硫化矿－溶液界面电子转移的前线分子轨道理论讨论

FRONTIER MOLECULAR ORBITAL THEORY CONSIDERATION FOR ELECTRON TRANSFER PROCESS ACROSS SULFIDE MINERAL-SOLUTION INTERFACE

本文通过半经验分子轨道法（ＣＮＤＯ／２）计算，得到了方铅矿和黄铁矿表面的电子结构、原子净电荷密度和前线分子轨道能量。用前线分子轨道理论探讨了电子在硫化矿－溶液界面转移的微观机理。硫化矿自诱导浮选涉及到电子从矿物表面转移到分子氧；硫化钠诱导浮选涉及到电子从ＨＳ－离子传递给矿物表面然后再给分子氧。研究表明，方铅矿表面电子能级较高，易给出电子，自诱导浮选好，黄铁矿表面电子能级较低，易接受电子，硫化钠诱导浮选好。

The surface electron structures on the surfaces of galena and pyrite,net charge density of atom and energy of frontier molecular orbital were obtained using CNDO/2 calculation.The micro-mechanism of electron transfer across sulfide mineral-solution interface were discussed with frontier molecular orbital theory.The self-induced flotation of sulfide mineral is associated with the electron transfer from the mineral surface to molecular oxygen.The Na_2S-induced flotation deals with the transfer of electron from HS-ion to the mineral surface,then further to molecular oxygen.The results have shown that the galena surface possesses higher electron energy level and easily donates electron,and hence the self-induced flotation is better.In the case of pyrite,the surface has lower electron energy level and easily accepts electron,and hence the Na2S-induced flotation is better.