中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 30 No. 11 November 2020 |
（1. College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China;
2. College of Metallurgy and Materials Engineering, Chongqing University of Science and Technology, Chongqing 401331, China;
3. Chongqing Key Laboratory of Vanadium-Titanium Metallurgy and Advanced Materials, Chongqing University, Chongqing 400044, China）
Abstract:A novel process of composite roasting with CaO/MgO and subsequent acid leaching was proposed to improve the recovery rate of vanadium from Linz–Donawiz (LD) converter vanadium slag. The effects of the MgO/(CaO+MgO) molar ratio and the roasting and leaching parameters on the recovery of vanadium were studied. The results showed that the leaching efficiency of vanadium decreased from 88% to 81% when CaO was replaced completely by MgO; however, it could be improved by roasting with the composite of CaO/MgO. The maximum vanadium leaching efficiency of 94% was achieved under the optimum MgO/(CaO+MgO) mole ratio of 0.5:1. The results from X-ray diffractometry (XRD) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS) confirm that the formation rate of acid-soluble vanadates can be enhanced during roasting with the composite of CaO/MgO and that the leaching kinetics can be accelerated owing to the suppression of calcium sulfate precipitation.
Key words: vanadium; vanadium slag; roasting; acid leaching; recovery
