REMOVING AND RECOVERING METHOD FOR URANIUM AND*OR THORIUM FROM SOLUTION CONTAINING URANIUM AND*OR THORIUM

摘要

PURPOSE:To considerably reduce radioactive solid waste by adding sodium silicate to a soln. contg. U and/or Th in the presence of F and NH3 and allowing the resulting amorphous silica to capture the U and/or Th. CONSTITUTION:Sodium silicate is added to a soln. contg. U and/or Th in the presence of F and NH3 to precipitate amorphous silica, and this silica is allowed to capture the U and/or Th by adsorption. Flocculation precipitation and filtration are then carried out, and to the resulting silica is added with an acid of ordinary temp. After recovering the U and/or Th thus eluted by filtration, the silica is well washed with water to sufficiently reduce anions in the silica. By adding an alkali metal hydroxide soln. to the silica in an SiO2/M2O (M is an alkali metal) molar ratio of 1.5-3.5, the silica is dissolved in the soln. and regenerated as sodium silicate.