Partition of pyrite and hematite in aqueous biphase systems: effects of pH and surfactants

The partitioning behavior of pyrite and hematite in the polyethylene glycol (PEG)/Na2SO4/H2O aqueous biphase system was modified by the adjustment of pH and addition of surfactants. Pyrite partitioning was highly dependent upon pH; however, pH had no direct effect on hematite behavior. In the presence of xanthate in alkaline and neutral solutions, pyrite transferred into the polymer-rich phase because of the chemisorption of xanthate on the solid surface. Similarly, oleate increased the partitioning of hematite into the polymer-rich phase under neutral or alkaline conditions. Sodium dodecyl sulfate (SDS) and oleate had no effect on partition of pyrite, and hematite partitioning behavior was not affected by SDS or xanthate. These results were attributable to the limited adsorption of the surfactants on the solid surfaces. (C) 2001 Elsevier Science B.V. All rights reserved.