Flotation separation of chalcopyrite from pyrite using baicalin as an organic depressant

In this study, baicalin (BA), a flavonoid compound, was used as a depressant for the selective separation of chalcopyrite and pyrite. The performance and mechanism of the depressant were comprehensively investigated. BA exhibited selective inhibition of pyrite during flotation separation. Under conditions of pH = 6, a BA dosage of 20 mg/L, a potassium butyl xanthate (KBX) dosage of 15 mg/L, and a MIBC dosage of 20 mg/L, the copper recovery rate in the concentrate reached 74.51%, with a grade of 33.707%. Contact angle and ToF-SIMS measurements showed that BA exhibited selective adsorption on the pyrite surface, thereby enhancing surface hydrophilicity. In contrast, the adsorption of BA on the chalcopyrite surface was found to be negligible. XPS and FTIR analyses further confirmed that the carboxyl or hydroxyl groups in baicalin exhibit strong adsorption at Fe sites on the surface of pyrite, whereas adsorption on the surface of chalcopyrite is weaker. Therefore, BA has the potential to serve as a depressant for the selective separation of chalcopyrite and pyrite.