Method of separating actinide from lanthanide

PURPOSE: To selectively extract actinide in an organic solvent by adding thiocyanate to an aqueous nitric solution and by contacting the solution with the organic solvent containing a specific propane diamide. CONSTITUTION: When actinide is separated from lanthanide in the aqueous nitric solution, thiocyanate is added first into the solution and next the organic solvent containing propane diamide shown by a following equation is brought into contact with the solution by using a pulse column. In the equation, R 1 and R 2 are each an alkyl group of 1-15C or -(CH 2 ) n -Z-(CH 2 ) m -O-R 4 , where R 4 is alkyl group of 1-6C, n and m and 1-6, Z is a single bond or an oxygen atom, R 3 is hydrogen, alkyl group of 1-25C, or -(CH 2 ) n -Z-(CH 2 ) m -OR 4 . According to the method, actinides can be recovered in high yield. COPYRIGHT: (C)1993,JPO