Research On The Influence Of The Mineralization Process Of Vanadium Titanium Sinter On Quality

The low mechanical strength,low yield and high return amount of vanadium titanium sinter directly affect the further strengthening of blast furnace smelting.How to make rational use of domestic vanadium and titanium magnet resources in order to improve the metallurgical properties of sinter and ensure the smooth operation of blast furnace is an urgent problem to be solved in domestic ironmaking process at present.According to the study on the phase structure of vanadium titanium sinter on site,perovskite appears in the high-titanium type sinter.Perovskite not only weakens the crystal connection of iron oxide,but also reduces the formation of bonding phase,resulting in the deterioration of low-temperature reduction degradation of high-titanium type sinter.For titanium sinter temperature reduction desintegration problem,also in this study using polarizing microscope and X-ray diffraction of titanium in the sinter reduction before and after the ore phase structure,the system of quantitative study found that before the reduction,microstructure has the typical mixed corrosion structure,titanium,hematite calcium ferrite as main metal respectively and binder phase,skeletal shape titanium hematite concentrate;After the reduction at 500 ?,the microstructure was dominated by granular structure,titanium magnetite was the main metal phase,calcium ferrite in the bonding phase was significantly reduced,and stomata and cracks were significantly increased.It can be seen that during the transformation from titanium hematite to titanium magnetite,the transformation of crystal structure causes volume expansion.After reduction,stomata increased obviously,and the microstructure changed obviously,from interlacing corrosion structure to granular structure.In view of the influence of the mineralization process on the quality of vanadium titanium sinter,vanadium titanium sinter with different temperature gradients was made by the laboratory.With the increase of temperature,various phases of the sinter were melted and decomposed one after another,forming compounds with low melting point and eutectic mixtures,which then became liquid phase.With the decrease of temperature,the sinter liquid phase began to cool down and crystallize,gradually forming various minerals.Among them,the amorphous/skeletal titanium hematite is mostly found in the heating section 1280?1400?,the low-melting point minerals are mostly formed in the heating section 900?1150?,and the corrosion structures with good metallurgical properties are mostly found in the cooling section 1200?1100?.In order to improve the quality of sinter,it is suggested that in the sintering production,in order to reduce the excessive formation of the content of the amorphous/skeletal metal phase,the sintering time at high temperature should be reduced,so as to improve the performance of reduction degradation.Similarly,in order to produce a corrosion structure with good metallurgical properties,the sintering time at low temperature should be increased,which can improve the quality of sinter.Figure 29;Table 23;Reference 78.