1. College of Materials Science and Engineering, Chongqing University, Chongqing 400044, PR China
2. Chongqing Key Laboratory of Vanadium−Titanium Metallurgy and New Materials, Chongqing University, Chongqing 400044, PR China
3. State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals, Lanzhou University of Technology, Lanzhou 730050, PR China