以CaSiO3和CaO为原料，采用固相法合成Ca2 SiO4，研究其在熔融NaOH中的熔出行为。通过正交实验，优化Ca2 SiO4在熔融NaOH中的熔出反应条件，得出最佳实验条件为：反应温度600℃，反应时间180 min，碱矿比6∶1。在优化实验基础上，考察了搅拌强度、反应温度、碱矿比对熔出过程的影响，利用液⁃固多相收缩未反应核模型研究了体系的熔出过程动力学。结果表明：Ca2SiO4在熔融NaOH中的熔出过程受固体产物层扩散控制，表观活化能为13．08 kJ／mol，得出了450～600℃实验温度范围内熔出过程的动力学方程。%With CaSiO3 and CaO as raw materials, Ca2 SiO4 was prepared by solid phase extraction at high temperature. The dissolution behavior of Ca2 SiO4 in molten NaOH was discussed. By orthogonal experiment, the optimal conditions for dissolution reaction of Ca2 SiO4 in molten NaOH were investigated and obtained, including reaction at a temperature of 600 ℃ for 180 min, with liquid/solid ratio at 6∶1. Effects of stirring speed, reaction temperature and alkali⁃to⁃ore ratio on the dissolution process were investigated based on the optimal condition tests. The kinetics of dissolution procedure was studied with unreacted shrinking core model. Results showed that the dissolution of Ca2 SiO4 in molten NaOH was affected by the diffusion through the solid product layer. The apparent activation energy was calculated to be 13. 08 kJ/mol and the kinetics model at 450~600 ℃ was expressed.
展开▼
