WERKWIJZE VOOR HET WINNEN VAN MANGAANDIOXYDE UIT NIET-GEREDUCEERDE MANGAANHOUDENDE ERTSEN.

摘要

Mn is recovered from unreduced Mn ore by (a) dissolving NO2 and water vapour in an aq. medium (b) contacting and leaching with this soln. a quantity of ore which contains a stoich. excess of MnO2 in relation to the HNO2 content of the soln., at a temp. 80 degrees C and a pH 4.0 under an equilibrium p.p. of a combination of NO and water vapour atmos. pressure, and (c) recovering a slurry containing Mn nitrate. The leaching is efficient and economical in a cyclic process. Pref. the Mn nitrate slurry is purified and controllably decomposed to give reagent grade MnO2 and NO2 and water vapour, the latter two being recycled to step (a).