Specific Application Scenario

A copper mine in the Atacama Desert region of Chile produces tailings slurry with a consistently low pH of 2-4 (highly acidic) and contains soluble metal ions. The project required the construction of a 50-hectare tailings storage facility with a 30-year design life. The core challenge was to find an absolutely reliable primary containment liner that could withstand the combined stresses of intense UV radiation (at 3000m altitude), significant daily temperature fluctuations (-5°C to 30°C), and chemical corrosion, to prevent toxic leachate from contaminating the underlying aquifer.

 

Solution and Long-Term Performance Data

After rigorous chemical compatibility testing, the project selected a 1.5mm thick textured HDPE geomembrane as the primary liner. The textured surface provided a high interface friction angle of up to 30 degrees, ensuring stability on 1:2.5 (H:V) slopes.

Material Specification: Virgin high-density polyethylene resin, density ≥0.940 g/cm³, with 2.5% carbon black content for UV resistance.

Chemical Durability Evidence: Laboratory accelerated immersion tests showed that after 18 months in a simulated tailings solution (pH=2) at 40°C, the membrane retained >95% of its original tensile strength and elongation at break.

Field Welding Quality Control: All seams were double-track fusion welded, with 100% non-destructive air pressure channel testing and destructive shear/peel tests performed every 500 meters. All welders held international certifications.

Five-Year Monitoring Results: Through a installed leakage detection layer and regular groundwater quality monitoring, no anomalous fluctuations were detected in the downgradient aquifer, confirming a zero-leakage containment system.

 

Comparative Analysis: Why Other Materials Were Not Selected

 

Alternative Option	Primary Risk in This Scenario	Conclusion vs. HDPE Geomembrane
LLDPE Geomembrane	Slightly inferior chemical resistance (especially to stress cracking), presenting higher risk in long-term contact with strong acids and metal ions.	Not Suitable. Insufficient long-term chemical safety.
PVC Geomembrane	Plasticizers can migrate in acidic environments, causing material embrittlement and a sharp drop in puncture resistance	Not Suitable. Fundamental chemical compatibility flaw.
Compacted Clay Liner	Acidic leachate alters the clay mineral structure, causing its hydraulic conductivity to increase by several orders of magnitude within years.	Not Suitable. Cannot serve as a sole reliable barrier.
1.0mm HDPE Geomembrane	Weaker resistance to stress concentration from differential settlement and puncture risks during construction	1.5mm thickness is a more robust choice, providing a greater safety margin.