Study On Production Process And Metallurgical Properties Of Low Magnesium Sinter In Tangsteel

In recent years,with the change of sintering raw materials,MgO in sinter has become an important component of the blast furnace ironmaking process,and its importance to the metallurgical properties of the sinter and the related impact on the blast furnace slag has received increasing attention.With the decrease of SiO₂ content in sinter,the soft-melting property is poor and the natural pulverization is improved obviously.The negative effect of MgO in sinter has become a fact.Therefore,the issue of reasonable MgO content in sinters has become a research topic urgently needed to be solved by steel companies.The effect of MgO content on the properties of low-Mg sintered sinter was studied through hot-state experiments.In combination with FactSage software,the effect of MgO content on the liquid phase of low-magnesium sinter was simulated.The Leica DM4500P microscope was used to analyze the MgO content.Influence of Mineral Composition and Microstructure of Low Magnesium Sinters.The effect of MgO content on the properties of low-Mg sinters shows that when the MgO content is reduced from 2.8 to 2.2,the strength of the sinter drum decreases slightly with decreasing MgO content,the MgO content continues to decrease,and the sinter strength improves.With the decrease of the content of MgO,the sintered product rate tends to increase.The sinter of small grain size（5¹0mm）tends to decrease,and the particle size composition tends to improve.However,when the MgO content is 2.2%,the drum strength of sinter is The rate of finished products deteriorated,the content of small-size sinters increased,the reduction performance at low temperature reduced,the index of low-temperature reduction increased,the index of reduction rate increased,the starting temperature of the refractoriness under load decreased,and the temperature range of the load becomes narrow.With MgO content rising higher,the liquid content of sinters showed a decreasing trend.MgO inhibited the liquid phase formation of sinter.Adding MgO to sinters,MgO promoted the formation of high-melting substances and suppressed the formation of low-melting substances.With MgO content rising higher,the hematite content in the sinter is reduced and the magnetite content is increased,the structure of the sinter ore phase is relatively uniform,the pore size is different,the porosity rate tends to decrease,and the magnetite is the main metal phase.Calcium ferrite,dicalcium silicate,and a small amount of vitreous cement form an intertwined and eroded structure.Hematite partially concentrates into a sheet.Calcium ferrite is the main binder phase,mainly in the form of he crystals and columns,and calcium silicate is mainly present.He crystallized and the glass was unevenly distributed.Figure 43;Table 18;Reference 52.