Adsorption and depression mechanism of carrageenan on chalcopyrite and pyrite for the efficiency flotation separation

In this study, an eco-friendly compound, carrageenan, was employed as a depressant for the selective separation of chalcopyrite and pyrite. The depressant performance and mechanism were comprehensively investigated. The results of the flotation experiments demonstrated that carrageenan exhibited selective depression towards pyrite as opposed to chalcopyrite, achieving flotation recoveries of 88.57 % for chalcopyrite and 9.57 % for pyrite with the combination of 2 × 10^-5 mol/L SIBX and 20 mg/L carrageenan. The results of AFM and contact angle measurements revealed that carrageenan exhibited selective adsorption on pyrite surface, resulting in an enhancement in surface hydrophilicity. In contrast, the adsorption of carrageenan on chalcopyrite surface was found to be negligible. Zeta potential and XPS analyses further confirmed the chemisorption of carrageenan on the pyrite surface, indicating the reaction involving sulfuric acid and hydroxyl groups on carrageenan and Fe sites on pyrite. Therefore, carrageenan holds potential as a promising depressant for the selective separation of chalcopyrite from pyrite.