Manganese carbonate from low-grade Indian manganese ores

In this paper a process for producing pure, manganese carbonate from low-grade Indian Manganese ores which are not easily amenable to other physical methods of beneficiation, has been described. The process depends upon the solubility of manganous oxide obtained by reducing the manganese ores, in an aqueous solution of ammonia containing ammonium carbonate. Most of the impurities are insoluble in the lixiviant or are not precipitated along with the manganese carbonate. Both ammonia and excess carbon dioxide can be recovered and cyclically used. (Mr. B.N. Singh, Scientist, Dr. B.C. Kar, Scientist and Dr. T. Banerjee, Scientist-in-Charge, National Metallurgical Laboratory, Jamshedpur)