Reextraction method and device of uranium loaded trifatty amine

The invention provides a back extraction method and device of uranium loaded trifatty amine. The back extraction method comprises the following steps that (a) mixed liquor of Na2CO3 and NaOH is prepared to serve as a back extractant; (b) the back extractant and the uranium loaded trifatty amine organic phase are subject to back extraction, the adding amount of the back extractant is determined according to the condition that the extraction terminal point pH value is controlled to range from 7.5 to 9, the back extraction time ranges from 5 min to 20 min, an aqueous phase keeps to be continuous in the back extraction mixing process, and the contact phase ratio Va/Vo is equal to 1-4; and (c) according to back extraction liquid, sodium hydroxide serves as a precipitator, the PH is larger than or equal to 13.5, uranium in a solution is precipitated in the manner of sodium diuranate, and after precipitates are separated, obtained precipitating mother liquor returns to be used for preparing the back extractant. According to the back extraction method and device, full and direct utilization of the uranium precipitating mother liquor is achieved; carbonate accumulation is avoided, reagent consumption and waste water amount are greatly reduced, the back extraction operation is more stable, and the concentration of the uranium in back extraction liquid is greatly improved.