Effect of Coating MgO on Sticking Behavior during Reduction of Iron Ore Concentrate Fines in Fluidized Bed

摘要

The effect of coating MgO with different methods on sticking behavior during the reduction of iron ore fines was investigated, at 1073 K with 70%CO-30%H_2 gas mixture in a visualization fluidized bed. It was found that coating MgO on particle surface could extend fluidization time from 12 min to more than 80 min, and improve the degree of metallization from 22% to more than 80%. The expansion level of bed after defluidization could also be obviously decreased. To achieve a similar effect, the initial coating content with solution method was less than that with powder method. The reason was that coating MgO could effectively insulate the contact of metallic iron on particle, which provided the reaction time for carbon deposition and the production of Fe_3C with low stickiness. Therefore, the decrease of metallic iron on particle surface led to the decrease of particle stickiness at high temperature.