Study on the Strength and Microstructure of Coal Gangue Concrete Using Sulfurized CO 2 Composite Gas and Steam Carbon Fixation

Huanjie Su, Hailong Wang (), Qingfu Li and Wengyan Zhang
Additional contact information
Huanjie Su: College of Water Conservancy and Civil Engineering, Inner Mongolia Agricultural University, Hohhot 010018, China
Hailong Wang: College of Water Conservancy and Civil Engineering, Inner Mongolia Agricultural University, Hohhot 010018, China
Qingfu Li: College of Water Conservancy and Civil Engineering, Inner Mongolia Agricultural University, Hohhot 010018, China
Wengyan Zhang: College of Water Conservancy and Civil Engineering, Inner Mongolia Agricultural University, Hohhot 010018, China

Sustainability, 2024, vol. 17, issue 1, 1-17

Abstract: Addressing the complex physicochemical properties of coal gangue from typical mining areas in Inner Mongolia, this study focuses on this area’s abundant reserves coupled with the low utilization rate and significant strength variability of ecological slope protection materials. Notably, research on the alkalization–carbonization of coal gangue remains scarce. To bridge this gap, we propose a method leveraging the moisture migration behavior of coal gangue porous media. By utilizing continuous displacement high-temperature steam carbon sequestration enhancement technology, internal moisture is gradually and precisely controlled to induce the formation of high-temperature carbonic acid gas. This process facilitates internal carbon sequestration and effectively locks in the sequestration effect. This approach enables effective loading of sulfurized CO 2 composite gases in a reversible manner, achieving passive carbon sequestration driven by moisture migration. Consequently, it enhances the negative carbon content within the aggregates while bolstering their mechanical properties. After alkalization pretreatment with various concentrations and three hours of carbon sequestration, the microhardness of the aggregate surface and transition zone were observed to have increased by 24.3% and 36.4%, respectively. Additionally, the compressive and splitting tensile strengths of coal gangue concrete rose by 4.8 MPa and 0.4 MPa, respectively, while porosity decreased by up to 3.6%, and the proportion of harmful pores dropped from 11.22% to 6.54%. A strong correlation between the proportion of harmless/low-harm pores and strength development was observed. Overall, the high-temperature carbonic acid steam displacement method with sulfurized CO 2 composite gases effectively improves the physicochemical properties of coal gangue aggregates and enhances surface activity and hydration in the interface transition zone, meeting the engineering standards for in situ ecological remediation in Inner Mongolia’s mining areas.

Keywords: coal gangue; concrete; carbon sequestration; porosity character; hydration performance (search for similar items in EconPapers)
JEL-codes: O13 Q Q0 Q2 Q3 Q5 Q56 (search for similar items in EconPapers)
Date: 2024
References: View references in EconPapers View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/2071-1050/17/1/243/pdf (application/pdf)
https://www.mdpi.com/2071-1050/17/1/243/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jsusta:v:17:y:2024:i:1:p:243-:d:1558106

Access Statistics for this article

Sustainability is currently edited by Ms. Alexandra Wu

More articles in Sustainability from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().