Thesis (M.Ing. (Chemical Engineering))--North-West University, Potchefstroom Campus, 2009.

Coal, as energy resource, possesses numerous characteristics and properties which all have an influence on its gasification behaviour. The two properties considered critically important when evaluating a coal source for gasification are its mineral content and slagging behaviour. Research has indicated that slag formation can be inhibited or even prevented by the addition of a fluxing agent. It is thus of great importance to understand the mineral interaction during gasification, in order to select a suitable fluxing agent for the prevention of slagging and clinker formation in the gasifier. The aim of this dissertation is to evaluate the slagging properties of a coal source with the addition of iron as a fluxing agent and to study the transformation of the mineral and added iron during gasification. A pre-determined amount of elemental iron (between 2 and 20 percentage by mass) was added to three different coal samples obtained from Sasol's operations in South Africa. The transformation of the iron in conjunction with the possible iron-containing minerals present in the coal was studied by means of Mossbauer spectroscopy. Typical characterisation analyses were also carried out on the original coal samples. The ash fusion temperature analyses (AFT) were used to study the slagging behaviour of the iron-spiked coal samples. Even though AFT analyses only provide an average flow property, it gives a good indication of the changes that the iron addition induces in coal properties. FactSage modelling was carried out in conjunction with the Mossbauer and AFT analyses. The AFT analysis on all of the samples indicated that the iron addition led to a 20% decrease in the AFT of all three the coal samples. The decrease observed, can be attributed to three main reasons: Formation of lower melting iron-containing phases, bridging of oxygen bonds by FeO and Fe203and the lowering of the viscosity by the iron-oxides, mainly hematite. Mossbauer spectra of the three original coal samples indicated that pyrite was the only iron-bearing mineral present / Thesis (M.Ing. (Chemical Engineering))--North-West University, Potchefstroom Campus, 2009.

Coal, as energy resource, possesses numerous characteristics and properties which all have an influence on its gasification behaviour. The two properties considered critically important when evaluating a coal source for gasification are its mineral content and slagging behaviour. Research has indicated that slag formation can be inhibited or even prevented by the addition of a fluxing agent. It is thus of great importance to understand the mineral interaction during gasification, in order to select a suitable fluxing agent for the prevention of slagging and clinker formation in the gasifier. The aim of this dissertation is to evaluate the slagging properties of a coal source with the addition of iron as a fluxing agent and to study the transformation of the mineral and added iron during gasification. A pre-determined amount of elemental iron (between 2 and 20 percentage by mass) was added to three different coal samples obtained from Sasol's operations in South Africa. The transformation of the iron in conjunction with the possible iron-containing minerals present in the coal was studied by means of Mossbauer spectroscopy. Typical characterisation analyses were also carried out on the original coal samples. The ash fusion temperature analyses (AFT) were used to study the slagging behaviour of the iron-spiked coal samples. Even though AFT analyses only provide an average flow property, it gives a good indication of the changes that the iron addition induces in coal properties. FactSage modelling was carried out in conjunction with the Mossbauer and AFT analyses. The AFT analysis on all of the samples indicated that the iron addition led to a 20% decrease in the AFT of all three the coal samples. The decrease observed, can be attributed to three main reasons: Formation of lower melting iron-containing phases, bridging of oxygen bonds by FeO and Fe203and the lowering of the viscosity by the iron-oxides, mainly hematite. Mossbauer spectra of the three original coal samples indicated that pyrite was the only iron-bearing mineral present / Thesis (M.Ing. (Chemical Engineering))--North-West University, Potchefstroom Campus, 2009.

The objective this study is verify the efficiency and occurrence of collateral effects with the use of carbonyl iron powder, in the form of chewable tablets, in order to enable the use of an alternative to the conventional treatment of iron deficiency anemia with ferrous sulfate, for children under 6 years of age. The intervention proposed for the treatment of iron deficiency anemia in children almost always consists of ferrous sulfate drops that do not have the desired effectiveness. Several studies have proven the low adherence to the treatment due to collateral effects of the medication (gastrointestinal intolerance, alterations in color and consistency of stools, impregnation of iron in diapers and teeth), to the prolonged daily administration in the form of drops, to the metallic taste, as well as to socio-cultural aspects. In choosing the preparation, the content of the iron ion, tolerance, absorption, effectiveness and cost must all be considered. Carbonyl iron powder is obtained by decomposition of Fe pentacarbonyl at high temperatures, resulting in extremely pure elemental Fe (Fe0), in the form of non-toxic micro-spheres of 4-7/μm, with bioavailability in relation to 58-70% ferrous sulfate and it does not confer a metallic taste to the preparation. An open randomized clinical assay was carried out. The group studied (CA) received Carbonyl Iron and the control group (SF) received a solution of Ferrous Sulfate, both at a dose of 5mg/Kg/day, for 90 days. Seventy-three children from Family Health Units (FHU) of Santa Maria, Brazil, participated in the study. Blood was collected at 0, 30 and 90 days of treatment. The hemograms were carried out in STKS (Coulter, USA), serum iron and TIBC, by colorimetric assay and ferritin by immunometric assay. The data was analyzed with the EpiInfo program, version 3.3.2, from CDC/USA. The increase in Hb after 30 days of treatment was of 1.3g/dl (SD 0.92) for group CA and of 1.2g/dl (SD 1.13) for group SF (p>0.05). After 90 days of treatment, CA had favorable results for Ht, MCV, MCH, TIBC and ferritin (p<0.05). None of the children from group CA presented side effects, in group SF, 62% of the children presented diarrhea and/or experienced vomiting. The number of children from the control group who continued to present a level of Hb lower than 11g/dl was two-fold that of the group that received carbonyl iron. Based on the results demonstrating the same effectiveness at 30 days as for the standard ferrous sulfate and the superior results at 90 days of treatment, together with the safety (low toxicity) and excellent acceptance, carbonyl iron should be considered an important option for the therapeutic treatment of iron deficiency anemia in children under the age of six. / O objetivo deste estudo é verificar a eficácia, ocorrência de efeitos colaterais e aceitação de ferro carbonila em pó, na forma de comprimidos mastigáveis, para possibilitar uma alternativa ao tratamento convencional da anemia ferropriva com sulfato ferroso, para crianças menores de seis anos. A intervenção proposta para tratamento da anemia ferropriva de crianças, quase na totalidade das vezes, consiste em gotas de sulfato ferroso que não tem tido efetividade desejada. Vários estudos comprovam a baixa adesão ao tratamento em virtude dos efeitos colaterais do medicamento (intolerância gastrintestinal, alterações na cor e consistência das fezes, impregnação de ferro nas fraldas e dentes), do esquema de administração em dose diária por tempo prolongado, do sabor metálico do medicamento, além de aspectos socioculturais. Na escolha do preparado, deve ser considerado o conteúdo do íon ferro, tolerância, absorção intestinal, eficácia e custo. O ferro carbonila em pó é obtido pela decomposição a altas temperaturas do ferro pentacarbonil, resultando em ferro elementar (Fe0) extremamente puro, em forma de micro-esferas de 4-7/μm, com boa biodisponibilidade, não tóxico e sem conferir sabor metálico às preparações. O desenho do estudo foi um ensaio clínico, randomizado, aberto. O grupo estudo (CA) recebeu comprimidos mastigáveis de Ferro Carbonila; o grupo controle (SF) recebeu solução de Sulfato Ferroso, na dose de 5mg/Kg/dia, por 90 dias. Participaram do estudo 73 crianças com diagnóstico comprovado de anemia ferropriva, atendidas em USFs de Santa Maria, RS. Foram realizadas coletas de sangue nos tempos 0, 30 e 90 dias de tratamento. Os hemogramas foram realizados em STKS Coulter, Ferro sérico e Capacidade Total de Ligação do Ferro, por química úmida (colorimetria) e Ferritina por quimioluminescência, todos por automação. Os dados analisados com programa EpiInfo, versão 3.3.2, do CDC/USA. O incremento de Hb após 30 dias de tratamento foi de 1,3g/dl (dp 0,92) no grupo CA e 1,2g/dl (dp 1,13) no grupo SF (p>0,05). Após 90 dias de tratamento, as médias do Ht, VCM, HCM, CTLF e ferritina são significativamente melhores no grupo CA (p<0,005). Nenhuma criança do grupo CA apresentou efeitos colaterais. No grupo SF, 62% tiveram diarréia e/ou vômito. O número de crianças que permanecia com Hb < 11g/dl, no grupo controle, era o dobro do que no grupo recebendo ferro carbonila. Pelos resultados de eficácia em 30 dias similares ao padrão sulfato ferroso e a superioridade em 90 dias de tratamento, aliados a segurança (baixa toxicidade) e ótima aceitação, o ferro carbonila deve ser considerado como uma importante opção terapêutica para tratamento da anemia ferropriva, de crianças menores de seis anos de idade.