中國有色金屬學報(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 23 No. 5 May 2013 |
（1. National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China; 2. University of Chinese Academy of Sciences, Beijing 100049, China; 3. China ENFI Engineering Corporation, Beijing 100038, China; 4. School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083, China）
Abstract:A novel process was developed for the decomposition of vanadium slag using KOH sub-molten salt under ambient pressure, and the effects of reaction temperature, alkali-to-ore mass ratios, particle size, and stirring speed on vanadium and chromium extraction were studied. The results suggest that the reaction temperature and KOH-to-ore mass ratio are more influential factors for the extraction of vanadium and chromium. Under the optimal reaction conditions (temperature 180 °C, initial KOH-to-ore mass ratio 4:1, stirring speed 700 r/min, gas flow 1 L/min, and reaction time 300 min), vanadium and chromium extraction rates can reach up to 95% and 90%, respectively. Kinetics analysis results show that the decomposing process of vanadium slag in KOH sub-molten salt can be well interpreted by the shrinking core model under internal diffusion control. The apparent activation energies for vanadium and chromium are 40.54 and 50.27 kJ/mol, respectively.
Key words: vanadium slag; spinel; sub-molten salt method; kinetics analysis; decomposition; activation energy
