Mechanochemical Interaction of Calcium Carbonate with Diopside and Amorphous Silica

Processes that occur during mechanochemical activation of the mixtures of diopside with calcite and amorphous silicon dioxide with calcite in a centrifugal planetary mill are investigated. According to the data of IR spectroscopy and XPA, with calcite content up to similar to 10 mass %, mechanochemical interaction of the mixture components results in the formation of a substance which is similar to carbonate-containing silicate glass. During mechanochemical activation of a mixture of amorphous silicon dioxide with calcite (at a molar ratio of 1 : 1) the degree of interaction between the components decreases substantially, the major part of input mechanical energy is consumed for the achievement of mechanochemical equilibrium between calcite and aragonite. Investigated processes were compared with the previously discovered mechanically induced absorption of carbon dioxide by calcium- and magnesium-containing silicates. The data on phase formation under heating of mechanochemically activated mixtures of silica with calcite are reported.