The effect of two anionic membranes (AMI 7001s and Neosepta AMX) on the electrodeposition of manganese from sulphate solutions

Abstract

The effect of two different anionic membranes on manganese deposition was studied in a two-compartment electrochemical reactor with a titanium cathode and a dimensionally stable RuO₂|Ti anode. Chronopotentiometry, ICP-OES, SEM, XRD and elemental mapping were used to understand the changes in concentration and characteristics of the metallic deposition at different current densities with the anionic membranes AMI 7001s and Neosepta AMX. The results demonstrate that AMI reduces more manganese than AMX below −100 A m⁻², generating more metallic deposition but also more low-solubility manganous by-products, whereas both membranes exhibited similar behaviours above −100 A m⁻² reaching the maximum current efficiency (63%) at −200 A m⁻². It was also observed that the membranes have a significant effect on sulphate consumption since they are anions.