Jamesonite and galena have similar flotation properties, leading to difficulties in effectively separating these two minerals by means of conventional flotation. This study assessed the depressing effect of calcium hypochlorite [Ca(ClO)(2)] on the flotation separation of galena and jamesonite in high-alkali systems. Flotation test results show that galena and jamesonite have substantially different floatability in high-alkali systems. The addition of Ca(ClO)(2) depresses the flotation of jamesonite, but the depressant is unselective against galena. A flotation separation test of a mixture of galena and jamesonite was conducted. The results show that the recovery of galena and jamesonite is 92.26% and 89.75%, respectively. Adsorption measurements and infrared spectral analysis indicate that when diethyldithiocarbamate (DDTC, collector) interacts with galena and jamesonite, chemical adsorption occurs on the mineral surfaces, producing hydrophobic lead diethyldithiocarbamate (PbD2). In a high-alkali solution, Ca(ClO)(2) exhibits little interference regarding the adsorption of DDTC on the galena surface, while it significantly inhibits the adsorption of DDTC on jamesonite. The flotation behavior of jamesonite is depressed by Ca (ClO)(2) mainly because the latter enhances the surface hydrophilicity of the former. These results provide a reference for separating galena and jamesonite concentrates prior to smelting. (C) 2015 Elsevier Ltd. All rights reserved.