A novel switchable collector for selective flotation of fine copper oxide from silica

•A novel switchable pseudo-Gemini collector T-OA was developed.•The structure and adsorption character of T-OA on CuO can be tuned by adjusting pH.•T-OA features pH-responsive collecting power and enhanced selectivity for flotation of fine copper oxides from silica.•T-OA at low concentrations is still an effective collector for fine CuO flotation.•T-OA adsorbed at pH 10 reversibly on the CuO surface.•A clear guidance for the development of a new series of fine copper oxide flotation collectors is provided.