Activation behavior of the novel CO2 foaming agent for mining on fly ash

Suwan Yao; Haibo Zhang; Chao Pan; Wei Zhou; Kangkang Wang; Chengyan Hou; Chaoyang Guo; Xuemao Guan; Dinghua Zou

doi:10.1016/j.wasman.2023.08.021

Activation behavior of the novel CO₂ foaming agent for mining on fly ash

Waste Manag. 2023 Aug 27:171:32-42. doi: 10.1016/j.wasman.2023.08.021. Online ahead of print.

Authors

Suwan Yao¹, Haibo Zhang², Chao Pan³, Wei Zhou⁴, Kangkang Wang⁵, Chengyan Hou⁶, Chaoyang Guo⁷, Xuemao Guan⁸, Dinghua Zou⁹

Affiliations

¹ School of Materials Science and Engineering, Henan Polytechnic University, Henan, Jiaozuo 454003, China; Shanghai Research Institute of Building Sciences Co, Ltd, Shanghai 200030, China. Electronic address: 849946795@qq.com.
² School of Materials Science and Engineering, Henan Polytechnic University, Henan, Jiaozuo 454003, China; Henan Key Laboratory of Materials on Deep-Earth Engineering, Henan, Jiaozuo 454003, China. Electronic address: zzhb@hpu.edu.cn.
³ School of Materials Science and Engineering, Henan Polytechnic University, Henan, Jiaozuo 454003, China. Electronic address: 1282355032@qq.com.
⁴ School of Materials Science and Engineering, Henan Polytechnic University, Henan, Jiaozuo 454003, China. Electronic address: 3233216166@qq.com.
⁵ School of Materials Science and Engineering, Henan Polytechnic University, Henan, Jiaozuo 454003, China. Electronic address: 1209596039@qq.com.
⁶ School of Materials Science and Engineering, Henan Polytechnic University, Henan, Jiaozuo 454003, China. Electronic address: 3524741775@qq.com.
⁷ School of Materials Science and Engineering, Henan Polytechnic University, Henan, Jiaozuo 454003, China. Electronic address: 1125291686@qq.com.
⁸ School of Materials Science and Engineering, Henan Polytechnic University, Henan, Jiaozuo 454003, China. Electronic address: guanxuemao@hpu.edu.cn.
⁹ School of Materials Science and Engineering, Henan Polytechnic University, Henan, Jiaozuo 454003, China. Electronic address: zoudinghua@hpu.edu.cn.

PMID: 37643482
DOI: 10.1016/j.wasman.2023.08.021

Abstract

Although there have been many research results on the chemical activation of fly ash (FA) as a supplementary cementitious material (SCM) in cementitious materials. However, there is a lack of research on the use of CO₂ foaming agent (sodium bicarbonate and potassium aluminum sulfate) to activate fly ash. In this experiment, the effects of CO₂ foaming agent, sodium bicarbonate, and potassium aluminum sulfate on the activity of FA mixed paste were investigated. The mechanism of FA activation by activator was revealed by selective acid dissolution, QXRD, BSE-EDS statistical analysis, and quantitative analysis of TGA. The results showed that the remaining fly ash amounts of MG, SBG, and PASG after 28 days were 17.5%, 25.9%, and 43.3% lower than those of the control group, respectively. In addition, potassium aluminium sulphate promoted hydration to generate more CH to activate the FA. Sodium bicarbonate promoted hydration and produces more CH to activate FA by generating nano-CaCO₃. The mixture of sodium bicarbonate and potassium aluminum sulfate took advantage of both nano-CaCO₃ and potassium aluminum sulfate to promote silicate hydration to provide CH. As a result, the two synergistically activate FA. The above results show that CO₂ foaming agents can be used not only as foaming agents to prepare lightweight materials, but also as chemical activators to activate solid waste. This will have a high practical application value.

Keywords: Fly ash; Nano-CaCO(3); Potassium aluminum sulfate; Quantitative analysis; Sodium bicarbonate.