烧结料面裂缝产生原因及其与点火温度的关系  

Causes of cracks in sintering material surface and its relationship with ignition temperature

作　　者：郭会良 薛玉卿[1] 玄振法 徐佳锋 李胜 GUO Huiliang;XUE Yuqing;XUAN Zhenfa;XU Jiafeng;LI Sheng(Shandong Taishan Iron and Steel Group Co.,Ltd.,Jinan 271100,Shandong,China)

机构地区：[1]山东泰山钢铁集团有限公司,山东济南271100

出　　处：《烧结球团》2024年第2期25-30,98,共7页Sintering and Pelletizing

摘　　要：为保证烧结矿具有良好的冶金性能,同时提高料层透气性,本文通过分析料面裂缝的形状、长度和生长规律,研究裂缝产生的原因及其与点火温度之间的关系,采用光学显微镜查看裂缝处烧结矿的微观组织,并对裂缝处烧结矿进行力学分析。结果表明:在一定范围内,随着点火温度的升高,裂缝条数呈增加趋势,当点火温度大于1150℃时,裂缝条数反而呈减少趋势;随着点火温度的升高,裂缝产生的位置逐渐后移,即点火温度越高,裂缝的产生时间越晚;随着点火温度的升高,烧结矿中FeO质量分数呈下降趋势,但当温度超过1150℃后,烧结矿中FeO质量分数反而呈上升趋势;裂缝处烧结矿内有大量针状铁酸钙,存在适当的晶间裂缝和孔洞,且赤铁矿含量适中,质量优于内部的烧结矿;裂缝的产生能改善料层内部空气流通,增加料层透气性,进而改善烧结矿质量。理论计算结果表明,固熔物的斥力大于引力(F引<F斥),且固相物强度小于液相表面张力(ξ<ε竖)是裂缝产生的必要条件。本文研究成果可为改善实际烧结生产提供理论依据。In order to ensure that the sinter has good metallurgical properties and improve the permeability of the bed of material,the shape,length and growth law of the cracks in the material surface are analyzed,the causes of cracks and its relationship with ignition temperature are studied,an optical microscope is used to view the microstructure of the sinter at the cracks,and a mechanical analysis is given to the sinter at the cracks.The results show that in a certain range,with the increase of ignition temperature,the number of cracks tends to increase,but when the ignition temperature is greater than 1150℃,the number of cracks tends to decrease.With the increase of ignition temperature,the location of cracks gradually moves backward,that is,the higher the ignition temperature,the later the time of cracks.With the increase of ignition temperature,the mass fraction of FeO in sinter tends to decrease,but when the temperature exceeds 1150℃,the mass fraction of FeO in sinter tends to increase.There is a lot of needle-like calcium ferrite in the sinter at the crack,there are appropriate intergranular cracks and holes,the content of hematite is moderate,and the quality is better than that of the sinter inside.The occurrence of cracks can improve the air circulation in the bed of material,increase the permeability of the bed of material,and then improve the quality of sinter.The theoretical calculation results show that the repulsive force of the solid melt is greater than the gravitational force(F attraction<F repulsion),and the strength of the solid melt is less than the surface tension of the liquid phase(ξ<εvertical),which is the necessary condition for the cracks to occur.The results can provide a theoretical basis for improving the actual sintering production.

关 键 词：铁矿烧结 料面裂缝 点火温度 化学成分 FEO 受力状态 

分 类 号：TF046.4[冶金工程—冶金物理化学]