Protection of blast holes

摘要

A method of protecting predilled, uncharged bore holes for use in an underground mine engaged in stope mining; the method comprising the steps of filling the uncharged bore holes with a liquid and sealing the entry of the liquid-filled blast holes prior to detonating adjacent blast holes. The liquid to be used will depend on the material being mined. In impervious material, the liquid is water. In porous material, the liquid may be viscous or have sealing properties such as a drilling mud or bentonite mud. Various plugs for sealing the bore holes are also described and claimed.