Phosphogypsum composite sandy soil anti-seepage material with crack self-healing property and preparation method thereof

The invention provides an ardealite composite sandy soil impermeable material with crack self-healing property, which comprises main materials and auxiliary materials, the main materials comprise the following components in percentage by weight: 10% of resin modified bentonite, 30-80% of common sand and the balance of ardealite, and the auxiliary materials are polyacrylamide polymers. The mixing amount is 1% of the weight of the resin modified bentonite; the resin modified bentonite is prepared from the following components in percentage by weight: 70 to 75 percent of sand grains with the particle size of not more than 1mm, 2 to 3 percent of sodium bentonite, 4 to 5 percent of high-molecular polymer and 15 to 20 percent of water; the high-molecular polymer is prepared from methacrylamide, acrylic acid and sodium hydroxide, and the mass ratio of methacrylamide to acrylic acid is 1: (12-13); the mass ratio of the acrylic acid to the sodium hydroxide is 1: (10.38-0.42). The invention also provides a preparation