Effect of clay crystal structure on froth rheology in flotation

It has been well acknowledged that clay minerals could impose deleterious effects on flotation performance by affecting pulp rheology. To date, it is still not clear regarding the role of clay minerals in influencing froth rheology which has been increasingly recognized as an important froth property in determining flotation performance. Hence, this work selected three typical clay minerals with different characteristics to study their impacts on froth rheology: montmorillonite, kaolinite and talc. The results showed that the clay minerals showed different froth rheological behaviors with increasing the solids concentration in the feed from 1 wt% to 9 wt%. For montmorillonite, the froth viscosity decreased first and then increased, reaching a lowest viscosity at 5 wt%. The froth viscosity continuously decreased for kaolinite while it kept increasing for talc over the solids concentration in the feed. In addition, talc generated much more viscous froths than the other two clays. The different varying behaviors of froth viscosity among the three clays were related to clay crystal structure and surface hydrophobicity which ultimately determined froth properties. It is believed that the outcomes of this study could facilitate the flotation optimization of complex ores with the presence of clay minerals. [Display omitted] •Froths generated with montmorillonite, kaolinite and talc showed different rheological nature.•The difference in froth rheology was related to the changes in froth properties.•Froth properties was affected by clay hydrophobicity and interparticle interaction in the pulp.•The clay interparticle interaction in flotation pulp was a function of clay crystal