Abstrakt: |
Gas-phase conversion to water-soluble compounds of individual rare-earth element (REE) (La, Ce, Pr, Nd, Sm, Eu, Dy, Ho, Er, Tm, Lu) oxides and oxide systems (U,Ce)Ox and (U,Nd)Ox in the atmospheres HNO3 (vapor)–air and NOx–H2O (vapor)–air was examined. It was shown that water-soluble compounds are formed in the gas-phase conversion of REE oxides in the atmosphere of both HNO3 vapor and NOx gases. In the case of (U,Ce)Ox in the atmosphere of HNO3 (vapor)–air, water-soluble compounds of uranium are formed, with a part of cerium remaining in the phase of the water-insoluble precipitate. The conversion of (U,Nd)Ox under the same conditions yields water-soluble compounds of both uranium and neodymium. It was found that these gas media can be used in principle to extract uranium from fuel systems containing rare-earth elements. [ABSTRACT FROM AUTHOR] |