Synthesis of amorphous KAlSi3O8 for cesium radionuclide immobilization into solid matrices using spark plasma sintering technique

An effective sorption material for cesium radionuclides immobilization in highly safe and reliable solid-state matrices was proposed. Prepared aluminosilicate (КAlSi3O8) adsorbent had amorphous mesoporous structure and Cs+ ions sorption capacity of ∼3.7 mmol/g. The physical-chemical characteristics of (Cs, К)AlSi3O8 sample saturated with Cs + ions were studied using XRD, FT-IR, SEM-EDX, and DTA-TG methods. Firstly, solid-state aluminosilicate matrices were obtained using spark plasma sintering (SPS) technology with high values of relative density (up to 99.9%), compressive strength (31.3–79.2 MPa), and Vickers microhardness (0.9–5.3 GPa). The sample obtained at 1000 °C had a low value of Cs+ leaching from matrices (RCs within the range of 10-7 g cm-2·day-1) and cesium diffusion coefficient (De 9.07 × 10-14 cm2/s). It was shown that prepared aluminosilicate cesium matrices comply with regulatory requirements of GOST R 50926-96 and ANSI/ANS 16.1. © 2021 Elsevier Ltd and Techna Group S.r.l.