Expanded delay mining hole sealing material

Abstract

The invention relates to an expanded delay mining hole sealing material which is prepared after modification of an expanding agent by microcapsules. The hole sealing material is prepared by aluminum powder microcapsules, water, cement, polycarboxylate superplasticizer, water-borne epoxy resins E-51 and T31 curing agents according to certain mass percentage. The aluminum powder microcapsules are prepared by water, gelatin, sodium alginate and aluminum powder in a mass ratio of 100: 2: 2: (4-6) (wt). According to the expanded delay mining hole sealing material, ineffective expansion of earlier stage of the cement is delayed so that the cement can reach certain strength and then is expanded, and coordinating growth of material strength and expansion can be guaranteed. Final expansion rate reaches 15%-25%, one-day compressive strength is 3.2Mpa, three-day strength is 20.8Mpa, seven-day strength is 45.8Mpa, and requirements of mine gas extraction drilling sealing and strength can be met. The hole sealing material and the microcapsules can be prepared and used on site in the environment of high temperature and high humidity of a mine, toxicity is absent, and the price is low.

Description

technical field [0001] The invention relates to a mine-used sealing material, in particular to an expansion-delayed sealing material suitable for drilling and sealing holes in coal mine gas drainage. Background technique [0002] Coal is the main energy source in our country. However, the mining process is also accompanied by many disasters and accidents. Gas outburst has become a prominent problem in coal mine safety production. Borehole drainage has always been the basic means of coal mine gas control. After the drilling is completed, the drilling is generally sealed, and the sealing of the drilling is a key part, and the quality of the sealing has a strong impact on the gas drainage effect. Chinese patent CN101215463 discloses a drilling sealing material, which is made of water 30-40%, ordinary silicon cement 30-40%, sodium bicarbonate 1.4-2%, sodium carbonate 1.5-2%, citric acid 3.0% -3.5%, calcium carbonate 8.0-8.5%, bentonite 8.0-8.5%, gypsum 8.0-8.5%, polyacrylamide ...

AI Technical Summary

Problems solved by technology

The expansion agent is encapsulated by the microencapsulation method, and the aluminum powder does not participate in the reaction at the initial stage of cement hydration under the protection of the capsule wall, so as to overcome the shortcomings of the aluminum powder being directly mixed with the reaction too fast, a large amount of gas escapes, and a through hole is produced; while the encapsulation The final aluminum powder is slowly released to participate in the reaction. At this time, the cement has a certain strength, and the gas generated by the reaction is enclosed in the solid phase space, which improves the expansion rate and solves the problems of gas escape and expansion loss.