Process intensification routes for mineral carbonation

Mineral carbonation of AOD stainless steel slag and calcium oxide were investigated. The main goal was to sequester the maximal amount of CO2 under optimal conditions. Carbonation was conducted on humid samples in a CO2 chamber and in slurry phase. The carbonation reaction was intensified by the introduction of ultrasound as a means to accelerate the carbonation reaction by particle fragmentation and carbonate layer removal. Several process parameters that influence carbonation were studied, such as temperature, moisture content and particle size. The highest conversion achieved with AOD steel slag in the CO2 chamber was 46.5% at 30oC, 20% CO2 partial pressure and 7 days duration. Carbonation of calcium oxide in slurry reached higher conversion (84.4%) than AOD slag (26.5%) over 35 minutes. Compared to stirring, the enhancement effect of sonication was dimmed by the fast reaction kinetics of calcium oxide. The sonication effect was observed by the reduction in particle size and the eroded morphology of the sonicated particles.status: publishe