Study On Kinetics Of High Chromia Vanadium-Titanium Magnetite Reduction And Migration Behavior Of Valuable Elements In Lumpy Zone

High chromia vanadium-titanium magnetite, widely distributed in the world, which is polymetallic symbiotic mineral resources including Fe, V, Ti, Cr Etc., has great comprehensive utilization value. Researching achievements on high chromia vanadium-titanium magnetite in lumpy zone in blast furnace are considerably scarce. Thus, it is necessary to research kinetics of high chromia vanadium-titanium magnetite reduction and migration behavior of valuable elements in lumpy zone.Therefore, preparation experiment of high chromia vanadium-titanium pellets was researched. Secondly, non-isothermal and isothermal process of pellets reduction and migration behavior of valuable elements in lumpy zone were studied. In addition, kinetics of pellets reduction was analyzed, including non-isothermal and isothermal reduction kinetics. In this study, several conclusions are obtained as follows:(1) Researching non-isothermal reduction process between 400? and 1100? in lumpy zone, it is concluded that total reduction time is 103 minutes and final reduction rate is 51.84 percent. Reduction swelling rate of pellet decreases after increasing, while cold-state crushing strength of reduced pellet increases after decreasing.(2) Studying isothermal reduction process between 800? and 1100? in lumpy zone, it is concluded that final reduction rate increases slightly from 800? to 1000?, but increases clearly from 1000? to 1100?. Reduction swelling rate of pellet increases, while cold-state crushing strength of reduced pellets decreases from 800? to 1100?.(3) Migration behavior of valuable elements in lumpy zone is as follows:Fe2O3? Fe3O4?FeO?Fe; Fe2Ti3O9?Fe2TiO4?Fe5TiO8?Fe2TiO4?FeTiO3; FeO·V2O3 ?V2O3?VO?[V]; (Fe0.6Cr0.4)2O3?FeO·Cr2O3?Cr2O3.(4) Analyzing gas-solid non-isothermal kinetics mechanism with shrinking core model of high chromia vanadium-titanium pellets reduction between 400? and 1100? in lumpy zone, based on the reaction activation energy, the conclusion is obtained as follows: The restrictive link is internal diffusion of gas through product layer in non-isothermal reduction process.(5) Analyzing gas-solid isothermal kinetics mechanism with shrinking core model of high chromia vanadium-titanium pellets reduction and solving the resistance rate of interfacial chemical reaction and internal diffusion between 800? and 1100? in lumpy zone, the conclusion is obtained as follows:At the beginning of reaction, interfacial chemical reaction is main restrictive link. Along with reduction continuing, restrictive link changes into interfacial chemical reaction and internal diffusion. In the later period of reduction, internal diffusion is main restrictive link.