Vanadium extraction and dephosphorization from V-bearing hot metal with fluxes containing CaO

WANG Yan-nan(王艳南)^{1, 2}, SONG Wen-chen(宋文臣)^{1, 2}, LI Hong(李宏)^{1, 2}

(1. State Key Laboratory of Advanced Metallurgy (University of Science and Technology Beijing),
Beijing 100083, China;
2. School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing,
Beijing 100083, China)

Abstract:Extracting vanadium and removing phosphorus simultaneously by adding CaO containing materials to V-bearing hot metal were investigated under the condition of simulating the process of vanadium extraction with insufficiently supplying oxygen in converter. Through preliminary experiments, 3 h and 1375 °C were chosen as the optimum holding time and reaction temperature for formal experiments, respectively. The results of the formal experiments suggest that making basic slag can extract vanadium and remove phosphorus simultaneously. The vanadium extraction rate (η_V) and phosphorus removal rate (η_P) both increase with an increase in the basicity of the original slag materials and the Fe₂O₃ contents. The vanadium distribution ratio is about an order of magnitude greater than the phosphorus distribution ratio but the latter is more sensitive to slag basicity than the former. The phosphorus distribution ratio is beyond 6 when the basicity of the original slag materials is beyond 1, which indicates a much better performance of phosphorus removal compared to the phosphorus removal in the current process. Therefore, it is very feasible to properly raise slag basicity to remove phosphorus with consideration of the grade of vanadium slag. The relations between η_V and η_P, and between L′_V and L′_P are linear under the experimental conditions.

Key words:vanadium extraction; phosphorus removal; basicity; vanadium distribution ratio; phosphorus distribution ratio