Several aspects of the process technology for treatment of antimony-bearing ores have been studied. The feasibility of separating contaminant antimony minerals as early as the mine planning stage is discussed. The possibility of separating contaminant antimony minerals depends on the mineralogy of the ores and the flotation properties of the antimony minerals. The flotation properties of stibnite jamesonite, gudmundite, boulangerite and bournonite have been studied in laboratory experiments. Information has been obtained which is fundamental to assessment of the possibilities for separating each of these antimony minerals in normal process environments for beneficiation of complex ores. Flotation of stibnite probably occurs as a result of formation of antimony xanthate on the mineral surface at low pH.