The Study Of Kinetics And Mechanisms Of Iron Ore Direct Reduction In Retort

Direct reduction iron is belonged to non-blast furnace iron-making, which hasmany potential advantages, and been more attention in recent years. The temperatureof direct reduction is low, and the dynamics are poor, so the sponge iron productionis severely affected. Therefore, according to similar principles, we determined ourlaboratory model of the reaction tank and the one-dimensional mathematical model,to restore the process of iron ore concentrate in-depth study from the point of view ofthe experimental and numerical simulation of the reaction tank.We setup the laboratory model and rule of charge. The charge was heated upfrom room temperature to1100℃,then kept warm for2hours in a resistor furnace.We found that there was a certain temperature field in the radial orientation, and itshows a low-high-low tendency. Through the X-Ray Diffraction (XRD) andchemical composition analysis, we know that exist for temperature field lead tovolatility of rate of the reducing-reaction. The rate of reduction was emerged "V"tendency. Simultaneously, we found swelling of iron ore in the reduction process.We had observed the surface changed obviously and whisker of iron by ScanningElectron Microscope (SEM). And we give a reasonable explanation to swell usingknowledge of crystallography and Heat Transfer. At the same time, we set up an one-dimensional mathematical model of thecylindrical coordinate system, and discrete equations by controlling the volumebalance method, the reduction process was simulated using MATLAB software. Thethermal conductivity of coal particles on the temperature field in the reaction tank;along the radius, the reduction degree of rendering of "U" changes,"U" font wide,means iron ore layer center to restore the lower and the wider the dark areas of thesponge iron center; only near the heat source at the coal particles, the gasificationreaction is happened, where the temperature curve decreased resulting in consistentwith the neighboring temperature curve intersects with the experimental data.Finally, this model is used in the reduction process of the reaction tank and theprocess parameters were predicted. Carried out numerical experiments on thereducing agent and crucible material, and results show that the selection of highthermal conductivity reducing agent and the crucible is beneficial to the reductionprocess, of course, we have to consider the volatile content of the reducing agent, thefixed carbon content, as well as the crucible of life factors such as.