Heap leach pad lining describes the construction of engineered containment systems beneath ore stacks at mine sites to prevent valuable pregnant leach solutions from seeping into the ground. Without a reliable lining system, chemical solutions are lost, soils and groundwater are contaminated, and regulatory compliance is at risk. Carbofol® + geomembranes, Bentofix® + X geosynthetic clay liners (GCLs) and Secutex® protective geotextiles form a complete, proven lining system solution for primary and secondary containment in heap leach mining.
Naue geosynthetic lining systems are used wherever reliable containment, long service life and chemical resistance are critical.
Lining pregnant solution ponds and collection trenches, preventing seepage losses of valuable leach solution.
Protect underground mining structures by controlling groundwater ingress with durable geosynthetic barrier systems.
Stabilise lining systems on steep mining slopes with textured geomembranes designed for increased friction and secure containment.
Heap leach pad lining is a high-consequence application. The lining system must withstand installation loads from heavy ore placement equipment, aggressive chemical exposure and long-term mechanical stress from the ore stack. Carbofol® HDPE geomembranes are specifically tested to GRI GM13. Secutex® protective geotextiles ensure that the geomembrane is not punctured during ore placement.
Practical advantages:
Regulatory requirements, site conditions and environmental risk levels determine whether a single geomembrane or a composite lining system is required. In most modern heap leach pad applications, a composite system comprising Carbofol® HDPE geomembrane and Bentofix® GCL provides the strongest environmental protection and the lowest total installed cost compared with a compacted clay liner (CCL).
Key principle: A composite liner combines two independent barriers - the Carbofol® geomembrane and the Bentofix® GCL. This provides double protection: if the geomembrane is locally damaged, the swelling bentonite of the Bentofix® GCL self-seals and containment is maintained.
Product selection depends on chemical conditions, regulatory requirements, slope angle, subgrade quality and available installation resources. Use this decision guide to identify the correct system configuration.
| Criterion | Project condition | Recommended product | Key technical reason |
|---|---|---|---|
| Subgrade type | Good quality compacted earth; CCL already present | Carbofol® S/S or F/F geomembrane | Single liner sufficient; Secutex® added for protection |
| Subgrade type | Weak, variable or remote subgrade; no CCL | Carbofol® + Bentofix® GCL composite | Bentofix® replaces CCL; hydraulic conductivity < 5 x 10⁻¹¹ m/s |
| Chemical resistance | Aggressive acid leach (pH 1 - 3, H2SO4) | Carbofol® HDPE (2.0–2.5 mm) | Exceptional chemical resistance; verified GRI GM13 + OIT |
| Chemical resistance | Alkaline cyanide solution (pH 9 - 11) | Carbofol® + Bentofix® NSP GCL | Composite system provides redundancy for regulatory compliance |
| Slope gradient | Flat base (slope < 1:9) | Carbofol® S/S smooth geomembrane | Standard smooth liner sufficient for flat applications |
| Slope gradient | Steep slopes (1:3 to 1:6) | Carbofol® F/F or BF/TF textured | Embossed surface provides frictional stability on steep slopes |
| Regulatory requirement | Single barrier - lower risk classification | Carbofol® geomembrane + Secutex® protection | Meets primary containment; verified quality by GRI GM13 |
| Regulatory requirement | Dual barrier - high environmental risk | Carbofol® + Bentofix® + Secutex® system | Composite liner accepted by regulators in place of CCL |
Reliable containment for mine operators
Carbofol® HDPE is qualified against aggressive mining leach solutions (acid, cyanide, alkaline). Minimising solution loss protects recovered value and reduces contamination liability. Carbofol® offers a long design service life per Naue technical documentation. CE-marked and ISO 9001 certified - audited by independent notified bodies.
Eliminate compacted clay liners - reduce costs and programme
Bentofix® GCL replaces a conventional compacted clay liner (CCL). Installation requires no heavy compaction equipment. This saves construction time and reduces cost - critical in remote or arid mining regions where clay is scarce.
Slope stability on the most challenging terrain
Textured Carbofol® geomembrane provides stable lining on slopes up to a 1:3 gradient. A full slope stability analysis is available from Naue engineers. Steep-slope heap leach pad developments, including mountaintop sites, become feasible.
Single-source supply and engineering support
Carbofol®, Bentofix® and Secutex® are all manufactured by Naue. Complete system documentation, installation guidelines and engineering design support are available from a single contact.
Heap leach pad lining describes the engineering of impermeable containment systems placed beneath ore stacks at mine sites. The lining prevents valuable pregnant leach solutions from seeping into the subgrade, protecting soils and groundwater from contamination. Without a reliable liner, chemical solutions are lost, regulatory compliance fails and environmental liability increases significantly.
The primary products are Carbofol® + HDPE geomembrane (primary containment barrier), Bentofix® + X GCLs (secondary barrier, replacing compacted clay), and Secutex® nonwoven geotextile (mechanical protection layer). These three products form a complete, engineered lining system available from Naue as a single-source supply.
Carbofol® HDPE geomembranes comply with GRI GM13 (the industry reference standard for HDPE geomembranes) and EN ISO standards. The material must be CE-marked and produced by an ISO 9001 certified manufacturer, tested by an independent notified body. National and regional environmental regulations (e.g. US EPA requirements) also govern minimum liner specifications.
Bentofix® GCL replaces a conventional compacted clay liner (CCL) without the need for heavy compaction plant or clay sourcing in remote locations. Installation is faster - a team can install large areas per day by simply unrolling. Water and wastewater management costs at the mine site are also reduced by improving process water containment efficiency.
Carbofol® is supplied in rolls and installed by trained, certified installers following Naue installation guidelines. Panels are welded using wedge or extrusion welding. Edge markings indicate recommended overlaps; removable edge strips provide a clean welding surface. Smooth Carbofol® S/S is used on flat areas; textured Carbofol® is specified for slopes. Installation must be carried out by a certified company per manufacturer guidelines.
GRI GM13 is the recognised reference test standard for HDPE geomembranes used in lining applications. Most project specifications and regulatory frameworks require GRI GM13 compliance as a minimum. Testing includes thickness, density, melt flow rate, carbon black content and distribution, NCTL (stress crack resistance) and OIT (oxidative induction time). Carbofol® HDPE 406 meets these requirements. Manufacturing must be certified by an independent notified body.
Yes. Carbofol® + geomembranes have been specifically selected for their chemical compatibility with aggressive sulphuric acid (H2SO4) leach solutions used in copper heap leach operations. The combination of high-density polyethylene formulation, OIT compliance and stress crack resistance (NCTL) ensures long-term chemical durability. Secutex® protective geotextiles provide additional mechanical protection above the liner under ore loading.
All Carbofol® geomembrane welds on heap leach pads are tested using dual-channel hot-wedge welding followed by air-pressure testing in the weld channel. Any failing seam is repaired and retested before ore placement. A complete weld log is maintained for each panel and forms part of the construction quality assurance (CQA) record. Certified installation specialists and independent CQA inspectors confirm compliance on large-scale projects.
A composite liner comprising Carbofol® HDPE geomembrane plus Bentofix® GCL is required when regulatory guidelines mandate dual-barrier protection, when the subgrade contains no compacted clay layer, or when the risk classification of the ore or leachate is elevated. Most modern heap leach pad applications for copper, gold and uranium ore processing specify a composite system as standard. Naue engineers provide site-specific liner system recommendations based on local regulations and ground conditions.
The engineering of geosynthetic lining systems for heap leach pads follows recognised standards and site-specific design criteria. Naue engineers provide full technical support - from preliminary product selection through slope stability analysis and weld testing verification.
Naue Carbofol® + HDPE geomembrane is an enhanced oxidation-resistant liner for mining containment, landfill sealing and other critical barriers.
Naue Bentofix® + X is a Thermal Lock GCL with enhanced oxidative resistance for mining, landfill and hydraulic engineering.
Naue Secutex® is a mechanically bonded nonwoven geotextile for separation, filtration and protection for the use in roads, railways, environmental and hydraulic engineering projects.
