A novel saponification process developed by the extraction and reduction of Ce(IV) from nitrate solution

Abstract

Traditional saponification methods lead to large amounts of alkali consumption and saline wastewater discharge. Herein, a novel saponification strategy was proposed via the extraction and reduction of Ce(IV) in nitrate solution. Several key parameters were investigated to explore the influence on extraction and reduction. The results showed that the concentration of NO3- and acidity had insignificant influence on the extraction, indicating that Ce(IV) could be effectively extracted without saponification even in highly acidic solution. The theoretical amount of H2O2 was selected for the reduction process, and the corresponding reduction rate was nearly 99 %. The concentration of Ce(III) in the reductive organic phase was 0.15 mol/L, and the extraction rate of Yb(III) was up to 84.62 % for one-stage extraction. The extraction and reduction mechanisms were established using the slope method and FT-IR spectrometric analysis, and the complexes of the organic phase before and after reduction were determined. Based on the new saponification strategy and the circulation of Ce and nitrate, the alkali consumption and wastewater discharge would be avoided thoroughly.