化学稳定剂对矿渣胶凝材料固化Pb2+的影响研究

摘要

The objective of this study was to evaluate the effect of some chemicals on stabilization/solidification of Pb2+ using cementitiou materials,mixed by blast furnace slag,silica fume and cement clinker.The samples were first mixed with sodium sulfide,thiourea,sodium dihydrogen phosphate,sodium phosphate,ferrous sulfate,ferric sulfate and heavy metal chelating agents,respectively,then with the cementitious materials.Comparison about their compressive strength,heavy metal leachability,hydration products' crystalline phases and micro-structures,were carried out on a micro-scale level by means of X-ray diffraction,sequential extraction method,electron probe microanalysis.Results showed that the addition of sulfide led to an aggregation of Pb and S,the added ferrite encouraged the hydration and compressive strength,and the heavy metal chelating agents led to the migration of Pb from unstable state to stable state.%针对化学药剂的添加对矿渣胶凝材料固化稳定化Pb“效果的影响进行了研究.首先分别采用硫化钠、硫脲、磷酸二氢钠、磷酸钠、硫酸铁、硫酸亚铁、有机重金属螯合剂对pb2进行化学稳定化,再进行矿渣胶凝材料固化.其中单一矿渣胶凝材料固化作为对比样,通过抗压强度测定、TCLP浸出、XRD、连续化学萃取、电子探针对各固化体的水化产物,Pb的化学形态迁移以及分布特征进行对比分析.结果表明:硫化物的掺入使Pb和S在水化产物中发生了聚集,铁酸盐的掺入促进了水化进程,提高了强度,螯合剂的掺入使Pb化学形态由不稳定态向稳定态发生迁移.