Separation of lanthanoid phoshates from the spent electrolyte of pyroprocessing

Amamoto, Ippei; Kofuji, Hirohide  ; Myochin, Munetaka; Tsuzuki, Tatsuya*; Takasaki, Yasushi*; Yano, Tetsuji*; Terai, Takayuki*

This study is carried out to make the pyroprocessing hold a competitive advantage. As one of the measures is to reduce the volume of HLW, the phosphate conversion method is applied for removal of FP from the spent electrolyte in this paper. Though the removing target elements in the electrolyte are alkali metals, alkaline earth metals and lanthanoid elements, only lanthanoid elements and lithium form the insoluble phosphates by reaction with LiPO. Therefore, as the first step, the precipitation experiment was carried out to observe the behaviours of elements which form the insoluble precipitates. Then the filtration was experimented to remove precipitates in the spent electrolyte using FeO-PO glass system as a filtlation medium which is compatible material with the glassification. The result of separation of precipitates by filtration was effective and attained almost 100.