Regulation mechanism of ultrasonication on surface hydrophobicity of scheelite

Centering on the roles of ultrasound in flotation kinetics, adsorptions of sodium oleate and scheelite, heat of adsorption and mineral surface properties, we investigated the effects of ultrasonic pre-treatment on scheelite surface dissolution, as well as properties and microstructure of sodium oleate solution. As a result, the ultrasonic treatment of sodium oleate or scheelite promoted the adsorption of sodium oleate on the surface of scheelite, which improved adsorption heat, thermal reaction rate, surface hydrophobicity , flotation rate and recovery rate of scheelite. However, the ultrasonic treatment effect of sodium oleate was better than that of scheelite. The dissociation of sodium oleate molecules was promoted by the ultrasound reduces the surface tension of collector solution to enhance its solution activity. In the meantime, the agglomeration structures of sodium oleate were disrupted by ultrasonication to form a small or single molecular structure, which helped accelerate the solute migration speed and reduced induction time between sodium oleate and scheelite. Ultrasonic treatment removed the adhesion of fine particles on the surface of scheelite and the severely corroded mineral surface, which accelerated the dissolution and increased the number of Ca 2+ reactive sites.