Colemanite is a calcium containing hydrated boron mineral. It is readily floatable with anionic and cationic collectors. However, the presence of montmorillonite type associated clay minerals hinders the floatability of colemanite due to the slime coating effect. In this study, a new strategy, ultrasonic treatment is put forward in order to selectively detach clay particles from colemanite. A column type cell is used both to float individual colemanite and clay as well as their mixture in the presence of sodium dodecylsulfate (SDS) as collector. It is found that while external sonication of pulp does not improve the floatability of colemanite+clay mixture, that conducted in-situ, i.e. the microflotation cell is directly placed in the ultrasonic bath for a minute, achieves full recoveries. Separate tests conducted with Ca~(2+) ions as activator for colemanite improves colemanite flotation significantly. Zeta potential and solubility measurements are carried out to understand the mechanism of this intriguing phenomenon.
展开▼
