Geopolymer-Assisted Conversion of Cs-Exchanged 13X Zeolite into Stable Cs-Aluminosilicates for Long-Term Cesium...

Area of Science:

• Materials Science
• Environmental Science
• Nuclear Chemistry

Background:

• Radioactive cesium (Cs+) poses significant environmental hazards due to its long half-life.
• Safe containment strategies are crucial for managing radioactive waste.

Purpose of the Study:

• To investigate a novel method for removing and immobilizing Cs+ ions from aqueous solutions.
• To evaluate the long-term stability and containment of cesium within geopolymer/zeolite composites.

Main Methods:

• Ion exchange using Na-13X zeolite to capture Cs+ ions.
• Geopolymerization of Cs-13X zeolite with kaolinite to form composites.
• Heat treatment of composites at 950 °C to induce phase crystallization.

Main Results:

• Geopolymer/Cs-13X zeolite composites were successfully prepared with varying Cs-13X zeolite content (10-50 wt%).
• Heat treatment resulted in the formation of stable Cs-bearing phases: CAS and pollucite.
• Increased Cs-13X zeolite loading enhanced crystallinity, density, and compressive strength (~53 MPa at 50 wt%).

Conclusions:

• The developed geopolymer/zeolite composite effectively immobilizes Cs+ ions through stable crystalline phase formation.
• The high compressive strength of the heat-treated composites ensures safe handling and long-term containment of radioactive cesium.
• This approach offers a promising solution for radioactive cesium waste management.