Geosynthetic clay liners for the mining industry

Geosynthetic clay liners (GCLs) are manufactured barrier layers containing high-quality sodium bentonite clay attached or adhered to geotextiles or a geomembrane. The low permeability and high strength of the GCL make it an ideal replacement for low permeability soil or clay liners used in mineral extraction and processing containment applications. Some of the advantages of utilizing a GCL versus compacted clay in containment applications include; a permeability of 5 × 10 -9 centimeters per second (cm/sec) and corresponding better composite liner leakage protection, greater resistance to desiccation, differential subsidence and freeze-thaw, and lastly, the ease and speed of installation. A number of important case studies related to the mineral extraction and processing industry are detailed. These case studies include using GCL in two large reclamation capping projects, as a secondary liner in three gold heap leach pads, and as a composite liner in a dam for stormwater runoff control.