光卤石中氯化钾溶解度、介穏区、诱导期测定

Determination of KCl solubility,interfacial region and induction period in carnallite

采用变温溶解动态法测定了光卤石中氯化钾的溶解度,并用简化固液平衡方程对溶解度数据做了拟合。研究了搅拌速度、降温速率对介穏区宽度以及不同过饱和度对诱导期的影响。结果表明:简化固液平衡方程能够对氯化钾溶解度拟合良好;介穏区宽度随降温速率的升高而变宽,随搅拌速度增大而变窄;诱导期随过饱和度的增大而变短,且在不同温度下,相同过饱和度下的诱导期相近。应用经典Nyvlt理论方程和3D成核原理,结合实验介穏区及诱导期数据,计算了光卤石中氯化钾的成核级数为2.46~2.51,在283.15、293.15、303.15 K条件下,氯化钾在该体系中表面张力γ为0.0198~0.5560,表面能因子f<3,结晶连续生长。

The solubility of potassium chloride in carnallite was determined by variable temperature dissolution dynamic method.Solubility data were calculated by simplified solid-liquid equilibrium equation.The effects of stirring speed and cooling rate on the width of the medial zone and the different supersaturation on the induction period were studied.The results showed that the simplified solid-liquid equilibrium equation can fit well to the solubility of potassium chloride;the width of the medial zone widens with the increase of the temperature drop rate,and becomes narrower with the increase of the stirring speed,the induction period is shorter with the increase of the supersaturation,and the induction period at the same supersaturation is similar at different temperatures.Using the classical Nyvlt theoretical equation and 3 D nucleation principle,combined with the data of experimental mediation and induction period,the nucleation series of potassium chloride in carnallite was calculated to be 2.46~2.51,and the surface tension γ of potassium chloride in the system is 0.019 8~0.556 0 at 283.15,293.15,303.15 K,the surface energy factor f<3,and the crystal grows continuously.