Bone ash Ca5(OH)(PO4)3 is a calcium-rich chemical made from concentrated animal bones. Bone ash occurs when bones calcinate when heated at high temperatures. Bone ash serves as a major component of traditional bone china, a form of porcelain ceramic, although most porcelain with high calcium and phosphorus content comes from alternative sources rather than animal bones.
Although the exact chemical composition of bone ash varies depending on the type of bone used for the white power, the substance is around 56 percent calcium oxide and 42 percent phosphorous pentoxide. The other 2 percent comes from water.
Uses for bone ash include bone china, but also as a fertilizer to add phosphorus to the soil. Industrial companies use bone ash as a polishing agent, a protective powder coating for metal tools and sealant for seams and cracks. Bone ash has a high melting temperature, which is why it’s ideal for high friction applications.