The nickel and zinc mine near the Finnish village of Kajaani at Talvivaara has a production capacity of some ten million tons of ore per year. In the past, large quantities of gypsum slurry resulting from mining operations were deposited in lagoons.

Due to a leak in one of the lagoons, SoilTain drainage tubes were used on a trial basis. The trials proved so successful that the tubes are now used for the disposal and permanent containment of the entire gypsum slurry produced at the mine. Thanks to a five-layer pyramid-shaped stacking of the tubes, the storage space requirement was greatly reduced compared to the original lagoon storage concept.

Summary

• Dewatering of large quantities of gypsum sludge
• Safe permanent containment of sludge cake
• Following successful trials, system now used for entire production
• Economy of space