Preparation of Manganese Oxide and Its Adsorption Properties

The in-situ oxidation of manganese sulfate solution with H₂O₂, sodium hypochlorite, potassium permanganate and oxygen as oxidants was investigated by means of SEM, EDS, XRD, BET and infrared analysis, and the effects of different oxidants on the morphology, phase composition, surface properties and specific surface area of manganese oxides were investigated. The experimental results show that the diameter of manganese oxide particles prepared with H₂O₂ is the smallest, about 50 nm, and the specific surface area is the largest, 63.8764 m²/g. It has the advantages of abundant surface hydroxyl groups, no introduction of other impurities and large adsorption potential. It is most suitable to be used as an oxidant for oxidizing manganese sulfate solution to prepare manganese oxide by in-situ oxidation. Nano manganese oxide prepard by H₂O₂ in-situ oxidation method is used as adsorbent to adsorb cobalt and nickel impurities in manganese sulfate. When the reaction pH is 6, the reaction time is 30min and the amount of adsorbent is 1.0 g, the adsorption rates of cobalt and nickel impurities in 100ml manganese sulfate solution are 97.59% and 97.67%, respectively. The residual amounts of cobalt and nickel meet the industrial process standard of first-class products (Co, Ni ω/%⩽0.005) of high-purity manganese sulfate (Hg/t4823-2015) for batteries. The study plays a guiding role in the preparation and regulation of manganese oxide, and provides a new method with high efficiency, purity and adsorbent availability for the preparation of high-purity manganese sulfate solution.