MSc(Eng) Project title The Use of Nuclear Techniques for in-situ Characterisation of Engineering Particulate Systems (Graduated: 2012)
Increasing atmospheric CO2 concentration is currently of considerable concern in terms of global warming. A possible technology that can contribute to the reduction of CO2 emissions is its sequestration by mineral carbonation. In this study, commenced in 2010, tailings from several different platinum mines in South Africa will be characterized mineralogically and their potential for mineral carbonation reviewed. Mg and Ca-rich minerals (plagioclase, olivine, orthopyroxene, clinopyroxene) present in platinum mine tailings are good candidates for mineral carbonation, which mimics natural weathering processes in which these minerals react with gaseous CO2 to form Ca or Mg carbonates. Since the reaction is influenced by particle surface area, the ultra-fine grained nature of the PGM tailings provides another reason for the promise of PGM tailings for mineral carbonation. A preliminary ranking of the tailings samples and their efficacy for mineral carbonation has been developed according to whether the samples showed harzburgtic (eg. Northam Platinum mine), pyroxenetic (eg. BRPM) or noritic mineral assemblages.
Results indicated mineral carbonation of the tailings produced by the PGM industry could account for both the direct and indirect CO2 emissions of the PGM industry, annually. More importantly, the CCS capacity from PGM tailings may account for 43.6% of the 32 million tons of 95% pure CO2 produced by the synthetic fuels industry annually. Proof-of-concept was demonstrated on a laboratory scale, although the conversion rates were low. This was attributed to the stability of the pyroxene minerals in the PGM tailings.
Peer-reviewed journal publications
Vogeli, J., Reid, D.L., Becker, M.E., Broadhurst, J.L. and Franzidis, J.-P. 2011. Investigation of the potential for mineral carbonation of PGM tailings in South Africa. Minerals Engineering, 24: 1348-1356.
Oral conference presentations
Vogeli J., Reid D.L., Becker M., Broadhurst J., Doucet F.J, Atanasova M. and Franzidis J-P. 2011. Mineral carbonation of Merensky Reef PGM tailings in South Africa: A kinetic investigation. The 2nd South African Carbon Capture and Storage Conference, Midrand, 25th October 2011
Vogeli J., Reid D.L., Becker M., Broadhurst J. Doucet, F.J., Atanasova, M. and Franzidis, J-P. 2011. Mineral carbonation of Merensky Reef PGM tailings in South Africa: A kinetic investigation. SAIMM Mineral Processing Conference, Cape Town, 4-5 August 2011
Vogeli, J., Reid, D.L., Becker, M., Broadhurst, J.L. and Franzidis, J.-P. 2010. Investigation of the potential for mineral carbonation of South African PGM tailings. Process Mineralogy 2010, Cape Town, 10-12 November 2010.