Effect of Agitation on Crystallization Behavior of CaO–SiO2–R2O (R = Li, Na, or K) System Characterized by Electrical Capacitance Measurement
Effect of Agitation on Crystallization Behavior of CaO–SiO2–R2O (R = Li, Na, or K) System Characterized by Electrical Capacitance Measurement
复制标题
DOI：
10.2355/isijinternational.52.2123
复制
发表时间：
2012-12
影响因子：
1.8
通讯作者：
N. Saito;Kakeru Kusada;Sohei Sukenaga;Y. Ohta;K. Nakashima
中科院分区：
文献类型：
--
作者：
N. Saito;Kakeru Kusada;Sohei Sukenaga;Y. Ohta;K. Nakashima
通过测量50 CaO-50SiO_2和45 CaO-45SiO_2 - 10R_2O（R = Li、Na或K，mol%）熔剂在液相区至低于液相线温度的较宽温度范围内的电容，系统地研究了搅拌对熔剂结晶行为的影响。众所周知，液体的电容通常比固体的电容高得多，这是由于它们各自的极化机制的差异。这些差异被利用作为一个敏感的指标，熔融硅酸钙的结晶在一个实验炉配备了电容测量系统。该系统包括Pt基合金坩埚和旋转棒，该旋转棒允许评估由连接到电容计（LCR计）的棒产生的搅拌的效果。正如预期的那样，在特定温度下，熔融硅酸钙的电容量急剧下降约三个数量级，这取决于化学成分。这表明存在结晶，并通过相应的微观结构表征证实。还发现，对于用旋转棒搅拌获得的测量，电容经历急剧下降的温度高于在没有搅拌的情况下确定的温度。这表明由旋转棒引起的搅拌效应加速了熔融硅酸钙的结晶。
The effect of agitation on the crystallization behavior of molten 50CaO–50SiO2 and 45CaO–45SiO2– 10R2O (R = Li, Na, or K, mol%) fluxes were systematically investigated by the measurement of their electrical capacitance over a wide temperature range from liquid region to well below the liquidus temperature. It is well known that the electrical capacitance of liquids is generally much higher than that of solids owing to the differences in their respective polarization mechanisms. These differences were exploited as a sensitive indicator of the crystallization of molten calcium silicates in an experimental furnace equipped with an electrical capacitance measuring system. The system comprised a Pt-based alloy crucible and a rotating rod that allowed evaluation of the effect of agitation generated by the rod, connected to a capacitance meter (LCR meter). As expected, at a particular temperature, the electrical capacitance of the molten calcium silicates underwent a precipitous decrease by roughly three orders of magnitude, which was dependent on the chemical composition. This indicated the presence of crystallization and this was confirmed by corresponding microstructural characterization. It was also found that, for the measurements acquired with rotating rod agitation, the temperatures at which the capacitance underwent the sharp decrease were higher than that identified without the agitation. This suggests that the agitation effect induced by the rotating rod accelerates the crystallization of molten calcium silicates.