Effect of limonite on morphology and micro-area composition of sinter calcium ferrite
In order to explore the influence of limonite ratio change on the morphology and micro-area composition of sinter calcium ferrite,and to clarify the change trend of drum strength performance of sinter when the limonite ratio increases,the FactSage 7.1 thermodynamic simulation software was used to calculate the adhesion powder con-tent and liquid phase formation performance of mixed ore under different limonite ratio conditions.At the same time,the mineralogical characteristics of sinter and the micro-area composition of calcium ferrite were investigated by using the mineral phase microscope combined with OIA automatic mineral phase system and EPMA electron probe according to the different micro-morphological characteristics of calcium ferrite.The results show that the binder phase of sinter is mainly composed of calcium ferrite and silicate.The morphology of calcium ferrite is mainly needle columnar,supplemented by fibrous.The fibrous calcium ferrite is mainly formed in the early stage of the formation of calcium ferrite,which has the characteristics of high content of SiO2 and low w(Fe2O3)/w(CaO).With the devel-opment of the binder phase of calcium ferrite,the content of Fe2O3 component increases and w(Fe2O3)/w(CaO)increases,which promotes the development and growth of calcium ferrite grains and forms needle columnar.When the proportion of limonite increases from 33%to 50%,the content of adhesion powder decreases by 2.16%due to the increase of 21%of the proportion of coarse-grained LB ore.Thermodynamic theory simulation shows that the amount of liquid phase produced by unit mass adhesion powder decreases by 0.25%and w(Fe2O3)/w(CaO)decreases by 0.3,indicating that the increase of limonite ratio is not conducive to the formation and development of calcium ferrite in sinter.The thermodynamic simulation results are consistent with the actual sintering results.The total amount of calcium ferrite in the actual sinter is reduced by 7.75%,of which the content of needle columnar cal-cium ferrite is reduced by 9.78%.The w(Fe2O3)/w(CaO)in needle columnar calcium ferrite is reduced by 0.68,which weakens the development of needle columnar calcium ferrite grains to a certain extent.The morphology of cal-cium ferrite is mostly fine fibrous calcium ferrite,and the development of calcium ferrite is limited,which eventually leads to the adverse effect on the drum strength of sinter.
NETL
NSTL
万方数据
