Preparation of Lightweight Ceramsite from Solid Waste Using SiC as a Foaming Agent

Area of Science:

• Materials Science
• Environmental Engineering
• Waste Management

Background:

• Lightweight ceramsite production often involves chemical additives.
• Solid waste utilization in construction materials is crucial for sustainability.
• Developing eco-friendly aggregates from industrial byproducts addresses waste disposal challenges.

Purpose of the Study:

• To prepare lightweight ceramsite from river bottom silt, waste oil sludge, paint bucket slag, and fly ash without chemical additives.
• To investigate the influence of silicon carbide (SiC) content and sintering temperature on ceramsite properties.
• To clarify the pore-forming mechanism and assess the environmental safety of the prepared ceramsite.

Main Methods:

• Raw materials: river bottom silt, waste oil sludge, paint bucket slag, fly ash.
• Foaming agent: silicon carbide (SiC).
• Characterization: thermal analysis, X-ray diffraction (XRD), compressive strength, water absorption, bulk density, porosity, and heavy metal leaching tests.

Main Results:

• Optimal properties achieved at 1.0% SiC and 1180 °C: compressive strength 2.15 MPa, water absorption 2.02%, bulk density 490 kg/m³, porosity 23.85%.
• Major mineral phases identified: quartz, fayalite, kyanite, and albite-low.
• Heavy metal concentrations below Chinese national standards (GB 5085.3-2007), indicating no secondary pollution.

Conclusions:

• Lightweight ceramsite can be successfully prepared from solid waste using SiC as a foaming agent.
• The developed ceramsite exhibits desirable properties for green lightweight aggregate concrete.
• This process offers an effective method for hazardous waste disposal and resource recovery.