Alkali-Activated Materials Show Promise in Reducing Greenhouse Gas Emissions

Researchers from the China University of Mining and Technology have investigated the feasibility of integrating carbon capture and backfill in coal goaf with municipal solid waste incinerated bottom ash (MSWI-BA) and granulated blast furnace slag (GBFS). The study aimed to develop a green, low-carbon emission material for backfilling coal goaf to mitigate rock burst disasters and capture CO.

The team, led by Tian Zhang, tested the CO capture ability and mechanical strength of alkali-activated materials incorporating MSWI-BA and GBFS. The results showed that the CO capture ability increased with increasing MSWI-BA incorporation, with a 4.46 wt% CO uptake observed in samples containing 40% MSWI-BA. However, compressive strength decreased following carbonation, but the sample with the highest CO uptake showed significant compressive strengths after 7, 14, and 28 days.

Key Takeaways:

• The study aimed to develop a green, low-carbon emission material for backfilling coal goaf to mitigate rock burst disasters and capture CO.
• Alkali-activated materials incorporating MSWI-BA and GBFS showed improved CO capture ability, reducing greenhouse gas emissions by at least 51.9% compared to ordinary Portland cement.
• The research demonstrated the feasibility of integrating CO capture and backfill in coal goaf using MSWI-BA and GBFS.
• The study found that increasing MSWI-BA incorporation proportion resulted in more carbonates being generated, indicating a promising material for CO2 capture.
• The compressive strength of the samples decreased following carbonation, but the sample with the highest CO uptake showed significant compressive strengths after 7, 14, and 28 days.

Statistics:

• CO capture ability of 4.46 wt% was observed in samples containing 40% MSWI-BA.
• Compressive strength of 19.6, 20.3, and 19.7 MPa were observed in samples after 7, 14, and 28 days, respectively.
• CO emission index was at least 51.9% lower than ordinary Portland cement.

Sources:

• Alkali-Activated CO2-Capturing Backfill Material for Coal Mining Incorporating Municipal Solid Waste Incinerated Bottom Ash. ACS Omega, 2025;10(25):26776-26790.
• China University of Mining and Technology, Key Laboratory of Gas and Fire Control for Coal Mines, Xuzhou 221116, People's Republic of China.
• Government of Xinjiang Uygur Autonomous Region of China, National Natural Science Foundation of China, Priority Academic Program Development of Jiangsu Higher Education Institutions.