Our manganese dioxide is a natural manganese ore type QF11 which is screened, dried and specially selected for its high catalytic activity. The media is free from contamination with no additives being used in the production process. Its main use is for catalytic iron and manganese removal from potable water. Usually used in rapid gravity and pressure filters with up to 20% by volume of manganese dioxide to a bed of 16/30 (0.5-1.0mm) silica sand. Manganese Dioxide is produced to a particle size of BS18/44 (0.355-0.850mm).