The disaggregation of hydrolytic polymaleic anhydride for serpentine-pyrite aggregates: From hydrophobic attraction to electrostatic repulsion

Eliminating the capping action of fine serpentine particles has been a long issue in the pyrite flotation. Herein, the hydrolytic poly(maleic anhydride) (HPMA) was adopted to impede the fine serpentine particles to approach the pyrite surface hydrophobized by sodium isobutyl xanthate (SIBX). Its impeding performance was compared with citric acid (CA), oxalic acid (OA) and glycolic acid (GA). The micro-flotation results indicated that 8.0 mg/L HPMA could effectively eliminate the depression of the fine serpentine particles against pyrite, and enhance the pyrite recovery from about 21 % to 89 %. The findings of contact angle, optical microscope, Zeta potential, adsorption capacity and FT-IR inferred that HPMA selectively adsorbed on serpentine surface, and transformed the hydrophobic attraction between serpentine and SIBX-hydrophobized pyrite into electrostatic repulsion, which made serpentine approach pyrite surface difficultly. In addition, the elimination efficiency of four carboxylic acids against serpentine coating was ranked as HPMA > > CA > > OA > GA, which was positively in accordance with the number of carboxylate group(s) in their molecules. Thus, HPMA efficiently impeded the approach of fine serpentine particles onto the hydrophobized pyrite.