[en] Presented are the results of experiments on finding the main peculiarities of flotation separation of uranium from diluted carbonate solutions of means of alkyl amides of nicotine acid, containing in the alkyl chain from 8 to 18 of carbon atoms. Interaction of the collectors with complex uranium containing anions, present in the solution, passes rapidly, and it is followed by formation of sublate colloid solutions. Flotation separation of uranium by means of alkyl amides is the best when pH constitutes 6-9. Suggested is a mechanism of the collector interaction with uranium containing complex anions. It is shown, that practically full separation of uranium takes place at 70-80% excess of the collector as compared with stoichiometrically necessary one for the formation of [UO₂(CO₃)₃](RN₂C₆H₇O)₄ compound