| In recent years,China's import of iron ore has gradually increased.In 2018,the import of iron ore has exceeded 1 billion tons,and its dependence on foreign countries has exceeded 80%.Due to the high Al2O3 content in the imported ore,the melting and fluidity of the slag become worse and the desulfurization capacity is reduced.These problems can be effectively alleviated by increasing the MgO content in the slag.The size and location of the soft melt zone have a great influence on the forward movement of the blast furnace.Therefore,the appropriate MgO content in the blast furnace raw materials(sinter and pellet)and the influence of different composite charge structures on the soft melt drop behavior are studied.The composition and distribution of the slag are detected by XRD and SEM-EDS,and the drop performance is verified by the wetting characteristics and viscosity tests.The results are as follows:1)In terms of the droplet performance,when the MgO/Al2O3 content of sinter and the MgO content of pellet are 1.0%and 2.0%respectively,and the ratio of sinter,pellet and lump ore is 60:24:16,the droplet characteristic value is 95.55 k Pa·?,the position of soft melt zone is lower and narrower,and the droplet performance is the best.2)According to the wetting characteristics,when the MgO/Al2O3 in sinter is 1.0,the MgO content in pellet is 2.0%,and the proportion of sinter,pellet and lump ore is60:24:16,the wettability of furnace charge to iron is the worst and the separation ability of slag and iron is the strongest.3)From the aspect of viscosity,when MgO/Al2O3 is 1.0,the mass fraction of pellet MgO is 2.0%,and the ratio of sinter,pellet and block ore is 60:24:16,the viscosity is small,the temperature of sharp rise is low,and the fluidity is good.4)Compared with changing the MgO content in sinter and pellet,increasing the MgO content by changing the ore proportion in the composite charge has less influence on the wet property and viscosity.Figure 30;Table 25;Reference 75... |
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