The previous paper concerning about the electrochemical properties of pure sulfide minerals was extended about those of natural flotation concentrates of Kuroko (complex sulfide ore). Teh redox potential of acidic suspension of Cu, Zn, Pb and Cu-Pb concentrates was measured by use of Pt electrode vs saturated calomel electrode of 97°C. The dissolution of a component of the concentrate in suspension of 1 Mole sulfuric acid at that temperature began to proceed at a certain redox potential which is characterized by the kind of component and mineralogical specification of concentrate. For example, Cu in Cu concentrate dissolved at 0.36 volt and Fe in the same concentrate dissolved at 0.48 volt; Cu in Cu-Pb concentrate dissolved at 0.36 volt, while Cu in Pb concentrate dissolved at 0.40 volt.
The results were discussed comparing with potentials of pure sulfide minerals.
