The flotation separation of pyrite from serpentine using lemon yellow as selective depressant

Abstract

To limit the adverse effect of serpentine on the flotation of pyrite, lemon yellow (LY) was used as a potential depressant for serpentine, and the depression effects and mechanisms were systematically investigated in this paper. Micro-flotation results revealed that the addition of LY could efficiently limit the detrimental effect of serpentine on pyrite flotation with a maximum increase of pyrite recovery from 14% to 96% at pH 9.0. X-ray photoelectron spectroscopy analysis indicated that LY adsorbed on serpentine surface through physical interaction, and electrostatic interaction was considered as the main driving force. Zeta potential results demonstrated that the serpentine surface charge changed from positive to negative after interacting with LY. Thus, the electrostatic attraction between pyrite and serpentine was converted to electrostatic repulsion. Adsorption measurements showed that the adsorption density of potassium butyl xanthate (PBX) on pyrite surface regained after the addition of LY in the presence of serpentine, and thus the pyrite floatability was restored.