RESOURCE RECOVERY METHOD FOR MATERIAL ESSENTIALLY CONSISTING OF ALUMINUM PHOSPHATE

摘要

PROBLEM TO BE SOLVED: To effectively utilize the aluminum phosphate in a method for recovering sludge incineration ash as material mainly composed of the aluminum phosphate as a resource recovery method of the sludge incineration ash, without converting aluminum phosphate to other phosphate such as calcium phosphate or sodium phosphate. SOLUTION: An aqueous alkaline metal hydroxide solution is added and dissolved to and in the material mainly composed of the aluminum phosphate and water is added thereto to gelatinize the solution, by which zeolite is produced. The remaining phosphorus is recovered as alkaline metal phosphate. As another method, the aluminum phosphate is subjected to the reaction of the aqueous alkaline metal hydroxide solution and alkaline earth metal salt, by which the phosphorus is converted to the calcium phosphate and the remaining aluminum is converted to the zeolite by adding the water thereto.