Crystallization-Foaming Coupling in Foam Glass-Ceramics from Multi-Source Coal Power Wastes

Area of Science:

• Materials Science
• Waste Management
• Ceramic Engineering

Background:

• Large-scale disposal of coal fly ash (CFA), coal bottom ash (CBA), and desulfurization gypsum (DG) presents significant environmental challenges.
• There is a critical need for high-value utilization strategies for these industrial byproducts.

Purpose of the Study:

• To develop a synergistic method for preparing foam glass-ceramics using CFA, CBA, and DG.
• To investigate the impact of sintering temperature and DG content on material properties.
• To understand the underlying mechanisms governing the preparation process.

Main Methods:

• Sintering-foaming method was employed to fabricate foam glass-ceramics.
• Systematic investigation of sintering temperatures ranging from 1200-1230 °C.
• Varied desulfurization gypsum content from 0-5 wt.% to assess its influence.

Main Results:

• Optimal foam glass-ceramics achieved at 1220 °C with 2 wt.% DG, exhibiting a bulk density of 1.0030 g/cm³, 62.09% porosity, 9.66 MPa compressive strength, and 0.6156 W/(m·K) thermal conductivity.
• Materials demonstrated excellent chemical stability with >96% acid resistance and >98% alkali resistance.
• Leaching of heavy metals remained well below regulatory limits, confirming environmental safety.

Conclusions:

• A synergistic crystallization-foaming coupling effect was identified as crucial for optimal properties.
• Appropriate DG content (2 wt.%) enhances pore structure stability and material performance.
• This research provides a foundation for utilizing multiple power plant wastes in foam glass-ceramic production.