Preparation method of reverse phase change hydrogel for preventing spontaneous combustion of gangue hill

The invention discloses a preparation method of reverse phase change hydrogel for preventing spontaneous combustion of a gangue dump. The preparation method comprises the following steps: firstly, preparing a biological derived flame retardant by taking nitrilotrimethylene phosphonic acid and 3-methyladenine as raw materials; then preparing a hydroxypropyl methyl cellulose solution, adding pluronic 127 powder into the hydroxypropyl methyl cellulose solution, and uniformly stirring and mixing to obtain a precursor solution; and dropwise adding glycerol into the precursor solution, uniformly stirring at a constant speed, adding a biological derived flame retardant, uniformly stirring again, pouring into a fixed mold, and standing in a constant-temperature and constant-humidity incubator for 20-24 hours to prepare the reverse phase change hydrogel. The method is wide in raw material source, mild in reaction condition and capable of reducing the cost; according to the prepared hydrogel, the gel position of the re