Liner system design for heap leach pads

Heap leach pads are used in the mining industry as an integral component for metal extraction and processing. The design of modern heap leach pads utilize an engineered liner system that often is a blend of natural and geosynthetic materials in order to achieve a desired performance, such as ore heap stability, solution drainage, and efficient recovery. An important issue that is often overlooked in the design of heap leach pad liner systems is the compatibility between geosynthetic materials (e.g. geomembrane, geopipe, geotextile, etc), native materials, ore, and operational conditions/restrictions. This issue becomes more pronounced as heap leach pads are constructed in steep terrain, harsh climates (wet, cold, etc), and subjected to high ore loads (exceeding 4 MPa). This paper discusses design approaches for heap leach pad liner systems, with a focus on compatibility with geosynthetic materials.