拉筒法和静滴法测定CaO-SiO_(2)-Na_(2)O-CaF_(2)结晶器保护渣表面张力

The Surface Tension of CaO-SiO_(2)-Na_(2)O-CaF_(2) Mold Flux Measured by Pulling Cylinder Method and Sessile Drop Method

由于冶金熔渣成分和结构复杂,表面张力的数据获取往往采用实验测定的方法,但实验测定方法的选取与熔渣组成密切相关。本 文以CaO-SiO_(2)-Na_(2)O-CaF_(2)结晶器保护渣为考察对象,在1350℃、1370℃、1390℃和1410℃下分别采用拉筒法和静滴法对保护渣表面张力进 行测定。实验结果发现拉筒法和静滴法测定的熔渣表面张力随温度的演变行为一致,均随着温度的升高而下降。同一温度下采用静滴法 测得的表面张力数值高于拉筒法测得的表面张力数值,这是由于CaO-SiO_(2)-Na_(2)O-CaF_(2)渣中含有挥发成分Na_(2)O和CaF_(2),在制备预熔渣和测定表 面张力过程中均有Na_(2)O和CaF_(2)的挥发,但采用拉筒法测定高温熔渣表面张力不需制备预熔渣,而静滴法测定熔渣表面张力需提前制备预熔 渣,从而使得静滴法测得的表面张力数值高于拉筒法测得的表面张力数值。

Due to the complex composition and structure of metallurgical slag,the surface tension data is often obtained by the experimental measurement methods,but the selection of the experimental measurement method is closely related to the composition of the slag.In the present paper,the CaO-SiO_(2)-Na_(2)O-CaF_(2) mold flux is chosen,and the surface tension of the molten slag is measured by the pulling cylinder method and the sessile drop method at 1350℃,1370℃,1390℃and 1410℃,respectively.The results indicate that the change rule of the surface tension of molten slag with temperature measured by the pulling cylinder method is consistent with that measured by the sessile drop method,and the surface tension of molten slag decreases with the increasing temperature.The surface tension value measured by the sessile drop method is higher than that measured by the pulling cylinder method at the same temperature.This is because the CaO-SiO_(2)-Na_(2)O-CaF_(2) slag contains volatile components Na_(2)O and CaF_(2),and some of these components will volatilize in the process of both preparing pre-melted slag and measuring surface tension.While,the preparation of pre-melted slag is not needed in the experimental process of the pulling cylinder method,but needed in the experimental process of the sessile drop method.Therefore,the surface tension value measured by the sessile drop method is higher than that measured by the pulling cylinder method.