黔东南综合地质大队勘探的地虎矿区内，铜、铅、锌矿均产于矽化片岩和石英岩中，岩性硬、脆、碎，被水冲刷研磨易粉化，其可钻性为7—8级，部分为9级，合金难于钻进。我队曾先后采用限制回次进尺、减少投砂量、开小水、使用分水接头等措施，均未获得高的采取率，有时甚至打丢矿、打薄矿，造成补孔，后改以岩心管做薄壁钻头；采用钻粒无泵反 Copper, lead, and zinc deposits are all produced in silicified schist and quartzite in the geo-ti mining area explored by the Qiandongnan Integrated Geological Brigade. The lithology is hard, brittle and fragmented, and is easily polluted by water scouring and grinding. Its drillability is 7 -8, some 9, alloy difficult to drill. Our team successively adopted the measures such as limiting the footage footage, reducing the amount of sand thrown into the sand, opening small streams of water, using water diversion joints, etc., and did not obtain high adoption rates. Core tube to do thin-walled drill bit;