Grouting and hole-sealing material used for drilling of underground coal mine gas

Abstract

The invention provides a grouting and hole-sealing material used for drilling of underground coal mine gas. The material comprises a dry grouting and hole-sealing material and water, wherein a weight ratio of the dry grouting and hole-sealing material to water is 1: 0.8-1.2; the dry grouting and hole-sealing material is composed of the following substances: Portland cement, fly ash, desulphurized gypsum, lime, aluminum powder paste, sodium chloride, metakaolin, and citric acid or sodium carbonate; and the substances composing the dry grouting-and-sealing material are required by weight as follows: 6 to 10 parts of the Portland cement, 0.5 to 3 parts of the fly ash, 0.5 to 3 parts of the desulfurized gypsum, 0.2 to 1 part of the lime, 0.0005 to 0.002 part of the aluminum powder paste, 0.05 to 0.15 part of the sodium chloride, 0.2 to 1.5 part of the metakaolin, and 0.0025 to 0.015 part of the citric acid or 0.005 to 0.03 part of the sodium carbonate. The grouting and hole-sealing material used fo drilling of underground coal mine gas provided by the invention has the advantages of adjustable coagulation time, improved air tightness of hole-sealing, improved hole-sealing efficiency and safety, lowered hole-sealing cost, simplified hole-sealing preparation work, etc.

Description

technical field [0001] The invention relates to the field of coal seam gas drainage in coal mines, in particular to a grouting sealing material for gas drilling in coal mines. Background technique [0002] Gas outburst has always been a major disaster that threatens the safe production of coal mines. Early gas drainage is one of the important means to effectively control gas outburst. At present, the sealing methods mainly include mechanical sealing method, casing sealing method, clay sealing method, cement mortar sealing method, polyurethane sealing method and so on. Among them, the performance of the sealing material directly affects the quality of the sealing. The commonly used sealing methods include the towel sleeve sealing method and the sealing bag sealing method. The essence is the same, that is, the polymer material sealing. The disadvantage of this type of hole sealing method is that the polymer foam material cannot fill the original cracks around the drilled hole...

AI Technical Summary

Problems solved by technology

The disadvantage of this type of sealing method is that the polymer foam material cannot fill the original cracks around the drill hole. During the foaming and expansion process of the polymer material, the hole in the sealing section is in an open state, and the foam material cannot form sufficient expansion. Force, so that the foamed polymer material cannot be squeezed into the cracks around the drilling of the sealing section, and these cracks will become air leakage channels (initial air leakage channels)

Secondly, the high-molecular foam material has low strength and large compressibility, does not have enough support for the drilling, and cannot maintain the stability of the drilling

[0003] Polymer materials such as polyurethane are not suitable as the first choice for grouting because of their high price. Ordinary cement is not suitable for grouting because of its inherent shrinkage, which may easily cause drilling air leakage.