OU Jinchen^a,b,LIU Qing^a,b,HEI Fuqian^b,ZHAO Guodong^c,JI Weijie^b,YANG Haozhen^b

(a.Hunan Provincial Key Laboratory of High Performance Special Concrete,b.School of Civil Engineering, c.School of Resource Environment and Safety Engineering,University of South China,Hengyang 421001,China)

Abstract：Geopolymer is a new type of gel material,which mainly solidifies heavy metals by physical adsorption or chemical encapsulation.Using iron ore tailing sand and S-95 slag powder as raw materials to prepare geopolymer to solidify heavy metal Pb²⁺ under the action of alkali activator.The effect of factors on the compressive strength of geopolymer was investigated by orthogonal test and the influence of the Pb²⁺ content on the compressive strength was studied.The curing effect and mechanism were studied by toxic leaching test and characterization by XRD and IR.The results show that when the mass ratio of tailing sand to S-95 slag powder is 3∶7,the modulus of sodium silicate is 1.1,the alkali solid ratio is 0.25,and the water solid ratio is 0.25,the compressive strength of the geopolymer 28 d can reach 47.1 MPa.When the mass fraction of Pb²⁺ is 0.5%,the curing effect can reach more than 98% in all three leaching solutions.Pb²⁺ affects the net structure of the geopolymer with weak chemical bonding interaction and exists in a non-crystalline form rather than bonds into the skeletal structure.

Keywords：geopolymer;lead ion;curing;tailing sand;slag powder

Get Citation: OU J C,LIU Q,ZHAO G D,et al.Properties and mechanism of lead ion solidification with tailing sand-S-95 slag powder geopolymer[J].China Powder Science and Technology,2023,29(3)：127-134.

Received： 2022-12-26,Revised：2023-02-02,Online：2023-04-23 17:10。

Funding Project：湖南省高校创新平台开发基金项目,编号：20k111;湖南省教育厅重点项目,编号：21A0286。

First Author：欧津辰(1997—),男,硕士研究生,研究方向为固废处理。E-mail：983275135@qq.com。

Corresponding Author：刘清(1979—),女,博士,教授,硕士生导师,研究方向为矿冶工程污染控制与资源化。E-mail：liuqing197901@163.com。