Abstract

Aiming at the bottleneck of the difficult scrubbing and separation of scandium and titanium in the solvent extraction process for scandium recovery, a novel strategy for scandium–titanium separation via citrate complex scrubbing is proposed based on the difference in complexation properties between scandium/titanium and hydroxycarboxylic acids. The mixed Na3Cit + H2O2 system was screened as the optimal scrubbing agent. The effects of key parameters including dosages of Na3Cit and H2O2 and phase ratio (O/A) on scrubbing performance were systematically investigated. The optimal process conditions were determined as follows: temperature of 25 °C, molar ratio n(Na3Cit)/n(Ti) = 30:1, molar ratio n(H2O2)/n(Ti) = 3:1, phase ratio (O/A) of 1:1, shaking speed of 200 r/min, and scrubbing time of 30 min. Under the optimal conditions, the titanium scrubbing efficiency reaches 97.37% with zero co-scrubbing efficiency of scandium. The separation efficiency is 14.47 times higher than that of the conventional H2SO4 + H2O2 scrubbing system, which significantly enhances the scandium–titanium separation performance. This work provides a feasible technical route for the deep separation and purification of scandium and titanium from titanium white waste acid.

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