Geosintéticos | TDM

The waterproofing of the Lagunas Norte heap leach pad platform has completed its Phase 2, a project in which TDM has been involved since Phase 0. The total volume of ore at the end of the pad’s service life will reach 115 million cubic meters over an area of 320,000 m². Material layers will be 10 meters thick, and the final height will be approximately 150 meters.

During Phase 0, the earthworks contractor was Skanska, and the scope of work consisted of covering a 330,000 m² heap leach platform with smooth HDPE geomembrane. This phase also included the construction of POP (Pond Overflow Process) and PLS (Primary Leachate System) ponds.

The waterproofing system for these structures incorporated a GCL (Geosynthetic Clay Liner— a bentonite-based geocomposite sandwiched between geotextiles that forms a low-permeability barrier and replaces the labor-intensive and costly installation of compacted clay liners), two layers of HDPE geomembrane, and a geonet placed between them as a leak detection layer. All works were carried out between August 2004 and June 2005.

In Phases 1 and 1ª, TDM began working with Empresa de Servicios Múltiples Chan Chan as the earthworks contractor, installing 360,000 m² of textured HDPE geomembrane on the lower face. A distinctive feature of this phase was that all leachate collection pipes were designed to be confined within trapezoidal channels measuring 1.50 meters at the base and between 0.80 and 1.00 meters in height. These pipes were HDPE ADS N-12, externally corrugated to provide greater structural strength and internally smooth to ensure optimal hydraulic conductivity.

In Phase 2, completed in August 2006, TDM installed an additional 250,000 m² of the same geomembrane type within a period of less than two months, receiving on-site personal recognition from Eng. Igor Gonzáles, Regional President of Minera Barrick. Following the completion of this phase, TDM was commissioned to perform additional works, including the lining of Phase 0 slopes— with inclinations ranging from 1:2 to 1:1— using 1.0 mm thick smooth geomembrane, as well as the installation of a 70,000 m² dynamic pad with 1.5 mm geomembrane.

TDM’s continued involvement at Lagunas Norte is undoubtedly the result of strong performance based on productivity, progress, and quality, achieving “zero accidents” despite the harsh climatic conditions at elevations above 4,000 meters above sea level, where rainfall and strong winds pose significant risks to field personnel. Project success was validated by Vector Engineering, the company responsible for construction supervision and for the design and engineering of Phase 2.