【作者】 杨剑；

【导师】 张林栋；

【作者基本信息】 河北工业大学 ， 化学工艺， 2004， 硕士

【摘要】 本课题主要是在前人研究基础上，进行了天然斜发沸石钾钙离子交换性能的研究。主要从热力学和动力学两部分对钙型斜发沸石钾离子的交换进行了试验，研究了不同外界条件对钾钙离子交换的影响，为寻求最佳的工作条件提供了一定的理论依据。 热力学试验研究表明：钙型斜发沸石钾离子交换的全交换量为164.42meq/100g沸石，该交换反应为不完全交换。绘制了离子交换等温线和Kielland图。结果表明在一定范围内温度越高越利于钙型斜发沸石对单—钾阳离子溶液中钾的吸附。并研究了不同温度下，钙型斜发沸石对海水中钾离子的吸附，得到试验范围内50℃为最佳交换温度。根据试验数据计算得到相关的离子交换热力学函数，并通过计算结果可以得知钙型斜发沸石的钾—钙离子交换为吸热反应，在一定温度范围内反应本身可以自发进行。 动力学试验研究表明：在试验范围内反应的控制机理为液膜控制。利用浅床技术，得到不同温度、浓度和流速下的动力学数据并绘制了动力学曲线。根据动力学数据计算出不同条件下的总传质系数和有效扩散系数。以上的试验结果表明，温度和浓度的升高，有利于钾离子的交换。另外溶液流速的增大也有利于钾离子的交换，但和温度和浓度相比效果并不明显。本课题还建立了离子交换传质模型并对模型进行了验证。 本课题的研究内容既填补了国内外该研究领域的空白，也可以帮助改进现有的海水提钾技术。钙型斜发沸石海水提钾可以使海水提钾的成本大大降低，也可以简化整个工艺的流程。试验结论为海水提钾技术最终实现工业化提供了必要的补充。更多还原

【Abstract】 The task is the studies on the capability of K+-Ca2+ exchange on natural clinoptilolite, which is based on the predecessor’s research. Two parts were studied which included thermodynamics and kinetics. The effect of different surroundings on the ion exchange was investigated. All the work can help us to find the best operation conditions.In the studies of thermodynamics some conclusions had been drawn. The ability of potassium exchange was 164.42meq/100g clinoptilolite. The reaction belongs to incomplete exchange. The isotherm of ion exchange and the diag of Kielland had been got. It showed that the selectivity would be higher with the temperature increasing. The adsorption of potassium in the seawater on the Ca-form clinoptilolite was studied at different temperature and the best operation temperature was 50℃. The functions of thermodynamics had been got, which showed the reaction was endothermic and it can progress spontaneously in the experiment.The studies of kinetics showed that the exchange process was controlled by film diffusion in the conditions of experiment. By the technique of shallow bed, the data and the curve of kinetics had been got under different conditions. The KD.a and D had been calculated. The results of experiments showed the increasing of temperature and concentration was in favor of the exchange of potassium. Although the increasing of flow can also be in favor of the exchange, the effect was not notable. The mass transfer model was founded in the research, and the data got from the model could be fit for the data got from the experiments well.The task can supply the research blank of the Ca-form clinoptilolite, it also can help us to improve the technique of extracting potassium. This method can reduce the cost and cut short the circuit. In a word, this task is an indispensable complement for extracting potassium from seawater.更多还原