含钾羟基磷灰石粉体的制备及其吸附性能研究∗

摘要

采用化学沉淀法制备出 Ca3(PO4)2粉体，经过高温煅烧得到α-Ca3(PO4)2粉体.将粉体投入到KOH 溶液中，在120℃温度下水化不同时间，制备出含钾羟基磷灰石粉体，利用 X 射线衍射，透射电子显微镜进行分析表征.再将含钾羟基磷灰石粉体投入到NaF溶液中，研究粉体对 F－的吸附性.实验结果表明，含钾羟基磷灰石粉体对氟离子的吸附采用Lagerg-ren拟二级反应动力学方程拟合效果较好，吸附速率较快，吸附机制主要是通过离子交换作用.将吸附过程通过 Langmuir/Freundlich 吸附等温模型拟合，采用Langmuir模型拟合效果较好，静态吸附饱和量为31．55 mg/g.%Ca3 (PO4 )2 powder was synthesized by chemical precipitation.Then put powder into the crucible of Al2 O3 ,after high temperature treatment obtain α-Ca3 (PO4 )2 powder.Soaking into the KOH solution at 120 ℃,after different times,obtained potassium contained hydroxyapatite powders.Characterized by X-ray diffraction, transmission electron microscopy.Then put the powder into the NaF solution for adsorpting F- .Experimental results was described by pseudo-first-order kinetic model and second-order kinetic model.It was found that pseudo-second-order kinetic model was effective,show faster adsorption rate and adsorption mechanism mainly through ion exchange.Process of fluoride ion adsorption was described by Langmuir/Freundlich model, used Langmuir model fit better,static adsorption maximum capacity is 31.55 mg/g.