Talvivaara Mining Company

The deposits, Kuusilampi and Kolmisoppi, were originally discovered in 1977, by the Geological Survey of Finland (GTK). Although the deposit was large, it was considered too poor for existing technology. Only bioheap leaching could concentrate the nickel enough, but the technology was still untested. The mining rights were eventually obtained by Outokumpu Corporation, which sold them at a nominal price of two euros to a former employee, Pekka Perä. The Talvivaara Mining Company was established in 2004 when it acquired the rights to mine sites at Sotkamo in Eastern Finland from Outokumpu. In 2006 a metals recovery trial was completed and the necessary financing was secured. Perä proceeded to list the company on the London Stock Exchange in 2007 and later on the Helsinki Stock Exchange in 2009. The firm was delisted from the London Stock Exchange in 2014, this was to reduce costs according to information on their website.

The appropriate permits to commence mining were obtained in 2007 and metals production started late in 2008. The construction of the mine cost 560 million euros in 2007–2008, and an additional 22 million from HEX in 2009 enabled investments that increased production by 45%.

In 2010 the company announced the commencement of uranium production as a by-product from its normal mining operations in Sotkamo. The uranium produced will be in the form of yellowcake with an estimated annual production of approximately 350 tons. At a yellowcake price of $40/lb the uranium production could result in an additional €20m annual revenue. The capital investment costs were €30m and estimated annual production costs are €2m. The resulting uranium production is estimated to meet 80% of Finland's annual uranium demand, although reprocessing and enrichment would be required to be conducted abroad, and would effectively double the production of uranium in the EU. Currently, the uranium is deposited into the gypsum pond.

The Talvivaara mine, since 2015 owned and operated by Terrafame, is one of the largest nickel mines in Finland. The mine is located in Sotkamo in Eastern Finland and employs 400 people. It is an open-pit mine, 22 km from Sotkamo and 28 km from Kajaani. The mine consists of two deposits 3 km apart, Kuusilampi and Kolmisoppi, and has an annual production capacity of over 10 million tonnes of ore. The mine has reserves amounting to 1 billion tonnes of ore grading 0.22% nickel, 0.13% copper, 0.5% zinc and 0.02% cobalt thus resulting 2.2 million tonnes of nickel, 1.3 million tonnes of copper, 5 million tonnes of zinc and 0.2 million tonnes of cobalt. 90% of the nickel is deposited in black schist rock, which contains 31% sulfides, most of which consist of iron sulfide minerals. Nickel-bearing sulfide minerals pentlandite, altered pentlandite and pyrrhotite are present in low concentrations, but are accessible by bioheap leaching.

The metals are extracted by bioheap leaching, a method where natural bacteria living in the rock accelerate metal leaching by oxidation. In conventional leaching, a coat of porous sulfide rock is left behind on the shrinking core of nickel in the grain. In contrast, in bioheap leaching, the oxidation of sulfides causes eventual disintegration of the porous rock, exposing more area than achievable by chemical means only. The ground ore is built into heaps 1.2 km long and 400 m wide, and a recycling irrigation system is used to keep the grains wet. The heat produced by the bacterial oxidation keeps the heap warm throughout the year. Extraction is done twice in primary and secondary heaps. In a pilot heap, over 90% of nickel and 80% of zinc was recovered within 500 days of leaching. Cobalt and copper recoveries were lower, 14% and 2%, respectively. The resulting green-colored solution is then refined to the metals. Treatment with hydrogen sulfide precipitates copper sulfide, then zinc sulfide and finally nickel-cobalt sulfide.

In 2011 Cameco signed an agreement with Talvivaara, where Cameco would pay US$60 million to construct a uranium extraction circuit at the mine in Sotkamo. Talvivaara would then pay back the initial construction costs in the form of uranium concentrate; once the initial costs are paid Cameco would continue to purchase the uranium concentrate at a pricing formula based on market price on the day of delivery.

A railway track was built in order to transport the nickel-cobalt concentrate to a Norilsk Nickel smeltery in Harjavalta, Finland.

Regulation

Based on stock exchange regulations according to the Courts of appeal in Finland Pekka Perä gave misleading information about Talvivaara mining production volume in 2012 and 2013. He was fined 240 euros by Courts of appeal in Finland in March 2019. Ahtium Oy (ex Talvivaara Kaivososakeyhtiö) was fined 20 000 euros.