Preparation Process of Li₄SiO₄ Pebbles as Tritium Breeding Materials

Li4SiO4 with a diameter of 0.52 mm has been candidated as solidstate tritium breeder material for the testing blanket module (TBM) of fusion reactor being developed in Europe and China. Performance designs of Li ceramics pebbles were discussed, extrusion-spheronisation-sintering process of Li₄SiO₄ pebbles were studied, and density, diameter, sphericity, grain size and crush load of pebbles were analyzed and characterized. Li₄SiO₄ pebbles sintered at 1 050 ℃ have a density of 90.4%TD, pebbled bed density 52.9%TD, diameter (0.95±0.15) mm, sphericity 1.10, crush load (18.50±2.76) N, average grain size 14 μm, phase structures of Li₄SiO₄ (main), Li₂SiO₃ and Li₂Si₂O₅. Products of Li₄SiO₄ pebbles can be fabricated by the improved extrusion-spheronisation and sintering processes.