Effect of ultrasonication on the separation kinetics of scheelite and calcite

The effect of ultrasound on the solution properties and microstructure of benzohydroxamic acid (BHA) were investigated to separate scheelite from calcite effectively in this study. The influence of ultrasound-treated BHA on flotation kinetics, surface properties and the adsorption heat of reagents and minerals was discussed. The results show that the difference in the flotation rate between scheelite and calcite was significantly increased by ultrasound-treated BHA. The grade and recovery rate of tungsten concentrate were increased and the flotation time was reduced, which resulted in the rapid separation of scheelite and calcite. Ultrasonic effects significantly increased the adsorption amount, adsorption rate and contact on the surface of scheelite with BHA, which have no noticeable effects on the surface of calcite. The adsorption heat of the interaction between BHA and scheelite was significantly increased by ultrasound due to the increase in the adsorption rate of scheelite on BHA. The ultrasonic effect promotes the dissociation of BHA in solution and the formation of a fine droplet structure, reduces the surface tension, resulting the decrease in the adhesion work and induction time between BHA and scheelite.