1. Engineering Research of Metallurgy Energy Conservation & Emission Reduction, Ministry of Education, Kunming University of Science and Technology, Kunming 650093, Yunnan Province, P. R. China
2. Kunming Metallurgy College, 650033 Kunming, China
3. State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming 650093, Yunnan Province, P. R. China