1. National Engineering Laboratory for High-Efficiency Recovery of Refractory Nonferrous Metals, School of Metallurgy and Environment, Central South University, Changsha 410083, P. R. China
2. College of Physics and Materials Science, Tianjin Normal University, No 393 Bin Shui West Road, Xiqing District, Tianjin 300387, China
3. School of Materials Science and Engineering, Tianjin University, China