Hydroxyapatite (HA) powder was prepared by a sol–gel method using Ca(NO₃)₂·4H₂O and (NH₄)₂HPO₄ as raw materials. The usage of preset parameters just mixing the two raw materials only produced Ca₂P₂O₇ and β-Ca₃(PO₄)₂, without any evidence of HA. Then, effects of the reactant concentration, dropping speed, pH value, and mechanical stirring time on the reaction products were studied, and the process parameters were optimized. Results show that the optimum condition for the preparation of HA powder could be obtained by adding Ca(NO₃)₂·4H₂O, (NH₄)₂HPO₄, and citric acid to the reaction base solution, in turn, adjusting the pH value of the reaction solution with concentrated nitric acid to 2.5 and stirring the reaction solution manually. The parameters of calcination process were optimized by DSC analysis, and the HA powder with good crystallinity was successfully prepared.

羟基磷灰石（HA）粉末通过溶胶-凝胶法以Ca（NO ₃）₂ ·4H ₂ O和（NH ₄）₂ HPO ₄为原料制备。刚混合仅产生的Ca两种原料预置参数的使用₂ P ₂ ö ₇和β-的Ca ₃（PO ₄）₂，没有HA的任何证据。然后，研究了反应物浓度，滴加速度，pH值和机械搅拌时间对反应产物的影响，并优化了工艺参数。结果表明，加入Ca（NO）可得到制备HA粉的最佳条件。₃）将₂ ·4H ₂ O，（NH ₄）₂ HPO ₄和柠檬酸加到反应基础溶液中，依次用浓硝酸将反应溶液的pH值调节至2.5，并手动搅拌反应溶液。通过DSC分析优化了煅烧工艺参数，成功制备了结晶度好的HA粉。