Abstract:Blast furnace operation line is restricted by material equilibrium points A and C, chemical equilibrium point W and thermal equilibrium point P. The operation line slope is fixed basically at certain raw materials and operating conditions. To find effective measures for lowering the slope, analyzes the influencing factors and calculation methods and discusses the effects of high temperature, metallic pellets, high pressure operation, low Silicon pig iron smelting operation and other technical measures on operation line slope.