Basic Research On Precipitation Of Ti-rich Phase In B₂O₃ Modified High Titanium Blast Furnace Slag

At present,the vanadium-titanium magnetite is smelted by the blast furnace ironmaking process,and most of the titanium components are difficult to extract and use in the slag,which not only brings environmental pollution but also huge waste of titanium resources.How to extract the second titanium resources and use waste slag is a serious problem in China.Based on the composition of the blast furnace slag,the simulation slag was used in this study.By adding B₂O₃ modifier,the titanium component in the high titanium blast furnace slag was enriched into anosovite.The distribution characteristics of titanium components in five yuan high titanium blast furnace slag,the precipitatio n characteristics of and the crystallization behavior of Ti-rich phase at high temperature were investigated by the theoretical thermodynamic calculation and experimental.Theoretically,during continuous cooling,four phases were predicted to form:perovskite,spinel,clinopyroxene and rutile in the Synthetic slag,and the titanium components are mainly distributed in perovskite and rutile phase.When the slag binary basicity increases,the titanium component transfers from rutile to perovskite.However,When the content of Mg and Al in slag increases simultaneously,a small amount of titanium component in slag is transferred from perovskite to rutile,and the crystalliza tio n temperature of perovskite decreases.The addition of B₂O₃ can promote the transfer of titanium component from perovskite to anosovite,At 1320,the B₂O₃ content in slag increased from 0 to 4%,and the precipitation of anosovite increased from 0 to 8.3%.And the particle size distributio n of anosovite was more homogeneous.Mg and Al are important factors affecting the precipitation of anosovite.When Mg and Al are dissolved into Ti₃O₅,the covalent property of Ti-O is stronger.The appropriate increase of（Mg+Al）content in the slag is conducive to the formation of more（Mg,Al）_xTi_（3-x）O₅ type anosovite and crystallization.The electronic structure analysis of the crystal shows that in the Mg_x Ti_（3-x）O₅（0<x≤1）,the energy band of the crystal as a whole moves in the positive direction compared to Ti₃O₅,that is,the Fermi level moves in the negative direction.The density of state analysis of Ti₃O₅,MgTi₂O₅ and CaTiO₃ shows that the valence around the Fermi level of the three crystals is contributed by the P orbital of O and the d orbital of Ti.The valence band near the Fermi level of Al₂TiO₅ is divided by the contribution of the p orbital of O and the d orbital of Ti,as well as the s orbital and p orbital of Al.The research on the crystallization behavior of the modified high titanium slag shows that,the stripe-like anosovite crystals and the perovskite crystals with an snow-like shape have their specific crystal growth paths.When perovskite and anosovite coexist,the two phases compete for growth.,and the crystal of perovskite is more easily nucleated.The growth of the perovskite crystal is controlled by nucleation.The growth of the anosovite crystal is controlled by the diffusion step.