3 | Glass-ceramic wasteforms for rear-earth

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.