A new model is proposed to estimate the density of molten slag,in which the temperature dependence of density is described by Arrhenius Law with the activation energy expressed as the linear function of optical basicity.Successful applications to the density calculations of CaO-Al2O3-SiO2 and Al2O3-CaO-MgO-SiO2 slag systems show that this formula can give a good description of composition and temperature dependence of density for molten slags.It is also found that the ionic band percentage of M-O band in MOx oxide is the intrinsic origin of the phenomenon that the slag with a high optical basicity has a large sensitivity to temperature.
Electrical conductivity of molten slag is an important physicochemical property for designing the refining process in electric smelting furnaces.Though conductivities of many slag systems have been measured,the quantitative relationships of conductivity with slag composition and temperature are still very limited.In this article,the Arrhenius law was used to describe the experimental data of conductivities for CaO-MgO-Al2O3-SiO2,CaO-Al2O3-SiO2,CaO-MnO-Al2O3-SiO2,as well as CaO-MgO-MnO-Al2O3-SiO2 systems,and it is found that activation energy can be expressed as a linear function of the content of components,where the optical basicity of slag must be within the range of 0.58 to 0.68.
The Nernst-Einstein equation is used to calculate the diffusion coefficient of calcium ion in the CaO-Al2O3-SiO2 system based on the data of the density and electrical conductivity.It is assumed that all the aluminium ions form tetrahedral structure and merge with chain or ring in the case of molar concentration of CaO higher than Al2O3.And in this case,calcium ion is assumed to be the conclusive charge carrier.A formula between the diffusion coefficient and concentration of calcium ion as well as temperature is deduced,which gives an increasing function relation between the diffusion coefficient and the concentration of calcium ions.
提供了一种新的钢液无污染脱氧的方法。对比研究了在钢液与CaO(35%)-Al2O3(55%)-MgO(10%)(质量分数)熔渣间不加电压(断路),外加电压U=0.5 V和U=1.0 V 3种条件下的脱氧情况,试验结果表明脱氧速率随着外加电压的增加而增加。此外,推导并分析了电化学脱氧的机制方程,发现可以通过增强钢液搅拌强度,加大外加电压,选择高电导率、高碱度、低黏度的渣系,降低外电路电阻等措施来加快电化学脱氧的速度。
