Optimization of sintering ore blending by response surface-satisfaction function method

The effect of sintering ore blending directly affects the quality and cost of sinter, and even affects the technical and economic indicators of blast furnace smelting. In order to explore the comprehensive relationship between raw material composition ratio and multi-index of sinter quality, an optimization method of sinter raw material blending based on response surface-satisfaction function method was proposed. The response surface method Box-Behnken design(RSM-BBD) was used to establish the response surface regression model with the mass percent of magnesium oxide w(MgO), the mass percent of alumina w(Al₂O₃) and the basicity R as independent variables, and the quality indexes such as low temperature reduction degradation index, porosity and calcium ferrite content as dependent variables. The effects of three factors and their interactions on the quality indexes such as low temperature reduction degradation index, porosity and calcium ferrite content of hematite sinter were studied respectively. On this basis, combined with the satisfaction multi-objective optimization method, the response surface Box-Behnken overall satisfaction function model (RSM-BBD-DFA) was constructed to optimize the sintering ore blending with the overall satisfaction of low temperature reduction degradation index, porosity and calcium ferrite content as the goal. The results showed that the influence of each factor on the low temperature reduction degradation index and calcium ferrite content was w(MgO)>R>w(Al₂O₃), and the influence on porosity was w(Al₂O₃)>R>w(MgO). The interaction between w(Al₂O₃) and basicity R has a significant effect on the low temperature reduction degradation index of sinter. The interaction between w(Al₂O₃) and basicity R has a significant effect on the porosity and calcium ferrite content. The effects of w(MgO), w (Al₂O₃) and basicity R on the overall satisfaction of sinter quality are extremely significant, and the order of influence is basicity R>w(Al₂O₃)>w(MgO). The optimal raw material ratio w(MgO) is 2.07%, w(Al₂O₃) is 1.96%, and the basicity R is 2.14. Based on the prediction formula and test of the overall satisfaction of sinter quality, the actual value (0.88) and the predicted value (0.90) of the overall satisfaction of sinter quality under the optimal raw material ratio are obtained.