Influence of coating MgO with coprecipitation method on sticking during fluidized bed reduction of Fe2O3 particles

• We introduce the quantitative determination method to measure actual coating amount.
• The uniformity of coating was satisfactory with this coprecipitation coating method.
• Lower precipitant solution adding speed and higher coprecipitation temperature were beneficial for coating.
• The sticking problem could be well prohibited with just 0.411 wt.% of actual coating amount of MgO.
• The coating amount of MgO on the particle didn't decrease after fluidized reduction.

Pure Fe2O3 particles were coated with MgO using coprecipitation method under different conditions. For the aim of improving the coating amount and uniformity, the coprecipitation coating method was firstly studied to avoid sticking during fluidized reduction of iron ore. The actual coating amount on the particle surface was quantitatively determined, the sticking problem during fluidizing reduction can be avoided with a MgO coating amount around 0.411 wt.%. The coating amount of MgO on the particle did not decrease after fluidized reduction. Samples were analyzed using (SEM/EDS) analysis, it was found that the MgO coating was effective and intact and merely no exposed part on the Fe2O3 particle surface. The coating uniformity was improved comparing to other coating methods. Precipitates of different crystal structures and morphology generated with different precipitation conditions tend to nucleated at the bottom part of the Fe2O3 particle as the nucleation energy there is lower.

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