1. Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation School of Chemistry and Chemical Engineering Changsha University of Science and Technology Changsha 410114 P.R. China
2. Department of Resources and Environment Hunan Nonferrous Metals Vocational Technical College Zhuzhou 412000 P.R. China
3. School of Chemistry and Chemical Engineering Changsha University of Science and Technology Changsha 410114 P.R. China
4. School of Traffic and Transportation Engineering Changsha University of Science and Technology Changsha 410114 P.R. China