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

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 RuO 2 |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. A more stable deposit was obtained with both membranes at current densities greater than 100 A m −2 and maximum efficiency of 63% at −200 Am −2 (with a purity of 92%), but the consumption of sulphate ions is different in each.