| 摘要 |
<p>Cesium values contained in an aqueous alkaline solution are extracted by treatment with a water-immiscible organic solvent phase consisting of an orthophenyl phenol, an orthobenzylphenyl or a para-substituted alkyl phenol, wherein the alkyl substituent contains from 9-20 carbon atoms, dissolved in an organic diluent to a concentration of at least 0.5 molar. The cesium rich organic phase is then stripped of its cesium preferably by treatment with a dilute acid, e.g. nitric, hydrochloric, sulphuric, acetic and citric. The efficiency of the separation may be improved by scrubbing the cesium-rich organic phase with a dilute alkali, and when using highly alkaline feed material it is advantageous in order to conserve the phenol extractant to add some acid to the raffinate layer of the last extracting stage and return the phenol so produced to the extracting process. Specific phenols exemplified are orthophenyl phenol, paradodecylphenol, 4-chloro-2-phenyl phenol and 4-sec.-butyl, 2-(alpha methyl benzyl) phenol. The process may be used for extracting cesium from its ores, or for extracting Cs137 from the radioactive waste produced in the processing of irradiated nuclear fuel elements.</p> |
