The separation behavior and mechanism of scheelite and dolomite using locust bean gum as depressant

Abstract

Dolomite is a common vein mineral in scheelite, but how to selectively suppress dolomite in flotation of scheelite has not been addressedin the past research works. In this paper, the depressive behavior of locust bean gum (LBG) in separating scheelite from dolomite is investigated and a possible inhibition mechanism is proposed. The flotation results proved that LBG (18 mg/L) could effectively inhibit dolomite in scheelite flotation at pH = 9, and the obtained grade was 65.69 % of scheelite concentrate. Moreover, combined with the results of XPS, FTIR, Zeta potential, and contact angle experiments, it was inferred that LBG would selectively accumulate on the dolomite surface due to the presence of denser and more active action sites on the surface; and LBG could be stably adsorbed on the dolomite surface based on the stable complexation reaction between the carboxyl groups in LBG molecules and Mg2+ on the dolomite surface. Notably, the preferential adsorption of LBG not only brings a large number of hydrophilic groups to dolomite but also interference with the adsorption of sodium oleate, leading to a substantial decrease of the hydrophobicity of dolomite and finally realizing the selective inhibition of dolomite in scheelite flotation.