Abstract:A continuous hot model of lumpish zone in a blast furnace was used to get the relationship between carbon loss rate of coke and temperature in lumpish zone. The limitation of carbon loss rate outside combustion zone was theoretically analyzed. The compressive strengths of coke at high temperature with relevant carbon loss rate were measured using a high temperature compressive machine with adjustable atmosphere. According to the influences of temperature and carbon loss rate, formulas to calculate the real strengths of different kinds of coke in a blast furnace were deduced and the transformation rule of coke strength in blast furnace was discussed. The influences of injection and combustion rates of coal powder on carbon loss rate of coke were analyzed. According to the influence of coal powder injection on coke strength, a method to calculate the suitable combustion rate of coal was given in this paper.