Tannins: the organic depressants alternative in selective flotation of sulfides

The use of quebracho extract as a pyrite depressing agent to improve Cu/Fe ratio in copper minerals flotation was studied. The depressing effect in the case of pure pyrite, pure chalcopyrite and a sample of disseminated copper ore was tested considering different pH values and modifiers, and different levels of tannin addition. Results show that quebracho extract can be considered a cleaner option in these processes.