Abstract: In light of the characteristics of refractory hemimorphite flotation, the synergistic effect between hydroxy radical and sulfhydryl radical in the process of hemimorphite flotation is studied by flotation of pure minerals and actual ores as well as infrared-spectrum tests.The results show that hemimorphite can be activated by both hydroxy radical or sulfhydryl radical dissociated from sodium sulfide, and the selectivity and effect of hydroxy radical is inferior to sulfhydryl radical in the selectivity and effect of hemimorphite activation.Hydroxy radical and sulfhydryl radical have an obvious synergistic effect at pH 9~11, improving the recovery of hemimorphite and reducing the activation concentration of sodium sulfide.These conclusions are further confirmed by the test results of actual ores.Good flotation performance of hemimorphite ore can be obtained using sodium sulfide at a half-reduced amount.

Key words: Hemimorphite, Sodium hydroxide, Sodium sulfide, Synergistic effect