| As the main raw material of blast furnace,high basicity sinter has a very significant impact on the technical and economic indicators of the quality of iron.There are lots of low-grade iron in the domestic iron and steel plant,it’s also has a high silicon content.These are unfavorable to the improvement of sinter quality and metallurgical properties.In order to make full use of the home-made concentrate and surrounding iron ore resources,it is necessary to analyze the sinter plant raw material.The influence of the ratio of fuel and basicity on the sintering index and sinter quality is studied,which provides a theoretical basis for the field production of sinter.Sinter as the object of study,research on the microstructure and mineral content by optical microscope and IPP software.The effects of fuel and basicity on mineral composition and microstructure were discussed,and the effect of mineral composition and microstructure on sinter strength and metallurgical properties was also analyzed.The use of FactSage7.0 software to study the influences of basicity on a large amount of liquid phase formation,investigated the theory of liquid sintering process phase effects on sinter strength and metallurgical properties.With the fuel ratio increased from 4.0% to 5.5%,sinter yield and drum coefficient increased linearly,the vertical sintering speed and the utilization coefficient increased firstly and then decreased.The average particle size of sinter increases with the increase of fuel ratio.The magnetite content increased,hematite content decreased by 5%,calcium ferrite content in the fuel ratio of 4.5% reached the highest value of 24%.The microstructure of sinter at this time was mainly interwoven structure,and the distribution of ore phases was relatively uniform.The metallurgical properties of sinter were the best when the fuel ratio was 4.5%,the reduction degree was higher,and the soft melting property was better.With the increase of basicity,the vertical sintering speed and drum index of sinter linear increased,yield,the utilization coefficient and firing and firing increased firstly and then decreased.When the basicity is increased from 1.5 to 2,the mass fraction of hematite sinter increased by 6%,the mass fraction of magnetite is reduced by 11%,the mass fraction of calcium iron increased 12%,magnetite and calcium ferrite formed the melting corrosion structure.RDI and reduction were greatly improved,softening and melting properties of sinter basicity in 1.7 to 2.0 sinter droplet characteristics was better.Basicity has a great influence on the amount of liquid formation in the sintering process.With the increasing of basicity increases from 1.5 to 2.0,the theory of liquid mixture phase production increased from 27.70% to 34.32%.With the increasing of sintering theory,the rotary drum index of sinter increased approximately linearly.When the theoretical liquid content was 29.38%,the yield of finished product reached the maximum value,which was 80.65%.The reduction degree of sinter was stable at about 90%,and the index of low temperature reduction powdering has been improved.When the liquid phase was 29%,softening and melting properties of sinter reached the minimum value,which is 1440kPa·℃.The comprehensive quality of sinter,the best fuel ratio was 4.5%,the basicity was 1.7,the suitable range of theoretical quantity of liquid phase was 29~30%,the sinter mineral composition was simple,calcium ferrite content was high,mainly in the mixed corrosion structure,and the sinter quality corresponding to be the best. |
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