Combustion synthesis and characterization of Nd-Al codoped zirconolite-rich waste forms using CuO as the oxidant

Zirconolite-rich composite material was rapidly obtained from combustion synthesis (CS) using CuO as the oxidant and Ti as the reductant. As the surrogate of trivalent actinides, Nd was incorporated to substitute the Ca site of zirconolite with Al₂O₃ as the charge compensator. The results demonstrate that Nd-bearing calcium zirconium titanium oxide (CZTO) was produced as the main phase after Nd₂O₃ and Al₂O₃ addition. Nd₂O₃ was consolidated into the lattice structure of zirconolite-rich waste forms with waste loading of about 20 wt%. The 42 days normalized leaching rates (LR_i) of Cu, Ca and Nd in the tested CNA-3 sample were evaluated to be 1.98×10^?2, 7.36×10^?2 and 6.35×10^?5 g m^?2·d^?1.