Abstract: Monomineral flotation tests have been carried out for investigating the flotability of hemimorphite and smithsonite in dodecylamine (DDA) system. Flotation test results show that flotability of hemimorphite is higher than smithsonite， both of them have the best flotability in the range of pH 10～11. Solution chemistry calculation and zeta potential measurement results show that DDA adsorbs on hemimorphite and smithsonite surface mainly through the electrostatic interaction， and the association reactions between DDA molecular and DDA cationic can enhance the collecting capacity. Zeta potential measurement， X-ray photoelectron spectroscopy (XPS) detection and solution chemistry calculation results show that the point of zero charge (PZC) of hemimorphite is less than that of smithsonite. The first-principles calculations and contact angle measurement results show that hemimorphite is more hydrophobic than smithsonite.

Key words: hemimorphite, smithsonite, dodecylamine(DDA), floatability, hydrophobicity