METHOD FOR RECOVERING PHOSPHORUS FROM INCINERATED ASH

摘要

In order to prevent clogging of a filter medium used in solid-liquid separation performed after cleaning of insoluble components after extracting phosphorus in incinerated ash into an alkaline solution, this method for recovering phosphorus mixes the alkaline solution with incinerated ash containing phosphorus to extract phosphorus into the liquid and generate a phosphorus extract, after which the phosphorus extract is separated from insoluble components. After cleaning the insoluble components using a cleaning liquid, the cleaning liquid and insoluble components are separated by means of membrane filtration. When precipitating calcium phosphate by adding a calcium component to the phosphorus extract, the amount of calcium component added is caused to be greater than a multiple of zero, and at least 1 time and less than 1.3 times the reaction equivalent amount of phosphoric acid in the phosphorus extract.