Influence of Coke Reactivity Improved on High Temperature Properties of Iron-bearing Burden

The influence of different reactivity coke on reduction, softening, melting and dropping properties of iron-bearing burden were studied by melting and dropping experiment, meanwhile reduction mechanism and softening-melting mechanism of stock column, as well as stock column pressure difference were also analyzed. The results show that reduction degree at 1 000 degrees C increases, softening-melting start temperature and dropping temperature decrease, and melting temperature rises, when the coke reactivity increases from 24.76% to 56.28%. Softening and melting temperature interval increases, melting and dropping temperature interval reduces and stock column permeability is improved as the coke reactivity increased, which lead to softening-melting and dropping properties value of iron-bearing burden reducing. In addition, industrial experimental analysis shows that reducing agent rate (RAR) can be reduced by 8.26 kg/t using high reactivity coke (HRC) of 12%. Therefore, the appropriate increase of coke reactivity could improve stock column permeability and high temperature properties of iron-bearing burden, so as to reduce RAR.