合成磷灰石的去氟机理研究

用固相反应法和sol-gel法合成了不同类型的磷灰石（AP），并采用TEM、XRD、IR、BET比表面积法及静、动态吸附等方法研究了不同AP的比表面积、结晶度、晶胞参数、结晶尺寸、晶格缺陷度、Ca/P摩尔比和煅烧温度等与吸氟能力的关系，结果表明：结晶度高、晶粒大的AP有较小的吸氟量，属表面单分子层化学络合吸附机理；酸活化的AP有较大的吸氟量，属溶解-沉淀与沉淀物表面纳米尺寸效应吸附的复合去氟机理；具纳米尺寸的HAP在常温、常压、无二次污染、小于11mg/L的低含氟浓度废水中且不酸化情况下有较大吸氟量，属纳米尺寸效应吸附机理。

A Study on the Mechanism of Removing F- ions from the Synthesized Apatite

Apatite (AP) was prepared by solid-phase reaction and sol-gel process. TEM, XRD, IR and BET measurements as well as static-dynamic absorption tests were applied to analyze the influences of specific surface area, crystallinity, lattice defect, crystal lattice parameters, crystalline size, Ca to P molar ratio (R) and calcination temperature (Tc) on the adsorption of F - ions. According to the data obtained, the AP with relatively high crystallinity and large crystalline size has poor adsorption capacity for F - ions and assumes a single molecule layer chemical complexing adsorption mechanism; the acidified AP has good adsorption capacity and responds to a compound mechanism of dissolving-precipitating and nanosurface adsorption; the nanoscale HAP, under the operating conditions of no acidification, room temperature and pressure, non-secondary pollution and comparatively low concentration of F - ions, has excellent adsorption capacity and shows a nanoadsorption mechanism.