Journal of Power Sources, Vol.270, 668-674, 2014
Electrochemical evaluation of manganese reducers - Recovery of Mn from Zn-Mn and Zn-C battery waste
Extraction of manganese from ores or battery waste involves the use of reductive reagents for transformation of MnO2 to Mn2+ ions. There are many reducers, both organic and inorganic, described in the literature. A series of 18 reducers has been discussed in the paper and they were classified according to standard redox potential (pE = -log a(e-) where pE is used to express formal electron activity and a(e-) is formal electron activity). The experiments of manganese extraction from paramagnetic fraction of Zn-C and Zn-Mn battery waste in the laboratory scale have been described for 3 reducers of different origin. The best result was achieved with oxalic acid (75%, with the lowest redox potential) and urea (with typical redox potential) appeared inactive. Extraction supported by hydrogen peroxide resulted in moderate yield (50%). It shows that formal thermodynamic scale is only preliminary information useful for selection of possible reducers for manganese extraction resources. (C) 2014 Elsevier B.V. All rights reserved.