Selective and ultrafast agglomeration of chalcopyrite by a water in oil emulsion binder

Abstract

A high internal phase water in oil emulsion has been used as the binder in a novel agglomeration process for achieving selective and ultrafast recovery of hydrophobic particles. For the first time, the novel agglomeration was applied to the selective recovery of chalcopyrite particles from a model feed formed from equal portions of high grade chalcopyrite (27.5 wt% Cu grade) and pure silica, with Sauter mean diameter of the chalcopyrite of 11.0 µm. While very high copper recovery was achievable when sufficient binder was added, the selectivity was found to depend on the solution chemistry. The separation performance achieved in a period of 7 s of agglomeration was found to be very strong for a pH of 8.5, 9.0, and 9.5, but very poor at a pH of 10.5. Interestingly, this pH dependence was not observed in froth flotation experiments. Further, the aging of the model feed had an impact on the agglomeration but not on the flotation. These effects were attributed to the emulsifier, SMO, being released from the binder used in the agglomeration experiments.