Effect of Gangue Minerals on Pulp Rheology and Flotation Behavior of Smithsonite

Abstract

The pulp rheology is an important factor affecting flotation performance. Gangue minerals have a significant impact on the rheological property of smithsonite (ZnCO3). The complex pulp rheology (high viscosity, poor dispersion) will adversely affect the grade and recovery of concentrate. To address this problem, the effect of gangue minerals (kaolinite, calcite, and quartz) on the rheological property and flotation behavior of smithsonite was investigated with the pulp rheology measurement and a flotation test. The results showed that the flotation recovery is closely associated with the pulp rheology and high apparent viscosity and that yield stress resulted in a low recovery. The detrimental influence of gangue minerals on the rheology and yield of smithsonite was kaolinite > calcite > quartz. The coarse mineral particles (150–74 μm, 74–38 μm) could reduce the apparent viscosity and yield stress and present good floatability, while fine particles (38–23 μm, −23 μm) could greatly increase the values and show poor floatability. Therefore, to control the pulp rheology of smithsonite, it is necessary to remove fine gangue minerals (−38 μm) before flotation, especially the fine kaolinite.