The effect of ultrafine kaolinite aggregation on the performance of quartz cationic flotation

This work presents a study on the interference of kaolinite particles, smaller than 10 μm, in the performance of the cationic flotation of quartz. The surface properties control the effects of heteroaggregation and provide the creation of a coverage of these ultrafine on the coarser particle surfaces (slime coating), which makes it difficult for the collectors to adsorb and/or contact the air bubbles. The flotation experiments revealed that the etheramine collector used is capable of recovering 76.9% of ultrafine kaolinite in the absence of coarse quartz particles. On the other hand, the flotation results carried out with the binary mixture (quartz - 150 + 45 μm and kaolinite ultrafines −6 μm) and in the presence of the same reagent system showed that kaolinite floats together with quartz depending on the content of ultrafines in the suspension. Micrographs from MEV/EDS showed that a heterocoagulation between coarse quartz particles and kaolinite ultrafine with a formation of hydrophobic agglomerates can be recovered in the flotation. (author)