摘要
针对目前没有合理方法处置含铜污泥的问题,利用水泥窑协同处置技术对含铜污泥进行处置,以达到废物资源化的目的。通过掺入不同量的含铜污泥煅烧成水泥熟料,探讨了含铜污泥对硅酸盐水泥熟料性能及其中所含重金属的浸出对环境安全性的影响。结果表明,含铜污泥的加入明显降低了熟料的f-CaO质量分数,改善了水泥生料的易烧性。当含铜污泥掺量为4%及以下时,含铜污泥掺入会有效促进硅酸盐水泥的水化,使3、7和28 d抗压强度最高分别可达到49.85、46.85和65.8 MPa;当其掺量超过4%后,会明显抑制水泥的水化,劣化水泥水化程度,使其力学强度迅速降低。熟料各矿物相对重金属元素的固化具有选择性,含铜污泥中含量最多的Cu主要存在于中间相中,少数分布于硅酸盐相中;含铜污泥中的Cu离子可以有效固化在水泥熟料中,固化率最高可达87%。Cu离子在水泥净浆中的浸出浓度低于工业固体废弃物浸出毒性鉴别标准的规定指标,水泥窑协同处置含铜污泥在使用中不会对环境造成二次污染。本研究结果可为水泥窑协同处置含铜污泥应用提供参考。
An experimental study to handle Copper-containing sludge by cement kiln technology was presented in the paper.Cement clinker was produced with raw meal after adding various amount of Copper-containing sludge.The effects of copper-containing sludge on the properties of silicate cement clinker and the leaching of heavy metals within the sludge on the environmental safety were discussed.Results indicated that an appreciate amount of Copper-containing sludge as mixed into raw meals would improve its burnability.An proper proportion sludge would not cause clinker’s mineral compositions change,while significantly reducing its f-CaO contents.Depending on the amount of sludge as mixed into the raw meals,Copper-containing sludge had a significant effect on hydration and mechanical strength of the silicate cement.It was found that the Coppercontaining sludge would effectively promote the hydration of silicate cement when amount of sludge in raw meal was 4%,resulting in an increase of its compressive strengths,however,cement hydration would deteriorate if amount of sludge exceeded 4.0%,as a result,mechanical strength of silicate cement decreased.Curing of clinker minerals was prone to heavy metal elements,both SEM-EDS images and the split-phase extraction method confirmed that Cu elements were mainly cured as intermediate phase in the cement clinker-this curing rate could reach as high as 87%.The amount of copper ions leached in cement slurry was usually small,lower than the limit as allowed in Standard for industrial solid waste,indicating that Copper ion cured in clink is stable,and would not cause secondary pollution to the environment.This study can provide a reference for cement kiln co-disposal of Copper-containing sludge.
作者
嵇鹰
刘博鑫
蒲奋飞
李榛
冯云
JI Ying;LIU Boxin;PU Fenfei;LI Zhen;FENG Yun(College of Materials Science and Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,China;Xi'an Yaobai Environmental Protection Technology Engineering Co.,Ltd,Xi’an 710100,China)
出处
《环境工程学报》
CAS
CSCD
北大核心
2022年第6期1900-1908,共9页
Chinese Journal of Environmental Engineering
基金
陕西省重点研发计划资助项目(2019TSLGY05-04)。
关键词
含铜污泥
水泥窑协同处置
固化
抗压强度
浸出
copper-containing sludge
cement kiln co-disposal
solidification
compressive strength
leaching
