Corrosion of MgO–C refractories by vanadium slag with high MgO content

Abstract

Due to the limitation of the subsequent process for producing V2O5, the converter of vanadium extraction needs to use the slag with high MgO content to splash slag. This paper focus on the corrosion behavior of vanadium slag with high MgO content on MgO–C refractory. Corrosion experiment, SEM-EDS analysis, XRF analysis, and theoretical calculation are utilized to study the interface and mass transfer between slags and refractory. The results indicate that the average width of the reaction interface decreases from 9.3 μm to 3 μm with the increase of MgO content from 2 wt% to 8 wt%. When the corrosion time increases from 15 min to 60 min, the average width of the reaction interface decreases from 9 μm to 5 μm, and stabilizes at 5 μm as the corrosion continues. The mass transfer coefficient of MgO rises to 0.663 × 10−2 cm s−1 in the first 60 min of corrosion time, and then falls to 0.592 × 10−2 cm s−1 as the corrosion continues to 120 min. The mass transfer coefficient of MgO also shows an increasing trend with the increase of temperature and rotation speed. When the temperature increases from 1445 °C to 1490 °C, the mass transfer coefficient of MgO increases from 0.1313 × 10−2 cm‧s−1 to 1.4556 × 10−2 cm‧s−1. When the rotation speed increases from 10 rpm to 30 rpm, the mass transfer coefficient of MgO increases from 0.411 × 10−2 cm s−1 to 0.818 × 10−2 cm s−1.