| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To utilize dust in a bled gas while reducing an amount of a chemical agent to be used when Se is removed from a treatment liquid of the dust contained in the bled combustion gas of a cement kiln. <P>SOLUTION: This treatment method comprises the steps of: bleeding a part of the combustion gas of the cement kiln; collecting the dust contained in the bled combustion gas; dissolving the collected dust in water; adding the chemical agent containing sulfuric acid into the dissolving solution; collecting a heavy metal; separating a solid from a slurry from which the heavy metal has been collected; and adding the separated solid content into a cement crushing process. The sulfuric acid added when the heavy metal is collected reacts with a calcium content contained in the dust in the bled gas to form gypsum, and the solid content containing the gypsum also contains Se. The solid content is utilized for cement manufacture by adding the solid content into the cement crushing process, a Se concentration in the dust is lowered by suppressing the enrichment of Se during the circulation, and the amount of the chemical agent for removing Se is greatly reduced, which is needed for the waste water treatment of a filtrate produced when the heavy metal is collected. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
