graded deposit meaning in Chinese

递级淀积层

The application of pointed prop mechanical slice stoping and backfilling mining in sanshandao gold mine is presented . it is characterised by high mechanization degree , great capacity of slice stoping and low mining loss rate and ore dillution rate . as a result , it is suitable for the large - scale mining of low grade deposit
介绍了点柱式机械化分层充填采矿方法在三山岛金矿的应用，该采矿方法机械化程度高，采场分层生产能力大，两率指标较低，适用于低品位矿床的大规模开采。