Effects of MgCl₂ and NaCl mass fraction, stirring rate, cooling rate, and flotation reagent on metastable zone width of KCl in the aqueous system K⁺, Mg²⁺//Cl^–-H₂O were investigated by a laser method. Metastable zone width increases with a decrease in stirring rate and saturation temperature and an increase in cooling rate. Moreover, metastable zone width increases significantly with the presence of dodecyl morpholine (DMP). The effect mechanism was revealed by molecular dynamics simulation. It demonstrated that diffusion inhibition in K⁺ of DMP contributes to the increase in metastable zone width. Furthermore, the self-consistent Nývlt-like equation and classical 3D nucleation theory were employed to study primary nucleation kinetics of KCl with acceptable accuracy. The activation energies E_sat of the KCl nucleation process calculated by the self-consistent Nývlt-like equation and classical 3D nucleation theory are 14.88 and 11.91 kJ/mol, respectively. Research on metastable zone width provides a thermodynamic basis for KCl production process optimization from cold decomposition of carnallite.

中文翻译：

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KCl-MgCl2-H2O 体系中 KCl 结晶的亚稳区宽度和初级成核动力学

采用激光法研究了MgCl ₂和NaCl质量分数、搅拌速率、冷却速率和浮选剂对水体系K ⁺、Mg ²⁺ //Cl ^– -H ₂ O中KCl介稳区宽度的影响。亚稳区宽度随着搅拌速率和饱和温度的降低以及冷却速率的增加而增加。此外，随着十二烷基吗啉（DMP）的存在，亚稳区宽度显着增加。通过分子动力学模拟揭示了其作用机制。结果表明，DMP K ⁺的扩散抑制有助于介稳区宽度的增加。此外，采用自洽类 Nývlt 方程和经典 3D 成核​​理论以可接受的精度研究 KCl 的初级成核动力学。通过自洽类Nývlt方程和经典3D成核理论计算出KCl成核过程的活化能E _sat分别为14.88和11.91 kJ/mol。介稳区宽度的研究为光卤石冷分解生产KCl工艺的优化提供了热力学基础。