Quantum-mechanical study of effect of lattice defects on surface properties and copper activation of sphalerite surface

• Published in: Transactions of Nonferrous Metals Society of China Vol. 20; no. 6; pp. 1121 - 1130
• Main Author: 陈建华 陈晔 李玉琼
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2010; College of Resources and Metallurgy, Guangxi University, Nanning 530004, China%College of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China
• Subjects: Activation; Cadmium; Copper; copper activation; DEFECTS; DFT calculation; ELECTRONIC STRUCTURE; Impurities; Iron; lattice impurity; LATTICES (CRYSTAL); Manganese; SPHALERITE; Surface chemistry; SURFACES; VALENCE; 密度泛函理论; 晶格缺陷; 杂质影响; 表面性能; 表面活化; 量子力学; 铜原子; 闪锌矿; DFT calculation; copper activation; sphalerite; lattice impurity
• ISSN: 1003-6326
• DOI: 10.1016/S1003-6326(09)60266-1

The electronic properties of sphalerite（110）surface bearing Fe,Mn and Cd impurities were calculated using density-functional theory,and the effects of impurities on the copper activation of sphalerite were investigated.Calculated results indicate that both Fe and Mn impurities narrow the band gap of sphalerite surface and lead to the Fermi level shifting to conduction band.Impurity levels composed of Fe 3d and Mn 3d orbital appearing in band gap are beneficial to electrons transfer from the valence band to the conduction band and promote the surface conductivity and the electrochemical activity.The results show that Fe and Mn impurities cannot be replaced by Cu atom,which reduces the exchange sites（Zn）for Cu atom,hence Fe-and Mn-bearing sphalerites are hard to be activated by copper.Cd impurity has little effect on electronic structure of sphalerite surface; however,Cd atom is easily replaced by Cu atom,and this is the reason why the Cd-bearing sphalerite can be easily floated.