**9. East Germany uranium mining after World War II**

The uranium exploration and mining in East Germany (GDR) started in 1946 as the Soviet stock company, SAG Wismut. In the first stage of this mining activity, an old silver-uraniumcobalt-nickel ore deposit Johanngeorgenstadt was open. Later, the uranium ore deposits near Schneeberg and Oberschlema were found and mined. The second stage of uranium exploration had started in 1950 in the vicinity of the radium spa at Ronneburg. In both uranium ore districts, using a variety of ground-based and aerial techniques, the exploration activities covered an extensive area of about 55,000 km<sup>2</sup> . About 36,000 boreholes in total were drilled in the area covering approximately 26,000 km<sup>2</sup> . Total expenditures for uranium exploration were on the order of 5–6 billion of GDR mark [31].

In 1954, a new joint Soviet-German stock company was created (SDAG Wismut). Both governments held the joint company equally. At the end of the 1950s, uranium mining was concentrated in the region of Eastern Thuringia (Ronneburg ore district). From the beginning of the 1970s the Ronneburg ore district provided about two-thirds of uranium annual production in the GDR. In East Germany, in contradiction to Czechoslovakia, the prisoners were used in uranium mining in limited extent. The prisoners were used mainly in 1946–1947 and the total number of prisoners used in SAG Wismut from 1946 to 1949 was 59,492 [38].

Total production in East Germany in 1946–1990 was 219,517 t U, making it the third largest producer in history behind the United States and Canada. The uranium mining and processing of uranium ores in two processing plants were stopped in 1989. Decommissioning of uranium mines and production facilities started in 1990. Between 1991 and 2012, uranium recovery from mine water treatment and environmental restoration amounted to a total of 2540 t U. Since 1992, all production in former East Germany has been derived from clean-up operations at the Königstein mine. In 2007, the production in the Königstein mine has been 38 t U [31].

Hydrozircon also occurs in the lower ore-bearing horizon. Rich uranium mineralisation rarely occurs in faults cutting the U-Mo mineralised horizons in the western part of the Novoveská Huta deposit. Uranium and Mo mineralisation in these faults is represented by uraninite, cof-

Some small uranium deposits and occurrences were found also in the other West Carpathian geological units in Slovakia, namely in the Hronicum (Vikartovce, Kravany, Švábovce), Tatricum (Kálnice, Selec) and the Veporicum. All these geological units could be distinguished into two morphological types of uranium mineralisation, namely stratiform mineralisation in the Permian volcanoclastic complexes and vein mineralisation evolved in tectonic zones

In 2012–2014, new exploration licences for uranium ore were active in the Slovak Republic. The most perspective exploration licence covers uranium mineralisation in Kuriškova, near Košice in the Eastern Slovakia. In this area, conventional resources in amount of 15,830 t U were calculated and identified. In the Novoveská Huta, resources in amount of 3488 t U are recently registered [31]. However, mining of both uranium deposits is recently blocked by

The uranium exploration and mining in East Germany (GDR) started in 1946 as the Soviet stock company, SAG Wismut. In the first stage of this mining activity, an old silver-uraniumcobalt-nickel ore deposit Johanngeorgenstadt was open. Later, the uranium ore deposits near Schneeberg and Oberschlema were found and mined. The second stage of uranium exploration had started in 1950 in the vicinity of the radium spa at Ronneburg. In both uranium ore districts, using a variety of ground-based and aerial techniques, the exploration activities cov-

In 1954, a new joint Soviet-German stock company was created (SDAG Wismut). Both governments held the joint company equally. At the end of the 1950s, uranium mining was concentrated in the region of Eastern Thuringia (Ronneburg ore district). From the beginning of the 1970s the Ronneburg ore district provided about two-thirds of uranium annual production in the GDR. In East Germany, in contradiction to Czechoslovakia, the prisoners were used in uranium mining in limited extent. The prisoners were used mainly in 1946–1947 and the total

Total production in East Germany in 1946–1990 was 219,517 t U, making it the third largest producer in history behind the United States and Canada. The uranium mining and processing of uranium ores in two processing plants were stopped in 1989. Decommissioning of uranium mines and production facilities started in 1990. Between 1991 and 2012, uranium recovery from mine water treatment and environmental restoration amounted to a total of

number of prisoners used in SAG Wismut from 1946 to 1949 was 59,492 [38].

. About 36,000 boreholes in total were drilled in the

. Total expenditures for uranium exploration were on

finite and molybdenite.

(quartz-carbonate, quartz-gold-bearing veins) [37].

12 Uranium - Safety, Resources, Separation and Thermodynamic Calculation

**9. East Germany uranium mining after World War II**

various environmental activities.

ered an extensive area of about 55,000 km<sup>2</sup>

the order of 5–6 billion of GDR mark [31].

area covering approximately 26,000 km<sup>2</sup>

The uranium mining in East Germany was concentrated in two main regions: the Ore Mts. region in Saxony (Schneeberg, Niederschlema-Alberoda, Johanngeorgenstadt, Schwarzenberg and Pöhla-Tellerhäuser) and the Ronneburg district in Thuringia. Small uranium deposits were evolved in the Cretaceous sandstones near the Königstein in Saxony [39–41]. Uranium deposits in the Ore Mts. region are hydrothermal vein deposits. In these ore deposits, three uraniferous mineral associations were established (quartz-calcite-pitchblende, carbonate-pitchblende-fluorite and bismuth-cobalt-nickel-silver-uranium). Uranium in these associations is represented by pitchblende, sooty pitchblende and coffinite. In veins of the Niederschlema-Alberoda deposit, coffinite constitutes up to 5% of the uranium content. The main ore deposit in this region was Niederschlema-Alberoda and it was one of the largest vein uranium deposits in the world, which has produced 73,900 t U. Other uranium deposits in the Ore Mts. region produced distinctly lower amount of uranium (Oberschlema 6700 t U, Johanngeorgenstadt 3600 t U, Pöhla-Tellerhäuser 1240 t U, Schwarzenberg 670 t U and Schneeberg 160 t U).

The Niederschlema-Alberoda uranium ore district is located in the Western Ore Mountains, in Germany, near the state boundary to Czech Republic. This ore district is evolved in the intersection of the SW-NE striking Loessnitz-Zwoenitz syncline with NW-SE trending Gera-Jáchymov fault zone. The Loessnitz-Zwoenitz syncline is one from sectional tectonic structures, which are ingredients of the Erzgebirge-Fichtelgebirge anticlinorium in the fold framework of the Saxothuringian Zone. The most important and central tectonic element of the Gera-Jáchymov fault zone is the vein structure Red Ridge (Roter Kamm), also defining the border between the Niederschlema-Alberoda ore district in NE and the Schneeberg uranium deposit in SW. In the Loessnitz-Zwoenitz syncline, predominantly Upper Ordovician-Silurian-Middle Devonian "productive" rocks are folded into Lower Ordovician schists of the northern edge zone of the Erzgebirge-Fichtelgebirge anticlinorium. The rock series of the "productive unit" are phyllites with intercalations of metamorphosed black shales and metacarbonates. The uranium-bearing veins occur in the contact metamorphic zone of the syncline beneath the late-Variscan Aue granite pluton. This granite body, located within the Gera-Jáchymov fault zone, intruded early-Variscan metasediments, especially low-grade garnet phyllites and medium-grade mica schists. The Aue granite body comprises various biotite granites. The Aue granite should have served as a major source for U accumulated in post-granitic deposits of Schneeberg and Schlema-Alberoda ore districts.

The uranium ore veins have a common thickness from 0.1 to 0.3 m with a maximum of 1 m. However, some ore veins show a massive pitchblende mineralisation with a thickness up to 2 m, which were mined down to a depth of about 2000 m. The hydrothermal mineralisation is usually divided into three main stages. The most important is first pitchblende-quartzcalcite-fluorite-sulphide stage. The second, post-Variscan stage contains dolomite-selenidepitchblende mineral association. For the third, Bi-Co-Ni stage, the predominance of arsenides and sulphides Co and Ni and native Bi is significant. The main mined ores were uranium ores, and accompanying ores (Co, Ni, Ag, Bi, Se and/or Pb, Zn and Cu from older quartz-sulphide veins) have been extracted only temporarily and in small quantities [39, 40].

**10. West Germany uranium mining after World War II**

**11. Polish uranium mining after World War II**

**12. Hungarian uranium mining after World War II**

duction was about 700 t U [31].

Starting in 1956, exploration for uranium ores in Federal Republic Germany (FRG) was carried out in several Variscan units, especially in Black Forest, Odenwald, Frankenwald, Oberpfalz, Bayerischer Wald and Harz. Three small uranium deposits were found: vein deposit near Menzenschwand in the southern Black Forest, sedimentary Müllenbach deposit in the northern Black Forest and the Grosschloppen deposit in the Fichtelgebirge. The total uranium pro-

History of Uranium Mining in Central Europe http://dx.doi.org/10.5772/intechopen.71962 15

Exploration and exploitation of uranium ore deposits in Poland began in 1948 by opening of the vein uranium deposits in the Karkonosko-Izerski block of the Bohemian Massif (Wolnosc, Miedzianka, Podgorze, Rubezal, Mniszkow, Wiktoria, Majewo, Walowa Gora, Radoniów and Wojcieszyce). For processing of uranium ores from these mined deposits, in 1948, an industrial plant in Kowary (Lower Silesia) was established. Later, small occurrences and deposits of uranium mineralisation were founded in the Ladek and Snieznik Klodzki metamorphic complex of the Bohemian Massif (Kopaliny-Kletno). During the period 1948 and 1967, approximately 650 t of uranium was mined and all uranium ores were exported to the Soviet Union. In 1956, exploration of uranium ore deposits by the Geological survey in areas of the Upper Silesian Coal Basin and the Polish lowlands began. During these exploration activities, small occurrences of uranium mineralisation were discovered in the Lower Ordovician sediments (Rajsk), in the Triassic sediments (Perybaltic Syneclize) and in the Sudetes area (Okrzeszyn, Grzmiaca and Wambierzyce). In May 2012, one concession for prospecting base metals and uranium deposit was granted in the Radoniów area. At present, research projects aimed at assessing the possibility of obtaining uranium from domestic low-grade uranium ores and waste rock piles left at historic uranium mining operations (Kowary) are being conducted. Special attention is being paid to the use of biological leaching. All these exploration activities concentrated on finding of potential uranium resources were provided from 2012 to 2014.

The first prospecting for uranium ores started in 1952 with Soviet participation. During airborne and surface radiometry in the western part of the Mecsek Mts., the Mecsek deposit of sedimentary ore deposit was found in 1954. The first shafts in this area were placed in 1955 and 1956. In 1956, the Soviet-Hungarian uranium joint venture was dissolved and uranium production from this ore deposit became the sole responsibility of the Hungarian state. Uranium in the Mecsek deposit was mined from 1956 to 1997. Total production of uranium from this ore deposit was about 21,000 t U. The uranium ore in the Mecsek deposit occurs in Upper Permian sandstones that may be thick as 600 m. The sandstones were folded into the

The second most significant area with uranium mineralisation in GDR was the Ronneburg district in Thuringia. This district is part of the Thüringisch-Fränkischen Schiefergebirge. The main geological structure of this district is the Berga anticlinorium. Uranium mineralisation occurs in the Upper Ordovician to Lower Devonian black schist series with total thickness about 250 m. The main part of uranium mineralisation is bounded on the Upper Ordovician Leder schists. In the Ronneburg ore district, three morphological types of uranium mineralisation, namely mineralisation in faults and shear zones, mineralisation in breccias and highly dispersed mineralisation in black schists, were distinguished. Uranium mineralisation was formed by two associations: carbonate-uraninite and uraninite-pyrite associations. The main mined association was uraninite-pyrite association containing uraninite, pyrite, coffinite, marcasite, chalcopyrite, arsenides, calcite, dolomite, hematite and hydrogoethite. The uranium deposits in the Ronneburg district were mined from 1951 to 1990 in three open pits (Ronneburg, Lichtenberg and Stolzenberg) and in seven shafts. Total open pit and mine production of the Ronneburg ore district was 112914.3 t U with average grade of 0.099% U [40].

Small occurrence of uranium mineralisation was also found in the Lower Permian hard coalbearing sediments of the NW-SE Döhla basin near Dresden. The basin that evolved along the late Variscan Elbe lineament contains the Upper Carboniferous and Lower Permian freshwater sediments (conglomerates, breccias, schists and hard coal-bearing sediments). The Lower Permian hard coal sediments contain hydrothermal uranium mineralisation (uraninite and coffinite) together with sulphide (sphalerite, chalcopyrite and galena) and carbonate mineralisation. Main uranium mining area in the Döhla basin was by Dresden-Gittersee and Freital. Total mine production of the Freital ore deposit mined from 1968 to 1989 was 3691 t U with average grade of 0.11% U [40].

In the natural park Saxony Switzerland, near Pirna was from 1967 to 1990 mined uranium deposit Königstein. This deposit was developed in the local Cretaceous basin that is NW part of the North Bohemian Cretaceous basin. From this large basin, the local Pirna basin was separated by the NNW-SSE Elbe lineament. The uranium mineralisation is developed in the three Cenomanian formations: lower freshwater continental, middle lagoon sediments and upper marine sediments. Bodies of the Lower Cambrian granodiorites and Variscan granites of the Markersbach granite body form the basement. Freshwater sediments are developed in depressions of the paleo relief and consist of sandstones and clay-bearing schists. All these rocks are often rich in organic matter (coalified plant detritus). The sediments of marine Cenomanian contain different sandstone types. Mostly horizontal lenses form the ore bodies. The thickness of ore bodies was between 0.5 and 1.0 m, sometimes up to 2.5 m. Some part of uranium mineralisation occurs also in the younger faults. Uranium mineralisation is formed by uraninite, coffinite and fourmarietite. Total mine production of the Königstein ore deposit mined from 1967 to 1995 was 18526.9 t U with average grade of 0.03–0.08% U [40]. After closing all uranium deposits in 1990, various large-scale remediation activities were provided from 1991 to 2014 [31].
