黄原酸甲酸酯的电子结构与浮选性能关系的密度泛函研究

Density functional theory study on the relationship between electronic structure and flotation performance of xanthogen formates

运用密度泛函理论计算一系列黄原酸甲酸酯捕收剂的几何构型和电子结构,结合Klopman的普遍化微扰理论,研究前线轨道性质(形状和能量)、自然键轨道电荷、电负性、绝对硬度等参数与捕收剂浮选性能之间的相关性.黄原酸甲酸酯的键合原子为CS双键中的S原子,最高占据轨道能量、自然键轨道电荷、电负性等参数只能推断捕收剂的浮选活性.黄原酸甲酸酯所表现出的选择性,主要是因为黄铜矿表面Cu原子的d轨道电子转移到捕收剂的最低空轨道(LUMO)和能量第二低空轨道(LUMO+1)形成反馈π键,从而增强了捕收剂对黄铜矿的浮选能力.空轨道能量(ELUMO、ELUMO+1)大小可较好地解释捕收剂的选择性强弱.

The density functional theory（ DFT） was applied to investigate the geometric and electronic structures of a series of xanthogen formates. According to the Klopman＇s generalized perturbation theory,the relationship between the flotation performance of collectors and quantum chemical parameters was analyzed by using the energy and shape of frontier orbitals,natural bond orbital charge,electronegativity,and hardness index. The results show that the bonding atom of xanthogen formates is the S atom in the CS bond. These parameters such as the energy of the highest occupied molecular orbital（ EHOMO）,natural bond orbital charge and electronegativity can only infer the flotation activity of collectors. The selectivity of xanthogen formates is mainly related to that copper atoms on the chalcopyritesurface donate d-orbital electrons to the lowest unoccupied molecular orbital（ LUMO） and second lowest unoccupied molecular orbital（ LUMO ＋ 1） of collectors and then resultin the formation of a back donation covalent π-bond,thus improving the flotation power for chalcopyrite and the selectivity against pyrite. The energies of LUMO and LUMO ＋ 1 can be used to interpret the selectivity of xanthogen formates.