Uranium mining in Thuringia and Saxony - a survey of geology and mining

Since the late forties East Germany has been one of the most important uranium producers of the world with a total output of 220000 metric tons uranium. Prospecting, exploration and exploitation were carried out by a Soviet-German joint-stock company (SDAG Wismut). Production has decreased since the mid-seventies and is now at about 3000 t U per year. - Five different types of deposits have been opened up since uranium mining started. Two of these are of greatest economic importance: The 'Ronneburg'-type in Lower Paleozoic slate, limestone and diabas (Eastern Thuringia) and hydrothermal vein deposits in the exocontact of granite (Western Erzgebirge). - More than 90% of the uranium have been produced by underground mining. The following mining methods have been used: Conventional mining methods (cut-and-fill stoping, room-and-pillar mining, roomwork, slicing and caving, slicing with cemented hydraulic fill) as well as underground leaching (in situ or with shrinkage) and surface leaching (heap or tip). Treatment has been carried out hydrometallurgically by acidic or soda-alkaline processes. - Because of the low price level of uranium on the world market and the end of uranium imports by the U.S.S.R., the mines will have be closed down and the land reclaimed. (orig.)