Simulation of the direct reduction conditions was performed in a laboratory furnace. Lump samples from natural hematite iron ore were reduced by a gas mixture of H2 and CO (H2/CO =1.5) at temperatures of 700°C, 800°C and 900°C. The effect of reduction temperature on the reduction degree, reduction rate of samples and carbon deposition were investigated and discussed in this study. The thermo-gravimetric data obtained from the reduction experiments was run in a programme that calculates the solid conversion rate. Also, three models: 1) Grain Model (GM), 2) Volumetric Model (VM), and 3) the Random Pore Model (RPM), were used to estimate the reduction kinetics of natural iron ores. It was found that the RPM model result agreed best with the obtained experimental results. Furthermore, it gave better predictions of the natural iron oxide conversion and thereby the reduction kinetics.
Turkdogan, E.T. and Vinters, J.V. (1971) Gaseous Reduction of Iron Oxides: Part II. Pore Characteristics of Iron Reduced from Hematite in Hydrogen. Metallurgical Transactions, 2, 3189-3196. https://doi.org/10.1007/BF02814971
Turkdogan, E. and Vinters, J.V. (1972) Gaseous Reduction of Iron Oxides: Part III. Reduction-Oxidation of Porous and Dense Iron Oxides and Iron. Metallurgical Transactions, 3, 1561-1574. https://doi.org/10.1007/BF02643047
Muwanguzi, J.B.A., Yunyun, W., Karasev, V.A., Byaruhanga, K.J. and Par, G.J. (2013) Investigation of Direct Reduction of Lumps from Natural Hematite Iron Ore. Research and Application of Materials, 1, 73-82.
Muwanguzi, A.J.B., Karasev, A.V., Byaruhanga, J.K. and Par, J. (2014) Effect of Different Factors on Low Temperature Degradation of Hematite Iron Ore Reduction. Metallurgical Research and Technology, 111, 57-66. https://doi.org/10.1051/metal/2014014
Muwanguzi, A.J.B., Karasev, A.V., Byaruhanga, J.K. and Par, J. (2012) Characterisation of the Physical and Metallurgical Properties of Natural Iron Ore for Iron Production. ISRN Materials Science, 2012, Article ID: 147420.