Geopolymer matrices based on alkali-activated natural aluminosilicates—kaolinite and clinoptilolite—are obtained. Their potential application for the immobilization of radionuclides is studied using Cs+ as an example. The optimal kaolinite/clinoptilolite ratios are determined, enabling the production of matrices with compressive strengths of up to 40 MPa and an immobilized cesium content of up to 1.5 wt % (as Cs2O). The leaching rate of Cs+ from the geopolymer matrix is estimated in aqueous and alkaline environments. It is shown that geopolymer matrices are promising materials for the disposal of radioactive waste.
Alekseev et al. (Wed,) studied this question.