Abstract: The permeability of piled body is the key in the dump leaching in copper mines. With Dexing Copper Mine as the case, the main factors influencing the permeability in the dump leaching are systematically studied from ore size, stacking mode, mechanical compaction, clay and powder ore content, etc. The results show that high content of clay and powder ore, gravity segregation in stacking and mechanical compaction are the main causes leading to low permeability. The technical means such as innovated blasting and stacking process, mechanical loosing, addition of loosing agent, installation of permeation-assisting facility and crushing-ageing-granulation leaching can effectively improve the permeability of the dump and the metal recovery.

Key words: Dumping site, Leaching, Permeability, Technical measures