Removal of uranium and radium from uranium ores by using sodium containing molten salts

Separation study of uranium and radium as their mixed oxides from the uranium ores was conducted by the reaction with NaCl or NaOH molten salts followed by leaching with dilute HNO3 with the aim of decontamination of the ore tailing. When the ore was heated in the NaCl melt bubbling with nitrogen or oxygen, even though 50 % of uranium remained in the residue, the amount of radium in the residue was selectively reduced to 5-8%. In the case of NaOH melt, on the other hand, the amount of uranium in the residue was reduced to less than 1 %, while radium was a few %. The composition of the bubbling gas did not effect the leaching behavior. Agitation of NaOH melt promoted the disintegration of the ore and the formation of mixed oxides.