Influence Of The Occurrence Regularity Of Mg And Al In Sinter On Metallurgical Properties

In recent years,the proportion of imported iron ore with high aluminum is gradually increased.As a result,sinter has higher Al₂O₃ content,which is harmful to sinter metallurigical properties.Mg O is used as a solvent to restrain deterioration of sinter properties.Occurrence and migration of magnesium and aluminum in the mineralization of sinter were studied systematically,relationship between them and mineralogical structure of sinter was found,and influence of occurrence and migration of magnesium and aluminum on metallurgical properties was revealed.Mineral and microstructure of sinter with different Mg O and Al₂O₃ content and different temperatures wered studied to find out the occurrence rule of magnesium and aluminum in sinter and the migration rule in mineralization process by optical microscope and electron probe.The result shows that magnesium is found in magnetite and calcium ferrite.When Mg O content is increased,content of magnetite is increased.Aluminum is distributed in calcium ferrite and vitreous in sinter.With the increase of aluminum content,the content of calcium ferrite increases.The morphology of calcium ferrite developed from columnar to plate.At the beginning of sintering process,magnesium and aluminum migrated in the form of ion diffusion.At the highest temperature,magnesium occurs mainly in magnetite,a small amount in vitreous,and aluminum in vitreous.In the late stage of liquid phase cold condensate,magnesium migrates from vitreous hematite to magnetite and calcium ferrite,while aluminum migrates from vitreous hematite and hematite to calcium ferrite.With the increase of magnesium content,the reduction degradation of sinter becomes better.The content of young crystal/skeleton hematite in the sinter from 1280? to 1400? decreased,at 1200?1100?,magnetite content increased,hematite content decreased,sinter strength increased.With the increase of aluminum content,the reduction degradation of sinter becomes worse.In the temperature range from 1280? to 1400?,the production of nestlings/skeleton hematite increased.The form of calcium ferrite in sinter develops from columnar to plate-like from 1200? to 1100?,and the crack develops,which reduces the strength of sinter,and reducing degradation of sinter becomes worse.The research results provide a theoretical basis for improving sinter.Figure 73;Table 43;Reference 68...