中文摘要：

采用第一性原理平面波赝势计算了含有空位缺陷的黄铁矿的电子结构,同时讨论了空位缺陷对黄铁矿浮选行为的影响.研究结果表明：硫空位对晶胞体积影响不大,铁空位使黄铁矿晶胞膨胀了1.29%;空位缺陷主要影响黄铁矿费米能级附近的电子能带结构,并在禁带中出现了新能级;空位的存在使黄铁矿的费米能级升高,不利于黄铁矿的浮选.另外,有效质量计算表明,空位的存在增强了黄铁矿导带底电子的定域性.Mulliken键布居分析表明,理想黄铁矿的S—Fe键的共价性大于S—S键的,空位导致周围原子的键之间的共价性增强,有利于黄铁矿浮选.综合考虑空位的存在对矿物费米能级及原子间共价性的影响,我们认为空位的存在不利于黄铁矿的浮选.

英文摘要：

Electronic structures of pyrites containing vacancies were calculated using a first-principles plane-wave pseudopotentials method.The influence of vacancy defects on pyrite flotation behavior is discussed.Results show that sulfur vacancy has little effect on volume while iron vacancy results in a cell volume expansion of 1.29%.The presence of vacancy defects mainly affects the electronic structure near the Fermi level while new energy levels are introduced into the forbidden band and this is caused by atoms close to vacancies.The presence of vacancies increases the Fermi level,which is undesirable in pyrite flotation.The calculation of effective mass indicates that the presence of vacancies increases the localization of electrons located at the bottom of the conduction band.Mulliken bond population analysis of atoms shows that the covalence of the S—Fe bond is greater than that of the S—S bond and that the presence of vacancies results in an increase in the covalence of bonds between the atoms close to the vacancies,which is beneficial to pyrite flotation.We conclude that the presence of vacancies adversely affects pyrite flotation when both the influence of vacancies on the Fermi level and the covalence between atoms are considered.