Mine closure and rehabilitation describes the permanent isolation of contaminated mining zones using engineered geosynthetic systems. Tailings and contaminated sediments pose long-term risks to groundwater and surrounding ecosystems. Carbofol®, Bentofix®, Secudrain® and Secutex® provide a proven, compliant containment and capping solution - from a single barrier to a composite double-liner.
Our geosynthetic systems are deployed wherever contaminated legacy mining areas must be safely contained, stabilised and returned to productive or ecological use.
Permanent containment of toxic tailings using HDPE geomembrane and GCL composite systems.
Protect underground mining structures by controlling groundwater ingress with durable geosynthetic barrier systems.
Encapsulating legacy contamination to prevent ongoing leachate migration into groundwater.
Supporting rapid, stable vegetation cover on capped surfaces using erosion control mats.
Mine closure sites present extreme installation challenges: steep slopes, reactive chemistry, remote locations, and compressed project schedules. Carbofol® HDPE geomembranes and Bentofix® GCLs are engineered for long-term performance in exactly these conditions. Their durability is verified by independent test standards, including ASTM D5397 (stress crack resistance ≥ 500 hours) and EN ISO 527-3.
Practical Advantages:
System note: All installation activities should follow Naue installation manuals, site-specific QA plans and applicable international guidelines. Certified installers are required for geomembrane welding on steep slope sections.
A mine closure capping system must fulfil several functions simultaneously: prevent infiltration, manage gas and leachate, protect liner integrity, and support vegetation. The following outlines which product addresses which function.
Key Principle: Sealing minimises infiltration. Drainage manages what is already inside. Protection preserves the barrier. All three must be designed together.
The correct barrier configuration depends on chemical aggressiveness, regulatory requirement, drainage need and slope conditions. Use the table below to identify the right system for your specific mine closure scenario.
| Criterion | Carbofol® HDPE Geomembrane | Bentofix® GCL | Carbofol® + Bentofix® Composite | Secudrain® Drainage Geocomposite |
|---|---|---|---|---|
| Substrate type | Any (firm to soft) | Stable, non-aggressive | Aggressive chemical environment | Drainage layer required |
| Chemical aggressiveness | High (HDPE resistant) | Moderate (GCL suitable) | Very high (dual barrier) | Not applicable |
| Filtration / drainage needed | No | No | No | Yes (gas/leachate venting) |
| Slope gradient | Up to steep (textured surface) | Up to 1:3 | Up to steep | Any |
| Regulatory requirement | Single barrier accepted | Secondary barrier | Double-liner standard | Venting/drainage standard |
| Recommended scenario | Standard closure capping | Low-risk closure | High-risk TSF / heap leach | Gas or leachate management |
Long-term contaminant isolation - minimal ongoing leakage
The engineered capping system minimises precipitation infiltration, helps prevent polluted run-off, and isolates contaminated soils from the surrounding environment. Long service life is confirmed by independent testing: stress crack resistance ≥ 500 hours, ASTM D5397.
Regulatory compliance and permit closure
Naue systems are designed and supplied in accordance with ICMM guidance, ISO 14001 requirements and applicable local mining regulations. Full documentation, welding logs and QA records support regulatory closure applications and liability transfer.
Simplified, verifiable installation - reduced QA burden
Metre scaling markings, lateral overlap indicators and protection strips on welding areas accelerate installation. Single-source supply from Naue reduces subcontractor interfaces and simplifies the quality assurance programme.
Land returned to productive use - ecological and social value
Secumat® erosion control mats facilitate rapid vegetation establishment on capped surfaces. This supports community commitments, ESG reporting requirements and in many jurisdictions reduces the ongoing bond liability held by the mine operator.
Mine closure and rehabilitation describes the permanent engineering of former mining zones to prevent environmental harm after operations cease. Geosynthetic capping systems isolate contaminated tailings, heap leach residues and contaminated soils, greatly reducing infiltration and enabling ecological restoration of the land surface.
Carbofol® HDPE geomembrane is the primary impermeable barrier. Bentofix® GCL provides a secondary sealing layer in composite designs. Secudrain® manages gas and leachate drainage. Secutex® protects and filters. Secumat® supports erosion control and vegetation. For soft tailings surfaces, Combigrid® stabilises access for installation.
Relevant standards include ICMM Guidance Note on Tailings, MAC TSF Design Guidelines (Mining Association of Canada), ISO 14001 Environmental Management, ASTM D5397 (stress crack resistance), EN ISO 527-3 (tensile properties), GRI GM13 and applicable national mining regulations. Naue can provide supporting documentation for all supplied products.
Geosynthetic systems reduce excavation volumes, shorten installation schedules and lower long-term bond liability. Single-source supply simplifies procurement. Confirmed cost reduction figure vs. conventional - contact Naue engineering for project-specific assessment.
Yes. Carbofol® with a textured surface on both sides is specifically designed for steep slope applications. Installation requires certified welding crews using industrial climbing safety equipment. Anchor systems can be designed for rocky or unstable sections. Naue provides full installation manuals and engineering support.
Geosynthetic capping reduces the volume of earthworks required, lowering transport movements and site disturbance. Secumat® enables rapid vegetation re-establishment, supporting biodiversity outcomes. Long service life reduces maintenance and monitoring costs over the closure period.
Naue products comply with applicable EN and ASTM standards and have been accepted by environmental regulators across Europe, the Middle East and globally. Full product documentation, quality certificates and welding logs are provided. We recommend early engagement with Naue engineers to confirm project-specific regulatory requirements.
Carbofol® geomembrane seams on steep slope sections are produced using certified dual-track hot-wedge welding and air-channel pressure testing on every seam. Destructive peel and shear samples are taken at regular intervals from trial seams. A site-specific CQA (Construction Quality Assurance) plan is prepared before works begin, identifying seam inspection frequency, repair procedures and the hold-point inspection regime. All weld logs are archived for submission to the regulatory authority as part of the closure approval package.
Secudrain® drainage geocomposite provides controlled gas and leachate venting within the closure cap structure. Gas generated by decomposing organic matter or chemical reactions in the tailings must be managed to prevent pressure build-up beneath the impermeable liner. Secudrain® channels these gases and any residual leachate to designated venting points or collection sumps. Its thermally bonded Secutex® filter layers on both sides prevent fine particle migration into the drainage core and maintain long-term flow performance over the closure lifetime.
The design of geosynthetic capping systems for mine closure follows recognised international and national standards. Our engineering team supports you in identifying the correct system for your site conditions — with full documentation for regulatory submission.
Naue Carbofol® is a HDPE liner for landfill sealing, mining containment, and groundwater protection.
Naue Bentofix® is a geosynthetic clay liner (GCL) for waterproofing in landfill engineering, groundwater protection and hydraulic applications.
Naue Secudrain® is a geosynthetic drainage geocomposite for landfill, groundwater protection and building structures.
Naue Secutex® is a mechanically bonded nonwoven geotextile for separation, filtration and protection in roads, railways and hydraulic engineering projects.
Naue Secumat® is an erosion control mat for the protection of slopes, channels and embankments.
Naue Combigrid® is a geogrid with integrated nonwoven geotextile that combines stabilisation, reinforcement, separation and filtration in a single installation step.
