Abstract: The paper describes the operating principles of negative-pressure drilling at high air pressure and its feasibility and implementation results at 200 m depth in certain deposit in Xinjiang. The main technology, procedure, key technical links and matters needing attention of negative pressure drilling are presented. When negative pressure drilling is used in construction, the drill-hole structure can be evidently improved, and the water amount remarkable raised, bringing good results. Therefore, negative pressure drilling technology can be an important means in optimizing in-situ leaching mining.

Key words: In-situ leaching mining, High pressure air, Negative pressure drilling, technology