New insights into the role of solution additive anions in Mg 2+ dehydration: implications for mineral carbonation

Computer simulations of the Mg 2+ dehydration mechanism show that solution additives can stabilise undercoordinated Mg 2+ hydration configurations, opening up coordination sites on the central Mg 2+ ion, promoting Mg-carbonates nucleation and growth. Simulations of hydrated Mg 2+ , in the absence and presence of several solution additive anions, show that in pure liquid water Mg(H 2 O) 6 2+ is the only stable coordination state; yet anions may stabilise undercoordinated five-hydration configurations. Solution composition can lower the barrier to Mg 2+ dehydration and subsequent incorporation into the lattice of Mg-carbonates, promoting low-temperature crystallisation.