A research report submitted in partial fulfilment of the requirements for the degree of Master of Science in Engineering (Mining) to the faculty of engineering and the built environment, University of the Witwatersrand, Johannesburg Date of final submission 25 May 2017 / The Australasian code for Reporting of Exploration Results, Mineral Resources and Ore Reserves, of the Joint Ore Reserves Committee (JORC) sets out minimum standards, recommendations and guidelines for Public Reporting in Australasia. (JORC, (2012)). The Committee for Mineral Reserve International Reporting Standards (CRIRSCO) created a set of standard international definitions for reporting Mineral Resources and Mineral Reserves based on the evolving JORC code’s definitions (CRIRSCO, (2013)). CRIRSCO’s members are National Reporting Organisations (NRO’s) which are responsible for developing mineral reporting codes for Australia (JORC), Canada (CIM Standing Committee on Reserve Definitions), Chile (National Committee), Europe (PERC), Russia (NAEN), South Africa (SAMCODES) and USA (SME) (JORC, (2012)). The NRO’s for; South Africa (SAMREC), Australia (JORC) and Canada (CIM Standing Committee on Reserve Definitions) published supporting standards for Coal Resource and Reserve Classification and Reporting namely, South African National Standard: South African Guide to the Systematic Evaluation of Coal Resources and Coal Reserves (SANS10320:2004), the Australian Guidelines for the Estimation and Classification of Coal Resources (Australian Guidelines (2014)) and the GSC Paper 88-21: A Standardized Coal Resource/Reserve Reporting System for Canada (Hughes, et al., (1989)). With the objective to identify the most appropriate Coal Resource Classification approach for the Witbank Coalfields in South Africa, Coal Resource Classification methods applied elsewhere in the world were investigated, these countries include Canada and Australia. SANS10320:2004 relies on a minimum drillhole spacing dependant on two different coal seam deposit types, whereas the Australian Guideline for the Estimation and Classification of Coal Resources (2014) provide a guide as to which geological aspects need to be considered when classifying a coal deposit into the appropriate confidence category, and no fixed drillhole spacing is recommended. The Canadian Standardized Coal Resource/Reserve Reporting System (1989) differs from the afore mentioned standards in that it is a prescriptive method based on specific levels of geological complexity, governed by specific fixed parameters. None of the other Coal Reporting codes/standards use a broad sweeping fixed drillhole spacing to classify Coal Resources as in South Africa. It is noted from experience as well as by Coal Resource Classification methods used elsewhere in the world that the use of proposed fixed drillhole spacing, such as currently in use in SANS10320:2004, is an unsatisfactory method for assessing the uncertainty and variability associated with coal deposits. The Coal Resource Classification methodologies utilised on a local scale in South Africa, were investigated to establish how mining houses manage and assess the variability in their Coal Resources. Fourteen mines operating throughout the Witbank coalfield were compared, it was found that although the Coal Resource Classification of the governing code requires a 350m drillhole spacing for highest level of confidence, the mines drill to a much smaller grid for increased confidence. Despite this, the mines still report on the SANS10320:2004 minimum standard in the public domain. A map was created based on the average drillhole spacing drilled per mine. From this it was deduced that there are zones of higher coal seam variability which required a closer spaced drilling grid to derive sufficient geological confidence in the estimates. Based on these deductions four zones of comparable continuity/variability, were identified. The zones identified by means of geological investigation and those identified by differences in variability as perceived by the Competent Person (CP) correlate. The highest variability and smallest drillhole spacing is located toward the western portion of the coalfield whereas the lowest variability with the largest drillhole spacing is located toward the east. The geologically complex Witbank coalfield was divided into four geo-zones/domains based on the depositional environment, basement rocks and post depositional influences. It is evident that a suitable Coal Resource Classification approach; which considers the characteristics of the geozones are followed. The question of which other classification methods are appropriate if not a predetermined drillhole spacing is addressed by this research. Statistics on relevant variables can provide a measure of uncertainty and therefore reliability in the estimates, for this reason three methods of uncertainty and probability characterisation were investigated. Of the three, namely; Non-linear estimation approach, conditional simulation (CS) and global estimation variance (GEV), the latter was deemed the most appropriate. GEV forms the basis of Drillhole Spacing Analysis (DHSA) and was applied to a mid-sized coal mine within the western portion of the Witbank coalfield. The analysis did not result in robust Coal Resource classification of estimates but rather provided more insight into the variability of the deposit. The results of DHSA are easily manipulated and are open for interpretation, it is therefore suggested as a valuable exercise/tool for understanding and assessing coal seam variability and to be used as a guide in Coal Resource classification. Onsite practical geological information should not be underestimated and geostatistics should always confirm the geology. A purely mathematical approach to Coal Resource classification would be a gross oversight, a combination of geological factors in association with statistical inferences is suggested. A scorecard method with associated weights is proposed to improve the confidence in the Coal Resource classification. / MT 2017

The Fluidised Bed Combustion (FBC) technology has been widely used internationally for power generation. This technology has good fuel flexibility and reduced S02 emissions with dry sorbent (Limestone or Dolomite) addition. South Africa has large reserves of coals that are difficult to combust in conventional pulverised fuel fired boilers. These reserves could be potential feedstocks for new build FBC boilers. The chemical composition of these coals is site specific and could have an impact on the combustion performance of the fuel. This necessitates the need for FBC coal tests in the presence of a sorbent. The objectives of this study were to investigate the changes in the production NO" SO" and the combustion efficiency of the three test coals under conditions of fluidised bed combustion, with the same sorbent. Tests with no sorbent were performed to evaluate the coals inherent calcium capabilities of capturing sulphur. Tests with varying ratios of sorbent were performed to evaluate the sorbent's capabilities for further levels of in-bed desulphurisation. The experimental equipment used in this investigation was the Eskom Fluidised Bed Test Facility (FBTF). This facility is a bubbling fluidised bed combustorlgasifier. The investigated bed temperature range was between 800 to 900°C, in intervals of 20°C. The operating pressure was 50kPa (gauge). The three coals were compared at CalS molar ratio of 1. Carbon in ash has shown to decrease with an increase in bed temperature for Coal A, Band C. The best performing coal in terms of least quantity of remaining carbon in ash was Coal A. The NO emissions increased for an increase in bed temperature for Coal A, Band C. The greatest NO emissions were recorded during Coal B tests. The N 20 emissions decreased with an increase in bed temperature for Coal A and B tests. Higher N 20 emissions were observed for Coal B than Coal A tests. In terms of S02 retention Coal C performed the best. The optimal operating bed temperature for S02 retention observed for the three coals was in the region of 800-860°C. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2007.

The aim of this project was to identify and assess all possible solutions to reduce carbon dioxide (CO2) emissions from coal power plants in South Africa, identify the most likely solution to be implemented industrially in the short to mid-term future, and contribute towards its development through lab measurement and further research. This thesis thus contains a substantial literature review conducted on the current state of CO2 emissions in South Africa, conventional and novel coal power plant processes, modes of CO2 capture, criteria regarding the implementation of CO2 capture techniques, and the various CO2 capture techniques currently investigated with varying levels of development. The study found gas absorption using solvents to be the most likely mid-term CO2 capture technique to reach industrial implementation. However, certain challenges still need to be overcome, particularly due to numerous limitations of current solvents, to make this technique feasible for CO2 capture. In an attempt to overcome the main challenge of solvent absorption capacity, it was decided to investigate the use of ionic liquids for CO2 absorption. An in-depth review of ionic liquids was conducted, as well as a review of measurement techniques and modelling of gas absorption in alkanolamine and ionic liquid solvents. Four ionic liquids, namely methyl trioctyl ammonium bis(trifluoromethylsulfonyl)imide [MOA][Tf2N], 1-butyl-3-methyl imidazolium bis(trifluoromethylsulfonyl)imide [Bmim][Tf2N], 1-butyl-3-methyl imidazolium tetrafluoroborate [Bmim][BF4], and 1-butyl-3-methyl imidazolium methyl sulphate [Bmim][MeSO4] were tested for CO2 and O2 absorption by measuring equilibrium Pressure-Temperature-Liquid mole fraction (P-T-x) data. Measurements were conducted using an Intelligent Gravimetric Analyser (IGA-01) at 303.15, 313.15, and 323.15 K. CO2 partial pressures of 0.05 to 1.5 MPa and O2 partial pressures of 0.05 to 0.7 MPa were investigated. Furthermore, density and refractive index measurements were conducted for all solvents. The ionic liquids were benchmarked against other ionic liquids and conventional alkanolamine solvents for CO2 absorption capacity and selectivity. The study found that ionic liquids achieved higher CO2 absorption capacity at high pressure than conventional alkanolamine solvents, but very low absorption capacity at low pressure. Of the ionic liquids studied, [Bmim][BF4] and [Bmim][Tf2N] achieved high CO2 absorption and high CO2 selectivity over O2. Therefore, these two ionic liquids were selected to be combined with conventional alkanolamine solvents, namely Monoethanolamine (MEA), Diethanolamine (DEA), and Methyl Diethanolamine (MDEA), in order to form hybrid solvents. P-T-x data was obtained for CO2 absorption in alkanolamine-ionic liquid hybrid solvents containing various compositions of the above alkanolamines and ionic liquids, by gravimetric analysis, under temperature and pressure conditions as described above. CO2 absorption in the hybrid solvents was analysed, compared, and benchmarked against absorption in pure ionic liquids and conventional alkanolamine solvents. Absorption data for pure ionic liquid systems was modelled using the Redlich-Kwong equation of state (RK-EOS), while absorption in hybrid solvents was modelled using the RK-EOS for the ionic liquid components and the Posey-Tapperson-Rochelle model for the alkanolamine components of each hybrid solvent. All modelling was programmed using MatlabTM R2012B engineering programming software. Further composition analysis was intended using Fourier transform infrared (FTIR) spectroscopy. The design and development of this apparatus is described herein. The apparatus possessed limitations in achieving the desired measurements. Recommendations are described for future modifications to make the apparatus more applicable for the systems in this work. The most important conclusion was that the hybrid solvents successfully achieved higher equilibrium CO2 absorption than conventional alkanolamine solvents and pure ionic liquids, at low pressure. Absorption increased with higher temperature, lower pressure, and alkanolamine concentrations lower than 40wt%. Modelling of CO2 absorption in hybrid solvents using the above stated model proved inadequate, with deviations nearly as high as 10% of measured data. A process of CO2 capture was simulated using the engineering software Aspen Plus V8.0. CO2 absorption in the hybrid solvent containing MEA:DEA:[Bmim][BF4] at 31.8:12.1:56.1 wt% was benchmarked against CO2 absorption in a conventional alkanolamine solvent. The simulation revealed a significant improvement in CO2 absorption using the hybrid solvent at low system pressure. However CO2 selectivity and solvent recycle heat duty results were undesirable. Finally, recommendations are listed for future research endeavours, simulation and apparatus development. / Thesis (Ph.D.)-University of KwaZulu-Natal, Durban, 2013.

M.Sc. / Please refer to full text to view abstract

Bibliography: pages 116-119. / In South Africa, ever increasing quantities of fine (-0,5 mm) coal are being produced as a result of the increased use of mechanised mining methods. Very few mines beneficiate the fines; in most cases they are discarded. However the fine size of this material suggests that it should be well liberated, with the potential to produce a low ash product. This thesis forms part of an ongoing research program examining the use of flotation to beneficiate coal fines to produce a low ash product. Coal is a highly heterogeneous material, consisting of a number of both organic (maceral) and inorganic (mineral) components with different physical and technological properties. Therefore in order to evaluate and interpret flotation results, an understanding of the liberation characterist ics of both the organic and inoganic components is required. This thesis presents a liberation study on fine coal from the Greenside Colliery, a typical colliery in the Witbank Coalfield which is the most important source of South African low ash coal. The study was performed by mining a run of mine coal sample to varying degrees of fineness (from 30 % finer than 150 micron to 90 % finer than 150 micron), screening, and assessing the liberation of each size fraction. These results were compared to those obtained from a sample of naturally arising fines (thickener underflow). Liberation was assessed by float and sink analysis, and for this purpose a new technique was developed that enables rapid and accurate float and sink analysis of coal down to a few micron in size. Petrographic analyses were performed to determine the liberation of the organic coal components.

M.Phil. / Coal is today providing more than seventy-five percent of South Africa's energy requirements and will, to a large extent, remain so in the future. It is thus important to evaluate the adequacy of the country's available coal resources against expected future demand. The main objective of this study, which was done under the supervision of Prof. D. J. Kotze, was therefore to analyse the specific consumption of coal in the various consumption sectors in order to establish historical trends. The specific comsumption of coal is defined as the amount of coal used to produce a unit of final product. The factors attributing to these observed trends were determined and their future role evaluated in order to establish whether it was possible to extrapolate historical trends into the future. By means of curve fitting to the observed data and extrapolation it was possible to obtain future values of specific coal consumption for each of the sectors. These values, together with the production output forecasts for the various sectors were then used to calculate the total coal requirements for three reference years, namely, 1990, 1995 and 2000. The role of coal prices in explaining trends in specific coal consumption of various sectors was also analised separately. Information to conduct the study was obtained mainly from the various coal producers' associations as well as from individual producers and other organizations such as Escom, Sasol and Iscor, the Department of Hineral and Energy Affairs and the Hinerals Bureau. In some instances private firms and producers' associations were also consulted as well as a wide variety of literature on the subject. The principal finding of the study was that coal was substituted or was still being substituted by electricity in most final applications because of the convenience of use. Coal, however, still plays and probably will continue to play an important role in future in basic industries such as the metallurgical industry. Coal prices have not up to now played a very important role in the overall specific consumption of coal which can probably be attributed to the relatively low prices of coal on the inland market. It was also found that it was not desirable to do away with the present system of price control entirely as a certain measure of control was still necessary to safeguard the usuage of coal in certain applications for which there were no other substitutes. It was further concluded that South Africa does not have the vast quantities of coal commonly thought and that measures have to be taken in order to ensure that the country's coal resources are conserved and that optimum use is made of available resources.

M.Phil. (Energy Studies) / Please refer to full text to view abstract

This paper investigates the sustainability, trans-boundary protection of resources and mining with particular emphasis on the Coal of Africa case example. It explores the issues pertaining to the sustainability and trans-boundary protection of resources that were taken into account as part of the decision- making process with regard to mining by Coal of Africa in the Greater Mapungubwe area in South Africa. At the centre of the dispute was the mining of coal by Coal of Africa without obtaining a water use licence and other related legal authorisations. This was in violation of sector specific legislation such as the National Environmental Management Act 107 of 1998 and the National Environmental Management Biodiversity Act 10 of 2004, to name just a few. The importance of the Mapungubwe area is that it has a world heritage site and the mining is taking place adjacent to the world heritage site. Therefore, the mining activities by Coal of Africa should be conducted in a sustainable manner and should take into cognisance the four pillars of sustainability, namely, the environment, economic, social and cultural aspects. Furthermore, the mining activities must also take into account principles of sustainable development. The role of the government in regulating mining activities in areas such as Mapungubwe to ensure trans-boundary protection of resources including mineral resources for the current benefit of the communities and future use. In addition, regional instruments such as the African Charter on Human and Peoples' Rights, the Convention on the Conservation of Nature and Natural Resources, the Cultural Charter for Africa, SADC Treaty, SADC Protocol on Mining, provide for sustainable development. Also, the Revised SADC Protocol on Shared Watercourses places an obligation to parties to a shared watercourse to consult before embarking on any activity that may have detrimental environmental consequences. This paper established that to a certain degree economic issues were considered, as mining has the benefits of job creation. However, the failure by Coal of Africa to obtain the water use licence in the beginning could have been avoided. It is recommended that for such future activities an Intergovernmental Mining and Sustainability Forum be established to deal with such issues. In order for such a Forum to effectively function, there is need to amend 2013 MPRDA Amendment Bill. / LLM (Environmental Law and Governance), North-West University, Potchefstroom Campus, 2014

This paper investigates the sustainability, trans-boundary protection of resources and mining with particular emphasis on the Coal of Africa case example. It explores the issues pertaining to the sustainability and trans-boundary protection of resources that were taken into account as part of the decision- making process with regard to mining by Coal of Africa in the Greater Mapungubwe area in South Africa. At the centre of the dispute was the mining of coal by Coal of Africa without obtaining a water use licence and other related legal authorisations. This was in violation of sector specific legislation such as the National Environmental Management Act 107 of 1998 and the National Environmental Management Biodiversity Act 10 of 2004, to name just a few. The importance of the Mapungubwe area is that it has a world heritage site and the mining is taking place adjacent to the world heritage site. Therefore, the mining activities by Coal of Africa should be conducted in a sustainable manner and should take into cognisance the four pillars of sustainability, namely, the environment, economic, social and cultural aspects. Furthermore, the mining activities must also take into account principles of sustainable development. The role of the government in regulating mining activities in areas such as Mapungubwe to ensure trans-boundary protection of resources including mineral resources for the current benefit of the communities and future use. In addition, regional instruments such as the African Charter on Human and Peoples' Rights, the Convention on the Conservation of Nature and Natural Resources, the Cultural Charter for Africa, SADC Treaty, SADC Protocol on Mining, provide for sustainable development. Also, the Revised SADC Protocol on Shared Watercourses places an obligation to parties to a shared watercourse to consult before embarking on any activity that may have detrimental environmental consequences. This paper established that to a certain degree economic issues were considered, as mining has the benefits of job creation. However, the failure by Coal of Africa to obtain the water use licence in the beginning could have been avoided. It is recommended that for such future activities an Intergovernmental Mining and Sustainability Forum be established to deal with such issues. In order for such a Forum to effectively function, there is need to amend 2013 MPRDA Amendment Bill. / LLM (Environmental Law and Governance), North-West University, Potchefstroom Campus, 2014

Thesis (MBA)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Severe flooding in Queensland, Australia in late 2010 and into February of 2011 resulted in significant losses to infrastructure, equipment and coal production. Xstrata Coal (XC) mines suffered billions of dollars worth of losses, resulting in insurance premiums increasing drastically in subsequent months. These events prompted Xstrata‟s top management to reconsider the way in which they managed risk. Initial revelations were that the focus of Risk Management had largely been on the areas of Health and Safety and that, particularly in South Africa, the outcome of all management‟s efforts to manage risk had been to comply with the relevant legislation. There was clearly an attempt to avoid litigation resulting in potential prosecution. The most stringent of this legislation was that of the Mine Health and Safety Act (No. 24 of 996), as promulgated by the Department of Mineral Resources. The requirements were prescriptive to the extent that mine management was required to utilise the Hazard Identification Risk Assessment process to identify hazards, assess the associated risk and apply mitigation, largely in order to prevent incidents which could affect the health and safety of employees. Little regard was given to the fact that mining houses could endure severe financial losses as a result of catastrophic events, which could stop production for significant periods of time. Whilst Xstrata did recognise Business Continuity Risk (BCR), the risk assessment process which was introduced along with the CURA risk register displayed a distinct division between Health and Safety Risk and BCR. Furthermore, this was not a systematic process. Initial risk categories were prescribed by XC mainly based on experiences in Australia. The floods prompted a rethink and Xstrata‟s prescription to conduct business continuity risk assessments (BCRAs) coincided perfectly with this writer‟s exposure to the Enterprise Risk Management Elective at the University of Stellenbosch‟s Business School. As the General Manager of the iMpunzi Complex that comprises three coalmines, it was the responsibility of the writer to carry out the instruction to review the business continuity process. Consequently, the research is intended to assess the current Risk Management environment within Xstrata Coal South Africa by means of an analysis of current documentation and interviews with select key personnel who largely influence and impact the management of risk in the company. Thereafter, the study will progress to the methodology involved in the Risk Assessments, followed by an assessment of the knowledge, skills and qualifications required for the relevant, accountable managers appointed to manage the risks. The findings of the research were that whilst there was quite a rigid framework, which was aligned with ISO 31000 principles for risk management, there were shortcomings in the methodology of the risk assessment process, as well as the considerations for dealing with latent or residual risk. To this extent, the writer recommended: A risk assessment template which prescribes, but is not limited to, the hazards which may be prevalent on a coal mine, including hazards specific to iMpunzi Complex; A revised template for the Risk Treatment Plan, which takes cognisance of Residual Risk; Other recommendations, which may deal with minor findings of the study.