Abstract:
Using a stepwise heating blast furnace simulation experiment, the reduction and softening-melting processes of iron ore were simulated to analyze the reduction and volatilization behavior of zinc under different charging methods, as well as its distribution within the blast furnace and its impact on coke performance. The results indicate that the regardless of whether ZnO blocks are introduced through furnace top charging or tuyere charging, zinc primarily accumulates in furnace top dust ash and coke, with extremely low content in molten iron. When ZnO blocks are introduced via furnace top charging, the zinc content in furnace top dust ash is comparable to that in coke. When ZnO blocks are introduced through tuyere charging, the zinc content in furnace top dust ash significantly exceeds that in coke.The primary reason is that zinc entering through the tuyere undergoes rapid high-temperature reduction, after which zinc vapor quickly penetrates the burden layer to reach the furnace top. Due to its short residence time in coke and iron ore, zinc does not accumulate significantly in coke.Zinc exhibits a catalytic effect on coke solution loss, leading to increased coke reactivity and decreased post-reaction strength. This is mainly attributed to zinc promoting the decomposition of ketonic groups and the generation of CO, which subsequently alters coke reactivity and post-reaction strength.