Self-propagating synthesis of Nd2O3-incorporated zirconolite/Mo composites and their aqueous durability

Zirconolite/Mo composite waste form was readily prepared within 5 min by self-propagating high-temperature synthesis (SHS) by using MoO3 as the oxidant and Ti as the reductant. Nd, which is the surrogate of trivalent actinides, was used to concurrently replace the Ca and Zr sites of zirconolite. The main crystalline phases in the Nd-bearing waste forms are 2M-zirconolite, Mo, perovskite, titania, and zirconia. Nd preferentially substitutes the Ca in zirconolite and perovskite after SHS reaction, which results in Nd2O3 waste loading higher than 30 wt%.158