Utilization of ferro-manganese slag for production of manganese sulphate and Electrolytic manganese metal/manganese di-oxide

Abstract

High and low ferro-manganese slags have been studied for production of manganese sulphate which forms the intermediate product for production of electrolytic manganese metall-di-oxide. With low manganese slag, a recovery of 72% manganese is obtained with 100% excess acid in the spent liquor over the stoichiometric equi-valent to contained manganese in the slag with the granulated slag ground to - 100 mesh. This recovery increases to 80% when the slag is ground to —200 mesh. With high manganese slag, a recovery of 86% is obtained with 37% excess acid. This recovery increases to 95% with excess acid, but aluminium and silicon going into the leached solution increases more than double fold. The leached purified manganese sulphate solution is found quite suitable for product Ton of EMM/EMD/CMD.