The Influence of Retreated Lithium Slag with a High Content of Alkali, Sulfate and Fluoride on the Composition and the Microstructure of Autoclaved Aerated Concrete

Dongqing Zhong; Shihong Wei; Hao Zhou; Xiaohang He; Binbin Qian; Bing Ma; Yueyang Hu; Xuehong Ren

doi:10.3390/ma17112569

The Influence of Retreated Lithium Slag with a High Content of Alkali, Sulfate and Fluoride on the Composition and the Microstructure of Autoclaved Aerated Concrete

Materials (Basel). 2024 May 27;17(11):2569. doi: 10.3390/ma17112569.

Authors

Dongqing Zhong¹, Shihong Wei¹, Hao Zhou², Xiaohang He¹, Binbin Qian³, Bing Ma², Yueyang Hu^{1

4}, Xuehong Ren⁴

Affiliations

¹ College of Materials Science and Engineering, Yancheng Institute of Technology, Yancheng 224000, China.
² Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment of the People's Republic of China, Nanjing 210042, China.
³ School of Chemistry and Environmental Engineering, Yancheng Teachers University, Yancheng 224002, China.
⁴ State Key Laboratory of Green Building Materials, China Building Materials Academy, Beijing 100024, China.

Abstract

In this paper, the possibility of retreated lithium slag (RTLS) with a high content of alkali, sulfate and fluoride as a partial replacement for fly ash (FA) to produce autoclaved aerated concrete (AAC) was investigated. The influence of the RTLS dosage on the AAC performance were examined. The composition and microstructure of hydrates as well as the microstructure of the RTLS-FA-based AAC compositions were determined by XRD, FTIR, TG-DSC and SEM. The results illustrated that the incorporation of RTLS changed the crystal structure and the microstructure of the tobermorite. With increased RTLS contents, the morphology of tobermorite was changed, and the grass-like tobermorite gradually transformed into network-like tobermorite. The newly formed tobermorite improved the mechanical performance of the AAC. Compared with the RTLS10, the content of tobermorite in the RTLS30 increased by 8.6%.

Keywords: autoclaved aerated concrete; retreated lithium slag; tobermorite.

Grants and funding

The authors are grateful for the financial support of the National Key Research and Development Program of China (2019YFC1907103), the National Natural Science Foundation of China (52300175), the Natural Science Foundation of Jiangsu Province of China (BK20220701), the Jiangsu Provincial Key Research and Development Project (No. BE2020630), the Postgraduate Research and Practice Innovation Program of Yancheng Institute of Technology (SJCX21-XY024), the special fund project for transformation of scientific and the special fund project for the development of strategic emerging industries in Jiangsu Province ([20176]1594-41).