城市生活垃圾焚烧底渣特性试验研究

EXPERIMENTAL STUDY ON PROPERTIES OF MUNICIPAL SOLID WASTE INCINERATION BOTTOM ASHES

以武汉市某垃圾焚烧厂的垃圾焚烧底渣为研究对象,进行了SEM扫描电镜分析、EDX检测、颗粒筛分试验、击实试验、直剪试验以分析其化学成分、物理性质、表观特征和工程特性。城市垃圾焚烧底渣是由许多小粒子团聚成的大颗粒,颗粒表面凹凸不平,主要化学元素有C、O、Ca、Si,有害元素含量少。底渣颗粒级配按照土的分类,属于粗砂,Cu=4.24,Cc=0.9。容易进行粒径调整、含泥量少。由试验结果可知:底渣击实性能较好,最优含水率为21.2%,最大干密度1.47g/cm3。抗剪指标C=7.95KPa,φ=7.0°,介于砂土和黏土之间,抗剪切能力较弱,属于良好的路基填充材料和混凝土、沥青路面的替代骨料等。

The subject of the study is waste incineration( MSWI) bottom ashes from a waste incineration plant in Wuhan. It was carried out SEM analysis,EDX analysis,particle screening test,compaction test and direct shear test. It was analyzed its chemical composition,physical properties,and the apparent characteristics and engineering properties. Municipal solid waste incineration bottom ashes were composed of many small particles with uneven surface. The principal chemical elements were C,O,Ca,Si,harmful element content was comparatively lower. Classification of particle size distribution of bottom ashes was as soil belonging to coarse sand,Cu= 4. 24,Cc= 0. 9,easy adjustment of particle size,low clay content. According to the test results,the slag compaction performance was good,the optimum moisture content was 21. 2%,and the maximum dry density was 1. 47 g /cm3. The shear index of the bottom ash,C = 7. 95 KPa,φ = 7. 0°,which were between sand and clay,with weak ability to resist shear,which was a good subgrade filling material and alternative aggregate for concrete and asphalt roadbed,etc.