SORPTION OF URANIUM (VI) COMPOUNDS BY FIBROUS CATION EXCHANGER FIBAN K-1 FROM ACIDIC MEDIA
The high efficiency of use the fibrous cation exchanger FIBAN K-1 for the extraction of uranium (VI) compounds from hydrochloric- and nitricacid model solutions, including combined iron containing solutions, was found. Compounds of uranium (VI) were extracted from hydrochloric- and nitricacid model solutions with 98,5-99,5% and 92-93% content of iron containing solutions in a short time (5-10 min) at a flow rate of sorbent, respectively, 1-5 and 10 g/dm<sup>3</sup>. It was shown that the kinetics of sorption of uranium compounds describes by the pseudo second-order model. Sorption isotherms were described by the equations of Langmuir, Freundlich and Dubinin-Radushkevich. The constants of the equations describing the sorption were calculated. These constants indicated a significant affinity of uranyl ions to the sorbent (ΔG<sup>0 </sup>sorption = -36,94 ±38,21 kJ/mol), ion-exchange mechanism of sorption (values of sorption characteristic energy >8 kJ/mol) and increasing of the binding energy of the bond sorbent-sorbate in a process of surface coverage. It was found that UO<sub>2</sub>-form of cation exchanger could be regenerated for 88-97% by 1 M solutions of NaCl, HCl, H<sub>2</sub>SO<sub>4</sub> and NaHCO<sub>3</sub>.