FLOCCULATING TREATING DEVICE AND METHOD FOR OPERATING THE SAME

PROBLEM TO BE SOLVED: To provide a flocculating treating device for high concentration silica-containing water in which space saving can be attained and an installing cost can be reduced.SOLUTION: The flocculating treating device for flocculating and treating substances to be treated included in the high concentration silica-containing water by adding poly aluminum chloride aqueous solution of a predetermined concentration having been aged for a predetermined time or longer after preparing to the high concentration silica-containing water has: a diluting/aging agent tank in which the highest liquid level and the lowest liquid level are set and the poly aluminum chloride aqueous solution is prepared and aged; an agent supplying tank connected to the diluting/aging agent tank at a position lower than the lowest liquid level, and at the bottom part or the vicinity of the bottom part of the diluting/aging agent tank by a liquid supplying pipe; and the liquid supplying means for taking the poly aluminum chloride aqueous solution in the agent supplying tank from a middle point between the lowest liquid level position and the bottom part of the agent supplying tank or the position higher than the middle point and supplying the same to the high concentration silica-containing water.