Low efficiency of mineral dissolution and unrecyclable use of additives are two barriers for the development of CO2 mineral carbonation. A new pH-swing CO2 mineralisation process using recyclable ammonium salts is proposed to overcome these barriers. This paper presents the studies of mineral dissolution with ammonium salts. In this study, dissolution of a serpentine sample was performed using a series of aqueous solutions, which include (NH4)(2)SO4, NH4Cl, NH4HSO4 and H2SO4. NH4HSO4 is the most efficient in terms of extracting Mg extraction from the serpentine sample. At 100 degrees C 1.4 M NH4HSO4 extracted 100% of Mg from serpentine in 3 h, as well as 98% of Fe and 17.6% of Si. The rate limiting mechanism of serpentine dissolution with NH4HSO4 is a chemical reaction with product layer diffusion control and the activation energy of this dissolution was 40.9 kJ mol (1). (C) 2010 Elsevier Ltd. All rights reserved.
- Ammonium salts
- Mineral carbonation