A PROCESS FOR THE PREPARATION OF HIGHLY PURE MANGANESE SULPHATE ELECTROLYTE USEFUL FOR ELECTRODEPOSITION OF HIGHLY PURE ELECTROLYTIC MANGANESE DIOXIDE (HPEMD')

摘要

In the process of the present invention the manganese sulphate solution containing monovalent cations, in particular K and Na are removed as a complex, viz. jarosite, which is highly crystalline and insoluble from manganese sulphate under optimum conditions. This has been done by digesting the manganese sulphate solution containing monovalent cations with ferric sulphate, at a pH of 1.5 to 3.0, for a duration of 15 to 180 minutes. The temperature being maintained between 80 to 100°C. Bringing about precipitation with suitable addition of seeding. Allowing to cool, followed by filtration. Subsequently treating either with CaO or calcine to raise the pH. The present invention thus provides a process for the preparation of highly pure manganese sulphate electrolyte by the removal of monovalent metal ions from manganese sulphate solution, which is a precursor for the electrodeposition of highly pure electrolytic manganese dioxide (HPEMD).