Powder for plugging air leaking crack

Abstract

The invention discloses a powder for plugging an air leaking crack. The powder comprises, by mass, 20 to 25 parts of bentonite, 30 to 35 parts of talcum powder, 18 to 20 parts of a super absorbent resin, 12 to 15 parts of sodium alginate and 10 to 15 parts of anhydrous calcium sulfate, and all the above-mentioned components are directly mixed for utilization. The powder is especially applicable to plugging of air leaking cracks in underground coal mines caused by drilling in the process of gas extraction. According to the invention, under the action of positive pressure from a compressed air system and negative pressure from gas extraction, lubricity of talcum powder enables the powder to be transported to a deep crack; when transportation of the powder is stopped, bentonite and the superabsorbent resin absorb water and swell, sodium alginate powder becomes wet when meeting water, hydration of the sodium alginate powder enables the surface of the sodium alginate powder to have viscosity, the sodium alginate powder enables all the components of the powder to bond together to form aggregate and to adhere to crack walls, the powder continues to swell after anhydrous calcium sulfate absorbs water, and anhydrous calcium sulfate turns into hard gypsum at the same time, which enables the hardness of the powder aggregate to be increased and the powder aggregate to firmly plug the crack. All the materials used in the invention are common material on the market, which enables a low cost to be obtained.

Description

technical field [0001] The invention relates to a material for sealing air-leakage fissures in surrounding rocks of drilling holes for gas drainage in coal mines, in particular to a powder material for sealing air-leakage fissures. Background technique [0002] Gas disaster is one of the main natural disasters in coal mines. Draining gas through boreholes is an important means of controlling gas disasters in coal mines. However, with the continuous development of gas drainage, cracks in the surrounding rocks of boreholes begin to develop, expand, and communicate, which will eventually cause The air in the roadway is easy to enter the drainage borehole from these air leakage cracks under the action of the negative pressure of drainage, resulting in a decrease in the concentration of gas drainage, shortening the effective drainage life of the drainage borehole, and reducing the utilization rate of the borehole . [0003] In the prior art, in order to solve the technical probl...

AI Technical Summary

Problems solved by technology

[0005] Under the action of the positive pressure of the downhole compressed air system and the negative pressure of gas drainage, the above-mentioned powders have relatively high resistance to migration in the cracks, which affects the distance of powder transportation, has little water absorption, cannot fully expand, has poor viscosity and low hardness, and is easy to It is pumped into the gas drainage system, thus affecting the effect of sealing air leakage cracks