Kaolin was utilized as a raw material for geopolymers with various Si/Al ratios, and a hydrothermal-microwave treatment was proposed to obtain Cs-containing ceramics to immobilize Cs-137. The results show that with Si/Al from 1/1 to 3/1, the hydrothermal treatment will tend to produce CsAlSiO4, pollucite (CsAlSi2O6) and pollucite solid solutions, respectively. Following the hydrothermal reaction, a rapid microwave process (30 min) enhances the loose microstructure of hydrothermal products, and higher microwave temperatures promote pollucite crystallization. Cs-containing ceramics with high Cs ...
