摘要
基于第一性原理的MS软件CASTEP模块,首先对磷灰石矿物晶胞进行了几何优化,计算得到了其能带结构、态密度、Mulliken布居,然后建立并优化了3种不同(001)表面,分别计算其表面能,并计算了磷灰石(001)低能面的差分电荷密度。结果表明:磷灰石晶体的禁带宽度为5.657 eV,属于绝缘体,其能带主要分布在-38.5^-15.1 eV之间。O3-Ca1键布居值最小,是断裂概率较高的键,且O3的2p轨道在费米能级附近电子密度贡献最大,易作为活性位点参加矿浆里的物理化学反应。相对于PO4终端面和Ca1-Ca1终端面,Ca1终端面具有最低的表面能,性质最稳定,是自然界存在概率较高的表面。(001)表面的差分电荷密度分析表明,与O3-Ca1键相比,O3-Ca2键共价性更强,键较难断裂,这与Mulliken键布居分析结果相符。磷灰石晶体和表面的第一性原理计算结果可以为完善基因矿物加工数据库的建设和磷矿浮选药剂作用原理分析提供参考和指导。
CASTEP module based on the density functional theory(DFT)is used to optimize the structure of fluorapa⁃tite unite cell and obtained the band structure,density of states,and Mulliken population.Then 3 different fluorapatite(001)cleavage surfaces,the Ca1,Ca1-Ca1,PO4 termination,were established and optimized,and their surface energy were calculated respectively.The results show that fluorapatite is an insulator with a band gap of 5.657 eV,and its band is mainly distributed between-38.5 eV to-15.1 eV.O3-Ca1 bond has the smallest population value and is most easily broken of all bonds in the fluorapatite bulk.O3 contributes most near Fermi level,easy to participate in physical and chemical reac⁃tions as active site.The results also show that the Ca1 terminal surface have the lowest surface energy,become the most sta⁃ble surface.Moreover,electron density difference plot of the optimum(001)surface shows that compared with O3-Ca1,O3-Ca2 shares more electrons,has stronger interactions,and are more difficult to break,which is consistent with the Mul⁃liken population analysis result.The first-principles calculation results provide reference and guidance for the construction of a perfect genetic mineral processing database and the selection of a fluorapatite flotation process.
作者
朱一民
张洋洋
南楠
谢瑞琦
刘杰
Zhu Yimin;Zhang Yangyang;Nan Nan;Xie Ruiqi;Liu Jie(School of Resources and Civil Engineering,Northeastern University,Shenyang 110819,China;National-Local Joint Engineering Research Center of Refractory Iron Ore Resources Efficient Utilization Technology,Shenyang 110819,China;Genetic Mineral Processing Research Center,Northeastern University,Shenyang 110819,China)
出处
《金属矿山》
CAS
北大核心
2020年第6期87-93,共7页
Metal Mine
基金
国家自然科学基金项目(编号:51774069,51974067)。
