Nucleation Thermodynamics and Nucleation Kinetics of Ammonium Sulfate under the Synergistic Action of Ammonium Chloride and Ammonium Fluoride

In order to investigate the nucleation thermodynamics and nucleation kinetics of (NH₄)₂SO₄ during cooling crystallization under the synergistic effect of different ratios of NH₄F and NH₄Cl, the solubility and width of the metastable zone width of (NH₄)₂SO₄ in the mixed solution were determined by gravimetric and laser methods by incorporation of (NH₄)₂SO₄ in a mixture of different ratios of NH₄F and NH₄Cl in this study. It is demonstrated that the dissolution of (NH₄)₂SO₄ is a heat-absorbing process, that the inhibition of (NH₄)₂SO₄ nucleation by NH₄F is much greater, and that the intermediate stabilization zone of (NH₄)₂SO₄ is enlarged with an increase in the cooling rate. Based on the self-consistent Nývlt-like equation and the classical three-dimensional nucleation theory, the nucleation kinetics of (NH₄)₂SO₄ under the synergistic interaction of NH₄F and NH₄Cl was investigated, and the critical nucleation parameters of (NH₄)₂SO₄ under the synergistic interaction of NH₄F and NH₄Cl were obtained.