Gyrolite Formation in CaO–SiO2źnH2O–gamma-Al2O3–Na2O–H2O System under Hydrothermal Conditions

The influence of gamma-Al2O3 and Na2O additives on the gyrolite formation process in the CaO–SiO2źnH2O–H2O mixture has been examined. It has been proved that gamma-Al2O3 is not recommended for the synthesis of gyrolite, because Al3+ ions stimulate the formation of C-S-H(I) and 1.13 nm tobermorite (where C – CaO, S – SiO2 and H – H2O). Na2O positively affects the formation of gyrolite: this compound is formed already after 8 hours of isothermal curing at 200 graduate C. On the contrary, in the pure mixtures gyrolite formed after only 32 h at 200 graduate C. In order to compare the cation exchange activity of synthesized gyrolite with (Al+Na)-substituted tobermorite, the ion exchange experiments were employed as a test reaction.