摘要
系统研究城市生活垃圾焚烧飞灰中的重金属湿法冶金浸出行为,主要包括两个过程:水洗和酸浸。研究发现,在最佳条件下,水洗可以提取出飞灰中86%Na、70%K和12%Ca,水洗飞灰在盐酸浸出时约有86%Pb、98%Zn、82%Fe、96%Cd、62%Cu和80%Al可被一次性提取出来。浸渣的主要成分为Ca2PbO4、CaSi2O5、Pb5SiO7、Ca3Al2Si3O12、SiO2。
The extraction behavior of heavy metals from municipal waste incineration (MWI) fly ash was investigated systematically. The extraction process includes two steps, namely, fly ash was firstly washed with water, and then subjected to hydrochloric acid leaching. The main parameters for water washing process were tested, and under the optimal conditions, about 86% Na, 70% K and 12% Ca were removed from fly ash, respectively. Hydrochloric acid was used for the extraction of valuable elements from the water-washed fly ash, and the optimal extraction was achieved for each heavy metal as follows: 86% for Pb, 98% for Zn, 82% for Fe, 96% for Cd, 62% for Cu, 80% for Al, respectively. And the main compositions of the finally obtained solid residue are Ca2PbO4, CaSi2Os, PbsSiO7, Ca3A12Si3012 and SiO2.
关键词
城市生活垃圾
飞灰
重金属
浸出
盐酸介质
municipal waste incineration
fly ash
heavy metals
leaching
hydrochloric acid