CaO-Al_2O_3-SiO_2熔体的电导率和离子扩散系数研究  

Studies on the electrical conductivities and diffusion coefficients of ions in CaO-Al_2O_3-SiO_2 melt

作　　者：张国华[1,2] 薛庆国[1,2] 李丽芬[1,2] 李福燊[1,2] 周国治[1,2] 

机构地区：[1]北京科技大学钢铁冶金新技术国家重点实验室,北京100083 [2]北京科技大学冶金与生态工程学院,北京100083

出　　处：《北京科技大学学报》2012年第11期1250-1255,共6页Journal of University of Science and Technology Beijing

基　　金：国家自然科学基金资助项目(51174022)

摘　　要：利用光学碱度的概念,对CaO--Al2O3--SiO2体系的电导率进行了模拟,模型可以体现Al2O3的两性行为对熔体电导率的影响,以及在一定成分范围内Al2O3替代SiO2使得电导率下降的现象.通过对比分析不同离子的扩散系数,得出CaO--Al2O3--SiO2熔体中起电荷传导作用的离子主要为Ca2+;并根据模型计算的电导率以及Nernst-Einstein方程计算了Ca2+的自扩散系数.最后讨论了计算的扩散系数与通过示踪原子法测量的扩散系数之间存在差别的原因,并对"随温度的增加,偏差减少"的现象进行了理论解释.The electrical conductivity of the CaO-Al2O3-SiO2 system was modeled based on the concept of optical basicity.The model can reflect the effect of the amphoteric behavior of Al2O3 on the electrical conductivity and the phenomenon that the electrical conductivity decreases when substituting Al2O3 for SiO2.According to the comparison between the diffusion coefficients of different ions,it is indicated that the charge transport process is mainly completed by Ca2＋.The self-diffusion coefficient of Ca2＋ was calculated by the estimated electrical conductivity and the Nernst-Einstein equation.The deviation between the calculated diffusion coefficient and that measured by a tracer atom method was discussed,and a theoretical interpretation for the decrease of deviation with increasing temperature was also given.

关 键 词：炼钢 渣系 电导率 扩散系数 光学碱度 

分 类 号：TQ171.733[化学工程—玻璃工业]