常見例句Blocking of drawpoint or orepass is often happened during drawing process.Traditionally, this has to be tackled by blasting, often with great difficulty and even big danger. 漏斗溜井堵塞在井下放礦作業(yè)中經(jīng)常發(fā)生,用普通爆破法處理堵塞時(shí),作業(yè)極為困難和危險(xiǎn)。Keywords Bottom drawpoint;Velocity distribution;Influence height;Mechanism of influence;Ore drawing at stope; 底部放礦口;速度分布;影響高度;影響機(jī)理;采場放礦;Keywords trench bottom structure;drawpoint effective height;drawpoint diameter;stoping and filling; 塹溝受礦底部結(jié)構(gòu);放礦口有效高度;放礦口直徑;充填采礦法;Keywords Blocking of drawpoint or orepass;Cutter hood of shaped charge;Mining rocket projectile;Horizontal periscopical system; 漏斗溜井堵塞;礦用火箭彈;聚能罩;水平潛望系統(tǒng);drawpoint brow 放礦點(diǎn)口 返回 drawpoint