag-bestuur van die afdeling. As deel van die studie sal die skrywer eerstens poog om die redes vir die herstrukturering te gee en ook hoe die nuwe struktuur daar uitsien. Tweedens sal die skrywer 'n deeglike literatuurstudie verskaf om 'n gemeenskaplike verstandhouding tussen die skrywer en die leser oor die beginsels van kultuur, leierskap en veranderingsbestuur te skep. Derdens sal die skrywer die resultate van twee klimaatstudies ontleed wat op die besigheidskultuur van die Boschmans-steenkoolmyn in 2005 voor die herstrukturering gedoen is en een wat in 2007 op die Tweefontein Complex na die herstrukturering gedoen is. Die werknemers van die Boschmans-steenkoolmyn maak tans die grootste gedeelte van die Tweefontein Complex se ondergrondse en aanleg- en logistieke afdelings uit. Na aanleiding van die analise van die twee klimaatstudies, bevind die skrywer dat die herstrukturering 'n daadwerklike invloed op die kultuur van die Tweefontein Complex gehad het. Die skrywer maak dan na gelang van sy bevindinge aanbevelings oor hoe die kultuur van Xstrata Coal South Africa (XCSA) as 'n geheel belyn kan word. Sy belangrikste aanbevelings is as volg: • Die implementering van 'n kultuurbelyningsprogram om 'n gemeenskaplike besigheidskultuur regoor Xstrata Coal South Africa (XCSA) daar te stel. • Die implementering van 'n leierskapsontwikkelingsprogram wat belyn is met die verlangde besigheidskultuur. • Die implementering van 'n kommunikasiestrategie wat die kultuurbelyningsprogram ondersteun. • Die loodsing van 'n Xstrata Coal South Africa (XCSA) bemarkingsveldtog am Xstrata Coal se beeld in die gemeenskap te bevorder.
13

Deposiotional systems of the permian Vryheid formation highveld coalfield, South Africa: their relationship to coal seam occurence and distribution

Cadle, Anthony Burnard January 1995 (has links)
The Permo-Carboniferous Dwyka Group and Vryheid Formation of the Karoo. Sequence in the Highveld Coalfield are analysed to determine the depositional systems operative during sedimentation. The investigation involves the processing of "629" borehole cores and logs in an area of 860km2.[Abbreviated Abstract. Open document to view full version] / AC2017
14

Adsorption of oxyanions of As, B, Cr, Mo and Se from coal fly ash leachates using A1/Fe modified bentonite clay

Masindi, Vhahangwele 10 January 2014 (has links)
MENVSC / Department of Ecology and Resource Management
15

An overview of energy minerals in the Springbok Flatsbasin, South Africa : implications for geochemical and geophysical exploration

Ledwaba, Lebogang John January 2015 (has links)
This study is informed by the rising demand for power needs in South Africa and aims at understanding the geophysical and geochemical characteristics of the energy minerals in the Springbok Flats Basin and relating them to the prevailing geological and structural setting for improved exploration targeting. The Springbok Flats Basin is part of the Karoo sediments and host to uranium, coal and coal bed methane (CBM) resources. The lithology sections in the basin indicate presence of basaltic lavas at the top, underlain by mudrocks, siltstones, sandstones, conglomerates and diamictite, with interbedded coal beds occasionally. The coals are uraniferous and shale bounded and of lower Beaufort age at 250 Ma. The regional radiometric data identifies the regional extent of the Springbok Flats Basin as a basin with low total count values. This information is useful in exploration as it gives an idea of the limits of the area where to focus application for prospecting licenses. The reduced to pole of the total magnetic field, residuals and first vertical derivative maps clearly show the high magnetic susceptibility nature of the surrounding Bushveld rocks as compared to the low Karoo sediment susceptibility within the basin. There are distinct ring shaped picks within the basin possibly due to known Karoo dolerite sills in particular to the central south western part of the grid. The regional geochemical mapping program is a cost-effective way of providing an overview of the relative abundance levels, regional trends and anomalous patterns in the underlying lithological units. Background values of elements in soils over different lithological units and the identification of anomalous values relative to these elements can easily be identified. The geochemical results show an excellent correlation between soil chemistry and underlying geological formations. A few distinct gravity highs are clearly shown within the basin. Assuming the effect of the Letaba basalt to the gravity readings is uniform across the basin; these distinct anomalies could be due to Karoo dolerite sills as they coincide with areas of distinct high magnetic signature. A conceptual model was generated assuming that the Karoo sediments’ layering is uniform across the gravity profile but changes in the residual are due to an increased thickness of the sill supported by the gentle changes on the surface topography. Satellite imagery has got its challenges especially in areas of vegetation but it does provide a very useful tool in exploration. A number of spectral analysis techniques and band rations can be used to differentiate the areas underlain by the Letaba basalts, the Karoo sandstones/shale and Bushveld granites for mapping purposes. The priority focus will be on the shallower Karoo sediments because of the potential for cheaper mining. Exploration targeting needs to be guided by observed geochemical and geophysical characteristics in order to prioritize areas taking into account the presence of Karoo intrusives such as the dolerite sills that tend to devolatize the coal hence affecting the quality/rank. Structures and gravity signatures are very important in delineating areas with thick sediments that have a potential for CBM. The same understanding in targeting goes a long way in planning drill holes, resource modelling and pre-feasibility stages for mine planning. A high resolution airborne geophysical survey is recommended over the basin to better resolve structures. Geophysical borehole logging is recommended to be part of the exploration drilling programs in the Springbok Flats Basin in order to define the in-situ geophysical characteristics. Geophysical logging is useful in particular for the uranium reserves that cannot be delineated from the surface due to deep intersection.

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