Based on breakthrough theory and fractal porous medium theory (FPM), the paper investigates the modelling mechanism of Ca²⁺ removal in dicyandiamide by dynamic ion exchange. In this work, parameters within consideration included the flow rate of dicyandiamide crystallization mother liquor, the height‐diameter ratio of the resin layer, and the temperature on Ca²⁺ exchange. It was found that the removal efficiency of Ca²⁺ reached 97.32%. Meanwhile, the through function of the process was obtained, and the behaviour of the dynamic process was modelled and simulated. In addition, using FPM theory, the calculation equation of the spectral dimension of the fractal surface of the resin in the ion exchange process was observed as linear and a mathematical model was established. This paper analyses the dynamics equation of the ideal surface and the fractal surface. According to the analytic results, it was linear relation on the ideal surface and power function on the fractal surface.

中文翻译：

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动态离子交换法模拟双氰胺去除Ca2 +的机理

基于突破理论和分形多孔介质理论（FPM），研究了通过动态离子交换去除双氰胺中Ca ²⁺的建模机理。在这项工作中，需要考虑的参数包括双氰胺结晶母液的流速，树脂层的高径比和Ca ²⁺交换温度。发现Ca ²⁺的去除效率达到97.32％。同时，获得了过程的贯穿函数，并对动态过程的行为进行了建模和仿真。另外，利用FPM理论，观察了离子交换过程中树脂分形表面光谱尺寸的计算方程为线性，并建立了数学模型。本文分析了理想表面和分形表面的动力学方程。根据分析结果，它是理想表面上的线性关系和分形表面上的幂函数。