After repeatedly washing and decanting the salts and excess caustic potash with water, and letting the oxides settle, finally, my manganese oxides are ready for thermiting with magnesium dust in order to liberate the Mn as metal. I'll be using a scrappy old crucible for that, that, given they are carbon, and it too can reduce manganese dioxide (which most if not all Mn oxides revert to upon heating above 1000 'C I've given the inside of it a thin layer of zinc metal, sprayed on in a highly volatile solvent (dimethyl ether, a gas at RT) then baked on solid with a blowtorch) there is a small gap betwen the top and side, a little hole in the crucible right at the top, where it has been used for electrolysis of fused alkali metal hydroxides, in this one, since I've used the side of the carbon crucible to strike a pilot arc in order to begin localized melting of the hydroxide prior to moving the anode away, into the then molten hydroxide to start the electrolysis.
This is actually, in this case, handy, since it will allow me to direct a flow of inert gas in there once the Mn-based thermite has ignited and prevent reoxidation of the (very, very hot) manganese, which otherwise likely as not would be pretty rapid) I plated it with the Zn in order to prevent the crucible itself from contributing as a reducing agent and ending up further damaged or disintegrated by reducing the oxide-magnesium mixture in there), the zinc will I hope act as a sacrificial layer, forming a protective zinc oxide layer that can be dissolved away with something like dilute HCl or spirit vinegar afterwards)
