Reducing the adhesion of mica on arsenopyrite surface using sodium phytate and the application in flotation separation

Abstract

ABSTRACT The adhesion of clay minerals into sulfides concentrate is one of the key problems of mineral processing industry. In this study, sodium phytate (SP) was used as a dispersant in mixed mica and arsenopyrite system. The addition of mica affected the rheological property of arsenopyrite pulp, and this effect could be mostly reduced after the addition of SP. The reflection polarizing microscope results confirmed the adhesion behavior of mica with arsenopyrite to form the aggregate structure; and the addition of SP could disperse them from each other, which is regarded as advantageous to the flotation separation. Adsorption test results revealed that the SP molecules selectively adsorbed onto mica surface. XPS results showed that the P-O groups in SP anions mainly adsorbed with the Al active sites on mica surface, resulting in the greater electrostatic repulsion between mica particles, mica and arsenopyrite particles. This is the mechanism for mica/arsenopyrite dispersion. In flotation tests, SP exhibited well performance in increasing the flotation indexes. A 6 × 10−5mol/L of SP enlarged the recovery difference between arsenopyrite and mica from 19% to 60.0%. In real ore flotation, it also showed better performance regardless compared with the system without dispersant or with traditional dispersant SHMP.