Abstract: Due to the existence of calcite and other calcium gangue minerals in scheelite ore,scheelite flotation technology was hindered,in which the key is to develop highly selective and efficient inhibitors. The inhibition effect of polyaspartic acid (PASP) was studied by flotation test,Zeta potential test and XPS analysis,and the mechanism was further analyzed by flotation solution chemistry and crystal chemistry calculation with lead ion-benzohydroxamic acid (PB-BHA) complex as collector. The results of pure mineral test showed that the difference of recovery rate between scheelite and calcite could reach more than 70% in the condition of c BHA = cPb = 2. 0×10-4 mol / L、cPASP = 2 mg / L and pH of 10,indicating that the selective inhibition effect of PASP on calcite. Then,the artificial ore mixing test was carried out based on the pure mineral test. The results showed that PASP can greatly improve the CaWO₄ grade of concentrate without affecting the recovery rate. When the mass ratio of scheelite to calcite is 1 ∶1,the recovery rate and grade of CaWO₄ in concentrate with 2 mg / L PASP are 95. 2% and 85. 0%, respectively. The results of Zeta potential test and XPS analysis confirmed that PASP had strong adsorption on the calcite surface,which changed the electrical and chemical environment of the calcite surface. Crystal chemical analysis showed that the matching degree of polyaspartic acid functional groups with calcite surface calcareous points was obviously better than that of scheelite,which resulted in the selective inhibition effect of polyaspartic acid on calcite.

Key words: polyaspartic acid,Pb-BHA complex,scheelite,calcite,Zeta potential,XPS,crystal chemistry analysis