Obtention of Manganous Sulfate from Manganese oxide concentrates

By Adolfo Rios Pita Giurfa

Manganese concentrates are mixed with coal, then this mixture is ignited with the use of a burner; it will keep on burning by itself, using its own oxygen content ( O2 of the MnO2).

This operation will reduce the MnO2 (Manganese dioxide)to MnO. This is done because this second compound -Manganous oxide- is easily soluble in sulfuric acid.

Manganous oxide so obtained is leached in two steps with sulfuric acid. Once we have a batch leached with acid we have two parts: one, the solution, which is a very  acid manganese sulfate solution and the other one which is a pulp with an amount of manganese to be leached, so what is to be done is the following: To use the acidic manganese sulfate solution to leach a new and unleached charge of manganous oxide until the solution “neutralizes” to pH > 2.5.

The pulp of the first operation is leached with a fresh sulfuric acid solution.

Leaching of manganous oxide with acid manganese sulfate solution is called “basic leach” and the leaching of the already leached and recycled Manganous oxide pulp with fresh sulfuric acid solution is called “acid leach”.

“Neutral” manganous sulfate solution is then polished passing it through filters to remove solids and contaminants and sent to spray drying.

Chemical reactions:

Back to Homepage