Selective flotation of scheelite from calcite using Pb-BHA complexes as collector and Al-Na_2SiO_3 polymer as depressant

摘要

The previous studies have proved Pb-BHA complexes to be selective for the separation of scheelite and calcium minerals by regulating the Pb/BHA ratio and pH value. In this study, sodium silicate (Na_2SiO_3) and Al-Na_2SiO_3 polymer were used as the depressant for the further separation of scheelite from calcite. Scheelite and calcite were both depressed by Na_2SiO_3 dramatically, while Al-Na_2SiO_3 polymer showed good selectivity. The depressing ability of Na_2SiO_3 for calcite was significantly improved by the reaction with aluminum ion, while it was reverse for scheelite, indicating new species of Al-Na_2SiO_3 polymer were responsible for the selective flotation. Zeta potential measurements show that Al-Na_2SiO_3 exhibits a stronger adsorption on the surface of calcite than that of scheelite. The Al-Na_2SiO_3 polymers on the surface prevented the calcite from adsorbing collector, but has a little influence on scheelite, contributing to a selective flotation. KScheelite;;Calcite;;Pb-BHA complexes;;sodium silicate;;Al-Na_2SiO_3 polymer