| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for recovering phosphate salt, capable of efficiently recovering the phosphate salt from incinerated ash, fly ash, etc. at a low cost. SOLUTION: This method for recovering the phosphate salt comprises a dissolving process where a solution containing acid is added to the incinerated ash and/or the incinerated fly ash containing phosphate radicals to adjust a pH of the solution to be 1.6 or less so that the phosphate radicals contained in the ashes is dissolved in the solution containing the acid, a residue-separating process where insoluble residues in the solution containing the acid is separated, and an alkaline component-charging process where an alkaline component is added to the solution separated from the residues so that the pH of the solution is adjusted to be in the range of 1.8-2.2, wherein an iron compound-charging process for charging an iron compound is performed at any time before the alkaline component-charging process is completed and further a recovering process for recovering iron phosphate is performed after the alkaline component- charging process is completed.
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