Effects of colloidal montmorillonite particles on froth flotation of graphite, galena and fluorite

The results of experiments on examples of a hydrophobic, a sulphide and an oxide mineral showed that the presence of sufficient amount of colloidal montmorillonite clay particles in the mineral slurry would be detrimental to flotation by reducing mineral recovery. This observation was attributed to a slime coating of clay on the coarse valuable mineral particles and entrainment of clay particles in the froth product together with water in the triangle froth zones. The former would reduce the recovery of the valuable minerals because of the hydrophilic nature of the coating, while the latter would decrease the concentrate grade. The degree of slime coating depended on slurry pH while the degree of entrainment was closely related to water recovery. It was also found that slime coating was a dominant factor in mineral flotation in acidic pH regions in the presence of colloidal montmorillonite particles.
The results of experiments on examples of a hydrophobic, a sulphide and an oxide mineral showed that the presence of sufficient amount of colloidal montmorillonite clay particles in the mineral slurry would be detrimental to flotation by reducing mineral recovery. This observation was attributed to a slime coating of clay on the coarse valuable mineral particles and entrainment of clay particles in the froth product together with water in the triangle froth zones. The former would reduce the recovery of the valuable minerals because of the hydrophilic nature of the coating, while the latter would decrease the concentrate grade. The degree of slime coating depended on slurry pH while the degree of entrainment was closely related to water recovery. It was also found that slime coating was a dominant factor in mineral flotation in acidic pH regions in the presence of colloidal montmorillonite particles.