METHOD AND APPARATUS FOR RECOVERING PHOSPHORUS FROM SLUDGE INCINERATION ASH

摘要

PROBLEM TO BE SOLVED: To provide a method and an apparatus for recovering phosphorus from sludge incineration ash by which the recovery efficiency of phosphorus is increased and the apparatus is made smaller.;SOLUTION: The method for recovering phosphorus from sludge incineration ash comprises an extraction step to obtain a silicon-containing phosphorus extract by mixing sludge incineration ash containing at least phosphorus and silicon with an alkaline reaction solution to extract phosphorus and silicon included in the sludge incineration ash into the alkaline reaction solutio, a calcium phosphate deposition step to deposit the phosphorus in the silicon-containing phosphorus extract in the form of calcium phosphate by mixing the silicon-containing phosphorus extract with a calcium compound at a deposition reaction temperature of not lower than 30°C and not higher than 70°C, and a calcium phosphate recovery step to recover the calcium phosphate. The apparatus for recovering phosphorus from sludge incineration ash is provided with a calcium phosphate deposition vessel, a temperature control means to control the temperature in the calcium phosphate deposition vessel in the range of not lower than 30°C and not higher than 70°C, and a calcium phosphate recovery means.;COPYRIGHT: (C)2012,JPO&INPIT