METHOD FOR DECONTAMINATING AND PROCESSING USED ALUMINA

PROBLEM TO BE SOLVED: To provide a method for decontaminating and processing used alumina contaminated with a radioactive substance used as a fluidizing medium or the like of a fluidized bed furnace in a fluorinating process of a nuclear fuel cycle. SOLUTION: The method comprises the chloride conversion process of bringing the used alumina into contact with chlorine gas to convert an oxide into a chloride for selectively vaporizing aluminum chloride and the aluminum chloride recovering process of condensing and collecting the aluminum chloride. If necessary, the method may include the oxidation conversion process of bringing the used alumina into contact with steam before the chloride conversion process to convert fluoride present in parallel into an oxide. Further, the method may include the aluminum chloride reconversion process of heating a cold trap after the aluminum chloride recovering process to revaporizing the aluminum chloride condensed and collected by the cold trap and then bringing the revaporized aluminum chloride into counter current contact with steam to convert aluminum chloride into aluminum oxide. COPYRIGHT: (C)2007,JPO&INPIT