The objective of this study was to investigate the feasibility of the application of low cost high capacity inorganic ion exchange material, synthesized form collected fly ash and acid mine drainage solid residues, for the decontamination of secondary co-disposal process waters, with emphasis on investigating the processes governing the solid/solution interface.

Dissertation submitted in fulfilment of requirements for the degree Master of Technology: Chemical Engineering In the FACULTY OF ENGINEERING 2014 / In South Africa only 5% of the coal fly ash produced annually by power stations finds use. Due to the high quantities of Si and Al in the coal fly ash researchers have explored the opportunity to use the fly ash as a feedstock in zeolite synthesis. Two principal methods have been successfully employed on a micro scale namely the 2-step method and fusion assisted method. However, in order to scale-up these processes some fundamental process design changes are required. Fly ash contains various elements including highly toxic elements such as As, Pb and Hg. The fate of these elements during the synthesis processes is not known. Both these processes generate large quantities of liquid supernatant waste. Disposal of these wastes would be expensive and environmentally harmful, thus making these processes industrially unfeasible. The well known fusion assisted process, contains an energy intensive fusion step operating at 550 C. Construction and operation of a furnace to implement fusion would be too expensive on an industrial scale. The 2-step method has a time consuming pre-hydrothermal treatment step (aging step). In order to improve the feasibility of the 2-step process the processing time of the aging step needs to be reduced. In order to breach the scale gap between micro and pilot plant scale a principal reactor design has been suggested. However, to date, no consideration has been given to the safety and operational reliability of this design. A HAZOP study is required to prevent costly incidents from occurring during the operation of this reactor. The aim of this study formed part of the overall initiative to scale-up the synthesis of zeolites to pilot and ultimately do at industrial scale. The aim of this study specifically was to perform some principal process design activities in order to prepare these processes for scale-up. The objectives were to perform material balances on the two principals synthesis approaches in order to determine the distributional fate of elements. Secondly, to make critical process design changes and develop protocols whereby the supernatant waste resulting from these processes can be minimised. Thirdly, to replace the fusion step (used in the fusion assisted process) and the aging step (used in the 2-step process) with a short high intensity sonochemical treatment step. Lastly, to perform a HAZOP study on the principal bench scale reactor design, and make design changes based on the outcome of the study. Material balances illustrated that most of the elements originating from the coal fly ash (Fe, Mn, Mg, Ca, Ti, Ba, Ce, Co, Cu, Nb, Ni, Pb, Rb, Sr, Y and Zn) do not leach out into solution during either of the two synthesis approaches. This was due to the CaO content in the ash retarding the mobility of these elements. This meant that during the 2-step process these elements reported to the overall zeolite product but did not form part of the zeolite crystal structure. On the other hand, during the fusion assisted process these elements reported to the solid residue waste. The yield efficiency of the fusion assisted process was found to be poor with only 19.6% of the Si and 21.6% Al reporting to the zeolite A product. The 2-step process on the other hand incorporated 72.2% of the Si and 81.5% Al into the zeolite product. However, the 2-step process produced a mixed phase zeolite product while the fusion assisted process produced a pure phase zeolite A product. Therefore there is a trade-off between yield efficiency and product purity. It was found that the liquid supernatant waste produced during both the synthesis processes contained toxic elements such as As, Pb, Hg, Al and Nb. This highlighted the importance to minimise the liquid supernatant waste generated. The waste minimisation studies illustrated that the liquid supernatant waste can be recycled while still producing highly crystalline zeolite products, in both the synthesis approaches. During the 2-step process the supernatant waste was recycled as a source of NaOH. By recycling the waste it was found that 40% of the supernatant could be recycled. However, by making a minor process design change a protocol was developed whereby 100% of the supernatant waste could be recycled. Also, by recycling the liquid waste, zeolite analcime became the dominant phase due to the accumulation of Si in the waste. In the fusion assisted process, protocols were developed whereby the liquid supernatant waste was recycled as a source of water. It was found that 100% of the supernatant could be recycled without compromising the relative crystallinity and purity of the zeolite A product. Both the fusion step (used in the fusion assisted approach) and the 48 hr aging step (used in the 2-step process) could be replaced with 10 min of sonochemical treatment. It was found in both cases that the introduction of ultrasound, during the pre-hydrothermal stage, increased the rate of crystal formation during the hydrothermal treatment step. It was also found that by replacing the high temperature fusion step, in the fusion assisted process, the required hydrothermal treatment temperature could be reduced to 90 C. By introducing sonochemical treatment in these two synthesis approaches their synthesis time and energy demands could be reduced successfully. A HAZOP study on the principal bench scale reactor design enabled design changes to be made preventing future loss during operation. A final optimised reactor design was proposed based on the outcome of the HAZOP study. This study effectively prepared both zeolite synthesis approaches for up-scale operation. Scale-up of this process will reduce disposal of coal fly ash offering relief to the financial and environmental strain caused to the country.

MSc (Botany) / Department of Botany

MESMEG / Department of Mining and Environmental Geology / The Mushithe coal occurrence is situated approximately 16 km west of the Tshikondeni coal mine in the Tshipise-Pafuri sub-basin of the Soutpansberg coalfield in South Africa. The Soutpansberg Coalfield has received comparatively less attention compared to other more notable South African coalfields. There is as a consequence very limited information in the public domain applicable to the geology as well as quality of coal in this coalfield, as a result there is no known study focused exclusively on the Mushithe coal occurrence. The aim of the study was to conduct detailed geological mapping of the Mushithe Deposit so as to ascertain the geological environment and petrological characteristics of rocks within the area. Further work involved coal sampling and analysis in order to establish coal quality and its physical and chemical characteristics. Samples were collected using geological field mapping and channel sampling. Nine coal samples were collected from the coalbed and host rock, exposed along the Mbodi River, during geological field mapping using channel sampling. Furthermore, 92 rock samples were collected during geological field mapping of which 10 representative samples were selected for further analysis. X-ray fluorescence spectrometry was conducted on all selected samples. Proximate analysis and ultimate analyses, and calorimetry tests were undertaken on coal samples. Three samples were selected based on calorific value for maceral identification, mineral analyses and vitrinite reflectance using petrographic study. Detailed geological mapping of the area around the Mushithe coal occurrence showed the geological setting of coal in this area. The following lithologies were identified in the study area: sandstone, mudstone, ironstone, calcrete, shale, quartzite, quartz vein with a general strike direction to the north-east. The host rocks including coal were intruded by dolerite dykes and this resulted in the devolatilization of coal. The current study concluded that the Mushithe coal was formed in a wet swampy environment. This has been confirmed based on tissue preservation index (1.69) and gelification index (2.35). Coal rank ranged from bituminous Rank C- B according to United Nations Economic Commission for Europe Coal Classification (UNECE) and samples were characterised by high ash (27.90%), high moisture (10.47%) and low sulphur (0.24%). Furthermore, coal was graded below grade D based on classification for use by ESKOM which consider any calorific value below 24.5 MJ/kg to be in this category. The coal is vitrinite rich (77.75 vol%) and low in Inertinite (22.25 vol%) and devoid of Liptinite and pseudovitrinite, thus it is of good coking quality. Geochemical analysis revealed that the coal was enriched in TiO2 and Fe2O3 which was corroborated by the mineral matter which was mostly clay and pyrite. Comparatively, coal quality analysis revealed the calorific value of 14.26 MJ/kg and vitrinite reflectance between 0.94 %ROV to 1 %ROV which was less than that of the Tshikondeni Deposit but greater than that at Waterberg coalfield. The study recommends further detailed exploration of coal in the area, applying such techniques such as geophysical exploration and borehole drilling leading to resource evaluation. Further studies are recommended to provide a better interpretation of the depositional environment of coal at Mushithe as well as the effect of devolatilaziton by a dolerite dyke. / NRF

In the Powder River Basin of Wyoming, our nation's interest in protecting its cultural heritage collides with the high demand for carbon fuels. "Clinker" deposits dot the basin. These distinctive buttes, created by the underground combustion of coal, are underlain by coal veins; they also provided the main lithic resources for prehistoric hunter-gatherers. These deposits signify both a likelihood of extractable carbon and high archaeological site density. Federal law requires that energy developers must identify culturally significant sites before mining can begin. The research presented here explains the need for and describes a statistical tool with the potential to predict sites where carbon and cultural resources co-occur, thus streamlining the process of identifying important heritage sites to protect them from adverse impacts by energy development. The methods used for this predictive model include two binary logistic regression models using known archaeological sites in the Powder River Basin. The model as developed requires further refinement; the results are nevertheless applicable to future research in this and similar areas, as I discuss in my conclusion.

No description available.

The objective of the study was to investigate the relationship between sense of coherence, work locus of control and burnout amongst mid-level managers in underground coal mining, and to determine whether sense of coherence and work locus of control can predict the level of burnout in the sample. A cross-sectional survey design was used and three questionnaires were administered, namely the Orientation to Life questionnaire, The Maslach Burnout Inventory – General Survey and the Work Locus of Control Scale. The sample consisted of 131 mid-level managers from a leading coal mining organisation in Mpumalanga, South Africa. The results indicated low to moderate levels of exhaustion, cynicism and reduced professional efficacy, as subdimensions of burnout, in the sample group. Sense of coherence and internal work locus of control showed statistically significant negative correlations with burnout. The two salutogenic constructs predicted a significant portion of the variance in burnout in the sample group. / Industrial & Organisational Psychology / MCOM (Industrial and Organisational Psychology)

Coal seams are commonly associated with poor quality water that requires treatment. Water treatment can be very expensive and can severely affect the profitability of mining projects. This study investigated the potential cultivation of Arthrospira maxima (Spirulina) in coal seam water to beneficiate coal seam water in order to effectively offset the water treatment cost. The study was conducted in Northern South Africa and formed part of a larger Coal Seam Water Beneficiation Project (CSWBP). The study consisted of laboratory based Flask Studies and outdoor High Rate Algal Pond Studies. The Flask Studies that were carried out in the on-site field laboratory, found that the coal seam water could provide a suitable medium for Spirulina cultivation. In addition, it was found that the optimal pH for the selected strain ranged between 9 - 10.5 and that the addition of excess iron, up to 100 times the concentration found in defined growth media such as Schlösser’s, to the culture media could enhance productivity. The High Rate Algal Pond Studies (HRAP) were carried out over a period of 18 months. The studies showed that the coal seam water at the CSWBP is a valuable resource that can reduce media costs by 50% without affecting productivity. In a study encompassing 334 days it was shown that heating the culture through plate heat exchangers would result in a significant increase in productivity and a heated productivity of 19.86 g/m2/day was recorded. An unheated productivity of 14.11 g/m2/day was recorded. Therefore, it was found that it would be economically feasible to beneficiate coal seam water found at the CSWBP through the cultivation of Arthrospira maxima (Spirulina). / Environmental Sciences / M. Sc. (Environmental Science)

Business Intelligence (BI) applications are consulted by their users on a daily basis. BI information obtained assist users to make business decisions and allow for a deeper understanding of the business and its driving forces. In a mining environment companies need to derive maximum benefit from BI applications, therefore these applications need to be used optimally. Optimal use depends on various factors including the usability of the product. The documented lack of usability evaluation guidelines provides the rationale for this study. The purpose is to investigate the usability evaluation of BI applications in the context of a coal mining organization. The research is guided by the question: What guidelines should be used to evaluate the usability of BI applications. The research design included the identification of BI usability issues based on the observation of BI users at the coal mining organization. The usability criteria extracted from the usability issues were compared and then merged with general usability criteria from literature to form an initial set of BI usability evaluation criteria. These criteria were used as the basis for a heuristic evaluation of the BI application used at the coal mining organization. The same application was also evaluated using the Software Usability Measurement Inventory (SUMI) standardised questionnaire. The results from the two evaluations were triangulated to provide a refined set of criteria. The main contribution of the study is the heuristic evaluation guidelines for BI applications (based on these criteria). These guidelines are grouped in the following functional areas: visibility, flexibility, cognition, application behaviour, error control and help, affect and BI elements. / Information Science / M.Sc. (Information Systems)

The objective of the study was to investigate the relationship between sense of coherence, work locus of control and burnout amongst mid-level managers in underground coal mining, and to determine whether sense of coherence and work locus of control can predict the level of burnout in the sample. A cross-sectional survey design was used and three questionnaires were administered, namely the Orientation to Life questionnaire, The Maslach Burnout Inventory – General Survey and the Work Locus of Control Scale. The sample consisted of 131 mid-level managers from a leading coal mining organisation in Mpumalanga, South Africa. The results indicated low to moderate levels of exhaustion, cynicism and reduced professional efficacy, as subdimensions of burnout, in the sample group. Sense of coherence and internal work locus of control showed statistically significant negative correlations with burnout. The two salutogenic constructs predicted a significant portion of the variance in burnout in the sample group. / Industrial and Organisational Psychology / M. Com. (Industrial and Organisational Psychology)