Work

Effects of Steel Slag and Ethylenediaminetetraacetic Acid (EDTA) on Enhancing the CO2 Sequestration Performance of Gangue-Based Cemented Backfill Materials

Year: 2025

Type: article

Abstract: To enhance the support capacity of cemented paste backfill (CPB) in goaf areas and its ability to sequester CO2, steel slag and ethylenediaminetetraacetic acid (EDTA) were incorporated into gangue-based cemented backfill materials. A stress–carbonation-coupled reaction system was employed to carbonate the CPB, and the effects of steel slag and EDTA on compressive strength, CO2 uptake, and microstructure were studied. The findings indicate that steel slag remarkably enhanced the performance of the CPB, with both strength and CO2 uptake initially increasing before declining as steel slag content increased. The optimum performance was achieved at a steel slag content of 10%. The incorporation of EDTA further enhanced the compressive strength and CO2 uptake, with the best results at 0.5 g/L. Microstructural analyses demonstrated that steel slag increased the availability of Ca2+ and Mg2+ in the cement paste system, while EDTA accelerated their leaching, promoted hydration products, and catalyzed carbonation via chelation. However, excessive steel slag or EDTA reduced hydration products and deteriorated material performance. This work may provide a reference for enhancing the properties of CPB and promoting the efficient utilization of coal-based solid wastes.

Source: Materials

DOI: 10.3390/ma18214852

Authors: Xinying Li, Dan Kang, Zejun Li, Nan Zhou, Qian Chen

Institutions: China University of Mining and Technology, Yankuang Energy Group Company Limited (China)

Language: English

Topic: Tailings Management and Properties

Subfield: Civil and Structural Engineering

Field: Engineering

Domain: Physical Sciences

SDGs: Responsible consumption and production, Climate action

Open Access status: gold

Estimated APC paid: $3,137