PURPOSE: To eliminate complex pH operation and to enhance the extraction efficiency by making the pH of an extracting soln. flowing from a washing process to a back extracting process alkaline to such a degree that washing waste water is provided with a prescribed pH and back-extracting the extracting soln. with an alkaline soln.
CONSTITUTION: Uranium leached into a sulfuric acid soln. in a leaching process 1 is extracted with an amine extracting soln. 8 in an extracting process 2. In a washing process 3 the soln. 8 is washed with an alkaline washing soln. 6 having alkalinity making the pH of washing waste water 6' 2W3.2. In a back extracting process 4 uranium in the washed soln. 8 is back-extracted with an alkaline ammonium sulfate soln 7, and the pH of the back-extracted soln. 7' is kept at a constant value.
TOUDOU MATSUZOU
FUJIWARA KIYOSHI
| JPS4735168A |