The effect of mineral composition on direct aqueous carbonation of ultramafic mine waste rock for CO<sub>2</sub> sequestration, a case study of Turnagain ultramafic complex in British Columbia, Canada
Jiajie Li, Anthony D. Jacobs, Michael Hitch
Abstract
The heterogenous mineralogy of ultramafic mine waste rocks make their carbonation rate hard to evaluate. This study investigated the effect of mineral composition on direct aqueous carbonation, through quantitative X-ray diffraction. The results show that magnesite was the main carbonated product, which was a stoichiometric conversion of forsterite. Diopside acted as a seed for quick crystallisation of magnesite. Lizardite could enhance the carbonation conversion, which reaches the optimum value when the weight ratio of lizardite to forsterite is 0.3–0.4. Sulphide in the reactant samples has a positive influence on carbonation. Brucite, magnetite and maghemite show little influence on carbonated products.