High-strength expandable mine sealing material capable of being solidified quickly

The invention discloses a high-strength expandable mine sealing material capable of being solidified quickly, which is prepared from the following raw materials: 45-50 parts of high-alumina cement, 0.05-0.2 part of citric acid, 10-15 parts of lime, 35-40 parts of gypsum and 0.8-1.2 parts of lauryl sodium sulfate. The invention has the advantages that the material can be solidified quickly under the condition of high water-cement ratio and can expand in the solidifying process (the maximum free expanding ratio can reach more than 10% in one day), and the solidifying body has higher strength which can reach 3-4MPa in one day. The material is nontoxic, harmless and pollution-free, can be used for grouting, strengthening and sealing of wall rocks of mines, and can also be used for sealing, covering, plugging and the like in the processes of pumping and discharging coal mine gas. Compared with similar polyurethane products, the material has the advantages of simple use method, low cost (about 1000yuan/ton), high strength and good plugging effect; and compared with cement mortar, the material has the advantages of strong expansibility and reliable plugging quality. The material is tested and applied to Jinlong coal mine and Daping coal mine of Zhengzhou Coal Industry Group Company, and good effect is obtained.