Effect of glauconite and SLS surfactant on phosphate and calcite rheology

The rheological properties of the flotation slurry are one of the most important factors affecting the separation by this process. The presence of clay in the flotation process causes many problems due to its effect on the slurry rheology. In this study, the effect of glauconitic clay on the rheological behaviour of semi-salt type minerals (phosphate and calcite) in the presence/absence of anionic surfactant (sodium lauryl sulfate, SLS) as flotation reagent was investigated as a preliminary step towards understanding their behaviour during flotation. The results showed that the flow behaviour of each mineral, either phosphate or calcite was Newtonian. When glauconite was added in the absence of surfactant, the behaviour shifted to that of Bingham fluids with yield stress for both slurries. When glauconite was added to phosphate slurry in the presence of the surfactant, the behavior was strictly Newtonian, with a slight increase in viscosity with increasing glauconite content. The addition of SLS to calcite slurries shifted the behaviour from Newtonian behavior to shear thickening, with an increase in yield stress and viscosity with addition of glauconite reaching a maximum value at 10 % addition and then decreasing with further addition of glauconite.