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测定出斜发沸石的阳离子交换容量为 192.18mmol/100g 沸石;通过 10℃、25℃、50℃、75℃钠型斜发沸石 Na+–K+离子交换等温线、温度对选择性校正系数的影响及 Kielland 图研究表明:钠型斜发沸石对钠钾混合体系中的钾具有很高的选择性,且随着温度的上升,沸石对钾的选择性下降,并回归出 Langmuir 模型;依据热力学平衡原理,导出了钠型斜发沸石 Na+–K+离子交换过程平衡常数表达式,并计算出该过程的焓、吉布斯自由能和熵变化,进一步验证该过程可自发进行,且为放热反应,低温有利于钾离子吸附。
The cation exchange capacity of clinoptilolite was determined to be 192.18mmol / 100g zeolite. The effect of temperature on the selectivity coefficient was studied by the Na + -K + ion exchange isotherm of sodium clinoptilolite at 10 ℃, 25 ℃, 50 ℃, 75 ℃ and The Kielland diagram shows that Na-type clinoptilolite has a high selectivity for potassium in the sodium-potassium mixed system. With the increase of temperature, the selectivity of zeolite to potassium decreases and returns to the Langmuir model. Based on the thermodynamic equilibrium principle , The balance constants of Na + -K + ion exchange process were derived and the enthalpy, Gibbs free energy and entropy change of the process were calculated. It is further verified that the process can proceed spontaneously and that it is an exothermic reaction, Low temperature is conducive to potassium ion adsorption.