Evaluating collector behaviour in coarse particle flotation of copper ores

Abstract

Most studies on collectors for copper flotation focus on conventional mechanical cells and fine particle sizes (<150 µm), leaving limited understanding of collector performance in coarse particle flotation. This study investigates the performance of four collector classes in the HydroFloat™ fluidized bed flotation cell, focusing on bubble-particle attachment, copper recovery and pyrite selectivity. Single mineral flotation tests showed comparable chalcopyrite recoveries (∼80 %) across collectors above 300 mmol/t concentration, despite variations in bubble-particle attachment behaviour. In contrast, real ore flotation using a composite dominated Cu ore revealed significant differences in collector performance, driven primarily by mineral liberation characteristics. While all collectors recovered particles with high Cu exposure effectively, xanthate (PAX) recovered a greater proportion (62 %) of composite particles with limited chalcopyrite exposure, resulting in higher overall copper recovery. Thionocarbamate, in contrast, showed stronger selectivity towards liberated chalcopyrite particles, producing however lower overall copper recovery. Mercaptan and dithiophosphate displayed intermediate behaviour. Single mineral studies also indicated potential for improved pyrite selectivity through pH control. Overall, the results demonstrate that collector selection in HydroFloat™ flotation of composite rich ores is governed not only by collector chemistry but also by the ability to recover composite particles with limited mineral exposure.