| 摘要 |
PROBLEM TO BE SOLVED: To wash a used denitrification catalyst with chemicals relatively low in cost and easy in the treatment of waste water and to regenerate the activity by washing a denitrification catalyst with a mixed acid of an oxalic acid aqueous liquid with a sulfamic acid aqueous liquid. SOLUTION: A washing tank 4 for taking out the used denitrification catalyst 2 from a denitrification device and washing the catalyst 2 is connected to a washing liquid feed means 5 for feeding the mixed acid prepared by mixing 0.1-5% the oxalic acid aqueous liquid with 0.1-5% the sulfamic acid aqueous liquid as the washing liquid. A washing liquid circulation means 7 for circulating the washing liquid in the washing tank 4 is provided on the washing tank 4. The denitrification catalyst 2 deteriorated in the catalyst activity due to sticking of Vd, etc., is taken out from the denitrification device together with a basket 9 by a crane, etc., and soot and dust and a Na component, etc., are removed as a preliminary work before washing, then moved into the washing tank 4. The washing liquid is properly circulated by the washing liquid circulation means 7 via a pump 8. Thus, the denitrification catalyst 2 is effectively washed with the washing liquid. |
