Al3+ enhanced the depressant of guar gum on the flotation separation of smithsonite from calcite

Abstract

Naturally, there are similar surface physicochemical and floatability properties between smithsonite and calcite, and their flotation separation has always been challenging. This research studied the function and mechanism of Al3+ and guar gum (GG) on the flotation separation of calcite from smithsonite through micro-flotation, chemical calculation of solution, adsorption measurement, FT-IR analysis, Zeta potential measurement and XPS analysis. The result of micro-flotation showed that Al3+ and guar gum as depressant could separate smithsonite from calcite effectively. Results of chemical calculation of solution, adsorption measurement, FT-IR analysis, Zeta potential and XPS analysis measurement indicated that the adsorption difference of Al3+ and GG on smithsonite and calcite surface was obvious. The hydrolyzate of Al3+ selectively adsorbed on calcite and provided the Al adsorption sites for GG. GG selectively adsorbed on the calcite surface through Ca-O bond and Al-O bond, which was formed by the O in the phosphate and hydroxyl groups with Ca and Al sites on the calcite surface. Al(OH)3 and Al2O3 produced by Al3+ in the solution system were also selectively adsorbed on the calcite surface, and hinder the adsorption of NaOL, finally achieving the flotation separation of smithsonite from calcite.