The mechanical properties and chemical durability of granite wastes based glass-ceramics for immobilization of high-level nuclear wastes

In this study, granite wastes based glass-ceramics containing Eu 2 O 3 as simulated radionuclides is successfully synthesized via solid-state sintering method. The structure, mechanical properties and chemical durability are deeply investigated. The main phase in this glass-ceramics is oxyapatite (Ca 2 Eu 8 (SiO 4 ) 6 O 2 ), which is dispersed homogenously in glass matrix. The density dominates the properties of Vickers hardness and bending strength . The glass-ceramics containing 40 wt % of Eu 2 O 3 has the optimal mechanical properties, with the Vickers hardness , bending strength and density of 5.12 GPa, 79.44 MPa and 98.77 %, respectively. The 28 days leaching experiments show that the glass-ceramics containing 40 wt % of Eu 2 O 3 possess excellent chemical durability. The leaching rate of Al 3+ , Si 4+ , Fe 3+ , Ca 2+ , Eu 3+ are 2.3 × 10 −4  g m −2  d −1 , 6.0 × 10 −4  g m −2  d −1 , 1.2 × 10 −7  g m −2  d −1 , 1.4 × 10 −4  g m −2  d −1 , 3.6 × 10 −8  g m −2  d −1 , respectively. This study indicates that granite wastes based glass-ceramics have excellent chemical stability and mechanical properties, which provides a novel idea for the immobilization of radioactive wastes .