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21	Remediation of acid mine drainage using magnesite and its bentonite clay composite Masindi, Vhahangwele 05 1900 (has links) PhDENV / Department of Ecology and Resource Management / See the attached abstract below Acid mine drainage Cryptocrystalline magnisite Bentonite clay Chemical species Batch experiments Adsorption Precipitation Geochemical modelling 628.168320968 Mineral industries -- South Africa Mineral industries -- South Africa Mineral industries -- South Africa Magnesite -- South africa Mine safety -- South Africa Mine drainage -- South Africa Acid mine drainage -- South Africa Clay -- South Africa Bentonite -- South Africa Bentonite deposits -- South Africa
22	Synthesis and characterisation of substituted smithsonite and calcite Hales, Matthew Cameron January 2008 (has links) Carbonate minerals play a very important role in nature, they represent some of the most diverse and common mineral species on the Planet. They are directly involved in the carbon dioxide (CO2) cycle acting as relatively stable long term chemical storage reservoirs, moderating both global warming trends and oceanaquatic chemistry through carbonate buffering systems. A range of synthetic metal carbonates have been synthesised for analysis under multiple experimental conditions, in order to study the variation in physical and chemical properties such as phase specificity, metal substitution, hydration/hydroxy carbonate formation under varying partial pressures of CO2 and thermal stability. Synthetic samples were characterised by a variety of instrumental analysis techniques in order to investigate chemical purity and phase specificity. Some of the techniques included, vibrational spectroscopy (IR/Raman), thermal analysis (TGA-MS) (thermal Raman), X-Ray diffraction (XRD) and electron microscopy (SEM-EDX). From the instrumental characterisation techniques, it was found that single phase smithsonite, hydrozincite, calcite and nesquehonite could successfully be synthesised under the conditions used. Minor impurities of other minerals and / or phases were found to form under specific chemical or physical conditions such as in the case of hydrozincite / simonkolleite if zinc chloride was used during hydrothermal synthesis. Raman Infrared IR spectroscopy characterisation synthesis synthetic natural scanning electron microscopy SEM thermo-gravimetric analysis mass spectroscopy TGA-MS X-Ray diffraction XRD carbonate hydrogen carbonate hydroxy hydrate minerals crystal point group factor group phase symmetry elements calcite magnesite aragonite vaterite aurichalcite azurite malachite hydrozincite zincite nesquehonite strontianite witherite oxide zone partial pressure carbon dioxide CO2 geological settling coral geo-sequestration green house gas

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Remediation of acid mine drainage using magnesite and its bentonite clay composite

Synthesis and characterisation of substituted smithsonite and calcite