(where M is Li, Na, K) are studied in the air and in an atmosphere of carbon dioxide. At the initial stage of
activation in a centrifugal planetary mill in an atmosphere of carbon dioxide, the main portion of supplied
mechanical energy is expended for grinding and the mechanosorption of
2 occurs in the regime of cleavage, i.e., on the freshly formed surfaces of particles. As the time of activation increases, the specific surface area
becomes constant, which, however, does not substantially affect the rate of interaction between carbon dioxide
and silicates. The absorption of
2 occurs in the regime of friction on the active sites of already formed sur-faces and is accompanied by the tribodiffusion of gas molecules into structurally disordered layers of particles.
With identical amounts of supplied energy, the
2/M2SiO3 molar ratio in the samples activated in the medium of carbon dioxide increases in the Li < Na < K series. The main product of mechanically induced interactions
between Li2SiO3 and
2 is the X-ray amorphous carbonate–silicate phase. In the case of sodium and potas-sium metasilicates, the reaction of mechanochemical substitution occurs to form corresponding carbonates,
hydrocarbonates, and amorphous silica. It is shown that the character of mechanochemical interaction between
M2SiO3 and CO2 depends on the change in the Gibbs energy of the transformation of silicate into corresponding
carbonate, as well as on the melting temperature and the hygroscopicity of silicate.