Influence of the coke and burden quality on the productivity of the blast furnace

Abstract

Low slag volumes favour high productivities. In the case of Sidmar, the burden consists of more than 90 % sinter. The iron content of the sinter has been optimized. Slag volume is thus reduced and productivity between 65-70 tHM/m².24h is achieved. At high pulverized coal injection rates, the residence time of the coke increases substantially and a higher degree of degradation is to be expected. Therefore, a careful monitoring of the coke and sinter quality is of prime importance. This paper describes the coke and sinter quality used in the Sidmar blast furnaces to control permeability of the furnace with long term PCI rates of 180 kg/tHM and coke rates around 300 kg/tHM. A global quality index has been defined which is well correlated with the blast furnace productivity. Sidmar believes that the quality requirements of the burden can directly be linked with the requested productivity and that good operational practices are necessary for optimization of that productivity.