The aim of this study was to determine the relationship between the Big Five personality traits and mental health within a cohort of black African teachers. A review of literature revealed that teachers frequently experience mental- and general health problems (e.g. Ngidi & Sibaya, 2002; Olivier & Venter, 2003; Johnson, Cooper, Cartwright, Donald, Taylor & Millet, 2005; Parker, Martin, Colmar, & Liem, 2012). However, very little could be found on personality traits and how this relates to the health and well-being of teachers, especially in the challenging South African context. This study forms part of the SABPA (Sympathetic Activity and Ambulatory Blood Pressure in Africans) project conducted within AUTHeR (Africa Unit for Transdisciplinary Health Research). The overarching purpose of this multidisciplinary project was to investigate the markers of bio-psycho-social health in urbanized teachers. This longitudinal project ran from January 2008 to November 2012 and involved a total of 409 Black and White secondary school teachers. The research was conducted in the North West province of South-Africa. This study focused on the 200 urbanized Black teachers who were recruited by means of convenience sampling from the Dr. Kenneth Kaunda educational district in the Potchefstroom area in the North West province during 2008. The sample included 101 men and 99 women, ranging between the ages of 25 and 60 years. Ethical permission for the SABPA and FORT3 projects was obtained from the ethics committee of the North-West University (ethical clearance numbers NWU-00036-07-S6 and NWU-00002-07-A2 respectively). Participants filled out informed consent forms prior to data collection, and after the objectives of the study and the research procedures were explained to them, all their questions were answered. Data collection for the baseline phase of the project lasted for 50 days during February to May 2008. Four participants arrived at the North-West University (NWU) Metabolic Unit on the Potchefstroom campus after work each day. After being welcomed and oriented, a battery of psychometric tests was administered in English. A secondary analysis was performed on data obtained by means of the Basic Traits Inventory-Short, Mental Health Continuum-Short Form and the General Health Questionnaire-28 in order to determine the relationship between personality functioning and mental health of the participants. Results showed that this cohort of teachers from the North West province experience distress in the workplace, but that they also experience surprisingly high levels of mental health. The findings suggest that there are few differences between the male and female subgroups in this regard. The study also found that there is indeed a relationship between personality traits and the general- and mental health of participants. Neuroticism showed a significant positive correlation with psychological distress, while Conscientiousness showed a significant negative correlation. All five personality traits showed significant correlations with the mental health of educators. Neuroticism correlated negatively with mental health, while Extraversion, Openness to Experience, Conscientiousness and Agreeableness correlated positively with mental health. Furthermore, certain personality traits (i.e. Neuroticism and Extraversion) were shown to be significant predictors of teachers’ levels of general and mental health. The strong association found between this cohort of teachers’ personality functioning and their general and mental health contributes toward an understanding of the processes that underlie the distress and mental health of teachers, and could play an important role in future attempts toward health promotion. / MSc (Clinical Psychology), North-West University, Potchefstroom Campus, 2014

Text in Afrikaans / Summaries in both Afrikaans and English / Religiositeit is 'n antropiese ontisiteit en kinders word in 'n bepaalde geloof opgevoed. 'n Christelik-Protestantse perspektief van godsdiensopvoeding word aangebied. Die betrokke opvoedingsmoveerders en hul verhouding tot mekaar word bespreek. Ter aanduiding van wat jeugdige-wees wesenlik kinder-antropologiese kategoriee beskryf, is, word bepaalde gevolg deur 'n sinkroniese en 'n diakroniese perspektief van godsdienswording. Die hedendaagse jeugdige se leefwereld en gepaardgaande struikelblokke word bespreek. Die taak, die doel, asook relevante religieuse kriteria en essensies van opvoeding word bespreek. Die Afrikaanse Christen-Studentevereniging is een van die opvoedingsmoveerders betrokke by die godsdienswording van sommige jeugdiges. Die oorspronklike struktuur en benaderingswyse van die vereniging, asook die veranderde struktuur en benaderingswyse en die redes daarvoor, word beskryf. Die missie, toekomsvisie en modus operandi van die vereniging word deur hierdie veranderinge geraak. Omdat persone van verskillende denominasies by die vereniging mag aansluit, word 'n oorsig van dogma binne die Christelike geloof gegee, gevolg deur 'n bespreking van ideologies-religieusestrominge wat van belang mag wees. Die vereniging se confessio van 1988, 1992 en 1994 word vergelyk met die oog op die moontlike veranderinge rakende godsdiensopvoeding. 'n Evaluering is onderneem vanuit sowel die struktuurdenke as die sisteemdenke. Hierdie evaluering geskied op drie vlakke. Op die ontologiese vlak word gekyk of die vereniging rekening hou met sekere neaniagogies-antropologiese kategoriee. Op die terrein van die pedagogiese word die realisering van bepaalde opvoedingsessensies, van die verhoudings- en verloopstruktuur en van Protestants-Christelike geestelike volwassenheid as doel ge-evalueer. Die vereniging se bewustheid van sekere bepalende aspekte rakende godsdiensopvoeding, asook die bantering van sommige van die leefwereldprobleme word geevalueer. Die aktualiteit van die werksaamhede word vergelyk met 'n Amerikaanse jeugbedieningsmodel. Op teologiese gebied word moontlike ooreenkomste tussen verskillende Christelike belydenisse aangedui. 'n Christelike evaluering van die werksaamhede van die vereniging word onderneem. Godsdiensopvoeding gaan moontlik in die "nuwe" Suid-Afrika veranderinge ondergaan en daarom word 'n prospektiewe blik op die moontlike rol van die vereniging in die veranderde situasie gebied. / Religiosity is an anthropological onticity and children are educated in a specific religion. A Christian-Protestant viewpoint of religious education is presented. The educational motivators involved, as well as their inter-relatedness, are discussed. To indicate what it means to be a youth, certain childanthropological categories are described, followed by a synchronical and diachronical perspective of religious growth. The influence on the life-world of today's youth and related problems are discussed. The task, aim and relevant religious criteria and essences of education are discussed. The Afrikaanse Christen-studentevereniging is one of the educational motivators involved with certain youths. The orginal structure and attitude of the organisation, as well as the changes in its structure and attitude and the reasons for these changes are described. The organisation's mission and vision, as well as its methods, are affected by these changes. Because people from different denominations can become members of the organisation a cursory description of dogma within the context of the Christian religion is given, followed by a discussion on ideological religious mainstreams that may be of importance. The organisation's confessions of 1988, 1992 and 1994 are compared in view of the probable changes concerning religious education. An evaluation is done from both a structural thinking and systems thinking point of view. This evaluation is conducted on three levels: On an ontological level it is evaluated with regard to what extent the organisation is taking neaniagogical categories into account. on a pedagogical level the realisation of the pedagogical relationship and sequence structures and its essences as well as Christian-Protestant religious maturity as aim are evaluated. The organisation's awareness of certain determining aspects concerning religious education, as well as the handling of some of the lifeworld problems are evaluated. The actuality of the organisation's activities are compared to an American youth program model. On a theological level possible similarities between different Christian confessions are indicated. A Christian evaluation of the organisation's activities is also rendered. Since religious education may undergo certain changes in the new South Africa a prospective view is presented of the possible role the organisation may fulfil. / Education Studies / D.Ed.

Thesis ( MMus (Music))--University of Stellenbosch, 2007. / Steven De Groote (1953-1989) was one of the most successful pianists to have emerged from South Africa. His international reputation rests largely on the fact that he won first prize in the Van Cliburn International Piano Competition in 1977, the only South African to date to have achieved this feat. As such he must be recognized as an important figure in the music history of South Africa. Because the performing musician’s product is transitory in nature and therefore his/her legacy is not tangible in all respects, the introduction to the thesis discusses the specific methodological problems arising from this fact in respect of the writing of a biography. The focus in this biography is on De Groote’s numerous achievements and especially on his career as concert pianist. It includes a discussion of his formative years, his subsequent years of study and the influence of competitions, and more specifically the 1977 Van Cliburn competition on his career. Discussion of his pianistic style, De Groote as teacher and his love for chamber music is also included. De Groote’s contribution to the South African musical scene is highlighted, especially his honorary professorship at the University of Stellenbosch during 1986 and 1987, as are his master classes in this capacity and his regular performances in South Africa. His role as a South African musician abroad is also examined. The biography is concluded with a brief discussion of his airplane accident and the influence this had on his career as a pianist and on his playing.

ENGLISH ABSTRACT: This study comprises an investigation into the restandardisation of Afrikaans. Since the 1980s, there have been various calls from the Afrikaans speech community for the democratisation of Afrikaans by making it representative of the whole Afrikaans speech community. Despite these calls for the restandardisation of Afrikaans, a matter which has been brought to the fore in recent years, there are still no real theoretically-based and practical suggestions for such a project. The practical approach to the restandardisation of Afrikaans suggested in this study, with a specific focus on the restandardisation of the orthography of Afrikaans, informs the suggestion of a model by which such a planned restandardisation programme for Afrikaans could be carried out. This is done based on existing theories of standardisation and restandardisation, as well as a thorough investigation into the history of the standardisation of Afrikaans in order to determine the reasons underlying this need for its restandardisation. Firstly, relevant theories of standardisation are considered in order to determine which aspects of language standardisation give rise to restandardisation and play the most important role in it. The history of the standardisation of Afrikaans is also considered, in order to indicate the factors which gave rise to the calls for the restandardisation of Afrikaans. The world-wide phenomenon of destandardisation – an increasing trend by which the validity of standardised languages is called into question – is subsequently considered. Following this, restandardisation is considered in greater detail. Although the term is used widely, there are not yet thorough theoretical descriptions of the nature of the process itself. Therefore, this study provides a theoretical consideration of what restandardisation comprises. An investigation into various examples of attempts at the restandardisation of languages in South Africa, Africa, and the rest of the world serves as a backdrop against which the need for the restandardisation of Afrikaans is discussed. The standardisation of the orthography of Afrikaans, as outlined in the ten issues of the Afrikaanse woordelys en spelreëls (“Afrikaans word list and spelling rules”) which have been published to date, is the next research focus. The purpose of this critical evaluation of the primary source for orthographic standardisation of Afrikaans is to point out the weaknesses in the current standardisation process which necessitate a new approach to the standardisation of Afrikaans (and by extension, its restandardisation). Finally, a model is presented for the restandardisation of the orthography of Afrikaans, but also Afrikaans as a whole, based on various theoretical and practical considerations contained in the study. / AFRIKAANSE OPSOMMING: In hierdie studie word die herstandaardisering van Afrikaans onder die loep geneem. Dit word gedoen teen die agtergrond van verskeie oproepe vanuit die Afrikaanse spraakgemeenskap sedert die 1980’s om Standaardafrikaans te demokratiseer deur dit verteenwoordigend te maak van die totale Afrikaanse spraakgemeenskap. Ten spyte van hierdie oproepe om die herstandaardisering van Afrikaans wat in die afgelope aantal jare op die spits gedryf is, ontbreek daar egter nog teoreties gefundeerde, praktiese voorstelle vir hoe so ’n herstandaardiseringsprojek daar sal uitsien. Hierdie studie verteenwoordig ’n praktiese benadering tot die herstandaardisering van Afrikaans, met ’n besondere fokus op die herstandaardisering van die Afrikaanse ortografie, deur ’n model daar te stel waarvolgens so ’n beoogde herstandaardiseringsprogram vir Afrikaans kan geskied. Dit word gedoen aan die hand van bestaande standaardiserings- en herstandaardiseringsteorie en ’n grondige ondersoek na die standaardiseringsgeskiedenis van Afrikaans ten einde te bepaal wat aanleiding gegee het tot hierdie herstandaardiseringstrewe in Afrikaans. Eerstens word daar gekyk na relevante standaardiseringsteorieë ten einde die belangrikste aspekte van taalstandaardisering te belig wat ’n rol speel in en aanleiding gee tot herstandaardisering. Die standaardiseringsgeskiedenis van Afrikaans word ook in oënskou geneem om te dui op die aspekte wat aanleiding gegee het tot die oproepe om die herstandaardisering van Afrikaans. Vervolgens word daar na die wêreldwye tendens van destandaardisering gekyk waardeur die geldigheid van standaardtale toenemend bevraagteken word. Hierna word herstandaardisering van nader beskou. Alhoewel die term reeds wyd gebruik word, bestaan daar nog nie diepgaande teoretiese beskrywings oor die aard van hierdie proses nie. Daar word dus vervolgens teoreties besin oor wat herstandaardisering behels. Verskeie voorbeelde van pogings tot die herstandaardisering van tale in Suid-Afrika, Afrika, en die res van die wêreld word ondersoek, waarna die redes vir ’n behoefte aan die herstandaardisering van Afrikaans uiteengesit word. Die standaardisering van die Afrikaanse ortografie, soos uiteengesit in die tien uitgawes van die Afrikaanse woordelys en spelreëls wat tot op hede verskyn het, kom volgende as navorsingsfokus aan bod. Die doel van hierdie kritiese evaluering van die primêre ortografiese standaardiseringsbron van Afrikaans is om te dui op die swakplekke in die huidige standaardiseringsproses wat ’n nuwe benadering tot die standaardisering van Afrikaans (dus die herstandaardisering van Afrikaans) noodsaak. Ten slotte word ’n model vir die herstandaardisering van die Afrikaanse ortografie, maar ook Afrikaans in geheel, voorgestel aan die hand van verskeie teoretiese en praktiese oorwegings soos in die loop van die studie uiteengesit.

Alkali compounds were added to a South African coal with a high swelling propensity and the behaviour of the blends were investigated. A vitrinite-rich bituminous coal from the Tshikondeni coal mine in the Limpopo province of South Africa was used. To reduce the influence of the minerals in the coal, the coal was partially demineralized by leaching with HCl and HF. The ash content of the coal sample was successfully reduced from 17.7% to 0.6%. KOH, KCl, K2CO3 and KCH3CO2 were then added to the demineralized coal in mass percentages of 1%, 4%, 5% and 10%. The free swelling indices (FSI) of the blends were determined and the samples were subjected to acquisition of TMA and TG-MS data. Addition of these potassium compounds to the demineralized coal reduced the swelling of the vitrinite-rich coal. From the free swelling indices of the various mixtures, it was concluded that the potassium compounds reduce the swelling of the coal in the following order of decreasing impact: KCH3CO2 > KOH > K2CO3 > KCl. From dilatometry experiments done on the blends with the 10% addition of potassium compounds, it was seen that with the addition of potassium compounds to the demineralized coal, a reduction in dilatation volume was obtained. The influence of the potassium compound in decreasing order: K2CO3> KOH> KCH3CO2> KCl. An increase in the softening temperature was observed for the demineralized coal-alkali blends. Thermogravimetric analyses were performed on the demineralized coal-potassium blended samples (<75 μm). These samples were pyrolyzed under a nitrogen atmosphere to a maximum temperature of 1200 °C using a heating rate of 10 °C/min. The relative reactivity for each of the blends with the different wt% addition was determined. From these results it was seen that KCH3CO2 increased the relative reactivity, whereas the KOH, KCl and K2CO3 showed an inhibiting influence. The attached mass spectrometer provided information on the low molecular mass gaseous products formed in the various temperature ranges as the thermal treatment proceeded. From the mass spectroscopy results, it was found that the potassium compounds decreased the temperature at which maximum evolution of H2 takes place. Thermomechanical analyses were performed on the 10 wt% addition of the potassium compounds to the demineralized coal. During TMA analyses, the sample was heated to 1000 °C using a heating rate of 10 °C/min. From the TMA result obtained it was clear that the addition of KCl did not have an influence on the swelling of the demineralized coal. All results are discussed. / MSc (Chemistry), North-West University, Potchefstroom Campus, 2014

This dissertation is devoted to a study of the homodiegetic, extradiegetic narrator (terms derived from Genette). The main premise was to study the child as narrator, to differentiate between the child as narrator and the adult narrator, to peg down specific problems but also to show the advantages of the child narrator over the adult narrator. With Genette as basis the writer has tried to clear up the widespread confusion in the literary world between the narrator who presents the narrative and the character whose consciousness orients the perspective, the who speaks and who sees of Genette. The first part of the study provides a theoretical background to the second part and is largely based on the typology of Gerard Genette. As the youthful reader is the most likely reader of the three chosen texts (Skrik kom huis toe by Dolf van Niekerk, Woorde is soos wors by Rona Rupert and Boom bomer boomste (Tree-more, tree-most - translated by Eve Merchant, 1983) by Elsabe Steenberg), a chapter in the first part is devoted to an investigation of the enforceability of the criterion used to differentiate between books meant for adults and books meant for children. Concerning these texts the writer 1 s contention is that the degree of presence of the narrator as well as die placing of emphasis, either on the narrator or on the character whose perspective orients the narrative (the one who focalizes), determine the specific perspective of the narration. Personal traits of characters are often revealed by their respective objects of focalization. The three short novels previously mentioned are thematically related, but because of the specific handling of the narrator and of focalization in each, a multiplicity of perspectives is opened. In Skrik kom huis toe, the younger, experiencing self is emphasised. Albert's vision , and not that of the narrator, orients the narrative to such an extent that the reader easily identifies with his personal existential crisis. The voice of a narrating instance is barely discernible and has, for all practical purposes, no role in the text. The protagonist focalizes intent1y upon matters of personal concern and thus reveals an egocentric personality. The thinly populated narrative space as well as the bleakness of this space suggests something of the unhappiness and utter loneliness of the boy, Albert. In Woorde is soos wors, which is thematically related to the previous work , a completely different perspective is revealed because of the accent falling on the narrating instance himself. Uncommon in Afrikaans , the use of het ge- is sustained throughout the text, thereby undeniably creating a distance between the narrator and his story. In contrast to the previous text the narrator emphasizes the fact that his experiences belong to a distant past. Direct identification with an experiencing self is ruled out because of the outspoken diegetic nature of the text. The stress fall s on the event rather than on the experience thereof. The protagonist seldom focalizes and if he does this text is obviously imbedded in the text of the narrator. His world is nevertheless populated by a variety of people with whom he, without exception, relates positively. The narrative space shows a much greater variety and is more colourful than that of Skrik kom huis toe. This is meaningful in the characterization of the protagonist, Josias. / MA, PU vir CHO, 1984

This dissertation is devoted to a study of the homodiegetic, extradiegetic narrator (terms derived from Genette). The main premise was to study the child as narrator, to differentiate between the child as narrator and the adult narrator, to peg down specific problems but also to show the advantages of the child narrator over the adult narrator. With Genette as basis the writer has tried to clear up the widespread confusion in the literary world between the narrator who presents the narrative and the character whose consciousness orients the perspective, the who speaks and who sees of Genette. The first part of the study provides a theoretical background to the second part and is largely based on the typology of Gerard Genette. As the youthful reader is the most likely reader of the three chosen texts (Skrik kom huis toe by Dolf van Niekerk, Woorde is soos wors by Rona Rupert and Boom bomer boomste (Tree-more, tree-most - translated by Eve Merchant, 1983) by Elsabe Steenberg), a chapter in the first part is devoted to an investigation of the enforceability of the criterion used to differentiate between books meant for adults and books meant for children. Concerning these texts the writer 1 s contention is that the degree of presence of the narrator as well as die placing of emphasis, either on the narrator or on the character whose perspective orients the narrative (the one who focalizes), determine the specific perspective of the narration. Personal traits of characters are often revealed by their respective objects of focalization. The three short novels previously mentioned are thematically related, but because of the specific handling of the narrator and of focalization in each, a multiplicity of perspectives is opened. In Skrik kom huis toe, the younger, experiencing self is emphasised. Albert's vision , and not that of the narrator, orients the narrative to such an extent that the reader easily identifies with his personal existential crisis. The voice of a narrating instance is barely discernible and has, for all practical purposes, no role in the text. The protagonist focalizes intent1y upon matters of personal concern and thus reveals an egocentric personality. The thinly populated narrative space as well as the bleakness of this space suggests something of the unhappiness and utter loneliness of the boy, Albert. In Woorde is soos wors, which is thematically related to the previous work , a completely different perspective is revealed because of the accent falling on the narrating instance himself. Uncommon in Afrikaans , the use of het ge- is sustained throughout the text, thereby undeniably creating a distance between the narrator and his story. In contrast to the previous text the narrator emphasizes the fact that his experiences belong to a distant past. Direct identification with an experiencing self is ruled out because of the outspoken diegetic nature of the text. The stress fall s on the event rather than on the experience thereof. The protagonist seldom focalizes and if he does this text is obviously imbedded in the text of the narrator. His world is nevertheless populated by a variety of people with whom he, without exception, relates positively. The narrative space shows a much greater variety and is more colourful than that of Skrik kom huis toe. This is meaningful in the characterization of the protagonist, Josias. / MA, PU vir CHO, 1984

A fundamental understanding of the process of devolatilization requires extensive knowledge of not only the intrinsic properties of the parent coal and its subsequent formed products (tars, gases and chars), but also its characteristic reaction rate behaviour. Devolatilization behaviour has been extensively addressed in literature with the use of powdered coal samples, which normally do not adhere to particle size constraints of coal conversion processes utilizing lump coal. The aim of this investigation was therefore to assess the devolatilization behaviour (with respect to product yield and -quality; and reaction rate modelling) of four typical South African coals (UMZ, INY, G#5 and TSH) confined to the large particle regime. All four coals were found to be bituminous in rank, with vitrinite contents ranging between 24.4 vol.% and 69.2 vol.% (mineral matter free basis). Two were inertinite-rich coals (UMZ and INY) and the other two were vitrinite-rich coals (G#5 and TSH). From thermoplasticity measurements it was evident that only coal TSH displayed extensive thermoplastic behaviour, while a comparison between molecular properties confirmed the higher abundance of poly-condensed aromatic structures (aromaticity of 81%) present in this coal. Product evolution was evaluated under atmospheric conditions in a self-constructed, large particle, fixed-bed reactor, on two particle sizes (5 mm and 20 mm) at two isothermal reactor temperatures (450°C and 750°C) using a combination of both GC and MS techniques for gas species measurement, while standard gravimetric methods were used to quantify tar- and char yield respectively. Elucidation of tar- and char structural features involved the use of both conventional- and advanced analytical techniques. From the results it could be concluded that temperature was the dominating factor controlling product yield- and quality, with significant increases in both volatile- and gas yield observed for an increase in temperature. Tar yields ranged between 3.6 wt.% and 10.1 wt.% and increased in the order UMZ < INY < TSH < G#5, with higher tar yields obtained for coal G#5, being ascribed to larger abundances of vitrinite and liptinite present in this coal. For coal TSH, lower tar yields could mainly be attributed to the higher aromaticity and extensive swelling nature of this coal. Evolved gases were found to be mainly composed of H2, CH4, CO and CO2, low molecular weight olefins and paraffins; and some C4 homologues. Advanced analytical techniques (NMR, SEC, GC-MS, XRD, etc.) revealed the progressive increase of the aromatic nature of both tars and chars with increasing temperature; as well as subsequent differences in tar composition between the different parent coals. In all cases, an increase in devolatilization temperature led to the evolution of larger amounts of aromatic compounds such as alkyl-naphthalenes and PAHs, while significant decreases in the amount of aliphatics and mixed compounds could be observed. From 13C NMR, HRTEM and XRD carbon crystallite results it was clear that an increase in temperature led to the formation of progressively larger, more aromatic and structurally orientated polycondensed carbon structures. Reaction rate studies involved the use of non-isothermal (5-40 K/min) and isothermal (350- 900°C) thermogravimetry of both powdered (-200 μm) and large particle samples (20 mm) in order to assess intrinsic kinetics and large particle rate behaviour, respectively. Evaluation of the intrinsic kinetic parameters of each coal involved the numerical regression of non-isothermal rate data in MATLAB® 7.1.1 according to a pseudo-component modelling philosophy. Modelling results indicated that the intrinsic devolatilization behaviour of each coal could be adequately described by using a total number of eight pseudo-components, while reported activation energies were found to range between 22.3 kJ/mol and 244.3 kJ/mol. Description of the rate of large particle devolatilization involved the evaluation of a novel, comprehensive rate model accounting for derived kinetics, heat and mass transport effects, as well as physical changes due to particle swelling/shrinkage. Evaluation of the proposed model with the aid of the COMSOL Multiphysics 4.3 simulation software provided a suitable fit to the experimental data of all four coals, while simulation studies highlighted the relevant importance of not only the effect of particle size, but also the importance of including terms affecting for heat losses due to particle swelling/shrinkage, transport of volatile products through the porous char structure, heat of reaction and heat of vaporization of water. / Thesis (PhD (Chemical Engineering))--North-West University, Potchefstroom Campus, 2013

Alkali compounds were added to a South African coal with a high swelling propensity and the behaviour of the blends were investigated. A vitrinite-rich bituminous coal from the Tshikondeni coal mine in the Limpopo province of South Africa was used. To reduce the influence of the minerals in the coal, the coal was partially demineralized by leaching with HCl and HF. The ash content of the coal sample was successfully reduced from 17.7% to 0.6%. KOH, KCl, K2CO3 and KCH3CO2 were then added to the demineralized coal in mass percentages of 1%, 4%, 5% and 10%. The free swelling indices (FSI) of the blends were determined and the samples were subjected to acquisition of TMA and TG-MS data. Addition of these potassium compounds to the demineralized coal reduced the swelling of the vitrinite-rich coal. From the free swelling indices of the various mixtures, it was concluded that the potassium compounds reduce the swelling of the coal in the following order of decreasing impact: KCH3CO2 > KOH > K2CO3 > KCl. From dilatometry experiments done on the blends with the 10% addition of potassium compounds, it was seen that with the addition of potassium compounds to the demineralized coal, a reduction in dilatation volume was obtained. The influence of the potassium compound in decreasing order: K2CO3> KOH> KCH3CO2> KCl. An increase in the softening temperature was observed for the demineralized coal-alkali blends. Thermogravimetric analyses were performed on the demineralized coal-potassium blended samples (<75 μm). These samples were pyrolyzed under a nitrogen atmosphere to a maximum temperature of 1200 °C using a heating rate of 10 °C/min. The relative reactivity for each of the blends with the different wt% addition was determined. From these results it was seen that KCH3CO2 increased the relative reactivity, whereas the KOH, KCl and K2CO3 showed an inhibiting influence. The attached mass spectrometer provided information on the low molecular mass gaseous products formed in the various temperature ranges as the thermal treatment proceeded. From the mass spectroscopy results, it was found that the potassium compounds decreased the temperature at which maximum evolution of H2 takes place. Thermomechanical analyses were performed on the 10 wt% addition of the potassium compounds to the demineralized coal. During TMA analyses, the sample was heated to 1000 °C using a heating rate of 10 °C/min. From the TMA result obtained it was clear that the addition of KCl did not have an influence on the swelling of the demineralized coal. All results are discussed. / MSc (Chemistry), North-West University, Potchefstroom Campus, 2014

A fundamental understanding of the process of devolatilization requires extensive knowledge of not only the intrinsic properties of the parent coal and its subsequent formed products (tars, gases and chars), but also its characteristic reaction rate behaviour. Devolatilization behaviour has been extensively addressed in literature with the use of powdered coal samples, which normally do not adhere to particle size constraints of coal conversion processes utilizing lump coal. The aim of this investigation was therefore to assess the devolatilization behaviour (with respect to product yield and -quality; and reaction rate modelling) of four typical South African coals (UMZ, INY, G#5 and TSH) confined to the large particle regime. All four coals were found to be bituminous in rank, with vitrinite contents ranging between 24.4 vol.% and 69.2 vol.% (mineral matter free basis). Two were inertinite-rich coals (UMZ and INY) and the other two were vitrinite-rich coals (G#5 and TSH). From thermoplasticity measurements it was evident that only coal TSH displayed extensive thermoplastic behaviour, while a comparison between molecular properties confirmed the higher abundance of poly-condensed aromatic structures (aromaticity of 81%) present in this coal. Product evolution was evaluated under atmospheric conditions in a self-constructed, large particle, fixed-bed reactor, on two particle sizes (5 mm and 20 mm) at two isothermal reactor temperatures (450°C and 750°C) using a combination of both GC and MS techniques for gas species measurement, while standard gravimetric methods were used to quantify tar- and char yield respectively. Elucidation of tar- and char structural features involved the use of both conventional- and advanced analytical techniques. From the results it could be concluded that temperature was the dominating factor controlling product yield- and quality, with significant increases in both volatile- and gas yield observed for an increase in temperature. Tar yields ranged between 3.6 wt.% and 10.1 wt.% and increased in the order UMZ < INY < TSH < G#5, with higher tar yields obtained for coal G#5, being ascribed to larger abundances of vitrinite and liptinite present in this coal. For coal TSH, lower tar yields could mainly be attributed to the higher aromaticity and extensive swelling nature of this coal. Evolved gases were found to be mainly composed of H2, CH4, CO and CO2, low molecular weight olefins and paraffins; and some C4 homologues. Advanced analytical techniques (NMR, SEC, GC-MS, XRD, etc.) revealed the progressive increase of the aromatic nature of both tars and chars with increasing temperature; as well as subsequent differences in tar composition between the different parent coals. In all cases, an increase in devolatilization temperature led to the evolution of larger amounts of aromatic compounds such as alkyl-naphthalenes and PAHs, while significant decreases in the amount of aliphatics and mixed compounds could be observed. From 13C NMR, HRTEM and XRD carbon crystallite results it was clear that an increase in temperature led to the formation of progressively larger, more aromatic and structurally orientated polycondensed carbon structures. Reaction rate studies involved the use of non-isothermal (5-40 K/min) and isothermal (350- 900°C) thermogravimetry of both powdered (-200 μm) and large particle samples (20 mm) in order to assess intrinsic kinetics and large particle rate behaviour, respectively. Evaluation of the intrinsic kinetic parameters of each coal involved the numerical regression of non-isothermal rate data in MATLAB® 7.1.1 according to a pseudo-component modelling philosophy. Modelling results indicated that the intrinsic devolatilization behaviour of each coal could be adequately described by using a total number of eight pseudo-components, while reported activation energies were found to range between 22.3 kJ/mol and 244.3 kJ/mol. Description of the rate of large particle devolatilization involved the evaluation of a novel, comprehensive rate model accounting for derived kinetics, heat and mass transport effects, as well as physical changes due to particle swelling/shrinkage. Evaluation of the proposed model with the aid of the COMSOL Multiphysics 4.3 simulation software provided a suitable fit to the experimental data of all four coals, while simulation studies highlighted the relevant importance of not only the effect of particle size, but also the importance of including terms affecting for heat losses due to particle swelling/shrinkage, transport of volatile products through the porous char structure, heat of reaction and heat of vaporization of water. / Thesis (PhD (Chemical Engineering))--North-West University, Potchefstroom Campus, 2013