Study on the permeability index of COREX melter-gisifer and its influencing factors

摘要

COREX is the main process of the current smelting reduction method. C-3000 introduced by Baosteel is the biggest production equipment of non-blast-furnace iron making in the world heretofore. However, some problems could often be met in operating practice, such as high coal and coke consumptions, low pre-reduction rate, and poor gas permeability etc. In this work, tuyere coke samples were firstly obtained after the screen and magnetic separation of tuyere samples taken out from COREX melter-gasifier. Then, the voidage and pressure difference experiments were undertaken, and the permeability index of tuyere coke in different position was calculated by the modified Ergun equation. Results show that the permeability index is positively correlated with particle size and negatively correlated with pressure difference. Moreover, the mean particle size in active region before tuyere and close to the deadman area is in the range of 10~12 mm and 4~6 mm, respectively. The gas permeability of the former is better than the latter. These findings could provide theoretical basis for improving the stable smooth operation of melter-gasifier, and be helpful for determining the reasonable fuel structures and finally raising production efficiency.