氟磷灰石Ca位点成键特性的密度泛函理论研究  

Study on the bonding characteristics of Ca sites in fluorapatite based on density functional theory

作　　者：谢俊 张覃 XIE Jun;ZHANG Qin(Guizhou University,Guiyang 550025,China;National&Local Joint Engineering Laboratory for Effective Utilization of Regional Mineral Resources in Karst Areas,Guiyang 550025,China;Guizhou Academy of Sciences,Guiyang 550001,China;Guizhou Key Laboratory of Comprehensive Utilization of Non-metallic Mineral Resources,Guiyang 550025,China)

机构地区：[1]贵州大学,贵州贵阳550025 [2]喀斯特地区优势矿产资源高效利用国家地方联合工程实验室,贵州贵阳550025 [3]贵州科学院,贵州贵阳550001 [4]贵州省非金属矿产资源综合利用重点实验室,贵州贵阳550025

出　　处：《贵州科学》2021年第1期89-96,共8页Guizhou Science

基　　金：国家自然科学基金项目(51864011);贵州省科技计划项目(黔科合平台人才〔2018〕5781)。

摘　　要：氟磷灰石Ca位点成键特性研究可确定Ca1和Ca2位点相对活性大小,为研究浮选捕收剂在氟磷灰石Ca位点特性吸附及选择合适磷矿浮选药剂提供一定理论参考。论文基于密度泛函理论(DFT)的第一性原理,研究了Ca1和Ca2位点成键态密度、Mulliken电荷布居和键布居、电荷密度和差分电荷密度,结果表明,在氟磷灰石晶体结构中,Ca1与O及Ca2与F之间成键类型基本一致,O2s或F2s与Ca3p形成σ键和σ反键,O2p或F2p与Ca3d成π键和π反键,F-Ca2键强较O-Ca1键强更大;O1-Ca1、O2-Ca1、O3-Ca1的Mulliken键布居值分别为0.11、0.09和0.04,键强满足O1-Ca1>O2-Ca1>O3-Ca1,O3-Ca1键更容易断裂,Ca2位点O1-Ca2、O2-Ca2、O3^(*)-Ca2、O3^(#)-Ca2和F-Ca2的Mulliken键布居值分别为0.06、0.11、0.14、0.08和0.11,键强满足O3^(*)-Ca2>O2-Ca2=F-Ca2>O3^(#)-Ca2>O1-Ca2,O1-Ca2键更容易断裂。Ca2位点活性小于Ca1位点。电荷密度和差分电荷密度结果与Mulliken布居分析结果一致。The study on the bonding characteristics of the Ca sites in fluorapatite can determine the relative activity of Ca1 and Ca2 sites,which can provide theoretical reference for studying the adsorption characteristics of collectors at Ca sites in fluorapatite and selecting suitable flotation reagents for phosphate ores.Based on first principles of density functional theory(DFT),the density of states,Mulliken charge and bond population,charge density and differential charge density of Ca1 and Ca2 sites in fluorapatite are studied.The results show that the bond types between Ca1 and O and Ca2 and F are basically the same.O2s or F2s formσbond andσanti-bond with Ca3p;O2p or F2p formπbond andπanti-bond with Ca3d.The strength of F-Ca2 bond is stronger than that of O-Ca1 bond.The Mulliken populations of O1-Ca1,O2-Ca1 and O3-Ca1 are 0.11,0.09 and 0.04,respectively;the bond strengths are in the order of O1-Ca1>O2-Ca1>O3-Ca1;O3-Ca1 bond is easier to break.The Mulliken populations of O1-Ca2,O2-Ca2,O3^(*)-Ca2,O3^(#)-Ca2 and F-Ca2 are 0.06,0.11,0.14,0.08 and 0.11,respectively;the bond strengths are in the order of O3^(*)-Ca2>O2-Ca2=F-Ca2>O3^(#)-Ca2>O1-Ca2;O1-Ca2 bond is easier to break.The overall activity of the bonds at the Ca2 site is smaller than that at the Ca1 site.The results of charge density and differential charge density are consistent with the results of Mulliken population.

关 键 词：氟磷灰石 Ca位点 成键特性 密度泛函理论 

分 类 号：TD91[矿业工程—选矿]