The Optimization Of Ore Proportioning Based On The High Temperature Characteristics Of The Iron Ore

Sinter generally accounts for more than 75%in China’s blast furnace iron-bearing charge structure,which is one of the most important iron-bearing charge materials for blast furnace ironmaking.Its reasonable and efficient utilization is of great significance to guarantee the sustainable development of China’s steel industry.In order to improve the quality of sinter ore and optimize the metallurgical properties of sinter,the aim of this paper is to study the high temperature characteristics of iron ore powder by optimizing the ore preparation by using the complementary raw materials with high temperature characteristics of iron ore.(1)This paper mainly introduces the sintering high-temperature special properties of iron ore powder used,including the assimilation of iron ore powder,the fluidity of liquid phase,the microstructure of iron ore powder and so on,and analyzes these sintering characteristics in-depth.The main results obtained from the experimental study on the basic properties of the high temperature of the six kinds of iron ore powders used in the earlier sintering are as follows:the six kinds of iron ore powder have high grade,four hematite powder backa powder,PB powder,Newman powder And Pakistani meal grade are more than 60%,Sandi powder and super-powder for the typical limonite,grade 57%.The assimilation of 6 kinds of iron ore powder are good,the assimilation temperature does not exceed 1250℃,to meet the conditions of low temperature sintering,the best assimilation for the di powder.The fluidity index of 6 kinds of iron ore powder at 1240℃ is more suitable for low temperature sintering.When the temperature is 1280℃,the fluidity index and the liquid phase formation rate are both higher.It is necessary to pay attention to avoid the formation of macroporous thin wall structure and try to satisfy Liquid complementary mobility with the principle of ore.The burning loss and crystallization water value of the diiron powder in the six kinds of iron ore powder are high,the burning value of the PB powder and the super-special powder are also higher,and the crystal water content of the super-powder is the highest among the six kinds of mineral powder of.The micro-morphologies of the six kinds of iron ore powders are quite different.The surfaces of Newman powder and bar flour are smoother and the water absorption capacity is poor,which is unfavorable for improving the granulation effect.Baccarat powder and PB powder rough surface,suitable for granulation.(2)The effect of alkalinity on the technical and economic indexes and metallurgical properties of sinter was studied by sintering cup experiment,and the suitable alkalinity of the mixture was given.Sinter alkalinity on the sintering of the indicators have two sides.Appropriate increase in alkalinity,sinter strength indicators,yield and fuel consumption have been improved.However,the alkalinity exceeds 2.3,and the indexes of sinter have a tendency to decrease.In this sense,the alkalinity of sinter should be appropriate,too high or too low are unfavorable to sintering production.Sinter low temperature reduction pulverization properties with the increase of sinter alkalinity increased.In a certain range,raising the alkalinity of sinter is conducive to the improvement of sinter low temperature reduction and pulverization.This also shows that the content of secondary hematite in sinter decreases with the increase of alkalinity,which reduces the transformation of secondary hematite to magnetite under low temperature and reduces the stress between sinter,Sinter low temperature reduction pulverization performance is improved.From this point of view,the alkalinity of sinter is 2.1 when the program is more appropriate.(3)In view of the high temperature characteristics of iron ore powder and the optimization of sintering alkalinity,the optimization of ore blending with iron ore was studied in depth.The influence of optimized ore blending on the technical and economic indexes of sinter and the metallurgical properties of sinter was explored.There are differences in the economic and technical indexes of sintering in the sintering cup experiment.Generally speaking,the reduction index of sinter,RI,has different degrees by optimizing the sintering with ore and changing the distribution of the refined powder of South Africa and Yangdi ore powder,Improve,sinter reduction is relatively good,there are programs 3 and 4,program 5,these three groups sinter.As a whole,the cryogenic reduction and pulverization index of sinter in each group is relatively good,which can meet the requirements of sintering production.Each group of sinter softening start temperature T10 are above 1050℃,the lowest softening start temperature is the benchmark sinter,the softening start temperature T10=1059℃,the softening temperature is relatively low due to the base of the sinter reduction performance Preferably,most of the Fe2O3 is reduced to FeO when entering the high temperature zone of more than 1000 DEG C,and part of the FeO is reduced to metallic iron,and FeO will form low-melting compounds with gangue minerals such as ferric orthosilicate or calcareous olives(Melting point 1100～1200℃)to form a liquid phase,thus reducing the softening start temperature T10 of sinter.Compared with the benchmark sinter,the softening start temperatures of the sinters of Scheme 1 to Scheme 5 all increased to some extent,The softening temperature of sinter in scheme 2 is the highest(T10=1188℃),and the sinter reduction index of scheme 2 is also the lowest,which shows that there is a significant difference between the softening onset temperature of sinter and the reduction index of sinter The negative correlation.The final softening temperature trend of each group of sinter is similar to the softening onset temperature.The lowest softening temperature is the base sinter(T40=1255℃),and the softening final temperature is the sinter(2)of scheme 2(T40=1356℃).