The prepurging of accumulation in BF hearth with acid charging material

In the No. 5 blast furnace of Chongqing Iron and Steel Group Co., the binary basicity and content of silicon dioxide matching with the titanium oxide is unreasonable in slag, and akermanite phase in slag is lower, etc. All which leads to become worse for stability of the slag, so accumulation is generated in blast furnace (BF) hearth. When adjusting the binary basicity of slag to between 0.98 and 1.05 and lowering of the coke load, the acid charging material, replacing manganese minerals, is adopted to wash hearth accumulation. The results show that the effect of acidic charging material is better than manganese minerals, and it does not affect the quality of pig iron. During washing the furnace, average daily output of blast furnace rises 142.3 tons, and the average saving of coke is 15.4 kg/tFe. The coal ratio reduces 4.4 kg/t, overall energy consumption and production costs are reduced significantly.