Amine–oleate interactions in feldspar flotation

This study concerns the interaction between residual amine (tallow amine acetate) and sodium oleate for floating mica and metal-oxides respectively from a feldspar ore of Cine-Milas region of Turkey. Zeta-potential measurements show the co-adsorption of oleate onto feldspar surfaces only if amine is present. Zeta-potential measurements are in good compliance with laboratory scale flotation tests. Flotation tests show that the amine concentration ought to be kept lower than 1.47 × 10−5 mol/l (≈5 ppm) to prevent feldspar loss during metal-oxides flotation stage and hence dewatering/washing operation after mica flotation seems to be a crucial step. Feldspar recovery in the concentrate, being 86.67% without dewatering/washing increases to 94.58% after three stage dewatering/washing between mica and metal-oxides flotation stages. In order to get rid of the residual amine, as an alternative to dewatering, 300 g/t bentonite as the residual amine adsorber is used right after mica flotation and it helps to remove 97.7% of the residual amine in the cell. Bentonite addition provided almost the same feldspar recoveries compared with that of dewatering/washing.