Escondida Copper Mine - Oxide Leach Expansion (OLE) project

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Pioneering heap leach technology in Chile

The Escondida Mine is located in the Atacama Desert, Chile. In 2012 it accounted for five per cent of global copper production and around 15 per cent of Chilean copper production. The mining operation includes an oxide ore heap leach plant processing approximately 20 Mt/y of ore.

Ausenco developed the conceptual, basic, and detailed engineering along with construction support, construction quality assurance (CQA) and commissioning of the Oxide Leach Expansion (OLE) project.

Ausenco continues to provide engineering support for the OLE project, including the development of two new expansions and upper lifts of the pad.

The surface area of the OLE heap leaching pad is 2,000,000m². The following innovative solutions were applied to the operation, to minimise cost and maximise efficiency:

  • stacking with a shiftable conveyor and spreader
  • PVC lining and elimination of cover layer
  • using a multi-platform for leaching, maximising natural ground slopes, and minimising earthworks.

Ausenco is currently developing a further expansion, a third heap leach pad (Pad 3 - Oxide Leach Area Project (OLAP)). The scope considers an expansion with a capacity to process an additional 120 million tonnes of ore.

The OLAP selection study considers configuration and location alternatives inside the facilities with the objective of defining the best technical and economical option for the continuity of the project.

One of the main challenges to be considered is the topographic conditions surrounding the project.

Ausenco’s scope of services included:

  • Environmental impact study support
  • Heap leach modelling, optimisation, and stacking plans
  • Geotechnical studies
  • Pipe crushing tests
  • Design for materials handling.

Project details

Heap leach facility design, Mining engineering
Antofagasta, Chile
Business line
Environment & Sustainability
Minera Escondida Ltd
2004 - to date
Solution phase
Evaluate, Innovate
Engineering, Studies and technical solutions