Abstract:Magnesia pellets are a highquality ironmaking charge with good metallurgical properties. The most suitable equipment for their production is straight grate, but magnesium pellets have high requirements for roasting uniformity. For the production of magnesia pellets by straight grate, the Fluent tool was used to simulate the roasting process to obtain a uniform temperature field. The decomposition of magnesium carbonate and the effect of magnesium oxide on the oxidation of magnetite were considered in the model. The simulation results are verified by the grate cup experiment. The temperature accuracy of the model simulation is greater than 90%. Then, using simulation, suitable thermal conditions for the production of magnesia pellets were obtained. After optimization, the maximum temperatures of the upper, middle and lower layers of the material layer were 1179, 1202 and 1166℃, respectively, and the holding time for temperature higher than 1000℃ is 17.5, 15.4 and 15.5minutes respectively, the temperature difference of the material layer is obviously reduced, the strength of threelayer pellets is 3630N/piece, 3422N/piece and 3296N/piece, respectively, the average strength of the material layer is 3449N/piece. Compared with the thermal system determined by the laboratory tube furnace test, the pellet strength is more uniform and the average strength increases by 842N/piece.
CAO Feng,GAN Min,FAN Xiaohui,CHEN Xuling,HUANG Xiaoxian,WANG Xin.
Simulation and optimization of thermal engineering system for magnesium pellets of straight grate[J]. Journal of Iron and Steel Research, 2021, 33(4): 284-292 https://doi.org/10.13228/j.boyuan.issn1001-0963.20200150