METHOD FOR PREPARING PHOSPHORUS-CONTAINING AQUEOUS SOLUTION FROM INCINERATED ASH OF LIVESTOCK FECES, METHOD FOR REMOVING HEAVY METAL AND METHOD FOR RECOVERING HYDROXYAPATITE AND/OR CALCIUM HYDROGENPHOSPHATE

摘要

PROBLEM TO BE SOLVED: To provide a technique by which a phosphorus-containing aqueous solution is prepared from incinerated ash from a livestock industry, the phosphorus is separated and recovered as hydroxyapatite or calcium hydrogenphosphate from the phosphorus-containing aqueous solution after removing a heavy metal, and the hydroxyapatite or calcium hydrogenphosphate can be used as a means to reutilize and store phosphorus resource.;SOLUTION: In a method for separating and recovering phosphorus, an aqueous mineral acid solution (preferably of pH 2 or less) is prepared from incinerated ash from the livestock industry, iron ions are removed from the aqueous mineral acid solution by adjusting its pH with sodium hydroxide or calcium hydroxide, and the solution is mixed with an alkaline aqueous solution, whereby phosphorus is selectively flocculated and precipitated as inorganic phosphorus compounds which are hydroxyapatite and/or calcium hydrogenphosphate. The recovered hydroxyapatite and calcium hydrogenphosphate can be reutilized or stored.;COPYRIGHT: (C)2007,JPO&INPIT