Flotation performances and surface properties of chalcopyrite with xanthate collector added before and after grinding

•The effect of collector added before and after grinding to the subsequent flotation was studied.•Collector added before grinding gave higher pulp potential which improved chalcopyrite flotation.•The lost particles during the flotation were clarified.•The surface properties of fine particles easily lost in flotation were discussed. In this study, effects of the collector added before grinding and after grinding on the subsequent flotation and mineral surface properties were investigated. The pH was controlled at 10 during the grinding and flotation processes opened to the atmosphere. With enough amounts of sodium butyl xanthate addition, adding the collector before grinding recovered more chalcopyrite than adding it after grinding in single mineral flotation. The Eh of each ground pulp before and after conditioning were measured and it was found that adding collector before grinding obtained higher and relatively suitable pulp potential for chalcopyrite flotation. Particle size analyses of the flotation products indicate that the different flotation recoveries occurred due to the different flotation losses in fine particles (