Recovery techniques

Talvivaara has developed its metals recovery techniques in collaboration with OMG, the nickel operations of which are now owned by Norilsk Nickel. The methodology was successfully tested in the laboratory and also with a pilot heap test which enabled the efficient design of production scale equipment. The methodology is based on a process which is currently being used commercially by OMG Kokkola Chemicals in Kokkola, Finland.

The first metal recovery pilot started in March 2006 at OMG, Kokkola, Finland. The product quality is high and recovery yields close to 100%.

Mining, bioheapleaching and metals recovery techniques for the Talvivaara mine have been tested in a 17,000 tonne on-site demonstration trial during 2005 and 2006. Subsequent construction of the mine started in 2007, with commencement of commercial production early 2009.

In metals recovery, nickel, copper, zinc and cobalt are precipitated from the pregnant leach solution and filtered to produce saleable metal products. After the metals are removed, the solution is further purified and returned to irrigate the heaps.

The solution is collected at the bottom of the heaps and either recirculated through the heap or fed to metals recovery. In all, the technology is expected to result in lower capital and operational costs than a substantial proportion of other nickel mines making the Talvivaara project less susceptible to price variations of commodities.