(1. 广西大学 资源与冶金学院, 南宁530004；2. 广西大学 化学化工学院，南宁530004；
3. 广西大学 物理科学与工程技术学院, 南宁530004)
摘 要: 采用基于密度泛函理论的第一性原理方法，计算黄铁矿、白铁矿和磁黄铁矿的电子结构，讨论这3种硫铁矿的电子结构与其可浮性之间的关系。计算结果表明：黄铁矿为直接带隙半导体，白铁矿为间接带隙半导体，而磁黄铁矿为导体。态密度分析结果表明，黄铁矿和白铁矿为低自旋态，而磁黄铁矿则为自旋−极化态。前线轨道计算表明：这3种硫铁矿被氧化由易到难的顺序为磁黄铁矿，白铁矿，黄铁矿；用黄药捕收的可浮性由强到弱的顺序为白铁矿，黄铁矿，磁黄铁矿。计算结果能够很好地解释这3种硫铁矿与氧气作用的难易程度以及用黄药捕收的可浮性顺序。
关键字: 黄铁矿；白铁矿；磁黄铁矿；电子结构；可浮性；密度泛函理论
pyrite, marcasite and pyrrhotite
（1. College of Resources and Metallurgy, Guangxi University, Nanning 530004, China;
2. College of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China;
3. College of Physics Science and Engineering, Guangxi University, Nanning 530004, China）
Abstract:The electronic structures of pyrite, marcasite and pyrrhotite were calculated using the first-principles method which was based on the density functional theory (DFT), and the relationship between the electronic structure and floatability of the three sulfurous iron minerals was discussed. The calculation results show that pyrite is a direct band-gap semiconductor, and marcasite is an indirect band-gap semiconductor, while pyrrhotite is a conductor. The density of state analysis reveals that pyrite and marcasite are in low spin state, while pyrrhotite is in spin-polarized state. In addition, the calculation of the frontier orbital indicates that the oxidized order of the three sulfurous iron minerals from easy to difficult is as follows: pyrrhotite, marcasite, pyrite, and the floatability order of the three sulfurous iron minerals from easy to difficult using xanthate as a collector is as follows: marcasite, pyrite, pyrrhotite. The interaction between the three sulfurous iron minerals and oxygen, and the floatability of the three sulfurous iron minerals collected by xanthate can be well explained by the calculation results.
Key words: pyrite; marcasite; pyrrhotite; electronic structure; floatability; density functional theory
