Fire accidents caused by coal spontaneous combustion
usually lead
to a large loss of coal resources and casualties. Not only that, the
greenhouse effect is polluted while the environment is polluted. At
present, the commonly used fire-extinguishing materials such as water,
inhibitors, and organic foams have the disadvantages of poor stability
and short fire-extinguishing cycles. It is difficult to effectively
suppress coal spontaneous combustion and quickly extinguish the fire
for a long time. To suppress the spontaneous combustion of coal, the
research team proposed an inorganic three-phase foam with a high foam
expansion rate, good cohesiveness, and excellent stability. In the
formulation, pulverized fly ash (PFA) is used as the matrix, sodium
dodecyl benzene sulfonate (SDBS) and α-olefin sulfonate (AOS)
are used as foaming agents, curdlan is used as the foam stabilizer,
and sodium silicate is the binder. The compound foaming agent with
the best performance is optimized, through the two-group compounding
test. The composite foaming agent’s optimal compound ratio
is SDBS/AOS (3:2). The optimal ratio of inorganic three-phase foam
(ITPF) components was obtained through the control variable method
experiment. The water–cement ratio is 5:1, the composite foaming
agent is 0.2%, the curdlan is 0.5%, and the sodium silicate is 1.6%.
In addition, it has been determined by experiments that ITPF has the
strongest foaming ability when the pH value is 9 and the temperature
is 60 °C. The fire-extinguishing performance of the new material
ITPF was investigated by thermogravimetry and coal spontaneous combustion
tendency test. It has been observed that the new material has the
effect of cooling down and isolating coal from contact with oxygen.
The results show that the new material ITPF has the potential to prevent
coal spontaneous combustion.