| 摘要 |
PROBLEM TO BE SOLVED: To obtain an activated carbon suitable for dioxin adsorption. SOLUTION: This method comprises repeating a series of processes of mixing a large amount of dried sludge circulating through an air flow dryer 36 and a dried sludge hopper 34 with a dehydrated cake of sludge, grinding the dried sludge by a grinder 38, drying the ground dried sludge, further drying the powder dry sludge by an air flow drying pipe 46 and recycling the sludge to the dry sludge hopper 34 to give a dried raw material sludge, introducing the sludge to a carbonizing furnace 40 of indirect heating type in which hot air for heating and the material to be treated flow in a countercurrent, water in the dried sludge is evaporated in the previous portion of carbonizing treatment (drying zone 78), then the dried sludge is thermally decomposed and carbonized. The carbonized sludge is activated (activated carbon treatment) by steam generated by the previous portion of the carbonizing treatment and steam produced during the thermal decomposition (carbonizing/activating zone 80) to produce a carbonized sludge (activated carbon of sludge) having pores having a large diameter suitable for dioxin adsorption. |
