8th International Congress on Science and Technology of Ironmaking - ICSTI 2018

Canadian hematite acid pellet with low magnetite content fluxed and olivine were isothermally reduced with hydrogen and carbon monoxide at 600 to 1000℃. The course of reduction was investigated by measuring the oxygen weight loss as a function of time using a thermogravimetric analysis. Macroscopic and microscopic examination, X-ray and carbon analyses were also used to elucidate the mechanisms of reduction of pellet. For CO atmospheres, CO content in mixture can stimulate carbon deposition behaviors in pellet reduction procedure and carbon deposition leads to the fracture of pellet at the low temperature. For H2 atmospheres, temperature from 600 to 700 and from 900 to 1000 oC have more influence on reduction fraction than one from 700 to 900 oC due to dense microstructures of pellet forming in the latter. Reduction of Fe2O3 to Fe3O4 is fastest and reductions of Fe3O4 to FeO and FeO to Fe happen at the same time. Pellet reduced by CO has porous structures, while pellet reduced by H2 has a dense product layer on the surface.