Abstract: The study aimed to select the appropriate synergic reagent LH，to increase the selectivity of scandium extraction from titanium white waste acid with the di-（2-ethylhexyl） phosphoric acid（P2O4）-tributyl phosphate（TBP）-sulfonated kerosene system，and to improve scandium-titanium separation coefficient and scandium-iron separation coefficient.The process including secondary extraction enrichment，secondary stripping for scandium，and chemical purification was adopted. Through orthogonal test，the optimum extraction conditions were obtained as follows：the best extractant volume ratio of P2O4∶TBP∶sulfonated kerosene=1.3∶0.7∶10， the first extraction phase ratio［V（O）∶V（A）］ was 1∶21， without synergic reagent LH， the secondary extraction phase ratio［V（O）∶V（A）］ was 1∶5，and the dosage of synergic reagent LH was 1.7% of the volume of the aqueous phase. Under those conditions the scandium-titanium separation coefficient reached 124 812，and scandium-iron separation coefficient reached 8 202.

Key words: synergic reagent LH, titanium white waste acid, scandium extraction, extraction, selectivity