PURPOSE: To enhance the U extracting synergistic effect, in extraction separation of U in an acidic aq. soln. with an extracting soln. contg. an acidic org. phosphorus cpd. as an extracting reagent, by adding a specified amt. of a polyethylene glycol diether to the extracting soln.

CONSTITUTION: In recovery of U contained in phosphate ore, the ore is treated with an aq. soln. of a mineral acid such as sulfuric acid, nitric acid or hydrochloric acid to extract U. The U-contg. soln. is then treated with a soln. contg. an acidic org. phosphorus cpd. such as di-2-ethylhexylphosphoric acid to extraction-separate U. At this time, to the extracting soln. is added 2W20 wt% of a polyethylene glycol diether represented by general formula RO(C2H4O)nR' (where 4 ≤ n < 14, and R and R' are same or different hydrocarbon groups of 12W36 C in total). Using this extracting soln. the U extracting synergistic effect is enhanced. The extracted U is recovered by back extraction with an aq. soln. of Na2CO3.