DEM study of burden distribution and segregation in an electrical smelting furnace

The electric smelting furnace (ESF) is emerging as a low-carbon alternative to conventional blast furnaces, but particle segregation in the burden has not yet been well understood. In this work, the charging process in the ESF is studied and the effects of several key variables on particle segregation are quantified under industrial ESF conditions, including reductant particle size, metallisation and charging layout, using discrete element method (DEM) simulations. The distribution of reductant mass fractions, Beaudry mixing indices, and reductant contact networks are analysed during the charging process. The results show that reductant particle size plays an important role in segregation; smaller reductant particles mix more thoroughly and have a higher mixing index, while forming a more extensive reductant contact network and minimising segregation. The influence of metallisation degree is less than that of reductant particle size: a higher degree of metallisation reduces the mixing index, indicating increased segregation, and decreases the extent of the reductant contact network due to lower coke content. The two-port feed layout significantly improves burden distribution compared to a single-port feed, with a higher mixing index and shorter dominant reductant contact chains.