Repellent component removal method from incineration ash and repellent component removal system from incineration ash

摘要

PROBLEM TO BE SOLVED: To remove chromium and other heavy metals, chlorine and the like, which are repellent components in cement raw material, from incineration ash by washing with water, and efficiently recover chromium from washing wastewater in which such chromium and the like are dissolved. To do. SOLUTION: Incineration ash is crushed to a predetermined particle size, and water is added to the crushed incineration ash to make a slurry having an acidic to neutral pH, and the incineration ash is washed with water. Next, after adjusting the redox potential of the wastewater generated from the ash water washing, a polymer flocculant is added to leave chromium in the liquid phase, and heavy metals other than chromium in the wastewater are recovered in the first aggregate flocs. To do. Then, after adding an inorganic flocculant to the wastewater generated by the recovery of heavy metals, a polymer flocculant is added to recover the residual chromium in the wastewater to the second aggregate flocs. [Selection diagram] Fig. 1