Separation and Extraction of Scandium from Titanium Dioxide Waste Acid

The solvent extraction method for extracting scandium from titanium dioxide waste acid is usually accompanied by co-extraction of titanium. In this paper, the scandium and titanium separation of the Sc(III) and Ti(IV)-loaded organic phase and the recovery of scandium were studied. A new scrubbing agent containing Na(3)Cit and H2O2 was used to selectively remove titanium from the Sc(III) and Ti(IV)-loaded organic phase. Results indicated that the removal ratio of titanium reached 100% with an nNa(3)Cit/nTi ratio of 1.5/1 and an nH(2)O(2)/nTi ratio of 3/1 at an O/A ratio of 1/1 and 25 degrees C for 15 min through a three-stage cross-flow scrubbing. The co-removal ratio of scandium was less than 0.06%. The Fourier-transform infrared spectra results showed that titanium could be completely removed from the Sc(III) and Ti(IV)-loaded organic phase. Compared with the traditional scrubbing agent containing H2SO4 and H2O2, the new scrubbing agent has the characteristics of high efficiency and strong selectivity.