Wang Yegui, Chen Weifang, Chen Yifan, Zhang Shuyue, Deng Baoqing
School of Environment and Architecture, University of Shanghai for Science and Technology, 516 Jun Gong Road, Shanghai 200093, China.
Materials (Basel). 2025 Mar 17;18(6):1319. doi: 10.3390/ma18061319.
This research investigated the volatilization and enrichment of metallic and non-metallic elements in municipal solid waste incineration fly ash during thermal treatment. The high-temperature treatment resulted in both the volatilization and stabilization of heavy metals in fly ash. The split of volatilization and stabilization depended highly on the original speciation. The results showed that loosely bound heavy metals were the main contributors to the leaching toxicity of the raw fly ash. These metals were also easily volatilized. The volatilization of heavy metals was accompanied by de-chlorination, indicating that the loss of heavy metals may be related to the evaporation of chloride compounds. On the other hand, heavy metals that were strongly bound with the fly ash were less volatile. For the six heavy metals investigated, 42% and 58% of Cd and Pb were volatilized at 800 °C. By comparison, the volatilizations of Cu, Zn, Cr, and Ni amounted to 18-31% at the same temperature. The remaining heavy metals became more stable. Stabilization could be attributed to reactions between decomposition products; thus, new and more complicated structures, such as CaMg(SiO), CaAlSiO and CuSiO were formed. Heavy metals were incorporated into the structures and stabilized. Moreover, analyses of other elements showed that thermal treatment resulted in the enrichment of elements, including Mn, Mg, Si, and Al. This is conducive to reusing fly ash.
本研究考察了城市生活垃圾焚烧飞灰在热处理过程中金属和非金属元素的挥发与富集情况。高温处理导致飞灰中重金属的挥发和稳定化。挥发和稳定化的程度高度依赖于原始形态。结果表明，松散结合的重金属是原生飞灰浸出毒性的主要贡献者。这些金属也易于挥发。重金属的挥发伴随着脱氯过程，这表明重金属的损失可能与氯化物化合物的蒸发有关。另一方面，与飞灰紧密结合的重金属挥发性较小。对于所研究的六种重金属，在800℃时，42%的镉和58%的铅挥发。相比之下，在相同温度下，铜、锌、铬和镍的挥发率为18% - 31%。其余重金属变得更加稳定。稳定化可归因于分解产物之间的反应；因此，形成了新的、更复杂的结构，如CaMg(SiO)、CaAlSiO和CuSiO。重金属被纳入这些结构并得以稳定。此外，对其他元素的分析表明，热处理导致了包括锰、镁、硅和铝在内的元素的富集。这有利于飞灰的再利用。
