精炼渣-粉煤灰基地聚合物固化重金属(Zn、Cd)机制研究
MECHANISM OF SOLIDIFICATION OF HEAVY METALS(Zn,Cd)BY LADLE FURNACE SLAG-FLY ASH BASED GEOPOLYMERS
刘伟 1伊元荣 2李春辉 1李洁 1迪娜·加阿拜1
作者信息
- 1. 新疆大学生态与环境学院,乌鲁木齐 830046
- 2. 新疆大学生态与环境学院,乌鲁木齐 830046;新疆绿洲生态教育部重点实验室,乌鲁木齐 830046;新疆精河温带荒漠生态系统教育部野外科学观测研究站,乌鲁木齐 830046
- 折叠
摘要
为改善重金属污染,提高固体废弃物利用率,以精炼渣(LFS)和粉煤灰(FA)为原料,氢氧化钠与水玻璃作为碱激发剂,在碱激发条件下制备地质聚合物固化重金属Zn2+、Cd2+.研究Zn2+、Cd2+掺量对固化体强度的影响,通过浸出实验评价地质聚合物对Zn2+、Cd2+的固定效果,结合XRD、SEM-EDS、FT-IR、XPS等表征方法对固定机制进行研究.结果表明:精炼渣-粉煤灰基地质聚合物与Zn2+、Cd2+具有良好的相容性,含有1.0％Cd2+固化体28 d的抗压强度可达到40.62 MPa,水化浸出实验中Zn2+、Cd2+固化率均在99.6％以上;Zn2+、Cd2+加入后固化体中不会有新相生成,且在固化过程中未发生化学价态变化.金属离子能有效地固定在精炼渣基地质聚合物中,主要通过物理包封、吸附作用,少量重金属离子则是通过化学键合,以Si—O—M和Al—O—M(M=Zn、Cd)的形式存在于固化体中.
Abstract
To improve the pollution of heavy metals and increase the utilization rate of solid waste,this study prepared geopolymers for the solidification of Zn2+,and Cd2+under alkaline excitation conditions using ladle furnace slag(LFS)and fly ash(FA)as raw materials,and sodium hydroxide and water glass as alkaline activator.The effect of Zn2+and Cd2+doping on the strength of the cured body was investigated,and the immobilization effect of the geopolymer on Zn2+and Cd2+was evaluated by leaching experiments,and the immobilization mechanism was investigated by combining the characterization methods such as XRD,SEM-EDS,FT-IR,and XPS.The results showed that the LFS-FA-based geopolymer has good compatibility with Zn2+and Cd2+,the compressive strength of the cured body containing 1.0％Cd2+for 28 d could reach 40.62 MPa,and the curing rate of Zn2+and Cd2+in the hydration leaching experiments was over 99.6％;there was no new phase generated in the cured body after the incorporation of Zn2+and Cd2+,and no chemical valence change occurred during the curing process.Metal ions can be effectively fixed in ladle furnace slag base polymer,mainly through physical encapsulation,and adsorption,while a small number of heavy metal ions exist in the curing body in the form of Si—O—M and Al—O—M(M=Zn,Cd)through chemical bonding.
关键词
精炼渣/粉煤灰/地质聚合物/重金属/固化机理Key words
ladle furnace slag/fly ash/geopolymer/heavy metal/solidification mechanism引用本文复制引用
基金项目
新疆自然科学基金资助项目(2022D01C388)
出版年
2024
NETL
NSTL
万方数据