Manganese Dioxide

Manganese dioxide is manufactured using specially selected manganese ore whose main constituent is manganese dioxide in the form of pyrolusite. Manganese ore of high catalytic activity, free from contamination and with no additives, is used in the production of this manganese dioxide. The manganese dioxide content varies between 70 and 85% as MnO2, suitable for the removal of iron and manganese from potable water by incorporation in a bed of sand or alone in rapid gravity and pressure filters.
Manganese dioxide {MnO2} is used to remove iron and manganese from drinking water by a process of catalytic oxidation.

Chemical Properties:

Natural manganese ores specially selected for their high catalytic activity, free from contamination, and with no additives, are used in the production of this manganese dioxide. 
The manganese content varies between 55 and 85% as MnO2, but the catalytic activity is not dependent upon the manganese content.

Uses and method of use:

Removal of Arsenic, Iron, Manganese, and heavy metals from potable water and water intended for bottling, brewing or soft drink manufacturing. The usual procedure for used in rapid gravity and pressure filters is to add up to 20% by volume of manganese dioxide to a bed of B.S 16/30 (0.50 - 1.00 mm) or B.S 14/25 (0.600 1.18mm) sand. 
After backwashing, the manganese dioxide will remain evenly distributed throughout the bed, thus ensuring maximum contact time between the water and the catalytic medium. The prepared sand and manganese dioxide bed should be backwashed gently before service. It is not necessary to backwash the sand before placing the manganese dioxide. Five bed volumes are usually sufficient to complete the washing after which the bed may be put into service, discarding the first half bed volume of filtered water.

Performance:

A bed constructed will behave in an identical manner to a bed of 100% B.S, 16/30, or B.S, 14/25 sand in respect of its filtration and backwash characteristics. Typical filtration rates in rapid gravity filters are of the order of 10m.h-1 but higher velocities are often used in pressure filters. In determining the optimum filtration velocity, a minimum contact time of 6 minutes should be used. Combined backwash and air scour are not recommended and backwash velocities should not exceed 25m.h-1