Calcium phosphate from hatchery by-product

A method of preparing attrition resistant granular proteinacious calcium phosphate animal feed minerals by coreacting calcareous by-products from poultry hatcheries and phosphoric acid, the method comprising:

• (a) providing a flowable aqueous hatchery by-product containing particles of dry matter amounting to between 35 and 70 percent of the flowable by-product;
• (b) comminuting the flowable by-product containing protein and calcium moieties in a weight ratio between 0.25 and 1.25, the calcium moieties consisting essentially of calcium carbonate, until the particles of dry matter exhibit diameters less than 1 millimeter and the calcium moieties exhibit coreactivity with phosphoric acid;
• (c) admixing with the comminuted flowable by-product an amount of phosphoric acid sufficient to provide between 1.0 and 2.0 molecules of phosphorus per molecule of calcium in the flowable by-product;
• (d) coreacting the phosphoric acid and the calcium moieties at a temperature between 20 and 100° C. to form proteinacious calcium phosphate and carbon dioxide gas until carbon dioxide gas formation ceases and the reacted aqueous flowable by-product exhibits a pH between 2 and 4;
• (e) admixing the reacted flowable by-product with an amount of recycled proteinacious calcium phosphate sufficient to provide a water concentration between 7 and 18 percent in the damp solids formed by the mixing;
• (f) rolling the damp solids by means of a granulator until spheroid granules containing calcium phosphate mixed with protein are formed;
• and,
• (g) drying the spheroid granules until the protein hardens and forms a matrix bonding the calcium phosphate into attrition resistant granules of animal feed mineral containing between 5 and 20 percent protein, between 12 and 18 percent calcium, and between 15 and 24 percent phosphorus.