| The redution rates of synthetic chromites consisting of FeO and Cr₂O₃ using graphite powder as a reductant have been measured by means of thermo-balance under Ar atmosphere at the temperature range of 1050˚∼1250℃. The synthetic chromites mixed with graphite of 20 w/o and bentonite of 3 w/o were shaped into briquette(10㎜ in dia. and 10㎜ in height) under 3 ton/㎠ pressure. From the comparison between the results of the experiment and the calculated values from Fick`s diffusion rate equation on the isothermal reduction of synthetic chromite, it can be concluded that the reaction rates of iron and chromium ion are controlled by diffusion process up to 70% reduction degree. Diffusion coefficients of iron or chromium ions For the sample CF1, CF2, and CF3(FeO/Cr₂O₃ mole ratio =1/1, 2/1, and 1/2, respectively) was 10^(-10)㎠/sec and the apparant diffusion coefficients could be expressed as 0.0674 exp(-55,447/RT) for sample CFl, 0.075exp(-51,955/RT) for CF2, and 1.971×10⁴exp(-89,176/RT) for CF3 using Arrhenius typ plotting, respectively. |
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