|About this Abstract
||2020 TMS Annual Meeting & Exhibition
||Characterization of Minerals, Metals and Materials
||Non-isothermal Carbothermic Reduction Kinetics of Calcium Ferrite
||Gang Li, Xuewei Lv, Xuangeng Zhou, Guishang Pei, Guibao Qiu
|On-Site Speaker (Planned)
Calcium ferrite is recognized as the ideal bonding phase with superior strength and reducibility in iron ore sintering process. In present study, the reduction behavior of CaO•Fe2O3 with graphite was studied by a non-isothermal method using thermo-gravimetric analysis coupled with mass spectrometry. Flynn-Wall-Ozawa method and Škvára-Šesták method were adopted to analyze the ‘kinetics triplet’ (activation energy, pre-exponential factor, and model function). Results indicated that the reduction process did not start until 1090 K, and the reactions shifted toward higher temperature with an increase of heating rate. The maximum reduction degree of CaO•Fe2O3 could reach 0.93 at 1473 K. X-ray diffraction measurements indicated that CaO•Fe2O3 was reduced to CaO and Fe with four steps (CF→CWF→CW3F→C2F→Fe). The apparent activation energy of CaO•Fe2O3 varied from 543.33 to 753.10 kJ/mol. The reduction of CaO•Fe2O3 can be described by 2-D diffusion model with an integral form of G(α)=[1-(1-α)1/2]2.