Effect Of Particle Size Of Iron Ore Powder On Basic Sintering Properties And Ore Mineralogical Structure

In recent years,with the increasing output of iron and steel in China,the demand for iron ore powder has also increased greatly.However,the types of iron ore powder are complex and the sources are wide,resulting in great differences in the basic sintering properties.The study on the basic sintering properties of iron ore powder is of great significance to optimize sintering ore blending,improve sinter quality and reduce production cost.Based on the research method of process mineralogy,and using micro sintering measuring instrument and Zeiss polarizing microscope and other equipment,the characteristics of four foreign iron ore powders(Brazil mixed iron ore powder,PB iron ore powder,Yangdi iron ore powder and South Africa refined iron ore powder)at Hangang are studied,and by changing the particle size of iron ore powder,The influence of iron ore powder particle size on Sintering Basic Properties and ore mineralogical structure was systematically studied.By measuring the sintering basic properties of four kinds of foreign iron ore powders with different particle sizes,the influence law of different particle sizes of single iron ore powder on its sintering basic properties is explored.The results show that the sintering basic properties gradually increase with the decrease of particle size of iron ore powder;Through sintering experiments,when four kinds of iron ore powders are mixed,the proportion of different particle sizes:(0.074～0.42 mm),(0.42～3 mm)and(>3 mm)is changed,and the influence law of particle size composition of mixed iron ore powder on its sintering basic properties is explored.The results show that with the increase of the content of iron ore powder with particle size of(0.074～0.42 mm),its sintering basic properties are gradually enhanced,With the increase of the content of iron ore powder with particle size of(0.42～3 mm)and(>3 mm),the sintering basic properties deteriorate.The effect of particle size composition of mixed iron ore powder on mineralogical structure and metallurgical properties of sinter was studied by changing the proportion of particle size of iron ore powder and making sinter in the laboratory.The results show that when the content of fine-grained(0.074 ～ 0.42 mm)iron powder gradually increases from 30% to 40% and 50%,the ore phase structure will change significantly,the content of acicular calcium ferrite gradually increases,and the melting structure will gradually change into interleaving melting structure;When the middle particle size of(0.42 ～ 3 mm)increases from 40% to 50%,the interlaced melting structure gradually changes to melting structure,and the content of acicular calcium ferrite decreases significantly.When the content of coarse particle size(>3 mm)increases from 30% to 40%,the interlaced melting structure gradually changes to melting structure,and the content of calcium ferrite decreases significantly.The metallurgical properties of mixed iron ore powder will also be affected by the different proportion of particle size.When the proportion of fine particle size of(0.074 ～ 0.42 mm)in mixed iron ore powder increases from 30% to 40%and 50%,the overall average particle size decreases,and its low-temperature reduction pulverization performance and reducibility will be enhanced;When the content of intermediate particle size(0.42 ～ 3 mm)and coarse particle size(>3 mm)increases by10%,its low-temperature reduction pulverization performance and reduction performance will be weakened.The research results provide a theoretical basis for optimizing ore blending and improving sinter quality.Figure 25;Table 19;Reference 69...