Hello everybody,
I'm busy doing my master thesis at this moment and seem to have this problem by precipitating manganese dioxide out of a sulphate solution with mangese (Mn2+) and zinc (Zn2+). According to the literature i should put 130-150 % of potassium peroxodisulphate (oxidant) at 90 C for 2 hours for the oxidation of Mn2+ to Mn4+ (MnO2). Manganese dioxide is a brown-black solid so the goal was to recover this by a filtration. I tried this experiment a few times but it seems not to work out. After the reaction I just have a colourless solution with no percipitation at all. What could be the problem? Is my solution (pH=1-2) maybe too acid and it reacts too much with my oxidant so the manganese gets not oxidated? I use 5 ml of my solution which has 0.1 g of Mn2+. Or could the Zn (2+) causes some trouble?
Best regards,
Simon
<i>The precipitation of manganese dioxide does not work out from a acid leaching solution of spent alkaline battery powder? - ResearchGate</i>. Available from: https://www.researchgate.net/post/The_precipitation_of_manganese_dioxide_does_not_work_out_from_a_acid_leaching_solution_of_spent_alkaline_battery_powder [accessed May 27, 2016].