Preparation and Characterization of Manganese and Zinc Oxides Recovered from Spent Alkaline and Zn/C Batteries Using Biogenerated Sulfuric Acid as Leaching Agent

GALLEGOS, MARÍA V.; PELUSO, MIGUEL A.; SAMBETH, JORGE E.

JOM (1989)

SPRINGER

Año: 2018

1047-4838

Manganese, zinc and mixed manganese-zinc oxides were synthesized after abiohydrometallurgical process to recycle alkaline and Zn/C batteries. A mixtureof alkaline and Zn/C batteries was leached with biogenerated sulfuricacid. The effect of pulp density, time and use of additives, namely, H2O2 andNa2SO3, was studied. Using an S/L = 0.04 g ml1, 2 h, 5 vol.% H2O2 or 1 wt.%Na2SO3 at 30C and in one step, 99% Zn and 90?98% Mn were extracted. Afterleaching, manganese (MnOx) and zinc oxides (ZnO) were obtained bysequential precipitation first with KMnO4 and then with Na2CO3, recovering90% Mn and 95% Zn. Additionally, a mixed manganese-zinc oxide was obtainedby precipitation with NaOH until pH = 8 (ZM) recovering 28% Mn and95% Zn. The Mn/Zn ratio was higher for the MnOx catalysts. Characterizationby x-ray diffraction (XRD) and transmission electron microscopy (TEM)revealed the presence of a-MnO2 in MnOx with globular shape, wurtzite inZnO oxide with spherical shape and a mixture of ZnO wurtzite and ZnMn2O4in the ZM sample with platelet-type shapes.