In this study, weight reduction of Li2TiO3 with excess Li and Li4SiO4 at elevated temperatures under hydrogen atmosphere or water vapor atmosphere was investigated. The Li mass loss for the Li2TiO3 at 900 °C was 0.4 wt% under 1000 Pa H2 atmosphere and 1.5 wt% under 50 Pa H2O atmosphere. The Li mass loss for the Li2TiO3 increased proportionally to the water vapor pressure in the range from 50 to 200 Pa at 900 °C and increased with increasing temperature from 700 to 900 °C although Li mass loss at 600 °C was significantly smaller than expected. It was found that water vapor concentration dependence and temperature dependence of Li mass loss for the Li2TiO3 and the Li4SiO4 used in this work were quite different. Water vapor is released from the ceramic breeder materials into the purge gas due to desorption of adsorbed water and water formation reaction. The released water vapor possibly promotes Li mass loss with the formation of LiOH on the surface.
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