To realize the thermal detoxification of municipal solid waste incineration (MSWI) fly ash in a relatively mild environment, molten salts thermal treatment technology was proposed in our previous research, which showed good effects. To investigate the properties of molten salts (NaCl-CaCl₂) during cycling reusing, the change of the main components and the physical properties of the used molten salts were estimated. Results showed that the salts in fly ash would dissolve into molten salts. During this process, the concentration of K⁺, SO₄^2- kept increasing while Cl^- was decreased. The changing trend of Na⁺ and Ca²⁺ was dependent on the ratio of Ca/Na in raw fly ash. Ca(OH)₂ in fly ash would react with CaCl₂ to form CaClOH. Moreover, the introduction of the salt components on the thermal properties of molten salts were also studied. The melting point hardly changed by NaCl, CaSO₄, and SiO₂. Nevertheless, it was lowered to 431 °C with 15% CaCO₃ addition, while increased to 523 °C with 20% KCl. Besides, there were no significant influences on the viscosity, stability, and thermal diffusivity of molten salts. KCl had the greatest influence on the specific heat capacity of molten salt, with an increase of about 20%.

为了在相对温和的环境下实现城市生活垃圾焚烧飞灰的热解毒，前人研究提出了熔盐热处理技术，取得了良好的效果。为了研究循环再利用过程中熔盐（NaCl-CaCl ₂）的性质，估计了所用熔盐的主要成分和物理性质的变化。结果表明，飞灰中的盐会溶解成熔盐。在此过程中，K ⁺、SO ₄ ^2-的浓度不断增加，而Cl ^-的浓度不断降低。Na ⁺和Ca ²⁺的变化趋势取决于原料飞灰中 Ca/Na 的比例。飞灰中的Ca(OH) ₂会与 CaCl ₂反应形成 CaClOH。此外，还研究了盐组分的引入对熔盐热性能的影响。NaCl、CaSO ₄和SiO ₂几乎不改变熔点。尽管如此，添加 15% CaCO _{3 后}温度降至 431 °C ，而添加 20% KCl 时升高至 523 °C。此外，对熔盐的粘度、稳定性和热扩散率没有显着影响。KCl对熔盐比热容的影响最大，增加了20%左右。