Oil Shale in Estonia - Mining

Mining

As of May 2007, Estonia has been actively engaged in exploiting oil shale on a significant scale and accounts for 70% of the world's processed oil shale, although China is likely to overtake Estonian production in the near future. In 2005, Estonia mined 14.8 million tonnes of oil shale. During the same period, mining permits were issued for almost 24 million tonnes, with applications for mining an additional 26 million tonnes. Estonia has adopted the "National Development Plan for the Use of Oil Shale 2008-2015", which limits the annual mining of oil shale to 20 million tonnes. Companies involved in oil shale mining are Eesti Põlevkivi, Viru Keemia Grupp, Kiviõli Keemiatööstus and Kunda Nordic Cement.

As of 2007, six oil shale underground mines and open-cast mines were in operation and one mine was in preparation phase in Estonia. The historical ratio of underground mining to open-cast mining is approximately fifty-fifty, although it is tending to move away from open-cast production as bed depths increase.

The Aidu and Narva opencast mines, operated by Eesti Põlevkivi, uses surface mining technology of stripping with relatively big bucket (10–35 cubic meters) excavators. Both the overburden and the bed are at first broken up by blasting. Stripping is done with smaller excavators in opencasts with thin overburden using front end loaders and hydraulic excavators. The Aidu opencast mine uses bulk extraction of all beds, while the Narva opencast mine and the Põhja-Kiviõli opencast mine, operated by Kiviõli keemiatööstus, use highly selective extraction in three layers of seams. Exhausted open-cast areas are gradually being regenerated through land recultivation and reforestation.

Underground mines exploit room and pillar method. Longwall mining, used earlier, was abandoned in 1990s. The largest oil shale mine in the world is the Estonia Mine, opened in 1972. It is operated by Eesti Energia Kaevandused.