Without question, heap leach has become an enormous driver to the growth of mining operations around the world. Several decades ago, only about 3% of copper and gold supplies were produced through heap leaching. Today, the volume is surpassing 30% annually. Valuable chalcopyrite copper, previously not considered economical in heap leach development, is now heap leached, as is nickel laterite, uranium, and even rare earths. The growth of heap leaching is heavily tied to the massive scale on which mines are being built, with some sites requiring huge investments. Heap leach stacks can near 200m as operations look to more quickly prove and sustain site yield.
Heap leaching accomplishes this—but only with the containment support of geosynthetics. Geomembranes and geosynthetic clay liners (GCLs) are used for heap leach pads liners, pregnant solution trench liners, processing pits, onsite water storage, raincoat covers over ore stacks to shed stormwater (rather than dilute the leach heap solution), and onsite wastewater management.
Geosynthetic lining solutions enable steep slope (including mountaintop) developments. Pregnant solution fl ows more easily from heaped ore, and valuable material is not lost in seepage into soils or local waters. Onsite water is managed more efficiently, which also improves site costs, as water and wastewater management is a major cost in mining.
In these ways, improving the economics of mining with geosynthetic containment solutions is also the best way to improve the long-term environmental performance in mining.
NAUE Solutions for heap leaching
Carbofol® high-density polyethylene (HDPE) geomembranes feature exceptional chemical, stress crack, and UV resistance. They have the durability and chemical compatibility to withstand aggressive mining heap leach solutions in stacks and solution trenches. Available texturing can enhance the frictional characteristics necessary for lining system slope stability. And for onsite water management and processing fluid containment, Carbofol® is exceptional.
Geomembranes are not all that mining sites require. Secutex® geotextiles provide long-term, robust protection of and frictional stability for geomembranes on difficult terrain and in tall ore stack scenarios.
Additionally, composite lining solutions (Carbofol® geomembranes with Bentofix® GCLs) provide dependable, efficient, long-term lining performance for improved heap leach economics and environmental performance in nearly all mining operations.