Deslagging mechanics and application of roadway floor anchor hole in coal mine

In view of slag-off difficult problem involve with roadway floor anchor hole drilling in coal mine, slag-off process was analyzed in the process of anchor hole drilling, boring mud three-field existence make slag-off difficult in floor anchor hole drilling was put forward, and boring mud three-field is dynamic in turn gradually formative, and simultaneous existing in finally. Utilizing basic principle of hydromechanics, frictional hydraulic loss in course of flush fluid circulate and mechanical formula of boring mud rising in flush fluid in the solid-liquid coupling effect were derived. According to the field basic condition, frictional hydraulic loss of the flush fluid minimal effecting to speed vt of boring mud rising in course of flush drilling and boring mud was obtained, and condition of boring mud three-field formation was determined. The results show that selection of drilling hole tool, requirement of flush fluid flow, rotational speed of boring machine, and control of pressure must be coordinated, and formation of boring mud gather area is controlled. In large part, avoiding formation of boring mud gather area is the key to speed up drilling velocity.