Although municipal solid waste incineration fly ash are fine particles and a priori considered as homogeneous, they have complicated structures inside their bodies. This study quantitatively investigated two categories of heterogeneity of fly ash produced from a fluidized bed combustor. They are the heterogeneity of a single fly ash particle body (intra-particle heterogeneity) and heterogeneity among fly ash particles (inter-particle heterogeneity). In the surface and semi-soluble components, Ca has smaller intra-particle heterogeneity than Al and Si. These results and ternary diagram analysis suggest that semi-soluble components consisted of mainly Ca-based matrices such as CaCO₃ and unreacted Ca(OH)₂ in which aluminosilicate domains. All major elements, excluding Fe and Ti, are 3–66% higher inter-particle heterogeneities on the surface than semi-soluble and insoluble core components. It shows that the surface component of the fly ash is more heterogeneous than other components of fly ash particles. Fly ash from fluidized bed combustor has intra- and inter-particle heterogeneity similar to stoker combustor. Besides, heterogeneity analysis can explain the fly ash formation process. Heterogeneity analysis suggests that Si plays more critical roles in the fly ash formation process of the fluidized bed combustor than that of the stoker combustor. Fly ash has heterogeneous bodies, and it might give non-negligible impacts on the leaching of metals included in fly ash components.

尽管城市固体垃圾焚烧飞灰是细颗粒，并且先验认为是均匀的，但它们的内部结构复杂。这项研究定量研究了流化床燃烧器产生的粉煤灰的两类异质性。它们是单个粉煤灰颗粒体的异质性（颗粒内异质性）和粉煤灰颗粒之间的异质性（颗粒间异质性）。在表面和半可溶性成分中，Ca的颗粒内异质性比Al和Si小。这些结果和三元图分析表明，半可溶性组分主要由基于钙的基质组成，例如CaCO ₃和未反应的Ca（OH）₂在其中铝硅酸盐域。除铁和钛外，所有主要元素在表面上的颗粒间异质性均比半可溶性和不溶性核心组分高3–66％。结果表明，飞灰的表面成分比飞灰颗粒的其他成分更不均匀。来自流化床燃烧器的粉煤灰具有类似于斯托克燃烧器的颗粒内和颗粒间异质性。此外，非均质性分析可以解释粉煤灰的形成过程。异质性分析表明，硅在流化床燃烧器的粉煤灰形成过程中起着比炉膛燃烧器更重要的作用。粉煤灰具有异质体，对粉煤灰成分中所含金属的浸出可能产生不可忽略的影响。