含钒钢渣中钒再资源化的基础研究

Fundamental Research on Vanadium Recovering from V-bearing Steelmaking Slag

采用熔融-冷却方法并在渣中分别添加SiO2和Al2O3进行改性,讨论了含钒钢渣中钒的富集以及钒富集相的结晶与生长。研究表明,在添加SiO2的含钒钢渣中,钒由分布在2CaO.SiO2(C2S)和2CaO.Fe2O3(C2F)两个相中转变为集中分布在Ca3[(V,P,Si)]O4]2固溶体相中,其中V2O5的质量分数达到24.38%,但是生成的钒富集相晶体尺寸较小;在添加Al2O3的钢渣中,钒同样也富集在Ca3[(V,P,Si)]O4]2固溶体相中,其中V2O5的质量分数达到14.90%。晶化试验表明,钒富集相核化存在非均匀核化与均匀核化,温度分别在1 350℃和1 325℃;在1 300℃保温条件下,钒富集相的晶体由5 min的6.24μm生长到580 min的25.19μm,单位面积上的晶体数随之下降。

The enrichment of vanadium and crystallization and growth of V-concentrating phase in V-bearing steelmaking slag are studied by adding SiO2 and Al2O3 with the method of melting-cooling. The results show that when 15% SiO2 and 20% Al2O3 are added in slag, respectively, vanadium can be enriched in solid solution of Ca3[（V,P,Si）]O2]2 from the orisinal phases of 2CaO·SiO2（C2S） and 2CaO·FeaO3（C2F）. The contents of V2O5 in Ca3 [ （V, P, Si） ] O4 ] 2 reach 24.38 % and 14.90 %, respectively. It is demonstrated that when the slag is added by Al2O3, V-concentrating phase can nucleates homogeneously at 1 325 ℃ and heterogeneously at 1 350 ℃. When holding at crystallization temperature of 1 300 ℃, the crystals of V-concentrating phase grow from mean diameter of 6.28 μm for 5min to 25.19 μm for 580 min, and the number of crystals per unit area is decreasing.