Hydrophobicity of Cu2+ activated sphalerite in solutions of Ca2+, Mg2+ and SO42− was studied.
CuS (Cu+1 and S−1) layer formed on copper activated sphalerite at mildly acidic pH.
Electrostatic adsorption occurred between sphalerite and Ca2+/Mg2+ at mildly acidic pH.
Ca2+ and Mg2+ decreased Cu2+ uptake and hydrophobicity of sphalerite.