摘要
锂渣是锂电行业锂盐生产过程中产生的大宗固体废弃物,其大量堆存引发的土地占用及重金属、氟化物污染风险亟待通过资源化利用途径解决。将锂渣作为辅助胶凝材料用于水泥基路面,是实现其规模化消纳的重要方向。为系统评估其资源化路径及潜在环境风险,通过设计12组配合比,结合抗压强度测试与重金属、F-浸出分析,系统对比了锂渣单掺水泥体系及锂渣复掺水泥、粉煤灰体系下路面材料的力学性能及环境风险特征。结果表明:随着锂渣掺量从4%增至20%,锂渣固化试块经28 d养护后,pH均呈碱性;锂渣固化试块的重金属Cd、Cr、Pb、As、Tl的浸出浓度均逐渐增大;锂渣固化试块的F-浸出浓度逐渐升高;实验条件下锂渣单掺水泥体系试块的抗压强度先增大后减小,锂渣掺量为8%时试块抗压强度最大,为38.70 MPa;锂渣复掺水泥、粉煤灰体系试块的抗压强度逐渐减小,锂渣掺量为4%时试块抗压强度最大,为34.45 MPa。研究显示,将锂渣掺量控制在8%以内可同时满足环境安全标准和力学性能要求,若工程应用中要求提高锂渣掺量,应优先选择复掺体系,对锂渣进行预处理,并加强对Cr和F-的针对性固化措施以及优化养护工艺。在锂渣路面材料实际应用中,建议重点关注锂渣固化材料Cr、F-等污染物进入地表水和地下水的环境风险。
Lithium slag,a bulk solid waste generated during lithium salt production for the battery industry,poses significant environmental challenges due to large-scale accumulation,including land occupation and risks of heavy metal and fluoride contamination.Utilizing lithium slag as a supplementary cementitious material in cement-based pavement construction represents a promising pathway for its large-scale valorization.This study systematically evaluates this utilization route by examining both mechanical performance and potential environmental risks.Twelve mix proportions were designed for two systems:a lithium slag-cement system and a lithium slagcement-fly ash system.Compressive strength tests were conducted,togather with analyses of the leaching concentrations of heavy metal(Cd,Cr,Pb,As and Tl)and fluoride ion(F-).The results showed that,as the lithium slag content increased from 4%to 20%,all solidified specimens maintained an alkaline pH after 28 days of curing.Leaching concentrations of heavy metals and fluoride ions increased gradually with increasing lithium slag content.In the lithium slag-cement system,compressive strength initially increased and then decreased,peaking at 38.70 MPa with 8%lithium slag content.In the lithium slag-cement-fly ash system,compressive strength decreased gradually with increasing lithium slag content,with a maximum value of 34.45 MPa at 4%lithium slag.The results indicate that controlling lithium slag content to within 8%can meet both environmental safety standards and mechanical performance requirements.For engineering applications requiring higher lithium slag contents,composite strategies should be adopted,including pretreatment of lithium slag,enhanced immobilization measures targeting chromium and fluoride ions,and optimization of curing conditions.Practical applications should also carefully consider the environmental risks associated with potential leaching of pollutants,particularly chromium and fluoride ions,into surface water and groundwater.
作者
梁瑾慧
林晔
孟棒棒
刘想
岳波
皮俊杰
LIANG Jinhui;LIN Ye;MENG Bangbang;LIU Xiang;YUE Bo;PI Junjie(School of Municipal and Environmental Engineering,Shenyang Jianzhu University,Shenyang 110168,China;Institute of Solid Waste Pollution Control Technology,Chinese Academy of Environmental Sciences,Beijing 100012,China)
出处
《环境科学研究》
北大核心
2026年第3期775-783,共9页
Research of Environmental Sciences
基金
辽宁省科技厅项目(No.2024-MSLH-403)。
关键词
锂渣
重金属浸出
F-固定
抗压强度
路面材料
lithium slag
heavy metal leaching
fluoride immobilization
compressive strength
pavement materials
