Abstract: To facilitate quick access to high purity hydroxyapatite,nano sized hydroxyapatite powder was prepared by precipitation method with (NH₄)₂HPO₄ and Ca (NO₃)₂·4H₂O as raw materials.Preparation process was described.Reaction conditions,such as temperature,pH,dispersing agent dosage,amount substance ratio of calcium to phosphorus,and sintering temperature,were studied and a detailed discussion was made on amount substance ratio of calcium to phosphorus and sintering temperature.Optimum preparation conditions of hydroxyapatite were as follows:pH=10.5,n(Ca)/n(P)=2.0,reaction temperature was 40 ℃,acute stirring for 2 h,aging temperature was 50 ℃,dispersant dosage was 3% (mass fraction),alcohol as abstergent,drying for 2 h at 120 ℃,and sintering for 2 h at 900 ℃.Nano sized hydroxyapatite with good dispersion and uniformity,high purity,small size,and intact morphology can be prepared under those conditions.

Key words: font-family: "Times New Roman", mso-bidi-font-size: 12.0pt, mso-font-kerning: 1.0pt, mso-ansi-language: EN-US, mso-fareast-language: ZH-CN, mso-bidi-language: AR-SA,  hydroxyapatite;precipitation method;sintering temperature;crystal form')">mso-fareast-font-family: 宋体"> hydroxyapatite;precipitation method;sintering temperature;crystal form