Development and coagulation mechanism of a high accumulation, highly stable alkali-activated solidified foam for preventing the spontaneous combustion of coal.

Alkali-activated foam with 4.12 MPa strength and 57.3% improved stability effectively prevents coal spontaneous combustion and reduces harmful gas emissions.

• Why it matters: Preventing coal spontaneous combustion is crucial for reducing greenhouse gases and ensuring mine safety, yet traditional foams lack stability and stacking capacity.
• What they did: Researchers developed a high-stacking, stable alkali-activated foam using fly ash and liquid sodium silicate, optimizing properties at specific modulus and alkali content, and elucidated its setting mechanism.
• The result: The foam significantly lowered free radical levels, CO and CO2 emissions, and maintained low temperatures in field tests, enabling durable, efficient leak sealing in coal mines.