垃圾焚烧飞灰的熔融特性研究

以飞灰从开始熔融到熔渣全变成液体这一过程中的4个温度段所得到的熔渣为研究对象，探讨了它们的外观结构、成分、浸出毒性以及液固比、浸取液的pH值对熔渣中Ba、Cd、Ni等重金属浸出量的影响规律．结果表明：飞灰开始熔融后，随着温度的升高，熔渣的颜色逐渐变深、质地逐渐变硬、玻璃化现象逐渐明显，Ca、Al、Mg、K、Fe等主量元素的质量百分含量逐渐升高；熔融温度在1230℃以上所得到的熔渣不再是具有浸出毒性的危险废物；液固比对Ba、Zn、Cd和Ni的浸出量影响较大，而对As的影响较小；Ba、Cu、Pb和Zn等重金属元素在强酸和强碱环境下比较容易浸出．

Study on melting characteristics of MSWI fly ash

Melting tests were conducted in an electric heated furnace to study the melting properties of the fly ash sample taken from municipal solid waste incineration power plant. With temperature rising, apparent color of the fly ash got darker, vitrification phenomena got more and more obviously, and the concentrations of most elements in the samples increased gradually. The effects of liquor/solid (L/S) ratio and pH value of leaching liquor on leaching concentrations of heavy metals of the slag were analyzed. The leaching concentrations of heavy metals in the slag were increased with the increase of liquor/solid (L/S) ratio. Heavy metals in the slag could leach out easily under the acidic and alkaline condition.