基于密度泛函理论的烧绿石晶体结构及(111)晶面特性研究  

Study on the Crystal Structure and(111)Crystal Plane Characteristics of Pyrochlore Based on Density Functional Theory

作　　者：曹钊 卢文达 张艳清 王介良 王鹏 王晓平[1,2,3] 王维维 CAO Zhao;LU Wenda;ZHANG Yanqing;WANG Jieliang;WANG Peng;WANG Xiaoping;WANG Weiwei(School of Mining and Coal,Inner Mongolia University of Science and Technology,Baotou 014010,China;Inner Mongolia Key Laboratory of Mining Engineering,Baotou 014010,China;Key Laboratory of Green Extraction&Efficient Utilization of Light Rare-Earth Resources,Ministry of Education,Baotou 014010,China;Baoshan Mining Co.,Ltd.,Baotou Steel Group,Bayan Obo 0140804,China;Key Laboratory of Bayan Obo Rare Earth Resource Researches and Comprehensive Utilization,Baotou Research Institute of Rare Earths,Baotou 014030,China)

机构地区：[1]内蒙古科技大学矿业与煤炭学院,内蒙古包头014010 [2]内蒙古自治区矿业工程重点实验室,内蒙古包头014010 [3]轻稀土资源绿色提取与高效利用教育部重点实验室,内蒙古包头014010 [4]包钢集团宝山矿业有限责任公司,内蒙古白云鄂博014080 [5]包头稀土研究院白云鄂博稀土资源研究与综合利用国家重点实验室,内蒙古包头014030

出　　处：《金属矿山》2024年第12期116-124,共9页Metal Mine

基　　金：国家自然科学基金(编号:52264033,52364034);国家重点研发计划(编号:2021YFC2901000,2022YFC2905302);内蒙古自治区杰出青年科学基金(编号:2024JQ02);内蒙古自治区教育厅一流学科科研专项项目(编号:YLXKZX-NKD-004,YLXKZX-NKD-037);内蒙古自治区自然科学基金项目(编号:2024QN05020,2024QN05044)。

摘　　要：基于密度泛函理论(DFT)的第一性原理计算,研究了烧绿石晶体及晶面结构、电子结构的特性,以及其表面活性位点和吸附行为,以优化浮选过程,提高矿物分离效率。能带和态密度分析结果表明:烧绿石属于半导体,其表面荷正电的活性位点为Nb原子和Ca原子,反应活性强,其次为O原子,活性最低的原子为F;F—Ca和O—Ca键主要呈离子键特性,在破碎和磨矿过程中,这些键易断裂,从而使烧绿石表面暴露更多的Ca原子活性位点。表面断键密度和表面能计算结果表明:烧绿石常见的解理面包括(111)面、(311)面和(400)面,其中(111)面最容易出现且最稳定。表面差分电荷密度分析表明:Nb和Ca原子具有较强的金属性,在浮选时需优先考虑能与Ca和Nb活性位点结合的捕收剂。吸附能计算结果表明:OHA-能与烧绿石表面的Nb和Ca位点发生化学吸附,OHA-与Nb形成的五元环螯合构型最稳定,但Ca位点数量更多,在捕收剂吸附过程中也具有重要作用。Based on the first-principles calculation of density functional theory(DFT),the characteristics of pyrochlore crystal,crystal plane structure and electronic structure,as well as its surface active sites and adsorption behavior were studied to optimize the flotation process and improve the mineral separation efficiency.The results of energy band and density of states analysis show that pyrochlore belongs to semiconductor,and the positively charged active sites on its surface are Nb atom and Ca atom.The reaction activity is strong,followed by O atom,and the lowest active atom is F atom.The F—Ca and O—Ca bonds are mainly ionic bonds,which are easy to break during crushing and grinding,thus exposing more Ca atom active sites on the surface of pyrochlore.The calculation results of surface bond breaking density and surface energy show that the common cleavage planes of pyrochlore include(111)plane,(311)plane and(400)plane,among which(111)plane is most likely to appear and stable.The surface differential charge density analysis shows that Nb and Ca atoms have strong metal properties,and collectors that can bind to Ca and Nb active sites should be given priority in flotation. The results of adsorption energy calcula-tion show that OHA- can chemically adsorb with Nb and Ca sites on the surface of pyrochlore. The five-membered ring chela-ting configuration formed by OHA- and Nb is the most stable,but the number of Ca sites is more,which also plays an important role in the collector adsorption process.

关 键 词：烧绿石 密度泛函理论 (111)面 活性位点 

分 类 号：TD912[矿业工程—选矿]