Manganese dioxide is one kind of black brown crystal or no aptotic shape powder. It can't dissolve in water and nitric acid, when in hot dense vitriol, it will release oxygen and create manganese sulphate, release chlorine and form manganese chlorine in hydrochloric acid. When mixed with caustic soda and oxidant eutectic forma permanganate, it is a strong oxidant. At present, there find five crystals styel of manganese dioxide, the most application value type are ? type and ?type. Our high purity manganese dioxide is pure ? type, in high purity, don't contain other valences, MnO2 ?91%, particle size 4~7?m, proportion?2.2g/ml, and performance is stable.