Simple and rapid preparation of granite-based waste form by laser sintering

In this paper, laser sintering technology is used for the first time to fabricate natural granite-based waste forms. Under different sintering powers (190 W, 240 W, and 270 W) and sintering times (10 min, 20 min, and 30 min), vitrified bulks derived from natural granite were fabricated. Based on this, simulated nuclear waste containing Cs was further immobilized by granite at 190 W. The phase, micromorphology and mechanical properties of the sintered specimens were characterized, and the results indicated that within the studied range, Cs could be immobilized by the glass network and by forming Cs(AlSi 2 O 6 ). FT-IR results show that the samples prepared by laser sintering have proper network structure to encapsulate waste elements. Furthermore, hardness and density measurements showed that the waste forms incorporating the waste exhibited considerable mechanical properties. The process condition 190 W 30 min was considered as the optimal sintering condition for solidifying granite based Cs containing waste. Chemical stability tests were conducted on the samples fabricated via this process. The 14-day normalized leaching rate of Cs reached ~10 -4 g·m -2 ·d -1 . This indicates that the waste forms prepared by laser sintering exhibit feasibility.