| 摘要 |
<p>A stemming plug (10) for stemming a blast hole in a mine comprises an elongate sleeve (12) of porous material having a first inner join line (14) and a second outer join line (16). The inner join line (14) is made of water-soluble material and defining a first diameter of the sleeve (12) which is smaller than. a second diameter defined by the second join line (16) and which is adapted to be received in a blast hole. The porous sleeve (12) contains a volume of dry grout material (18) in particulate form. When the plug (10) is immersed in water it dissolves the first inner join line and mixes with the grout material (18) to form a paste which can squeeze through the porous sleeve when the plug is tamped into the drill hole. The porous sleeve (12) is now free to expand towards the second diameter as the plug is tamped and in this way the stemming plug (10) can be used to block the blast hole once the grout material (18) cures.</p> |
