The invention relates to a preparation method of a fire preventing and extinguishing material for a
coal mine and belongs to the technical field of
flame-retardant materials. The prepared fire preventing and extinguishing material for the
coal mine is water absorption gel, a large amount of
condensed water and a small amount of immobile water exist in the water absorption gel, and 2-3 water molecular
layers with the thickness of 0.5-0.6 nm are formed on the surfaces of molecules through hydrophilic hydration; the first layer is hydrated water formed by polar
ion groups and water molecules through coordination bonds or
hydrogen bonds; the second layer is a combined
water layer formed by water molecules and hydrated water through
hydrogen bonds; the gel absorbs water mainly through the interaction between internal three-dimensional space networks, a large amount of
free water is absorbed and stored in grids, and the larger the
pore diameter of the gel three-dimensional space networks is,the higher the water
absorption rate is; the water absorption gel covering the surface of the
coal body reduces the probability of contact between a coal body and
oxygen, blocks an air leakage channel, reduces the
oxygen concentration, absorbs heat for cooling and reduces the
oxidation activity of the coal, so that the prepared fire preventing and extinguishing material for the coal mine is highin fire extinguishing efficiency and high in speed.