Three alternative raw materials for improving the performances of Li4SiO4 pebbles

Currently, Li4SiO4 has been considered one of the best candidates for tritium breeders. In order to improve the crush load and the density of Li4SiO4 pebbles with reasonable pores and small grains for tritium breeding, three alternative raw materials were used for fabricating Li4SiO4 pebbles: the fabrication of Li4SiO4 pebbles from Li2CO3 and SiO2, the fabrication of Li4SiO4 pebbles from Li2CO3 and Li2SiO3 (for the first time), and the fabrication of Li4SiO4 pebbles from Li4SiO4. The Li4SiO4 pebbles were fabricated by a graphite bed process and sintered in Ar with a series of sintering techniques which based on the different reaction paths deduced from the TG-DTA and XRD results. And they were compared particularly with regard to their effects on the crush load and the density. The results show that the optimal crush load, density, and open porosity of the Li4SiO4 pebbles using Li2SiO3 and Li2CO3 as raw materials reached 64.7 N, 90.3%, and 9.2%, respectively, at sintering technique i, i.e., two holding temperatures (650 and 750 °C) with 5 °C/min heating rate.