Abstract: Vanadium slag is considered to be a secondary resource of polymetallic symbiosis for the reason that it contains various metal elements such as iron, vanadium, chromium, etc. Currently, a variety of technologies for extracting vanadium and chromium from vanadium slag have been explored in detail. While the treatment of iron in vanadium slag is reported rarely. What's more, a great deal of iron elements cannot be effectively recovered and enter the tailings in the existing research, which leads to the waste of iron resources. For achieving the synergistic recycle of vanadium and iron in vanadium slag, Fe-V alloy was prepared successfully by high-temperature carbothermal reduction smelting with vanadium slag and high-iron red mud. Thermodynamic analysis of the whole reduction system is carried out by using thermodynamic information such as oxygen potential diagram and phase diagram. The result indicates that the oxides of iron and vanadium can be deoxidized easily at high temperature and developed a completely miscible alloy in solid and liquid phases. Therefore, it is feasible to prepare Fe-V alloy in this way. Experimental studies have been made in this work systematically and comprehensively for the effect of raw material ratio on metal recovery rate as well as the impact of adding Na2CO3 and coke on the microstructure and performance of the alloy. The results indicate that the addition of high-iron red mud can improve the basicity of the mixture, and Na2CO3 can improve the reduction conditions of Fe2SiO4 and FeAl2O4, which is beneficial to improving the reduction efficiency of the reaction system. When the addition amounts of Na2CO3 and coke are 8wt% and 30wt%, respectively, the recovery rate of Fe and V in the raw material is the highest. Furthermore, V can promote the pearlite transformation during the solidification, which improves the mechanical properties of the alloy. This work is able to provide a new and reasonable pathway for high value utilization of vanadium slag.

Key words: vanadium slag, thermodynamic analysis, microscopic structure, recycling, Fe-V alloy

摘要： 围绕钒渣的资源化利用的研究热点，以钒渣和高铁赤泥为原料，采用高温碳热还原熔炼的方法成功地制备了铁钒合金。热力学分析表明铁和钒的氧化物在高温下均可被还原为金属单质，且二者在固液相中均能无限互溶，证明以此种方法制备铁钒合金可行。实验研究了原料配比对金属回收率的影响，以及Na2CO3和焦炭添加量对合金组织及性能的影响，结果表明，高铁赤泥的加入可以提高炉料碱度，Na2CO3的加入改善了Fe2SiO4和FeAl2O4的还原条件，有利于提高反应体系的还原效率；Na2CO3和焦炭的最佳添加量分别为8wt%和30wt%，此时原料中Fe和V的回收率最大。V在合金凝固过程中促进了珠光体转变，提高了合金的力学性能。

关键词: 钒渣, 热力学分析, 微观组织, 再利用, 铁钒合金