Flotation behaviour of Bitlis kyanite ore

Flotation behavior of kyanite has been studied using different collectors. Tests were conducted with the pure mineral sample in micro-flotation cell and ore sample in bench flotation machine. Surface charge was measured on pure kyanite sample and isoelectric point was found to be pH 5.9. Kyanite floated with an amine type of collector above isoelectric point when mineral surface is negatively charged. In contrast, the sulfate type of collector (sodium dodecyl sulfate) was effective in acidic pH range where surface is positively charged. Furthermore, kyanite floated with oleate in neutral and mildly basic pH values. Saleable concentrates assaying 58-60% Al₂O₃ content with 80-85% recoveries were produced using sulfonate type of collectors (AERO series). Depressant reagents were found not to be effective for gangue minerals in oleate flotation. Furthermore, slimes were found to have no adverse effect on the flotation of kyanite. However, steel ball milling lowered the flotation recovery compared to ceramic ball milling.