Immobilization of Simulated Radionuclide ⁹⁰Sr by Fly Ash-Slag-Metakaolin–Based Geopolymer

Abstract

In this work, the immobilization of simulated radionuclide ⁹⁰Sr by fly ash-slag-metakaolin–based geopolymer was investigated. It was found that the thermal stability (high-temperature and freeze-thaw resistance) of the geopolymer waste forms were better than that of cement. The geopolymer waste forms can acquire a compressive strength up to 10 MPa after 2 h calcination at 1000°C. Furthermore, the leaching tests revealed that the fly ash-slag-metakaolin–based geopolymer waste forms had lower cumulative fraction leaching rates of ⁹⁰Sr than that of cement. These results gave encouragement for the idea that the fly ash-slag-metakaolin–based geopolymers could be used as low cost and high efficiency host materials for the immobilization of radioactive wastes.

Keywords:

• Geopolymers
• immobilization
• ⁹⁰Sr

Acknowledgments

This work was supported by the National Natural Science Foundation of China (41302028, 41272050), the Fundamental Science on Nuclear Wastes and Environmental Safety Laboratory (15kffk05, 15yyhk04, 15yyhk01), the Scientific Research Fund of Mianyang City (14S-01-2), and Doctor Research Foundation of Southwest University of Science and Technology (13zx7136).