Abstract
Calcium phosphates were prepared from sea urchin shells and phosphoric acid solution. The calcined sea urchin shell was mixed with phosphoric acid solution. It was then adjusted to pH 7 using ammonia or sodium hydroxide solution. The main component of obtained precipitate was CaHPO4·2H2O. The chemical composition, particle shape, and size of phosphate prepared using sea urchin shell were less different as compared with calcium phosphate prepared using commercial calcium nitrate.
