Potato starch and dextrins resulting from thermolysis of potato starch in the absence of reagents and presence of L-amino acids are promising depressants for separation of lead and copper minerals present in the Polish industrial copper concentrates. The polysaccharides were used for differential xanthate flotation of the final industrial concentrates produced by flotation with sulfhydryl collectors in the absence of depressants. The polysaccharides depressed galena and provided froth concentrate rich in chalcocite and other copper minerals as well as cell product containing lead minerals. The best results of separation were obtained in the presence of plain dextrin prepared by a thermal degradation of potato starch. The industrial concentrate containing 18.5% Cu and 5.5% Pb was divided into a froth product containing 38.1% Cu with 77% recovery of copper and a cell product assaying 7.3% Pb with 83% recovery of lead. It was accomplished using 2500 g/t of dextrin, 50 g/t of potassium ethyl xanthate, and 50 g/t of frother (alpha-terpineol). The pH of flotation was 8.0-8.2. (C) 2003 Elsevier Science B.V. All rights reserved.