Magnesium phosphate-based cement grouting material, preparation method therefor and use thereof

A magnesium phosphate-based cement grouting material, wherein raw materials of the magnesium phosphate-based cement grouting material comprise a component A and a component B;

• wherein, the component A comprises the following raw materials in parts by weight:
• 140-200 parts of calcined magnesium oxide, 0-30 parts of bentonite, 0.2-0.5 part of hydroxypropyl methyl cellulose, 1-10 parts of additive and 70-140 parts of water;
• the component B comprises the following raw materials in parts by weight:
• 70-100 parts of first dihydric phosphate, 20-50 parts of pretreated polymer water-absorbent resin, 0.5-2 parts of sodium polyacrylate and 30-70 parts of water;
• the calcined magnesium oxide is prepared by compounding lightly calcined magnesium oxide and heavily calcined magnesium oxide in a mass ratio of (2-4):1;
• the additive comprises at least one of a defoaming agent and a water reducing agent;
• the pretreated polymer water-absorbent resin is obtained by soaking a polymer water-absorbent resin in an aqueous solution of second dihydric phosphate;
• the first dihydric phosphate and the second dihydric phosphate are both at least one of ammonium dihydrogen phosphate, potassium dihydrogen phosphate and sodium dihydrogen phosphate;
• and a molar ratio of magnesium to phosphorus in the calcined magnesium oxide and the first dihydric phosphate is (5.5-6.5):1.