Study On Sintering Ore-forming Mechanism Of Vanadium-titanium Magnetite In Chengde

Vanadium-titanium magnetite is very significant iron ore resources in our country. There are poor knot strength,low yield in the sintering process of vanadium-titanium. Especially, the sintering and blast furnace production targetsare difficult to improve due to RDI particularly serious. We studied the vanadium-titanium magnetite sinteredmechanism by means of HSC Chemistry6.0and FactSage6.4combined with experimental results. Base on it, we gotthe theoretical basis of improving the quality of vanadium and production practice guidance.The results showed that the combination of vanadium-titanium magnetite TiO2and CaO better than Fe2O3. Therewere difficulties in the process of generating high-quality calcium-based material and the higher temperature was morebenefit to the combination TiO2and CaO. The perovskite was sintered by solid-phase reaction and presented in thebinder phase in solid state. The content of SiO2of vanadium-titanium magnetite was low and the amount of silicatematerial generated was small. There were many reasons causing poor vanadium-titanium magnetite sinter quality. Themainly were many perovskite content, about50%of the number of the ordinary binding phase and a small quantity ofcalcium ferrite.We found that a maximum amount of liquid phase volume of Chengde ordinary flour being up to82.58%and aleast one of Montengro powder only78.88%by calculating the amount of vanadium-titanium generated liquid phase.In the sintering process of mixed ore, the liquid phase volume increased with the increasing temperature, alkalinity andcarbon content but it reduced with the increasing TiO2content. The perovskite generation seriously affected the amountof other liquid in vanadium-titanium sintering process. Then it caused the liquid phase decreased and affected thequality of sintered ore.From the sintering experiments it can be seen that vanadium-titanium sintered quality indicators were lower thanordinary ore, such as, yield, drum index and RDI index. Furthermore RDI was most serious and it did not meet therequirements of blast furnace. Through the mineral phase analysis, we also found that there were more holes andsecondary hematite and skeletal crystalline hematite in the sintering process of vanadium-titanium. There was a greaterstress when Fe2O3into Fe3O4.Perovskite has many features as hard texture, no binding effect and dispersed in sinteredore. The crack propagation was exacerbated and played a catalytic action for chalking when the crack reachesperovskite in the reduction process of Fe2O3. The root cause of vanadium-titanium magnetite reduction powder wereFe2O3expansion, small amounts and poor quality of bonding phase and the powder increased in the sintering process.