Non-isothermal reduction behavior and appropriate hydrogen enrichment rate of blast furnace with vanadium titanium ore

Hydrogen-rich metallurgy in blast furnace(BF) is an important way to reduce energy consumption and carbon emission. In order to determine the proper hydrogen enrichment rate of blast furnace, the influence of hydrogen enrichment rate on the process of softening and melting of vanadium titanium ore was studied, and the non-isothermal reduction behaviors of sinter and pellets with vanadium-titanium are analyzed by the process interruption method. The results showed that,the hydrogen-rich metallurgy in BF improves the reduction condition of vanadium titanium ore. With the increase of hydrogen enrichment rate, the reduction degrees of sinter and pellets with vanadium titanium increase, especially under the condition of high temperature, the effect of hydrogen enrichment rate of gas is more obvious. The FeO content and the amount of primary melting slag decrease with hydrogen enrichment in BF. The hydrogen-rich operation of BF with vanadium titanite ore will make the cohesive zone move down and the thickness thin, especially the melting zone with the worst permeability become narrowed, and the permeability of burden increases. Due to the different physical morphology and structural characteristics, the reduction rates of sinter and pellets with vanadium-titanium show different trends with the increase of hydrogen enrichment rate. After hydrogen enrichment, the reduction rate of sinter with vanadium-titanium reaches the maximum value at 900-1 000 ℃, while the reduction rate of pellets increases with the increase of temperature. The hydrogen-rich operation of BF worsens the pulverization index of vanadium titanite in non-isothermal reduction process, so properly decreasing the furnace body Angle can alleviate the pulverization of vanadium titanium ore in BF lumpy zone with hydrogen enrichment. When the hydrogen enrichment rate in gas increases by 5%, the influence on the non-isothermal reduction and soft-melting dripping of vanadium titanium ore is different. The effect is the greatest when the hydrogen enrichment rate increases from 0 to 5%, followed by 5% to 10%. When the hydrogen enrichment rate exceeds 10%, the effect on the reduction and soft-melting dripping behavior of vanadium titanium ore is small. After considering the effects of hydrogen enrichment rate on the non-temperature reduction of vanadium titanium ore, the dripping property of softening-melting and the distribution of cohesive zone, the optimal hydrogen enrichment rate can be concluded about 10% in BF with burden containing vanadium-titanium.