| 摘要 |
PURPOSE:To provide a high temp. adsorptive filtrating material having heavy metal adsorbing ability by using natural ore of manganese dioxide as a base material, particulating it, subjecting to heat treatment and acid treatment, and by using granular manganese dioxide including crystal structure other than beta type thus obtained. CONSTITUTION:Natural ore 1 of manganese dioxide is in beta type crystal structure with low adsorption activity, but can be acquired at low cost and is equipped with high hardness and mechanical strength. After the ore 1 is crushed, a certain extent of particle sizes are selected to provide granular substance 2. This undergoes modifying treatment to enhance the heavy metal adsorbing ability. This treatment provides modification of crystal structure by heat treatment and modification of surface structure by acid treatment. That is, the substance is modified into gamma type crystals having adsorption activity with modification of surface structure of the grains, and at the same time, the lost crystal water is reformed. This is followed by removal of residual acid by water rinsing. Thus a high temp. adsorptive filtrating material is obtained, which includes gamma type crystal structure, is equipped with heavy metal adsorbing ability, and can be acquired at low cost. |
