The effect of catalysts during the carbothermic reduction of manganese dioxide
Manganese dioxide is reduced by graphite first to Mn2O3, then to Mn3O4 and MnO, followed by Mn5C2, which then reacts with the remaining MnO to form metallic manganese. This reduction process is accelerated strongly by additions of K2CO3 or Na2CO3, and to a lesser extent by additions of CaO, Al2O3 and MgO. Silica retarded the reduction kinetics. © 1988.