Investigation on the thermo-dynamics of alkali-activated carbonatite

Abstract

The thermo-dynamics of reactions between carbonatite and sodium silicate solution at ordinary temperature (25 °) were investigated. The calculated results indicate that at ordinary temperature, the reactions between dolomite, calcite, Ca²⁺ and Mg²⁺ in carbonatite and H₄SiO₄, H₃SiO₄ ⁻ and H₂SiO₄ ²⁻ in sodium silicate solution to form the cementitious products of hydrated calcium silicate or hydrated magnesium silicate all possibly happen; among these reactions, the reactions to form gyrolite (2CaO·3SiO₂·2.5H₂O) and serpentine (3MgO·2SiO₂·2H₂O) are the most possible to occur. Further, the dissociation degree of dolomite and calcite and the activity of H₃SiO₄ ⁻, H₂SiO₄ ²⁻ and H₄SiO₄ ions are the key factors to influence the reactions.

Keywords

carbonatite / sodium silicate solution / alkali-activation / thermo-dynamics

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