The cathodic active materials of spent Zn-Mn batteries are complicated. The majority materials that they contain are Mn(OH)(2), Mn2O4, lambda-MN2O2, ZnMn2O4, Zn(NH3)(2)Cl-2, [Zn(OH)(2)](4)center dot ZnCl2, etc. Dissolving these kinds of materials is important to the environmental pollution control and materials recycle. In present paper we investigated the dissolution mechanism of the cathodic active materials in HCl by testing the factors that can influence the dissolution procedure, including temperature, time, and the concentration of HCl and H2O2. Our results showed that both neutralization and oxidation-reduction reactions occurred in the dissolution process, and that H2O2 had a great effect on the dissolution efficiency. (c) 2005 Elsevier B.V. All rights reserved.