Selective depression of molybdenite using a novel eco-friendly depressant in Cu-Mo sulfides flotation system

The effective separation of molybdenite from chalcopyrite is a challenging job. In this work, an environmentalfriendly reagent pectin was investigated as a novel molybdenite depressant in the flotation separation of Cu-Mo sulfides. The micro-flotation results indicated that pectin selectively depressed molybdenite, and satisfactory separation results were achieved using sodium butyl xanthate (SBX) as collector even in the presence of kerosene. The addition sequence of pectin and kerosene influenced the depression of molybdenite significantly but hardly affected the flotation of chalcopyrite. The pre-adsorption of kerosene prior to pectin on molybdenite surface slightly attenuated the depression effect, while the pre-adsorption of pectin before kerosene moderately diminished the depression effect. Zeta potential, contact angle and Fourier Transform Infrared Spectroscopy (FTIR) suggested that pectin was adsorbed on molybdenite and chalcopyrite surface mainly through hydrophobic interaction and electrostatic attraction, respectively. SBX replaced the adsorbed pectin from chalcopyrite surface and restored its hydrophobicity. However, SBX hardly adsorbed on pectin treated molybdenite and molybdenite surface maintained hydrophilic.