Treatment of molten chloride waste salt from pyrometallurgical process

Chloride waste salt arises from pyrometallurgical processes for high level radioactive liquid waste (HAW) treatment. The immobilization of the waste has been developed experimentally using simulated salts by the following three stages: (1) Li recovery from the salts into a liquid Cd cathode by electrolysis, followed by (2) fission products (FPs) and Na recovery into a liquid Pb cathode by electro-reduction. Finally, (3) the recovery of the metal elements by air oxidation to separate into oxide slag. This slag can be stabilized as borosilicate glass. Lithium was recovered into the Cd cathode efficiently from the simulated waste salt by electro-reduction in the Li recovery stage. In the FPs and Na recovery stage almost all the residual metal elements were further recovered from the waste salt, composed of mainly CsCl, using the liquid Pb cathode by electrolysis. In the final Pb alloy oxidation stage, all the metal elements in the Pb alloy was also removed into the oxide slag