It is established by calculating the equilibrium partial pressure of carbon dioxide gas p CO 2 or the equilibrium activity of carbonation CO 3 2 - in the carbonation reactions of various mineral compounds that practically all investigated compounds are capable of carbonation under the influence of dry or wet carbon dioxide with the formation of calcium or magnesium carbonates. The comparative thermodynamic activity of certain mineral compounds in the carbonation reactions is much higher than that of the minerals wollastonite CS and rankinite C3S2, which are present in clinker for the production of carbonate hardening cement Solidia.