School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, P. R. China.
School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, P. R. China.
Waste Manag. 2024 Dec 1;189:127-136. doi: 10.1016/j.wasman.2024.08.021. Epub 2024 Aug 25.
This study used the horizontal tubular heating furnace to explore the melting potential of circulating fluidized bed (CFB) incinerator fly ash and mechanical grate furnace (MGF) incinerator fly ash. The horizontal cyclone melting furnace was then built to explore further the feasibility of scale melting of MSWI fly ash. The melting characteristic temperature, amorphous content, and heavy metal leaching concentration characterized the melting potential and solidification effect of MSWI fly ash. The experimental results show that the amorphous content of CFB fly ash after melting is up to 92.37%, and the volatilization rate of heavy metals Zn, Pb, and Ni does not exceed 30%. MGF fly ash exhibits the "sintering into shells" phenomenon during heating, and the leaching concentrations of heavy metals Pb in the sintered products still exceed the standard limits. In addition, the volatilization rates of heavy metals Cu, Zn, Cd, Pb, Cr, and Ni in Slag II are above 50%, and the volatilization rate of Cr reaches 85%. So, slag's amorphous content also affects heavy metals' volatilization rate. The MSWI fly ash melting characteristic temperature decreases with the decrease of alkalinity value. When the alkalinity value drops to 0.6, the melting characteristic temperature reaches its lowest value. Mixing 80% CFB fly ash or 50% MGF bottom ash into MGF fly ash can significantly enhance the melting potential to reduce hazardous waste. When using the horizontal cyclone melting furnace to process MSWI fly ash on a large scale, MSWI fly ash achieves an excellent melting effect with an amorphous content of over 93% at the positions of the furnace middle section, inner tail cone, slag discharge outlet, and flue gas outlet. The fly ash particles are in motion in the melting furnace, so the particle size distribution affects the melting effect of MSWI fly ash.
本研究采用横管式加热炉对循环流化床（CFB）炉和机械炉排炉（MGF）炉飞灰的熔融潜力进行了探索，随后搭建了卧式旋风熔融炉，进一步探索了城市生活垃圾焚烧飞灰规模化熔融的可行性。利用熔融特征温度、非晶态含量和重金属浸出浓度对 MSWI 飞灰的熔融潜力和固化效果进行了表征。实验结果表明，CFB 飞灰经熔融后其非晶态含量可达 92.37%，且重金属 Zn、Pb 和 Ni 的挥发率均不超过 30%；MGF 飞灰在加热过程中呈现“烧结成壳”的现象，烧结产物中重金属 Pb 的浸出浓度仍超过标准限值。此外，重金属 Cu、Zn、Cd、Pb、Cr 和 Ni 在渣Ⅱ中的挥发率均在 50%以上，Cr 的挥发率达到 85%，因此，渣的非晶态含量也会影响重金属的挥发率。MSWI 飞灰的熔融特征温度随碱度值的降低而降低，当碱度值降至 0.6 时，熔融特征温度达到最低值。将 80%的 CFB 飞灰或 50%的 MGF 底灰混入 MGF 飞灰中，可以显著提高其熔融潜力，降低危险废物的产生。当采用卧式旋风熔融炉对 MSWI 飞灰进行规模化处理时，在炉膛中段、内尾锥、排渣口和烟道出口等位置，飞灰的熔融效果极好，非晶态含量均超过 93%。飞灰颗粒在熔融炉中处于运动状态，因此颗粒大小分布会影响 MSWI 飞灰的熔融效果。
