Outotec has agreed with Yara Suomi Oy on the design and delivery of a paste plant for tailings treatment. The contract, valued at over €40 million, has been booked in Outotec’s third quarter order intake. Outotec’s EPC delivery includes engineering, equipment supply, construction and commissioning of the paste plant as well as spare parts and services. The new plant is expected to become operational in the first half of 2017.

The Siilinjärvi mine produces about 1 Mt/y of apatitite concentrate, which creates approximately 10 Mt/y of tailings. The tailings, a mixture of sand and water, are currently disposed in the tailings storage facility as conventional tailings slurry. The new high density tailings disposal system with dewatering will increase the percentage of solids in the slurry, making it possible to deposit as paste and extending the lifetime of the tailings storage facility. Reclaim water is returned to the process water circulation.

“Yara is our long-term partner with whom we have developed and pilot tested an optimal thickened tailings solution based on Outotec’s paste thickener technology. Extended lifetime of the existing tailings surface facilities and efficient water circulation are noteworthy from the environmental point of view”, notes head of Outotec’s Minerals Processing business area Kalle Härkki.