Glass-ceramic wasteforms containing calcium neodymium(cerium) oxide silicate [Ca₂Nd₈ - xCex(SiO₄)₆O₂] were synthesized to immobilize lanthanide oxide wastes generated from pyro-processing.

1. These Caesilicate crystals (~100 mm in size) were formed from alkali borosilicate glasses by heat-treating at 750 C for 3 h. Ce and Nd ions were partitioned inside the Caesilicate crystalline phases, constituting ~44 wt.% of the crystals.

2. Maximum leaching of these ions in the glasses was >26.8 wt.%. The normalized values of Ce and Nd ions released from specimens were ~10⁶ g m² for PCT test and below the detection limit of ICP-MS (<0.1 ppb) for MCC-1 test.

 

3. Glass-ceramics containing calcium neodymium(cerium) oxide silicate are good candidate wasteforms for immobilization of lanthanide wastes generated by pyroprocessing.