Study On The Reduction Kinetics Of Iron Ore And Crystallization Behavior Of Iron-rich Slag

Non-blast furnace ironmaking is the main direction of current research,in order to investigate the possibility of using entrained flow gasifier for iron ore reduction,High-temperature stage microscopy(HTSM)was applied to the experiment in the paper,CO was chosen for the reducing gas to investigate the reduction kinetics of iron ore and crystallization behavior of iron-rich slag.HTSM was used for the experiment.EDS was used for analysis of elements to determine the reduction degree.By drawing the image of reduction degree versus reduction time,activation energy E of FeO?Fe was obtained,E=109.6kJ/mol.In order to get the mechanism function f(a),activation energy E and pre-exponential factor A,models matching was used to analyze the experimental data.f(?)=1-?,E=103.3kJ/mol and A=38.86s-1.The CO-Reduction kinetics equation of iron ore was established.Shenfu coal was chosen as raw material to make the slag with 20%,30%and 40%Fe2O3.HTSM was applied to observe the crystallization process of different cooling rate.X-ray diffraction(XRD)was used to determine the crystalline phases and Factsage was used to predict solids in equilibrium in high temperature.As the iron oxide concentration increased,precipitation of crystal was promoted and incubation time of crystals was reduced,the initial precipitation temperature of crystals was increased and the size of crystals was larger.The iron in crystals was increased and the crystalline phase was changed from gehlenite to esseneite when the Fe2O3 content reached 20%,magnetite was precipitated when the Fe2O3 content was more than 30%.It was agreed with the results of Factsage.