Effect of SO42- and PO43- on flotation and surface adsorption of dolomite: Experimental and molecular dynamics simulation studies

H 2 SO 4 and H 3 PO 4 are commonly used as depressants for flotation of dolomite from apatite . Unsatisfactorily, the dissociated anions such as SO 4 2- and PO 4 3- may cause trouble to the flotation . In this study, the effect of SO 4 2- , PO 4 3- on the floatability and surface adsorption of dolomite were revealed by experimental and molecular dynamics simulation studies. The results show that SO 4 2- and PO 4 3- , especially PO 4 3- , have a negative effect on flotation of dolomite. The mechanism is that the presence of SO 4 2- and PO 4 3- could inhibit the adsorption of sodium oleate collector on the dolomite surface, and decrease its adsorption capacity. In addition, SO 4 2- and PO 4 3- could react with Ca 2+ to form the hydrophilic CaSO 4 ·2H 2 O and Ca(H 2 PO 4 ) 2 , respectively, the synergistic effect resulted in a decrease in the surface hydrophobicity . As a result, the flotation of dolomite was inhibited. This study clarifies the adverse effects of dissociated anions on dolomite flotation, which also lays a foundation for the targeted removal of these ions in the next step.