Effect of silica on crystallization process of calcium ferrite:thermodynamic and kinetic analysis  

作　　者：Xu-chao Wang Cheng-yi Ding Xue-wei Lv Hong-ming Long Yu-xi Wu Feng Jiang Ren-de Chang Sheng Xue Qing-lin Chen 

机构地区：[1]Key Laboratory of Metallurgical Emission Reduction&Resources Recycling,Anhui University of Technology,Ministry of Education,Ma’anshan,243002,Anhui,China [2]School of Metallurgical Engineering,Anhui University of Technology,Ma’anshan,243032,Anhui,China [3]School of Materials Science and Engineering,Chongqing University,Chongqing,400044,China

出　　处：《Journal of Iron and Steel Research International》2024年第12期2893-2902,共10页钢铁研究学报(英文版)

基　　金：This work was supported by the National Natural Science Foundation of China(52204331);Natural Science Foundation of Anhui Province Youth Project(2208085QE145);the Open Project Program of Key Laboratory of Metallurgical Emission Reduction&Resources Recycling(Anhui University of Technology),Ministry of Education(JKF20–03).

摘　　要：SiO_(2)is the main component of gangue in sinters and a crucial constituent in the formation of the SiO_(2)–Fe_(2)O_(3)–Cao(SFC)system.The non-isothermal crystallization kinetics of the SFC system were investigated using differential scanning calorimetry.The crystallization process of SFC was studied under different cooling rates(5,10,15,and 20 K/min),and the crystalline phases and microstructures of the SFC crystals were verified through X-ray diffraction and scanning electron microscopy.The results indicate that when the SiO_(2)content is 2 wt.%,increasing the cooling rate promotes the precipitation of CaFe_(2)O_(4)(CF)in the SFC system,thereby inhibiting the precipitation of Ca_(2)Fe_(2)O_(5)(C_(2)F).In contrast to the Cao–Fe_(2)O_(3)(C–F)system,the addition of SiO_(2)does not alter the precipitation mechanisms of C_(2)F and CF.By further adding SiO_(2),the precipitation of Ca_(2)Sio_(4)(C_(2)S)significantly increases.Simultaneously,the Cao content in the liquid phase decreases.This leads to the crystallization process of the CF_(4)S(4 wt.%Sio_(2))system bypassing the precipitation of C_(2)F and directly forming CF and CaFe_(4)O_(7)(CF_(2)).In the case of the CF_(8)S(8 wt.%SiO_(2))system,the crystallization process skips the precipitation of C_(2)F and CF,directly yielding CF_(2).The crystallization process of both CF_(2)S(2 wt.%Sio_(2))and CF is similar,comprising two reaction stages.The Ozawa method was used to calculate the activation energy for the crystallization of C_(2)F and CF as-329 and-419 kJ/mol,respectively.Analysis using the Malek method reveals model functions for both stages.

关 键 词：SILICA Calcium ferrite Sinter Cao–Fe_(2)O_(3)–SiO_(2) system Differential scanning calorimetry CRYSTALLIZATION 

分 类 号：TF123.5[冶金工程—粉末冶金] O642.1[冶金工程—冶金物理化学]