The effect of composite reducing agent on the reduction process and the tail gas of carbon-containing pellets

Abstract

In order to explore a reasonable way for the efficient utilization of coal resources in the ironmaking process. In this paper, lignite and bituminous coal are used as reducing agents, and two types of vanadium-titanium magnetite composite reducing agent pellets are prepared for different content ratios and mixed forms of the two coal powders. Under the simulated rotary kiln pre-reduction conditions, the influence of the ratio and mixing of pulverized coal on the metallization rate and tail gas composition of the reduction process was explored. The results show that increasing the proportion of high volatile lignite is beneficial to the reduction of pellets and can obtain pellets with a higher metallization rate. Under the new pre-reduction process conditions of the rotary kiln, the vanadium-titanium magnetite double-layer pellet with 75wt% lignite inside and 25wt% bituminous coal outside has the highest metallization rate of about 76%. At the same time, this new type of composite reducing agent pellets reduced gas emissions. This pellet is of great significance to the coal-based ironmaking process.