2013 Volume 54 Issue 5 Pages 844-849
We have conducted studies to produce chemical manganese dioxides (CMDs) from ternary cathodic materials by oxidative precipitation. In this study, a cathodic material was concentrated by pretreatment and leached with sulfuric acid to recover 1 L of a leachate containing 22.0 g/dm3 of Co, 21.6 g/dm3 of Mn, 24.2 g/dm3 of Ni, 9.5 g/dm3 of Li and 8 mg/dm3 of Al as valuable metals. For selective oxidative precipitation of Mn (II), the leachate was reacted with 1 equivalent of Na2S2O8 based on the Mn concentration with stirring at 500 rpm at a temperature of 363 K for 18000 s. As a result of the reaction, it was confirmed that the majority of Mn was precipitated from the solution. XRD, PSA, TG–DTA, LECO and ICP analyses were performed to characterize the precipitate. The analytical results revealed the production of a chemical manganese dioxide (CMD) having a chemical composition of 84.60% MnO, 1.40% Co3O4, 0.11% Li2O, 0.25% NiO, 0.02% Al2O3, 0.06% S and 0.52% Na2O, an average particle diameter of 10.7 µm, a crystal form of γ-MnO2, and a purity of at least 98%.