| 摘要 |
PROBLEM TO BE SOLVED: To obtain an activated carbon having excellent quality by calcining a plant-based source material or mineral-based source material at specified temp. or higher while a gas containing a specified amt. of oxygen is in contact with the source material. SOLUTION: A plant-based source material such as waste woods from construction is dried to obtain a source material having about 10wt.% water content. The source material is put in an externally heating furnace, into which a mixture gas prepared by mixing each proper at. of oxygen and air or inert gas and controlling the oxygen concn. to 0.5-5vol.% is blown into the furnace by the flow rate of about 60 to 1000l per 1kg of the source material and the inner temp. of the furnace is raised to >=400 deg.C, preferably about 600 to 1000 deg.C at about 3 to 50 deg./min, rising rate. Further, the source material is calcined till 80 to 90% of the absolute dry weight is removed so as to obtain an activated carbon having a larger surface area by about 50-500m<2> /g increase compared to an activated carbon calcined in an atmosphere without oxygen. When a mineral source material such as peat coal is used, the source material is calcined under the same conditions at about >=500 deg.C, especially at 550 to 1200 deg.C till 40 to 90% of the carbon content is lost. Thus, an activated carbon is obtd. |
