崩落采矿法的覆盖层消耗与补充技术研究

Research on Consumption and Supplementary Technology of Cover layer with Caving Mining Method

深部铜矿现阶段使用分段崩落法采矿工艺由于覆盖层厚度不足,甚至局部地段没有覆盖层,出现了严重的矿石的贫化、损失现象,影响了崩落采矿工艺的正常使用。在反思矿山露天转地下初期覆盖层的形成方案的基础上,对矿山东、西采区现有覆盖层厚度、块度进行了调查,分析得出覆盖层损失或不足的原因主要为放矿过程中的消耗、采矿悬顶阻塞下降通道、矿体形态变化大等。通过计算得出:矿山最小覆盖层厚度为23.5m,覆盖层的最小块度应为800mm。提出了在矿山东部采区采用上盘硐室倾斜扇形深孔挤压爆破补充覆盖层方案和西部采区采用在正常开采时崩落表外矿补充覆盖层方案;在覆盖层补充完成后,总结出端部留矿方案和矿石隔离层方案两项能够进一步完善矿山现有的崩落法采矿工艺的技术措施。

Due to insufficient thickness of the cover layer and even the absence of overburden in local sections,serious ore dilution and loss has occurred in the mining technology of sublevel caving in deep copper mine at the present stage,which has affected the normal use of caving mining technology.On the basis of rethinking the formation scheme of the initial overburden in the transformation from open-pit to underground mining,the existing overburden thickness and block size in eastern and western mining areas were investigated.The analysis showed that the loss or deficiency of cover layer was mainly caused by the consumption in the process of ore drawing,blocking of descending passage by overhanging roof,the large change of ore body shape and so on.By calculation,the minimum cover thickness of the mine was 23.5 m and the minimum block size of the cover layer should be 800 mm.The schemes of supplying cover layer by fan-shaped deep hole extrusion blasting in the upper chamber in eastern area of the mine and supplying cover layer by collapsing graded rock during normal mining in western area were proposed.After the supplementary of cover layer,two technical measures of retaining ore in ends and setting ore spacer layer in stope were put forward to further improve the existing caving mining technology in the mine.