Effectively enhancing recovery of fine spodumene via aggregation flotation

The effects of shear strength on aggregation flotation processes for fine spodumene (particle size less than 19 μm) were investigated in this study. Sodium oleate was used as a surfactant and collector. The shear strength was controlled by varying the agitation speed of a self-made stirring apparatus. The aggregation process was studied by measuring the continuous transformations in the size distribution and shape of flocs. The results showed that as the shear strength increased, the distribution of fine spodumene transformed from bimodal to unimodal mode. The flocs tended to bridge more branches with a high shear strength and form globule-like flocs with very high strengths. The parameter “aggregation degree” was introduced to evaluate the aggregation process as a function of shear strength. The flotation rate of flocs formed with different shear strengths was also studied. These results demonstrated that the flotation rate was closely related to shear strength and that there was a close correlation between this and aggregation degree. These results could be used to guide the actual production of fine particles via shear aggregation flotation. Aggregation process was divided into formation, growth, bridge, and breakage stage. A parameter named aggregation degree was proposed to elaborate floc growth under various shear conditions. Optimizing shear strength in aggregation stage further improved flotation efficiency.