| Sintering-blast furnace-converter production is the main process of iron and steel production in China,the sintering ore is the main burden of blast furnace ironmaking in our country,which accounts for about 78%of the blast furnace iron furnace charge,it is very important for the production quality of blast furnace ironmaking technology,as the main raw material of sintering,between different kinds of iron ore powder of optimization is to improve the yield and quality of sinter ore matching and authors efficiency the important technical means for the enterprise.In recent years,in the process of sintering production,increasing imports of iron ore powder consumption,is not stable,easy to cause the chemical composition of sinter quality is reduced,and the iron ore powder sintering basic characteristics under high temperature has important influence on yield and quality of sintering,the sintering is the important prerequisite of optimizing ore matching,therefore,research the sintering basic characteristics can give full play to the high quality iron ore resources at home and abroad,to realize iron ore.The optimized ore blending of sintering powder provides important theoretical basis for the optimization of sintering process.In this paper,four typical limonites from Australia are studied.Firstly,the physical and chemical properties of four kinds of iron ore powders were analyzed.Secondly,the basic sintering characteristics of the single iron ore were measured,and the basic sintering characteristics of the single ore were evaluated according to the test results.Finally,through the study of the basic characteristics of mixed sintering of two minerals,the complementarity of each basic characteristics of sintering is determined,and the optimal ore blending scheme for the most suitable sintering performance is formulated.The above research has drawn the following conclusions:(1)The iron ores imported from Australia have high iron grade,high content of Al2O3 and SiO2,and large loss on ignition;the four kinds of iron ore powder are limonite,with high crystal water content,loose structure,good hydrophilicity,good pelletizing performance,abundant reserves and easy exploitation,which has great research value.(2)The basic sintering characteristics of different iron ore powders are quite different.Among the four iron ore powders studied,iron ore powder D has the best assimilation property and liquid flow property,with the lowest assimilation temperature and liquid flow index of 1214℃ and 5.56;the bond phase strength of iron ore powder A is the highest,which is 1.975KN;the intergranular properties of iron ore powder B are the best,and the intergranular strength is 1.163KN;the bonding phase strength and intergranular strength of the four iron ore powders all meet the demand of sintering production;Iron ore powder D produced the most complex calcium ferrite(SFCA),and the formation characteristics of calcium ferrite were the best,while A produced the worst calcium ferrite,and produced more silicate glass phase;the sintering loss of SiO2,Al2O3 and the content of crystal water are the main factors affecting the basic sintering characteristics of iron ore powder.(3)Based on the research results of the basic characteristics of the mixed sintering of the two minerals,the complementarity between the sintering characteristics of iron ore powder has been clarified.From the perspective of assimilability,the optimum minimum assimilability temperature can be obtained by mixing A with B,B with C,B with D,A with D.From the perspective of liquid phase fluidity,A,B and C have good complementarity with D and can improve liquid phase fluidity after mixing.From the point of binder phase strength,the binder phase strength of mixed iron ore powder of two minerals is significantly improved,and the binder phase strength of A and D,B and D,Cand D is the best.All the binder phase strength of mixed iron ore of two minerals can meet the requirements of sintering production.The intergranular properties are improved after mixing.From the characteristics of calcium ferrite generation,the amount of calcium ferrite generation after sintering of C and D,A and B,B and D mixed iron ore powder is the largest.Based on the study of the basic characteristics of mixed sintering of two minerals,according to the principle of complementary characteristics to develop the optimal ore blending scheme,the optimal ore blending scheme is obtained,that is ption 2,25%of A ore,55%of B ore,15%of C ore,5%of D ore. |
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