In this study, we estimated the growth kinetics of ammonium bicarbonate crystallized from aqueous ammonia solutions containing an impurity in the form of ammonium sulfate. The evolution of the ammonium bicarbonate concentration of seeded desupersaturation experiments, estimated by attenuated total reflection–Fourier transform infrared measurements, has therefore been fitted to a population balance model that accounts for the real speciation of the system in the computation of the solution supersaturation. Furthermore, nonidealities of the liquid phase have been considered through the extended-UNIQUAC model. In this work, it has been found that the presence of sulfate ions in solution leads to a progressive decrease in the ammonium bicarbonate crystal growth rates as the concentration of the sulfate ions increases. A competitive adsorption model based on a Langmuir-type isotherm in which the sulfate ions represent the impurity in the system has been found to describe the experimental data rather well. Moreover, the analysis of the ammonium bicarbonate crystal purity revealed that sulfate ions have been sparingly included in the crystals at the experimental conditions reported, thus indicating that the foreign species is only temporary adsorbed on the crystal surface.

中文翻译：

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通过分批结晶实验估算碳酸氢铵在氨水溶液中的生长和溶解动力学。2.硫酸盐杂质的影响†

在这项研究中，我们估计了从含有以硫酸铵形式存在的杂质的氨水溶液中结晶出来的碳酸氢铵的生长动力学。因此，通过衰减全反射-傅立叶变换红外测量值估算的种子去饱和度过高的碳酸氢铵浓度的演变，已经适合于种群平衡模型，该模型在溶液过饱和度的计算中考虑了系统的真实形态。此外，已通过扩展UNIQUAC模型考虑了液相的非理想性。在这项工作中，已经发现，溶液中硫酸根离子的存在会导致随着硫酸根离子浓度的增加，碳酸氢铵晶体生长速率逐渐降低。已经发现一种基于Langmuir型等温线的竞争性吸附模型，其中硫酸根离子代表系统中的杂质，可以很好地描述实验数据。此外，对碳酸氢铵晶体纯度的分析表明，在所报道的实验条件下，硫酸根离子很少包含在晶体中，因此表明，异物只是暂时吸附在晶体表面上。