基于铝热还原制备FeV50渣中钒的赋存状态

Existing States of Vanadium in Slag during the Preparation of FeV50 by Aluminum Thermal Reduction

通过渣金V-O平衡及VO-Al平衡理论研究,分析了铝热还原FeV50合金制备过程不同冶炼阶段对渣中钒赋存状态的影响,计算得到钒在渣中的热力学还原极限。通过不同物相分析手段,得到铝热还原FeV50合金制备过程实际渣中钒的稳定结构。研究结果表明:渣金共存时渣中钒的稳态为VO;出渣后VO与V2O3的稳定性与冶炼氧分压有关,其平衡氧分压为0.41 Pa,常压条件下,VO会进一步氧化。渣中钒含量随合金铝含量的增加而降低,当合金铝质量分数分别为8.0%和20.0%时,对应渣中理论钒质量分数分别为0.16%和0.10%。实际冶炼过程中,冷态刚玉渣中的钒除了已还原FeVx初级合金之外,主要以类质同象的形式与镁、铝、铁等元素固溶形成Mg(Al,V)2O4和(Mn,Fe)V2O4复合尖晶石结构。

The effect of different smelting stages on the occurrence of vanadium in the slag during the aluminum thermal reduction for FeV50 alloy preparation was analyzed,the thermodynamic reduction limit of vanadium in the slag was calculated by the study of V-O and VO-Al equilibrium theory.The actual stable structure of vanadium in the slag was obtained by different means of phase analysis.The results demonstrate that the steady state of vanadium in the slag is VO when the slag and alloy coexist,while the stability of VO and V2O3 is related to the partial pressure of oxygen after slag discharge.VO would be further oxidized under the condition of atmospheric pressure with the equilibrium oxygen partial pressure of 0.41 Pa.The total vanadium in the slag decreases with the increasing of aluminum in alloy,and the theoretical vanadium in the slag is 0.16%and 0.10%when the aluminum content is 8.0%and 20.0%,respectively.During the actual smelting process,the main materials of vanadium in corundum slag are composed of reduced FeV alloy as the primary phase and composite spinel structure of Mg(Al,V)2O4 and(Mn,Fe)V2O4 in the form of isomorphism.