Chemical and Mineralogical Stabilization of Municipal Solid Waste Incinerator Bottom Ash for Recycled Material

在这项研究中，实验在两种条件下进行。第一个是为了检查润湿和干燥过程对风化的影响而进行的（测试1）。用纯水调节焚烧残渣的含水量至30%，分别在17、60和120℃烘箱中干燥。在完全干燥后，通过加入蒸馏水将它们再次润湿至30%的水含量。重复这样的过程以加速风化。在风化之后，基于日本浸出试验No.46（JLT 46;日本官方方法）和pH依赖性试验分析样品的重金属浓度，以检查它们的洗脱特性。主要实验结果如下：（1）通过反复的干湿处理，铅的浓度从19.0mg/l降低到0.01mg/l; 110℃干燥样品的铅固定化程度高于低温干燥样品，说明高温干燥对铅的固定化效果更好。(2)As X射线衍射分析结果表明，风化前的铅主要以Pb、PbS和PbSO_4的形式存在。在试验2的风化作用后，PbSO_4转变为PbCO_3。认为铅的固定化是由碳酸化作用引起的。

In this study, experiments were carried out under two conditions. The first one was carried out in order to examine the effect of wetting and drying processes on weathering(Test 1). The incineration residue, adjusted to 30% water content by adding pure water, was dried by oven set at 17,60 and 120℃, respectively. After completely drying, they were wetted again to 30% water content by adding distilled water. Such a process was repeated to accelerate weathering. After weathering, samples were analyzed for concentrations of heavy metals based on Japan leaching test No. 46(JLT46;Japanese official method), and pH dependency test in order to examine their elution characteristics. The X-ray diffraction was also carried out to identify the crystalline phases existing on the samples as a function of weathering.The main experimental results are as follows :(1)By repeating the wetting and drying process, the concentration of the lead decreased from 19.0mg/l to 0.01mg/l. The lead immobilization of the sample dried at 110℃ progressed more in comparison with the lower temperatures, which suggests that high temperature is more effective on immobilization of lead.(2)As a result of identifying lead compounds by X-ray diffraction, it was confirmed that the lead before weathering existed mainly in the form of Pb,PbS and PbSO_4 forms. After the weathering in Test 2,PbSO_4 has changed in PbCO_3. It is considered that the immobilization of lead is caused by carbonation.