以煤矸石为原料水热法制备4沸石的动力学研究

Dynamics Study of Using Hydrothermal Method to Prepare 4 Zeolite from Coal Gangue

以依兰矿区煤矸石为原料研究了4型沸石的合成方法及其合成动力学模型。推导出含有速率常数的分段式动力学方程;实验分析了最佳反应条件下,不同反应时间内产品的结晶度,通过待定系数法确定出各方程速率常数,整合动力学方程,最终得到利用煤矸石制备4沸石的动力学模型。采用模型方程对实验晶化曲线进行拟合,得到如下结论:4沸石结晶反应发生在凝胶后期;在晶化后期,凝胶的溶解速率决定了晶体生长速率和在有限晶化时间内产品的结晶度。

This paper discussed synthesis methods, mechanisms and dynamics models of preparing 4A zeolite using coal gangue from Yilan. The authors derived a multi-stage dynamics equation contains reaction rate constants, and analyzed crystallization degrees at the different reaction times under the best reaction condition. The final dynamics equation of producing 4A zeolite with gangue was estimated by solving reaction rate constants through undetermined coefficients method and integrating dynamics equations of the different reaction steps. After fitting crystallization curves to the dynamics equation, we concluded that crystallization of 4A zeolite was happened in the late period of gel forming, and the dissolving rate of gel controlled the crystal growing rate and the crystallization degree in a limit crystallization period.