生活垃圾焚烧飞灰的加速碳酸化处理

针对垃圾焚烧飞灰中钙及两性重金属含量高的特点,在高液固比(10:1)条件下对焚烧飞灰进行加速碳酸化处理以改善飞灰的理化特性.采用XRD、SEM、压汞分析以及硫酸硝酸毒性浸出方法,对加速碳酸化处理后飞灰的晶相、形貌、孔隙特征及重金属(Pb、Cu、Zn、Cd、Ni、Cr)浸出特性进行了研究.结果表明,加速碳酸化处理后飞灰中的CaClOH峰消失,而CaCO3的峰增加,且强度增加.加速碳酸化处理可以有效降低焚烧飞灰的pH值, Pb、Cu、Zn和Ni的浸出分别减少了99.7%、93.9%、90.6%和27.8%,而Cr的浸出浓度增加了29.7%.

Accelerated carbonation of municipal solid waste incineration fly ash

Because of the high Ca and amphoteric heavy metals content of the municipal solid waste incineration (MSWI) fly ash, accelerated carbonation at high liquid to solid ratio of 10:1 was investigated to improve its physical and chemistry properties. Carbonation and heavy metals (Pb, Cu, Zn, Cd, Ni, Cr) mobility were studied by applying mineral analysis, morphology analysis, porosity analysis and leaching assays. XRD analysis showed the disappearance of the CaClOH peak and the appearance of CaCO3 in the accelerated carbonated fly ash were showed. Treatment through carbonation reduced the pH of the fly ash from 12.4 to 7, and reduced the leaching concentration of Pb Cu, Zn and Ni by 99.7%, 93.9%, 90.6% and 27.8%, respectively. However, the leaching concentration of Cr increased 29.7%.