Investigation of shear flocculation behaviors of colemanite with some anionic surfactants and inorganic salts

The variations of shear flocculation of colemanite mineral with sodium oleate and sodium dodecyl sulfate (SDS) as anionic surfactants with suspension pH, surfactant concentration, stirring speed, and flocculation time have been investigated. It was determined that sodium oleate was more effective in the flocculation than SDS and the colemanite particles could be flocculated by oleate in the broad pH range. Also, a stirring speed of 500 rpm and a flocculation time of 3 min were required to achieve the maximum flocculation degree of colemanite particles. The effects of magnesium, barium, aluminum, and ferric chlorides as inorganic salts on the shear flocculation of colemanite suspension were also studied. In the presence of these cations, the flocculation degrees of colemanite suspension reached high values at particular conditions. However, some differences in the behavior of flocculation of colemanite mineral were observed depending on pH, cation concentration, type of surfactant and inorganic salt.

The increase in the magnesium ion concentration reduces the pH at which shear flocculation enhanced by the cation is possible.Figure optionsDownload as PowerPoint slideHighlights
► The isoelectric point (i.e.p.) of the colemanite sample was determined as a pH of 10.2.
► The shear flocculation degree of colemanite suspension increases with increasing sodium oleate concentration due to the increasing surface hydrophobicity.
► Some differences in the behavior of flocculation of colemanite mineral were observed depending on pH, cation concentration and type of surfactant and inorganic salt.