Removal of Ruthenium from PUREX Process

Ruthenium in nitric acid solution is oxidized by the addition of ceric nitrate to ruthenium tetroxide, which is extracted with n-paraffin oil. Ruthenium tetroxide in paraffin is immediately reduced by the solvent to black ruthenium dioxide as suspension, which can be readily filtered off through the ordinary cellulose filter paper. Through the combined process of extraction and filtration, the ruthenium in a nitric acid solution can be eliminated.