充填钻孔是充填法矿山的关键工程之一,容易受到充填料浆的冲击而造成破损.金川公司数字化钻孔电视观测结果表明,充填钻孔存在一个严重破损区域,该区域位于充填钻孔内空气和料浆的接触面上.充填料浆自由降落,具有较高的末期下落速度,而以较高的动量和冲量冲击充填钻孔的内套管管壁.因此,充填钻孔的严重磨损深度,即空气与料浆的接触面高度,可以根据充填钻孔的高度、水平管道的长度、浆体的密度和水力坡度进行估算.实例研究结果表明,该估算方法具有足够的精度,有利于充填钻孔的日常管理和维护.%Vertical backfill drill-hole is usually a key project in an underground mine with backfill method and can be easily damaged by impact of backfill slurry.Observation of the damaged vertical backfill drill-holes in Jinchuan Nonferrous Metal Corporation (JNMC),Gansu Province,China,given by a digital drill-hole video camera,indicated that there usually exist serious wear zones in casing pipe in vertical backfill drill-hole (CVBH).It was suggested that serious wear position of CVBH should be located at an interface between air and solid-liquid mixture within CVBH.Backfill slurry falls freely and impacts the wall of CVBH near the interface with great momentum and energy coming from high speed free fall of backfill slurry.The depth of serious wear position of CVBH,i.e.,free fall height of backfill slurry in CVBH,can be estimated by the height of vertical backfill drill-hole,the length of horizontal pipeline,the density of slurry and the hydraulic gradient of pipeline system.A case study indicated that the estimation equation of serious damage depth of CVBH was of enough accuracy and was helpful for daily maintenance and management of vertical backfill drill-hole.
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