水洗对焚烧飞灰熔融固化过程重金属挥发的影响

打开文本图片集

中图分类号：TQ171 文献标志码：A 文章编号：1671-8755（2025）02-0040-06

Abstract：The high-temperature melting and solidification technology can effectively decompose the organic pollutants in the flyash and solidify the heavy metal elements.However，the flyash often contains Cl elements with a mass fraction exceeding 10% ，which makes the heavy metals extremely volatile during the high-temperature process.In this study，the Cl elements in the fly ash were removed through water washing，and the high-temperature phase transformation of the fly ash glass batch materials before and after water washing as well as the rules of heavy metal volatilization at high temperatures were investigated. The results show that the water washing process can remove 95% of the Cl elements in the fly ash．After theflyash glass batch materials are subjected to high-temperature heat treatment，the chlorides，sulfates and intermediate phases in them gradually disappear before water washing，and a typical amorphous glass is formed after the temperature reaches 1 200°C . The washed fly ash glass batch shows complete absence of chlorides after water washing，the carbonates in the sample decompose as the temperature rises，and all other phase transformations remain consistent with the pre-washed samples.The washed flyash glassbatch demonstratesvolatilization ratesbelow 10% for Gu ， Zn ，and Pb elements when melted at 1 300‰ .In contrast，the unwashed batch contains approximately 7% mass fraction of Cl element，which readily forms heavy metal chlorides during high-temperature melting.Thischloride formation accelerates the volatilization of heavy metals，resulting in volatilization rates exceeding 30% for Gu ， （204号 Zn ，and Pb at 1 300cC ：

Keywords： Incineration fly ash；High-temperature melting and solidfication；Heavy metal；Volatilization； Water washing

垃圾焚烧发电，具有占地面积小、减容减量高、资源利用率高等优势，已在我国大力推广应用。（剩余8104字）