Abstract
Livestock animal manure incineration ash contains phosphorus, which has fertilizer effect and is exhaustible resource. This paper describes the technique of phosphorus recovery from livestock animal manure incineration ash. Phosphorus concentration and chemical compound in recovered product were determined. Phosphorus was extracted from ash with 1.5M HCl solution and the products contained phosphorus was recovered as precipitate by alkali addition to the acid solution. Citric acid soluble phosphate content in the recovered product is 150 mg/g, which is comparable to commercially available calcined phosphate fertilizer. Phosphorus existed in the recovered product as calcium hydrogen phosphate dihydrate (DCPD) or hydroxy apatite (HAP). The ratio of DCPD and HAP in the products was depended on pH of the precipitation.
