Precipitation behavior of V-enrichment mineral in steelmaking slag bearing vanadium modified by SiO_2

摘要

In order to concentrate vanadium in converter slag bearing vanadium, the effect of SiO_2 on behavior of vanadium in the process of enriching was studied. Experimental results show that, during cooling, dicalcium silicate containing vanadium and phosphorus precipitate first from original slag. For original with 7% SiO_2, most of vanadium dissolves in calcium silicate phase. However, the proportion of dicalcium silicate is big. For slag modified by 12% SiO_2, during cooling, two vanadium-rich minerals precipitate firstly, i.e. Ca3(V,P)_2O_8(30-33%V_2O_5) and Ca3(V,P)_2O_8·nCa_2SiO_4 (14-31%V_2O_5), then 3CaO·2SiO_2 (2-4%V_2O_5) generates. With addition amount of SiO_2 increasing, the proportion of 3CaO·2SiO_2 decreases gradually, and the content of vanadium in vanadium-rich phase increases gradually. So appropriate SiO_2 addition can suppress the precipitation of Ca_2SiO_4 and Ca_3·Si_2O_7, and promote the generation of vanadium-rich phase.