- Location: Finland
- Product: COLETANCHE® ES1 / COLETANCHE® ES2
- Surface: 520 000 m² / 5 597 200 ft²
- Installation date: 2007 to 2008
The company owns and operates the Kittilä gold mine, which is the second mine located in northern Finland. The Kittilä mine Suurikuusikko, is about 560 miles (900 km) north of Helsinki. In July the average temperature is 59°F (15 °C) and in January is 5°F (-15 °C). Two basins were designed. To obtain approval from the Ministry of the Environment in order to construed the mine, the basin had to be waterproofed. The purpose of these basins is to confine the water from ore processing. The pool water returns later in the treatment process. Consequently, the flow of water is a substantial closed circuit.
A layer of mineral sealing was built under the bituminous geomembrane. The layer consists of locally excavated compacted moraine. Its thickness is 1000 mm and its performance in sealing water of less than 5 x 10E-8 m / s. Bituminous geomembrane combined with the mineral sealing layer acts as composite coating. For the bottom of the pool, the COLETANCHE® ES1 of 3.5 mm thickness was used. For slopes, the coating must have a thickness of 4.0 mm, COLETANCHE® ES2.
REASONS OF CHOICE
The COLETANCHE® geomembrane in this project, promotes:
- Conducting the installation by a local company in Helsinki (no specialty installer for a total flexibility)
- Installing the barrier COLETANCHE® directly on the mineral sealing layer
- Installation in extreme weather conditions (rainfall, wind, cold temperatures down to -40°C or -40°F
- High puncture resistance
- Excellent weathering resistance even when exposed
- Long life expectancy
On average, about 5 000 square meters (54 000 ft²) per day were installed by two teams of welders.
All tests done to check weld quality and destructive tests were collected and recorded daily by a computer to establish a data report.
