When mining company LKAB needed to drain 35 million cubic meters of water from a flooded mine in northern Sweden, it contacted Xylem for a complete dewatering solution. Thanks to Xylem’s Flygt pumps and agitators, LKAB will soon be able to begin extracting approximately 110 million metric tons of iron ore.
The Leveäniemi open pit mine in Svappavaara first opened in 1961 and operated until 1983 when the worldwide recession meant that the work had to be discontinued. When LKAB, the world’s leading producer of processed iron ore products for steelmaking, decided to undertake the challenging task of draining the mine after almost 30 years of inactivity, the company commissioned Xylem to deliver a complete dewatering solution.
An enormous volume of water
“We were acutely aware of the challenges involved in emptying the mine given the volume of water we were dealing with,” says Peder Nensén, Project Manager at LKAB. “A project like this could have serious consequences if handled incorrectly. An added challenge was northern Sweden’s harsh climate, which meant that any solution would have to be able to cope with freezing temperatures.”
Xylem was selected for its strong presence in northern Sweden and its longstanding relationship with the customer. In addition, Xylem has significant experience of dewatering projects in the mining sector, having developed similar solutions for mine dewatering projects in other areas of Sweden and Norway.
Unique pumping solution with no freezing
The complete dewatering solution provided by Xylem consists of two submersible Flygt 3351 pumps and four LS350/450 Flygt pumps, delivering a total pumping output of more than 2.5 megawatts. These pumps are housed in a floating pumping station in the center of the flooded mine and in a dry station on land. Xylem also supplied 20 Flygt agitators that are designed to prevent water around the pipelines from freezing in winter months.
The Xylem team worked closely with LKAB to deliver a customized turnkey solution for this project. This unique installation was designed specifically for this application, demonstrating how Xylem combines technical expertise and innovative approaches to solve complex dewatering challenges.
A double set of pipes, approximately 1,500 meters in length, connect the floating station to the dry station, which in turn is connected to a five kilometer long gravity pipe, leading to the discharge point. The water from the mine eventually runs out into the Torne River, which flows into the Gulf of Bothnia.
30 million cubic meters dewatered
Since September 2012, Xylem has drained about 30 million cubic meters of water from the mine. It is estimated that the project will be completed by 2015 after which time LKAB intends to extract 12 million metric tons of iron ore each year.