The spodumene pegmatite deposit of Länttä is located in the city district of Ullava, about 60 km south-east of the city centre of Kokkola.
The Länttä deposit was discovered by Suomen Mineraali Oy in the early 1960s. Paraisten Kalkkivuori Oy explored the deposit and carried out diamond drilling in 1963–1967. Pilot testing, metallurgic studies and tests to manufacture lithium salts were carried out in 1978 and 1980. Partek Oy (previously Paraisten Kalkkivuori) gave up its mining rights in 1982.
Keliber has continued the exploration of the Länttä deposit with diamond drilling programmes in 2004–2005 and 2011–2013. Bulk samping has also been carried out in Länttä for benefication tests and metallurgic tests. The latest bulk sampling was conducted in the summer of 2013. About 300 tonnes of ore was mined from two different sections of the main vein.
The pegmatite in Länttä is a typical example of uniform albite-spodumene pegmatite. The deposit consists of two main veins. The maximum thickness of the veins is about ten metres. Small, thinner veins parallel to the main vein occur in the vicinity of the main veins.
Both intermediary-mafic metavolcanites and metamorphic sedimentary rock (metagreywacke, mica schist) occur as host rock in the area. The pegmatite veins run from north-east to south-west and are almost vertical, sloping by 70 degrees towards the southeast.
The ore reserve estimates have been prepared according to the guidelines of the JORC Code 2012 by Pöyry Finland Oy by competent persons under the supervision of Ville-Matti Seppä MSc (Geology), EurGeol acting as the qualified person. The mineral resource estimates for Länttä have been prepared by Markku Meriläinen (MAusIMM) and Pekka Loven (MAusIMM). Estimates have been prepared and reported in accordance with the guidelines of the Australasian Code for the Reporting of Mineral Resources and Ore Reserves (JORC Code 2012).