SDAG Wismut
Encyclopedia
Uranium
Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...
mining company in East Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
producing 230,400 tonnes of uranium between 1947 and 1990. In 1991 it was transformed into the Wismut GmbH owned by the state of Germany which is now responsible for the recultivation of the former mining and milling areas. The head office of the SDAG Wismut / Wismut GmbH is in Chemnitz
Chemnitz
Chemnitz is the third-largest city of the Free State of Saxony, Germany. Chemnitz is an independent city which is not part of any county and seat of the government region Direktionsbezirk Chemnitz. Located in the northern foothills of the Ore Mountains, it is a part of the Saxon triangle...
-Siegmar.
History
Radium
Radium is a chemical element with atomic number 88, represented by the symbol Ra. Radium is an almost pure-white alkaline earth metal, but it readily oxidizes on exposure to air, becoming black in color. All isotopes of radium are highly radioactive, with the most stable isotope being radium-226,...
and Polonium
Polonium
Polonium is a chemical element with the symbol Po and atomic number 84, discovered in 1898 by Marie Skłodowska-Curie and Pierre Curie. A rare and highly radioactive element, polonium is chemically similar to bismuth and tellurium, and it occurs in uranium ores. Polonium has been studied for...
and radioactive waters were used in several towns for health treatment. After World War II, the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
became interested in the East German uranium occurrences as a source for its nuclear weapons program
Soviet atomic bomb project
The Soviet project to develop an atomic bomb , was a clandestine research and development program began during and post-World War II, in the wake of the Soviet Union's discovery of the United States' nuclear project...
. They discovered significant resources and started mining in 1946. In 1947 the Soviet stock company "Wismut" (SAG Wismut, named after the German word for the metal bismuth
Bismuth
Bismuth is a chemical element with symbol Bi and atomic number 83. Bismuth, a trivalent poor metal, chemically resembles arsenic and antimony. Elemental bismuth may occur naturally uncombined, although its sulfide and oxide form important commercial ores. The free element is 86% as dense as lead...
) was formed. In the following years the company became the most important source for uranium for the Soviet Union and several tens of thousands of people were employed. Safety and environmental standards were very low leading to the exposure of many thousands of workers to dangerous levels of radon
Radon
Radon is a chemical element with symbol Rn and atomic number 86. It is a radioactive, colorless, odorless, tasteless noble gas, occurring naturally as the decay product of uranium or thorium. Its most stable isotope, 222Rn, has a half-life of 3.8 days...
and quartz dust leading to lung cancer and silicosis. At the end of 1953 the company was liquidated and the Soviet-German stock company Wismut (SDAG Wismut) was newly founded with the Soviet Union and the German Democratic Republic
German Democratic Republic
The German Democratic Republic , informally called East Germany by West Germany and other countries, was a socialist state established in 1949 in the Soviet zone of occupied Germany, including East Berlin of the Allied-occupied capital city...
owning 50% each. Working and technological standards improved significantly in the following years. Uranium exploration and mining concentrated in the first years after World War II on the old mining areas of the Erzgebirge and adjacent Vogtland Mountains. Many uranium occurrences have been known there for a long time and often were already accessible by old adits and shafts from silver and base metal mining of former centuries. In 1950 the giant ore deposit of Ronneburg and the medium sized Culmitzsch deposit (both in eastern Thuringia) were discovered and in 1965 the deposit Königstein in the Elbe Sandstone Mountains
Elbe Sandstone Mountains
The Elbe Sandstone Mountains, also called the Elbe sandstone highlands is a mountain range straddling the border between the state of Saxony in southeastern Germany and the North Bohemian region of the Czech Republic, with about three-quarters of the area lying on the German side...
. The uranium production of the Wismut had its peak from the mid 1960s to the early 1970s reaching nearly 7,000 tonnes of uranium per year. After that it declined to 3,500 tonnes of uranium in the last normal production year 1989. Through the political and economical changes in East Germany and the following reunification of Germany uranium mining was stopped in December 1990. The Federal Government of Germany took over the ownership of the East German and Soviet stocks of the company and transformed it into the Wismut GmbH in 1991. This new company is responsible for recultivating the former mining and milling sites with a total budget of around 6.2 billion Euro. This activity includes securing / filling of underground cavities, covering of dumps and tailings
Tailings
Tailings, also called mine dumps, slimes, tails, leach residue, or slickens, are the materials left over after the process of separating the valuable fraction from the uneconomic fraction of an ore...
, treatment of mine water
Acid mine drainage
Acid mine drainage , or acid rock drainage , refers to the outflow of acidic water from metal mines or coal mines. However, other areas where the earth has been disturbed may also contribute acid rock drainage to the environment...
and removal / decontamination of the buildings at the mine and milling sites.
Erzgebirge Mts. and Vogtland Mts.
The Erzgebirge and Vogtland Mts were the first exploration targets for uranium and host the largest number of deposit mined by the Wismut. All deposits in these mountain ranges are hydrothermal vein style mineralisations in Palaeozoic metasedimentary/-igneous rocks and Variscan age granites. Most deposits are situated in the western Erzgebirge Mts and the neighbouring Vogtland region while the central and eastern Erzgebirge Mts contains just few smaller deposits. The deposits are related to deep crustal northwest-trending fault structures with the most important being the Gera-Jáchymov fault zone containing most of the larger deposits including Jáchymov on the Czech site of the Erzgebirge Mts., Johanngeorgenstadt, Pöhla-Tellerhäuser, Schneeberg-Schlema-Alberoda in the German part of the Erzgebirge Mts. and the Ronneburg blackshale-type mineralisation in Thuringia. The size of the mineralisations ranges from very small deposits with some hundred kg uranium content and few mineralised veins up to the giant deposit of Schneeberg-Schlema-Alberoda containing nearly 100,000 tonnes of uranium and about 2,000 mineralised veins. There are three major vein types carrying uranium: uranium-quartz-calcite veins (270 million years old), dolomite-uranium veins (Triassic age) and biconi-Ag-U veins (Tertiary age). Only the first type of veins is a primary mineralisation, while the latter two carry remobilised pitchblende from the older vein types. The biconi-Ag-U mineralisation was mined since the 15th century for its content of silver, bismuth, cobalt and nickel. The heavy black mineral often occurring in these veins was useless for the miners in the former times and was therefore called "Pechblende" (pitchblende), the word still used for the most important uranium mineral. Pitchblende is the most important uranium mineral in all veins types, but coffinite does also occur. In the oxidation zones of the deposits occur a wide range of secondary uranium minerals. The distribution of uranium minerals in the veins is very unsteady with the highest concentration of uranium in places where they crosscut reducing host lithologiesLithology
The lithology of a rock unit is a description of its physical characteristics visible at outcrop, in hand or core samples or with low magnification microscopy, such as colour, texture, grain size, or composition. It may be either a detailed description of these characteristics or be a summary of...
like carbon-rich schist and skarn. The width of the veins ranges from a few centimeters to several meters with an average ore grade of 0.1% of uranium, also locally lenses of massive pitchblende occur with a width of over 1 m. In the following the most important deposits are described:
Schneeberg-Schlema-Alberoda (Objects 02/03/09; mining division Aue)
Zwickau
Zwickau in Germany, former seat of the government of the south-western region of the Free State of Saxony, belongs to an industrial and economical core region. Nowadays it is the capital city of the district of Zwickau...
in the western Erzgebirge Mts. Schneeberg
Schneeberg, Saxony
Schneeberg is a town in Saxony’s district of Erzgebirgskreis. It has roughly 16,400 inhabitants and belongs to the Town League of Silberberg . It lies 4 km west of Aue, and southeast of Zwickau.- Location :...
was an important mining center since the 15th century producing silver, cobalt, nickel and bismuth and Oberschlema
Bad Schlema
Bad Schlema is a community in the district of Erzgebirgskreis in the Free State of Saxony in Germany and belongs to the Silberberg Town League . Through town runs the Silver Road...
was known for the strongest natural occurring radioactive waters at the beginning of the 20th century. A radium health center was established in the town in 1914.
After the Second World War Soviet scientists started exploring the old mining areas for uranium and mining commenced in 1946 even before the SAG Wismut was established in 1947. Schneeberg at the southern end of the deposit became Object 03 and Oberschlema Object 02. Subsequently the blind (no mineralisation reaches the surface) northern part of the ore field (Niederschlema-Alberoda) was discovered and mining started there in 1949. Object 09 was established to mine the Niederschlema-Alberoda part of the ore field.
Mining in Schneeberg went on just until 1954 using many shafts left over from the silver and cobalt mining. To this point, about 200 tonnes of uranium have been extracted from Schneeberg. Oberschlema was mined to depths of over 700 m. Mining ceased in 1960 after a production of more than 7,000 tonnes of uranium. A high density of veins near the surface and the "wild" mining methods in the 1940s and 1950s caused the complete destruction of Oberschlema. Most houses were so badly damaged and the underground so unstable that the whole small town was removed in the 1950s. Today the former mining area hosts the radon-health center reestablished in the 1990s. After a restructuring of the company in the 1960s Object 09 became Bergbaubetrieb Aue
Aue
Aue is a small town in Germany at the outlet of the river Schwarzwasser into the river Mulde in the Ore Mountains, and has roughly 18,000 inhabitants. Aue was the administrative seat of the former district of Aue-Schwarzenberg in Saxony, and is part of the Erzgebirgskreis since August 2008...
(mining division Aue). It developed to the single largest producer of uranium within the SAG/SDAG Wismut with a peak production of 4,000 tonnes of uranium in 1965. In the last normal production year 1989 it produced about 550 tonnes. This deposit was the first of all Wismut deposits getting large modern mining shafts in the middle of the 1950s and powerful ventilation shafts. The most important shafts where Shaft 38 (Niederschlema), Shaft 366 (Aue-Alberoda) and Shaft 371 (Hartenstein). The latter one went into production in 1959 and was the main shaft of the deposit up to the end of production in 1990. Shaft 371 possessed an automated sorting plant used to separate different classes of ore and to increase the overall ore grade. High grade ore was sent directly to the Soviet Union without further processing, while ore containing less than 1% uranium was shipped to the mill at Crossen near Zwickau. This was done until 1980, afterwards all ore was milled with the sorting plant raising the average ore grade to 0.4% before it was sent to Crossen for processing. It was also tried to produce basemetals, silver and selenium
Selenium
Selenium is a chemical element with atomic number 34, chemical symbol Se, and an atomic mass of 78.96. It is a nonmetal, whose properties are intermediate between those of adjacent chalcogen elements sulfur and tellurium...
as by-products, but this remained unsuccessful. Shaft 371 was connected to the -540 and -990 m level (the depth is related to the Markus Semmler adit dewatering the upper part of the deposit into the Zwickauer Mulde river). Deeper levels were connected by blind shafts. The deepest level opened in 1988 was the -1800 m level nearly 2,000 m underground making the mine the deepest in Europe. The mining method used was the same as in the centuries before, although with more modern equipment: galleries were driven along strike of the mineralised vein on a lower and upper level (vertical distance 30 to 45 m). They were connected by small shafts from the lower to the upper level. Following, the vein was mined upwardly using drilling and blasting. The ore was transported to the lower level and was brought to the main shafts by rail carriages, while the stope was filled with waste rock if possible. After a vein was mined out, the entrances were sealed to prevent radon from the old stopes to enter the active mine parts. This mining method was used in all vein type deposits of the Erzgebirge Mts. The total production from Niederschlema-Alberoda is more than 72,000 tonnes of uranium. Together with the production of Schneeberg and Oberschlema, production losses and unmined resources the total uranium content is about 96,000 tonnes of uranium, making Schneeberg-Schlema-Alberoda the largest vein-style uranium deposit in the world.
After the political changes the production was already slowed down in 1990 and eventually stopped on the 31 December 1990. Together with the closure of the uranium mine at Pöhla and the tin
Tin
Tin is a chemical element with the symbol Sn and atomic number 50. It is a main group metal in group 14 of the periodic table. Tin shows chemical similarity to both neighboring group 14 elements, germanium and lead and has two possible oxidation states, +2 and the slightly more stable +4...
mines at Altenberg
Altenberg
Altenberg is a German language place name and may refer to:Places in Germany:*Altenberg, Germany, a city in the Free State of Saxony, Germany...
and Ehrenfriedersdorf
Ehrenfriedersdorf
Ehrenfriedersdorf is a town in the district of Erzgebirgskreis, in the Free State of Saxony, Germany. It is situated 8 km northwest of Annaberg-Buchholz, and 21 km south of Chemnitz.- Theatre :...
this ended the 800 year old history of metal mining in the Erzgebirge. After the end of production, the newly formed Wismut GmbH as succeeder of the SDAG Wismut start recultivation of the area. Flooding of the mine started in 1991 and in 1997 the -540 m level as the uppermost level of shaft 371 was reached by the water. To this point, the mine was open for the public and it was the deepest tourist mine in Europe. A water treatment plant was erected with a final capacity of 1,300 m3 per hour removing uranium, radium, arsenic and iron from the contaminated mine water before it is finally released in the Zwickauer Mulde River. Underground work especially in Oberschlema is carried out to secure surface near galleries and shafts from collapse and to provide safe airways for the radon containing mining air to prevent it from uncontrolled movement into populated areas of the region. The huge waste rock dumps are either relocated ore recontoured and covered with 80 cm clay and 20 cm top soil. In 2008, most of the underground work was finished and nearly all shafts were sealed. Most dumps are recultivated. Shaft 382 with a depth of 1,400 m will stay open (although it is flooded) and provide a controlled way for radon-bearing air from the mine.
Like most deposits in the western Erzgebirge Mountain, the Schneeberg-Schlema-Alberoda deposit is situated on the Gera-Jachymov fault zone. This major geological structure with a length of several hundred kilometres strikes NW-SE running from the central Bohemian Massive in the Czech Rebublic to the central part of Germany. The central element of this fault zone in the Erzgebirge Mts is the Roter Kamm (Red Ridge) fault carrying a young quartz-hematite mineralisation, but no uranium. This fault forms the boundary between the deposits Schneeberg and Oberschlema having a vertical displacement of about 400 m. The second controlling element for the deposit are Variscan granites, which underlie the deposit. The veins carrying mineralisation are within the exocontact of the granite, although the oldest uranium mineralisation is about 20 Ma younger than those granites. The third controlling factor is a heavily deformed unit of Ordovician to Silurian Meta-sedimentary rocks. This so called Loessnitz-Zwoenitz through runs about E-W broadening to the east. These rock unit is formed by quartzites, meta-blackschales, amphibolites and skarns. It is contained within phyllites which form the major rock type in this area of the Erzgebirge Mts. The rocks of the Loessnitz-Zwoenitz-Through are called the "productive series", because they carry nearly all of the mineralisation. Also the vein structures can be followed from the productive series into the phyllites and granites, no significant mineralisation was observed outside of it. The ore field contains about 1,800 mineralised veins. Uranium bearing veins strike about NW-SE parallel to the Roter Kamm fault.
The oldest type of mineralisation consists of quartz, calcite, fluorite, pitchblende and minor hematite. The age of this primary mineralisation is about 270 Ma and it was the most important type in Oberschlema. About 100 Ma years later a second uranium mineralisation formed. Veins of this type contain dolomite, calcite, pitchblende, minor sulphides and selenides (especially clausthalite). This mineralisation event did not bring new uranium into the deposit but remobilised uranium from the older mineralisation. These dolomite-uranium veins were the major uranium formation in Niederschlema-Alberoda. A third uranium bearing vein type contains quartz, calcite, Co- and Ni- Arsenides, native bismuth and silver and pitchblende. Like the dolomite veins, there was no input of new uranium but only remobilisation. These were the most important veins in Schneeberg, not only for uranium but also for the Ag and Co-Ni production. Telescoping is also a common feature with different types of mineralisation are found stuck together in the same part of the vein.
Beside the uranium bearing mineralisation types, there are about one dozen different styles of other mineralisation ranging from Sn-W, Pb-Zn, fluorite-barite to quartz-hematite. However, they had no economic importance but contributed to the large variety of minerals known from the deposit, which are several hundreds. Especially in the oxidation zones of Schneeberg and Oberschlema, many rare secondary minerals are found with may of them newly discovered there. For example, in samples from a single ore shot in Schneeberg 5 new uranium minerals were discovered in 1871, which were walpurgite, zeunerite
Zeunerite
Zeunerite is a green copper uranium arsenate mineral with formula Cu22•10-16. It is a member of the autunite group. Metazeunerite is a dehydration product....
, troegerite, uranospinite and uranosphaerite.
Zobes and Bergen (Object 06)
Zobes is a small village in the Vogtland Mts.. Between 1949 and 1961 the second largest vein-type deposit of the Wismut was mined there. The geology is very similar to that of Schneeberg-Schlema-Alberoda with similar types of veins and host rocks. But the size is much smaller, the total uranium content is roughly 5,000 tonnes. Unlike most other deposits in the Erzgebirge and Vogtland Mts., there was no historical mining preceding the activities of the Wismut. Because of the smaller size of the deposit and the relative low population in the area mining had not such an impact like at other deposits of the Wismut. Only the dump of shaft 362 is left today, others have been removed as construction material and low grade ore. The small uranium deposit Bergen was mined only few kilometers away and was connected underground to the Zobes mines. While the Zobes deposit was in meta-sedimentary rocks, Bergen was an intragranitic deposit. It became worldwide recognised for its excellent and large crystals of secondary uranium minerals like uranocircite. There is also a mineral named after the deposit: bergeniteBergenite
Bergenite is a rare uranyl phosphate of the more specific phosphuranylite group. The phosphuranylite-type sheet in bergenite is a new isomer of the group, with the uranyl phosphate tetrahedra varying in an up-up-down, same-same-opposite orientation. All bergenite samples have been found in old...
. A part of the Bergen deposit was later mined for granite
Granite
Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...
as construction material in a large open cut.
Johanngeorgenstadt (Object 01)
Johanngeorgenstadt
Johanngeorgenstadt is a mining town in Saxony’s Ore Mountains, 17 km south of Aue, and 27 km northwest of Karlovy Vary. It lies in the district of Erzgebirgskreis, and right on the border with the Czech Republic, is a state-recognized health resort , and calls itself Stadt des...
is situated in the westernmost part of the Erzgebirge Mts directly on the border to the Czech Republic and on the boundary between Vogtland Mts and Erzgebirge Mts. It has a special relationship to the metal uranium: In 1789, the chemist M.H. Klaproth discovered uranium in a sample from the silver mine Georg Wagsforth in the town. About 160 years later, the town became Object 01 of the Wismut and the old town center was completely destroyed through intense underground mining near the surface for uranium. From the old town center, only the church survived this part of town history while all other houses had to be removed through severe damages. Mining took place from 1946 to 1958 and about 3,500 tonnes of uranium were extracted. The deposit extended over the border into Czechoslovakia
Czechoslovakia
Czechoslovakia or Czecho-Slovakia was a sovereign state in Central Europe which existed from October 1918, when it declared its independence from the Austro-Hungarian Empire, until 1992...
. While the Czechoslovakian uranium company carried out own exploration and mining on its site of the deposit, one vein was mined by the Wismut under Czech territory by a contract between the East German and Czechoslovakian Government.
The deposit is situated on the western edge of the Gera-Jachymov fault zone. It is located in the exocontact of the Eibenstock-granite underlying the deposit. The granite itself carries only minor U-Bi veins, most mineralisation is contained in veins in micaschist. Major mineralisation styles are quartz-carbonate-pitchblende and quartz-calcite-arsenide-Ag-pitchblende veins.
The Wismut GmbH is not responsible for recultivating mining areas which did not belong to the company in 1991 when it was formed out of the SDAG Wismut and there are no funds included in the initial 6.2 billion Euro budget for those areas. Because most of the smaller deposits in the Erzgebirge and Vogtland Mts. were mined out in the 1950s and 1960s and the old mining sites were transferred to the local authorities after mining stopped, there were no plans of the Wismut GmbH to recultivate those areas in their original rehabilitation program. However, after negotiations between the federal state of Saxony, the federal government of Germany and the Wismut GmbH contracts were made and funds were provided to rehabilitate these old areas, including Johanngeorgenstadt. In this town activities of the Wismut GmbH include mainly contouring, relocation and covering of dumps and securing hazardous underground mining areas.
Pöhla (mining division Aue)
Pöhla is a small village in the western Erzgebirge Mts on the feet of the Fichtelberg, the highest mountain in eastern Germany. Mining in the area started centuries ago but mining activity remained minor in the area until after World War II. The Wismut started exploration in the 1940s and mined small mineralisation in the area containing a few tonnes of uranium. A shaft was sunken at Pöhla-Globenstein but found only very little uranium mineralisation. However, a magnetite-skarn mineralisation was discovered and the shaft was transferred to an east German iron company for exploration uses. During exploration in the 1960s, drillings showed radioactive anomalies in areas named Hämmerlein and Tellerhäuser south of Pöhla. It was decided to explore these deposits underground using an adit which was started in 1967. The portal of the adit was in a valley outside Pöhla. At an adit length of about 3 km the adit cut the mineralisation at Hämmerlein. It showed that there was just a minor uranium mineralisation which was mined out during exploration phase resulting in a production of 15 tonnes of uranium. However, a significant tin mineralisation was discovered in skarns and schists. Further, the skarns contained also zincZinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...
, magnetite
Magnetite
Magnetite is a ferrimagnetic mineral with chemical formula Fe3O4, one of several iron oxides and a member of the spinel group. The chemical IUPAC name is iron oxide and the common chemical name is ferrous-ferric oxide. The formula for magnetite may also be written as FeO·Fe2O3, which is one part...
, indium
Indium
Indium is a chemical element with the symbol In and atomic number 49. This rare, very soft, malleable and easily fusible post-transition metal is chemically similar to gallium and thallium, and shows the intermediate properties between these two...
and cadmium
Cadmium
Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, bluish-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Similar to zinc, it prefers oxidation state +2 in most of its compounds and similar to mercury it shows a low...
. This mineralisation was intensively explored during the 1970s and studies were made to set up a major tin mine. However, although resources are high and ore grades were better than in the producing tin mines in East Germany at that time, the mineralogy was very complex preventing the usage of proven milling technologies. The Wismut developed a special milling technology for the complex tin ore but it proved to be too expensive and the project was stopped.
From Hämmerlein, the main adit was driven further during the 1970s to investigate the mineralisation at Tellerhäuser which was cut at about 7.5 km adit length. This uranium mineralisation was much larger than at Hämmerlein and two blind shaft were sunken to deeper parts of the deposits. Mining started in 1983 and 1,200 tonnes of uranium were produced until the end of production in 1990. Like Hämmerlein, also Tellerhäuser showed a significant tin mineralisation in skarns as well as magnetite. Some of the magnetite was mined as additive to concrete for nuclear power plants constructed by the East German Government in the 1980s. Small amounts of silver were also extracted, but high arsenic contents of the silver ore made processing very expensive and production of silver was stopped in the late 1980s. An ore shoot with massive native arsenic and silver was made in 1990 shortly before the end of uranium mining. Some tons of the material were mined, but no processing was done on it.
The positive results regarding base metals at Hämmerlein and Tellerhäuser led to an reivestigation for tin, tungsten and further resources at Globenstein and a significant mineralisation was discovered in the 1980s. But like Hämmerlein, the complex mineralogy prevented further projects so far.
After production ceased, the area was recultivated including the flooding of the mine, removal of the mine buildings and covering of waste rock area. A water treatment plant was set up to remove uranium, radium and arsenic from the mine water. Because of the low water flow from the mine, it was possible to replace to initial active chemical water treatment plant by a passive biological unit (wetland). The adit is still open to the Hämmerlein part of the deposit and is operated by a private society as a visitor mine. The Wisutec GmbH, the daughter company of the Wismut GmbH, holds the exploration license for the Pöhla-Globenstein area at the moment.
Schneckenstein and Gottesberg (Object 06)
These two deposits are in the Vogtland Mts and were operated by Object 06 of the SAG/SDAG Wismut. Mining for tin and silver had a long tradition in the area and as well as the production of gem-quality topazTopaz
Topaz is a silicate mineral of aluminium and fluorine with the chemical formula Al2SiO42. Topaz crystallizes in the orthorhombic system and its crystals are mostly prismatic terminated by pyramidal and other faces.-Color and varieties:...
. When the Wismut started exploration and mining in the area there was still active mining for tin. Before the Wismut discovered the uranium mineralisations nearby, it already took over the processing plant from the tin mine Tannenbergsthal
Tannenbergsthal
Tannenbergsthal is a village and a former municipality in the Vogtlandkreis district, in Saxony, Germany. Since 1 October 2009, it is part of the municipality Muldenhammer.-Description:...
on top of the Schneckenstein Mountain in 1948. It investigated the tin mine itself but no uranium mineralisation was found. However, in a distance of about 2 km from the tin mine, the company discovered a uranium mineralisation which was mined from 1950 to 1960 producing about 1,000 tonnes of uranium. After uranium resources were depleted the mine was transferred to another mining company which started mining for barite on a fault zone parallel to the uranium veins. Tin mining ceased in 1964 and barite mining in 1991. On the other side of the valley further uranium mineralisations were discovered called Gottesberg. In contrast to the Schneckenstein mineralisation which is hosted by metasedimentary rocks, veins at the little Gottesberg deposit are within granites. The small deposit was mined for a few year in the 1950s producing about 70 tonnes of uranium. The Gottesberg area hosted also tin mines and is today under exploration license by a private German exploration company.
Schwarzenberg (Object 08)
Object 08 mined a dozen of small deposits around Schwarzenberg in the western Erzgebirge Mts between Aue and Johanngeorgenstadt. The largest deposit is the "Weißer Hirsch" mine (Shaft 235) in Antonsthal, which produced about 700 tonnes of uranium until 1959. The other deposits yielded between 2 and 230 tonnes of uranium resulting in a total production of the object of 1,100 tonnes. The dump material of the "Weißer Hirsch" mine is currently recycled as construction material.Further deposits in the Erzgebirge Mts.
The deposit Niederschlag-Bärenstein is situated in the central Erzgebirge Mts close to the border to the Czech Republic. There was an unsuccessful try to open a uranium mine in the 1930s. Uranium mining by the SAG Wismut started in 1947 and ended in 1954 producing about 140 tonnes of uranium. The vein containing most of the mineralisation contains a fluorite-barite mineralisation below the uranium mineralised parts. A private company wants to start mining this mineralisation in 2010.
Marienberg is also an old silver mining town in the central Erzgebirge Mts founded in the 16th century. The Wismut mined about 120 tonnes of uranium between 1947 and 1954. A large resource of fluorite is left. A shaft from the uranium mining era provides today thermal water for heating purposes.
The eastern Erzgebirge hosts only very small uranium mineralisation which produced only 50 tonnes in total. Mining took place at Bärenhecke, Niederpöbel, Johnsbach and Freiberg
Freiberg, Saxony
Freiberg is a city in the Free State of Saxony, Germany, administrative center of the Mittelsachsen district.-History:The city was founded in 1186, and has been a center of the mining industry in the Ore Mountains for centuries...
. The latter was the historical most important deposit of the Erzgebirge, and produced silver since the 12th century. However, it contributed only very little to the uranium production of SAG Wismut. The deposit which produced at least 6,000 tonnes of silver contained just 5 tonnes of mineable uranium.
Thuringia
Eastern Thuringia developed in the 1950s to one of the major mining centers of the Wismut hosting the giant orefield of Ronneburg and the medium sized deposit Culmitzsch. Although the mineralisation at Ronneburg is hosted by the Gera-Jáchymov fault and it is likely its formation is linked to the vein-style deposits in the Erzgebirge sitting on the same structure, it is a completely different kind of mineralisation. This led to many problems in the first decade of mining.Ronneburg (Object 90)
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Ronneburg
Ronneburg may refer to:*Ronneburg, Hesse, a town in Germany*Ronneburg, Thuringia, a town in Germany*Rauna Castle, a former residence of the Archbishop of Riga in modern Latvia...
is a small town close to the Autobahn BAB 4. It is situated about 10 km east of the next major city Gera
Gera
Gera, the third-largest city in the German state of Thuringia , lies in east Thuringia on the river Weiße Elster, approximately 60 kilometres to the south of the city of Leipzig and 80 kilometres to the east of Erfurt...
. Ronneburg hosted a small radon-spring, but that was not as famous as those in the Erzgebirge Mts.. Exploration in the area started in 1949, and the first shafts were sunken in 1950. The deposit was operated by Object 90 with its head office in Gera. During the 1950s exploration work at Ronneburg contributed the most uranium to the resource base of the Wismut showing the significance of the new discovered deposit. However, there were many difficulties with mining of the deposit because that particular style of mineralisation was unknown to the German and Soviet mining experts.
The mineralisation is hosted by Palaeozoic meta-blackshales and Meta-basalts. Uranium mineralisation occurs in irregular shaped bodies of highly variable size and uranium content (in average 70 tonnes uranium per body). The uranium minerals (mainly pitchblende) occur as impregnations, thin veinlets or in breccia zones in these bodies. The deposit formed by remobilsation of uranium which was already enriched in the blackshales by synsedimentary processes. Remobilsation was caused by hydrothermal and supergene processes leading to the further enrichment of uranium. The background uranium content in the blackshales is 40 to 60 ppm. Like the major vein-style uranium deposits in the western Erzgebirge Mts., the Ronneburg deposit is located on the Gera-Jachymov fault zone which is called Crimmitschau fault zone in this particular area.
The black shales contain also high amounts of sulphides (marcasite, pyrite) and carbon. The Wismut tested several different methods to mine this deposit in the 1950s and 1960s. Some of them seemed to work, but during the 1950s many fires started in the mines. Sabotage was considered first as cause for the fires, but the increasing number of fires showed that there must be another reasons, which laid in the sulphur and carbon content of the blackshales in combination with wrong mining methods. The initial mining methods led to many fractures in the rocks which allowed oxygen to enter the rock. Resulting oxidation of sulphides produced enough heat to start fires in the carbon-rich material. These fires developed to such a major problem, that whole parts of the underground area had to be sealed of and production was heavily impacted. This led also to the decision to mine a part of the deposit using an open pit, which was a serious impact to the Ronneburg area. However, in the 1960s a special mining technology was developed involving backfilling of the stopes using drillings from the surface. Since then, underground fires had been no major problem any more.
In the late 1960s the company was restructured and Object 90 was split up into several mining division: Bergbaubetrieb (mining division) Schmirchau (underground), Bergbaubetrieb Paitzdorf (underground), Bergbaubetrieb Reust (underground) and Bergbaubetrieb Lichtenberg (open pit). Open pit mining ended in 1976 when the pit reached a final depth of 300 m. Exploration for new parts of mineralisation led to the formation of two further mining division on the northern part of the deposit in 1974 (Bergbaubetrieb Beerwalde) and 1982 (Bergbaubetrieb Drosen). The mineralisation is downward dipping into northern direction which resulted into larger depths of mining. The shafts of the northernmost mine Drosen reached nearly 900 m.
The grade of the ore mined was 0.08% uranium in average with a cut-off
Cut-off
A cut-off, also known as a kutte or "battle jacket" in heavy metal subcultures, is a type of vest or jacket which originated in the biker subculture and has now found popularity in the punk and various heavy metal subcultures...
of 0.02% uranium. However, restricted zones of high grade mineralisation with more than 1 % uranium occurred. An ore treatment plant was tested in Schmirchau to increase the grade before shipping to the mills, but this proved not to be effective. Most of the ore was sent without further treatment to the mills at Seelingstädt and Crossen. Small amounts of uranium were also produced by underground in-situ-leaching and heap leaching of low grade ore and even waste rock. The mined resources of the orefield was 113,000 tonnes of uranium, of which about 100,000 tonnes were produced (the difference are losses through the production process). The total resource of the deposit is about 200,000 tonnes uranium (mined and unmined reserves as well as inferred and speculative resources).
After production ceased in 1990 recultivation work began. The mine dumps were the largest task in this mining area. It was decided to relocate most of the dump material of the southern mining divisions (Schmirchau, Reust, Paitzdorf, Lichtenberg) into the open pit Lichtenberg and to relocate those of the mine Korbußen (part of mining division Beerwalde) and Drosen to the major dump at Beerwalde. To accomplish this task, the Wismut GmbH ordered and operated the largest fleet of Caterpillar
Caterpillar Inc.
Caterpillar Inc. , also known as "CAT", designs, manufactures, markets and sells machinery and engines and sells financial products and insurance to customers via a worldwide dealer network. Caterpillar is the world's largest manufacturer of construction and mining equipment, diesel and natural gas...
mine trucks in Europe. After relocation was finished, the dumps were covered. The southern mining area with the refilled open pit Lichtenberg was part of the federal garden exhibition Gera-Ronneburg in 2007.
Culmitzsch (Object 90)
The Culmitzsch deposit is about 15 km south of Ronneburg. It belonged also to Object 90 in Gera. However, it had a totally different geology than the Ronneburg orefield. Culmitzsch is a sedimentary deposit in Permian sand-, silt- and limestones. There are two ore horizones containing disseminated pitchblende and coffinite. An interesting feature are pseudomorphoses of uranium minerals after wood. Specimens show still the cell structure of the wood but made of pitchblende. The deposit was mined from 1950 to 1967 in three open pits named Culmitzsch, Trünzig and Sorge-Katzendorf. The average ore grade was 0.06% and total production from the three pits was about 11,000 tonnes of uranium. The deposit extends further north from the mined area. This part of the deposit called Gera-Süd was explored underground, but difficult geotechnical conditions prevented the mining of this resource. The open pits Culmitzsch and Trünzig were used as tailings management facilities after they were mined out by the mill Seelingstädt, which was established in 1961 nearby the deposit.further deposits in Thuringia
In the southern part of Thuringa called Thüringer Wald mining of three small uranium deposits was undertaken in the 1950s. The largest deposit was Dittrichshütte and was mined underground by several small shafts producing about 112 tonnes of uranium from a blackshale-type mineralisation. Steinach was also a small blackshale-type deposit being mined in a small open cut producing about 40 tonnes of uranium. The Schleusingen mineralisation was hosted by Triassic sandstones and was mined underground producing 14 tonnes of uranium.Königstein (Königstein mining division)
Königstein is situated about 40 km southeast of DresdenDresden
Dresden is the capital city of the Free State of Saxony in Germany. It is situated in a valley on the River Elbe, near the Czech border. The Dresden conurbation is part of the Saxon Triangle metropolitan area....
in the Elbe Sandstone Mountains
Elbe Sandstone Mountains
The Elbe Sandstone Mountains, also called the Elbe sandstone highlands is a mountain range straddling the border between the state of Saxony in southeastern Germany and the North Bohemian region of the Czech Republic, with about three-quarters of the area lying on the German side...
. The castle Königstein is one of the major attractions in this touristic area. Exploration for uranium started in the early 1960s for sandstone hosted uranium mineralisation similar to the ones discovered further south in the Czech Republic. Finally a major mineralisation was discovered in 1963. The mineralisation is hosted by Cretaceous sandstones with disseminated uranium minerals in Rollfront-type orebodies. However, there are also small veins containing barite and pitchblende and the nature of this deposit is under discussion. Most likely it is a combination of a sedimentary style and hydrothermal mineralisation. Construction of the mine started immediately after the discovery and two main shaft along with several ventilation shafts were sunken to depths up to 300 m. Mining started in 1967 and it developed to one of the main producers of the SDAG Wismut in the 1970s with more than 1,000 tonnes of uranium per year in this decade. The ore mined was transported by a cable way down to the Elbe river valley from where it was transported by rail to the mill at Seelingstädt. Besides the conventional mining using drilling, blasting and transport of the ore to the mill, already in 1969 studies were started for unconventional production methods for low grade ore using leaching. The low permeability of the sandstone prevented usual in-situ-leaching from drillings. Therefore different methods were developed to blast the ore underground, seal those blasted blocks and press sulphuric acid into them. Heap leaching was also carried out as well as uranium extraction from mine water before it was released in the Elbe River. In 1984 conventional ore production was finally stopped and only unconventional methods were used from this year on. Production sunk to about 450 tonnes uranium per year, but the mining division Königstein produced at the lowest costs of all Wismut mining divisions. The uranium bearing solution from leaching were transported by rail to the Seelingstädt mill where the final concentrate was produced. Total production of uranium until 1990 was about 18,000 tonnes with 12,250 tonnes through conventional mining and 5,750 tonnes by unconventional methods.
In 1990 production ceased as on the other mining divisions. However, the hydrogeological situation was difficult through the high amount of uranium-bearing solution in the sandstone units hosting the mineralistion. Above that unit there are three aquifer
Aquifer
An aquifer is a wet underground layer of water-bearing permeable rock or unconsolidated materials from which groundwater can be usefully extracted using a water well. The study of water flow in aquifers and the characterization of aquifers is called hydrogeology...
supplying water to Pirna
Pirna
Pirna is a town in the Free State of Saxony, Germany, capital of the administrative district Sächsische Schweiz-Osterzgebirge. The town's population is over 40,000. Pirna is located near Dresden and is an important district town as well as a Große Kreisstadt...
and Dresden. Therefore large amounts of water have to be treated before the mine could finally be flooded. The uranium extracted in these cleaning process is sold to an American company in form of a solution. The total production of uranium from the mine water treatment between 1991 and 2008 can be estimated to be 1,000 t.
Freital / Dresden-Gittersee (mining division "Willi-Agatz")
This mining area covers parts of the cities DresdenDresden
Dresden is the capital city of the Free State of Saxony in Germany. It is situated in a valley on the River Elbe, near the Czech border. The Dresden conurbation is part of the Saxon Triangle metropolitan area....
(part Gittersee) and Freital
Freital
Freital is the biggest town in the Sächsische Schweiz-Osterzgebirge district, in the Free State of Saxony, Germany. It is situated on the small river Weißeritz, 8 km southwest of Dresden.- Geography :...
. Mining for hardcoal in the area is known since the 16th century. In 1949 the Wismut studied radioactive anomalies in parts of the coal field and took over some mines. The ownership of mines changed several times between the Wismut and the local hard coal mining company. In the early 1950s, while the coalfield belonged to the hard coal mining company, two new main shafts in Dresden-Gittersee were sunken to depths of about 700 m and the mine was renamed "Willi-Agatz", after a leader of the German communistic party. In 1968 production of coal for energy production was eventually stopped and the mine was transferred a last time to the SDAG Wismut. From that time on coal was only mined for its uranium content. The deposit was depleted in 1989 after producing about 3,700 tonnes of uranium since 1949 and 40 million tonnes of hard coal since the 16th. It was the last Saxonian hard coal mine to be shut down. The uranium-bearing coal was milled at small local plants in Freital when the Wismut first was active in the area in the 1950s. After 1968 the coal was milled at Crossen.
Rehabilitation of the area after 1991 is carried out by the division Königstein of the Wismut GmbH. The deposit is connected by a several kilometer long adit to the Elbe
Elbe
The Elbe is one of the major rivers of Central Europe. It rises in the Krkonoše Mountains of the northwestern Czech Republic before traversing much of Bohemia , then Germany and flowing into the North Sea at Cuxhaven, 110 km northwest of Hamburg...
River in Dresden. This adit was built in th 19th century to ship coal directly from the underground part of the mines to the river, although it was later never used for these purposes. However, this adit had to be refurbished by the Wismut GmbH at one of the major tasks at the deposit to provide a secure dewatering of the mining area. Further the dumps had to be covered including ash dumps from the firing of uranium bearing coal in former times.
Seven coal seams are present in the Permian
Permian
The PermianThe term "Permian" was introduced into geology in 1841 by Sir Sir R. I. Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Edouard de Verneuil; Murchison asserted in 1841 that he named his "Permian...
(Rotliegend) volcano-sedimentary rocks of the Döhlen-basin. Three of these seams carry in restricted parts a uranium mineralisation, which was mined by the Wismut. Uranium was introduced into the coal forming organic material in early stages by surfical waters. The source for the uranium were most likely volcanic rock units in the area. In a later stage, some remobilisation took place producing uranium mineralised veinlets in the host rocks of the coal seams. The average ore grade was 0.11% uranium.
Unmined deposits
The SAG/SDAG Wismut carried out exploration in the whole German Democratic Republic. Several uranium mineralisations were discovered but eventually not mined because of the small size or the high costs of mining. The largest unmined resource was discovered north of LeipzigLeipzig
Leipzig Leipzig has always been a trade city, situated during the time of the Holy Roman Empire at the intersection of the Via Regia and Via Imperii, two important trade routes. At one time, Leipzig was one of the major European centres of learning and culture in fields such as music and publishing...
hosted by Carboniferous volcano-sedimentary rock units in the late 1970s and early 1980s. This uranium occurrence near Delitzsch
Delitzsch
Delitzsch is a large district and also an important regional center in Saxony. With over 26,300 inhabitants Delitzsch is the largest city in the northern district of Saxony...
consists of several separate mineralisations. An inferred resource of 6,660 tonnes was taken into the resource base of the Wismut and studies were made for underground exploration. However, the high costs for that project prevented it from realisation. The Wismut discovered also a significant resource of tungsten
Tungsten
Tungsten , also known as wolfram , is a chemical element with the chemical symbol W and atomic number 74.A hard, rare metal under standard conditions when uncombined, tungsten is found naturally on Earth only in chemical compounds. It was identified as a new element in 1781, and first isolated as...
, niob, rare earth elements and phosphate
Phosphate
A phosphate, an inorganic chemical, is a salt of phosphoric acid. In organic chemistry, a phosphate, or organophosphate, is an ester of phosphoric acid. Organic phosphates are important in biochemistry and biogeochemistry or ecology. Inorganic phosphates are mined to obtain phosphorus for use in...
in the area which is reinvestigated by a private company since 2008.
The Wismut explored a blackshale-type uranium mineralisation below the villages Hauptmannsgrün and Neumark, Saxony west of Zwickau. Finally 2,500 tonnes of inferred uranium resources were taken into the resource base of the Wismut but of the complex nature and small size it was decided to not mine it. Another unmined blackshale-type resource is Rudolstadt
Rudolstadt
Rudolstadt is a town in the German Bundesland of Thuringia, close to the Thuringian Forest to the southwest, and to Jena and Weimar to the north....
in the Thüringer Wald area having inferred resources of 1,300 tonnes.
Several small uranium mineralisations were also explored in the Erzgebirge Mts outside the mined deposits. Together they account for another 11,200 tonnes of inferred resources which were taken into the resource base of the SDAG Wismut.
Milling
Lengefeld
Lengefeld is a town in the district Erzgebirgskreis, in the Free State of Saxony, Germany. It is situated in the Ore Mountains, 23 km southeast of Chemnitz....
(Vogtland), the mill of the tin mine Tannenbergsthal (Vogtland), a plant processing cobalt ore to produce colours at Oberschlema, a nickel processing plant at Aue and some industrial areas at Freital. Further, a new mill was erected at Johanngeorgenstadt. These small mills produced different concentrates: mechanical concentrates, wet-mechanical concentrates and chemical concentrates ("Yellow Cake"). A total of 18 million tonnes of ore was processed in these smaller mill and the last was shut down in 1962. Milling was concentrated at two central milling sites situated between Zwickau and Ronneburg.
The mill at Crossen (a northern suburb of Zwickau) was already erected in 1950 using the site of a former paper mill. It was called Object 101 / Factory 38 (later renamed in Aufbereitungsbetrieb 101 - milling division 101) and processed ore from all major deposits of the Wismut. It produced mechanical as well as chemical concentrates and used for the latter one an alcalic-based technology resulting in Yellow Cake containing more than 70% uranium. The mill processed a total of 74.7 million tonnes of ore producing 77,000 tonnes of uranium before it was shut down in 1989. Experimental milling was also carried out processing silver and tin ore from the deposit Niederschlema-Alberoda and Pöhla.
In 1961 the most modern milling plant got into production at Seelingstädt called Aufbereitungsbetrieb 102 (milling division 102). It was built near the open pits of the Culmitzsch deposit which it used as tailings management facilities. It processed the majority of ore from Ronneburg, ore and solutions from Königstein but also ore from the Erzgebirge Mts. It used both acid and soda-alcalic processes depending on the chemistry of the ore to produce Yellow Cake. It processed in total 108.8 million tonnes of ore producing concentrate containing 86,273 tonnes of uranium.
About 216,000 tonnes of uranium were delivered in chemical and mechanical concentrates from the mills to the Soviet Union and about 15,000 tonnes were shipped in unprocessed high-grade ore directly from the mines.
The rehabilitation of the tailings storage facilities at the milling sites is a major issue for the Wismut GmbH. The tailings at both sites have a total volume of 152 million m3 and contain between 50 and 300 g/t uranium and between 50 and 600 g/t arsenic. The activity of radium in the tailings has a total value of 1.5*1015 Bq.
Other company branches
Besides the direct mining and milling divisions, the Wismut owned also several other company divisions. The Central Geological Service in Grüna near Chemnitz was responsible for exploration work as well as special geological tasks. This service did also carry out work for other mining companies in East Germany. In Chemnitz-Siegmar there was a plant for construction and maintenance of the vehicle fleet of the company. In ZwickauZwickau
Zwickau in Germany, former seat of the government of the south-western region of the Free State of Saxony, belongs to an industrial and economical core region. Nowadays it is the capital city of the district of Zwickau...
-Caisndorf and Aue there were major factories procuing equipment for the milling and mining divisions. They delivered also equipment to other mining companies in East Germany and Eastern Europe. The Wismut had also its own transport branch responsible for bringing the workers to their work places. The construction branch was responsible for all building tasks within the company and carried out also public contracts. The company also operated sand pits for its construction needs but mostly to get material to refill stopes at Ronneburg. Some of these divisions were liquidated in 1990 because there was no need for them any more. Other were taken out of the Wismut GmbH because there was no need for rehabilitation on these sites and formed the DFA GmbH, which was subsequently privatised.
In 2002 the Wismut GmbH founded the daughter company Wisutec GmbH. This company is responsible for consulting and marketing the rehabiliations technologies developed by the Wismut GmbH. It also owns the exploration rights for the tungsten-tin-base metal deposit at Pöhla-Globenstein.
Impacts for the employees
Although the Erzgebirge had a nearly 700 year old mining history when uranium mining started after World War II, mining had nearly ceased in the area. Resulting, there was neither a qualified workforce nor mining equipment which could be used. However, after the war the unemployment rate was high in Germany, and the Soviet Administration in East Germany ordered the employment centers across the country to supply them with workers. Within few years thousands of people from all across Germany including refugees from the formerly German regions now being part of Poland and the Soviet Union were drafted to the uranium mining centers. People got orders that they had to start working in the uranium mines otherwise there would be strict sanctions for them. At the end of the 1940s, more than 100,000 people worked for the SAG Wismut. This also included women, although they did not work on the stopes itself but operated machinery (locomotives, hoisting machines) on the mines, worked in the mills, laboratories and administration. In contrast to the Czech Republic and the Soviet Union, no prisoners were forced to work in the mines. Most of these people had never worked in the mining industry before and had no qualifications. This and the lack of mining equipment caused that the mines were operated like centuries ago with a high number of deadly work accidents. Forced drafting of workers ended in 1949, however security measures on the mine sites remained very strict. Between 1951 and 1953, 73 miners accused of espionage and sabotage were deported to the USSR and executed.The low technology standards caused significant health risks to the miners. Drill hammers arriving for the mines in the late 1940s did not allow wet drilling which led to the exposures of thousands of miners to the dangerous quartz dust. Furthermore, the narrow galleries in combination with the lack of proper ventilation leading to high concentrations of radon and its decay products in the mines. The quartz dust and radon were responsible for the two most serious work related diseases, silicosis and lung cancer. By beginning of 1997, 14,592 cases of silicoses and 5,275 of lung cancer were officially recognised as work-related disease for miners at the Wismut. It is estimated that there were 200 deadly accidents between 1946 and 1948 and 376 in the years between 1949 and 1964, including 33 miners being killed in a fire on a mine in Schlema in 1955. The total number of deadly accidents including the estimates for the early years is 772.
During the 1950s the technological equipment and the skill of the work force of the Wismut improved dramatically. The exposure to radon and quartz dust was reduced significantly by improving mining methods, equipment, ventilation and knowledge of the miners. But at this time it was already to late for the health of thousands of miners starting earlier in the company. During the 1950s, the workforce of the company shrank to about 45,000 and stabilised at this level to the end of the 1980s. During these later years, the Wismut had one of the best educated workforces of all companies in East Germany with the highest number of degrees per employee.
Resources
The following table presents the Resources of the Wismut on 1 January 1991. All values are in tonnes uranium (not uranium oxide). Total unmined resources are the combination of reserves plus inferred resources. The total uranium potential are the total unmined resources plus the mined resources.After 1990 there was a little mining in Ronneburg, Niederschlema-Alberoda and Pöhla to reduce the contact surface between uranium ore and groundwater after flooding the mines. In Königstein the cleaning process of mine water still produces uranium today which is sold to international customers. The total production after 1990 is about 1,500 tonnes uranium and is not included in the table.
| Deposit / Occurrence | Years of production | Type | Production | mined resources | Reserves C1 + C2 | inferred resources | total unmined resources | total uranium potential | other resources |
|---|---|---|---|---|---|---|---|---|---|
| uranium field Ronneburg (East Thuringia) | 1950 - 1990 | blackshale | ? | 112,914.0 | 51,820.0 | 35,423.0 | 87,243.0 | 200,157.0 | |
| Schmirchau / Reust | 1952–1990 / 1957–1988 | blackshale | ? | 65,264.9 | 6,622.8 | 1,512.9 | 8,144.7 | 73,409.6 | |
| Paitzdorf | 1954–1990 | blackshale | ? | 22,562.5 | 6,186.5 | 0.0 | 6,186.5 | 28,749.0 | |
| Stolzenberg | 1954-1957 | blackshale | ? | 175.5 | 0.0 | 0.0 | 0.0 | 175.5 | |
| Lichtenberg | 1958–1976 | blackshale | ? | 14,115.3 | 0,0 | 0,0 | 0,0 | 14,115.3 | |
| Beerwalde (including Korbußen) | 1974-1990 | blackshale | ? | 7,658.4 | 15,912.7 | 0,0 | 15,912.7 | 23,571.1 | |
| Drosen | 1982–1990 | blackshale | 2,941.1 | 3,137.7 | 23,098.0 | 3,760.4 | 26,858.4 | 29,996.1 | |
| Paitzdorf Flanken | exploration area | blackshale | 0.0 | 0.0 | 0.0 | 367.0 | 367.0 | 367.0 | |
| Zeitz-Baldenhain | exploration area | blackshale | 0.0 | 0.0 | 0.0 | 16,000.0 | 16,000.0 | 16,000.0 | |
| Kauern | exploration area | blackshale | 0.0 | 0.0 | 0.0 | 453.0 | 453.0 | 453.0 | |
| Prehna | exploration area | blackshale | 0.0 | 0.0 | 0.0 | 8,531.0 | 8,531.0 | 8,531.0 | |
| Untitz | exploration area | blackshale | 0.0 | 0.0 | 0.0 | 2000.0 | 2000.0 | 2000.0 | |
| Crimmitschau Fault Zone | exploration area | blackshale | 0.0 | 0.0 | 0.0 | 2,560.0 | 2,560.0 | 2,560.0 | |
| Lichtenberg-North | exploration area | blackshale | 0.0 | 0.0 | 0.0 | 230.0 | 230.0 | 230.0 | |
| uranium field Schlema (western Erzgebirge Mts.) | 1946–1990 | vein | 80,413.5 | 90,554.4 | 1,032.0 | 5,017.0 | 6,049.0 | 96,603.4 | Ag, Co, Ni, Bi, Pb, Zn, Se, Fe |
| Niederschlema-Alberoda | 1949–1990 | vein | 73,105.0 | 82,609.4 | 1,032.0 | 1,017.0 | 2,049.0 | 84,658.4 | Ag, Co, Ni, Bi, Pb, Zn, Se |
| Oberschlema | 1946–1960 | vein | 7,098.9 | 7,945.0 | 0.0 | 0.0 | 0.0 | 7,945.0 | Cu, Fe |
| Schneeberg | 1946–1956 | vein | 209.7 | >210 | 0.0 | 0.0 | 0.0 | >210 | Ag, Co, Ni, Bi |
| Bernsbach | exploration area | vein | 0.0 | 0.0 | 0.0 | 4000.0 | 4000.0 | 4000.0 | |
| Königstein (Elbe Sandstone Mts.) | 1967–1990 | sedimentary (sandstone) | 17,756.0 | 19,257.0 | 4,304.0 | 4,251.0 | 8,555.0 | 27,812.0 | |
| uranium field Culmitzsch (eastern Thuringia) | 1951–1967 | sedimentary (sand-, silt- and limestone) | ? | 11,956.0 | 0.0 | 3,350.0 | 3,350.0 | 15,306.1 | |
| Culmitzsch | 1955–1967 | sedimentary (sand-, silt- and limestone) | ? | 9,216.6 | 0.0 | 0.0 | 0.0 | 9,216.6 | |
| Sorge-Trünzig | 1951–1957 | sedimentary (sand-, silt- and limestone) | ? | 2,292.4 | 0.0 | 0.0 | 0.0 | 2,292.4 | |
| Gauern | 1953–1957 | sedimentary (sand-, silt- and limestone) | ? | 427.7 | 0.0 | 0.0 | 0.0 | 427.7 | |
| Gera-Süd | exploration area | sedimentary (sand-, silt- and limestone) | ? | 19.4 | 0.0 | 3,350.0 | 3,350.0 | 3,369.0 | |
| Zobes (Vogtland Mts.) | 1949–1963 | vein | 4,673.1 | 5,031.0 | 0.0 | 0.0 | 0.0 | 5,031.0 | Cu, W |
| Freital (Döhlen basin near Dresden) | 1947-53; 1952–55; 1968-89 | sedimentary (hard coal) | 3,691.0 | 3,977.0 | 0.0 | 0.0 | 0.0 | 3,977.0 | hard coal |
| Johanngeorgenstadt (western Erzgebirge Mts.) | 1946–1958 | vein | 3,585.0 | 4,100.0 | 0.0 | 0.0 | 0.0 | 4,100.0 | Ag, Bi, Co, Ni |
| mining area Pöhla | 1957–1990 | vein | 1,217.0 | 1,322.0 | 765.5 | 4,577.4 | 5,342.9 | 7,882.0 | magnetite, Sn, Zn, W, In, Cd, Ag, As |
| Tellerhäuser | 1983–1990 | vein | 1,203.6 | 1,307.5 | 765.5 | 4,577.4 | 5,342.9 | 7,854.0 | magnetite, Sn, Zn, W, In, Cd, Ag, As |
| Hämmerlein | exploration area | vein | 12.8 | 14.0 | 0.0 | 0.0 | 0.0 | 14.0 | Sn, Zn, W, In, Cd |
| Globenstein | 1957–1960 | vein | 0.6 | 0.6 | 0.0 | 0.0 | 0.0 | 0.6 | magnetite, Sn, W |
| mining area Schwarzenberg (western Erzgebirge Mts.) | 1947–1959 | vein | 1,346.5 | 1,445.8 | 0.0 | 0.0 | 0.0 | 1,445.8 | magnetite, Sn, Zn, W |
| Antonsthal (Weißer Hirsch) | 1949–1959 | vein | 747.7 | 826.8 | 0.0 | 0.0 | 0.0 | 828.8 | magnetite, Sn, Zn, W |
| Seifenbach | 1947–1955 | vein | 230.0 | 280.0 | 0.0 | 0.0 | 0.0 | 280.0 | |
| Tannenbaum (September) | 1948–1955 | vein | 90.0 | 100.0 | 0.0 | 0.0 | 0.0 | 100.0 | |
| Neuoberhaus | 1947–1955 | vein | 62.0 | 70.0 | 0.0 | 0.0 | 0.0 | 70.0 | |
| Mai | 1949–1955 | vein | 50.0 | >50.0 | 0.0 | 0.0 | 0.0 | >50.0 | |
| Unruhe-Halbe Meile | 1950–1953 | vein | 47.0 | 55.0 | 0.0 | 0.0 | 0.0 | 55.0 | |
| Tellerhäuser-Kaffenberg | 1950–1954 | vein | 42.0 | 50.0 | 0.0 | 0.0 | 0.0 | 50.0 | |
| Rabenberg (Juni) | 1949–1955 | vein | 32.0 | >32.0 | 0.0 | 0.0 | 0.0 | >32.0 | |
| Raschau-Grünstaauml;dtl | 1950–1954 | vein | 22.0 | 25.0 | 0.0 | 0.0 | 0.0 | 25.0 | |
| Rittersgrün (Segen Gottes) | 1948–1954 | vein | 20.4 | 24.0 | 0.0 | 0.0 | 0.0 | 24.0 | |
| Erla-Crandorf | 1948–1954 | vein | 12.3 | 15.0 | 0.0 | 0.0 | 0.0 | 15.0 | |
| Breitenbrunn (Margarethe) | 1946–1951 | vein | 7.0 | >7.0 | 0.0 | 0.0 | 0.0 | >7.0 | |
| Bermsgrün | 1950-1953; 1956 | vein | 2.1 | >2.1 | 0.0 | 0.0 | 0.0 | >2.1 | |
| Schneckenstein (Vogtland Mts.) | 1949–1959 | vein | 953.2 | 1,136.3 | 0.0 | 0.0 | 0.0 | 1,136.3 | |
| Annaberg-Buchholz (central Erzgebirge Mts.) | 1947–1958 | vein | 450.0 | 520.0 | 0.0 | 0.0 | 0.0 | 520.0 | Ag, Co, Bi, Ni |
| Bergen (Vogtland Mts.) | 1949–1959 | vein | 162.4 | 197.0 | 0.0 | 0.0 | 0.0 | 197.0 | |
| Niederschlag-Bärenstein (central Erzgebirge Mts.) | 1947–1954 | vein | 132.7 | 155.0 | 0.0 | 0.0 | 0.0 | 155.0 | fluorite, barite |
| Marienberg (central Erzgebirge Mts.) | 1947–1954 | vein | 121.0 | >121.0 | 0.0 | 0.0 | 0.0 | >121.0 | fluorite, barite, Ag, Co, Ni, Bi |
| Dittrichshütte (southern Thuringia) | 1950–1953 | blackshale | 112.6 | 163.4 | 0.0 | 0.0 | 0.0 | 163.4 | |
| Gottesberg (Vogtland Mts.) | 1949–1955 | vein | 56.4 | 68.6 | 0.0 | 0.0 | 0.0 | 68.6 | Sn, W |
| Steinach (southern Thuringia) | 1953–1954 | blackshale | 43.6 | 59.7 | 0.0 | 0.0 | 0.0 | 49.7 | |
| Niederp&oouml;bel (eastern Erzgebirge Mts.) | 1948–1953 | vein | 30.3 | >30.3 | 0.0 | 0.0 | 0.0 | 30.3 | |
| Bärenhecke (eastern Erzgebirge Mts.) | 1949–1954 | vein | ? | 44.2 | 0.0 | 0.0 | 0.0 | 44.2 | |
| Schleusingen (southern Thuringia) | 1950–1953 | sedimentary (sandstone) | 14.0 | 27.0 | 0.0 | 0.0 | 0.0 | 27.0 | |
| Freiberg (eastern Erzgebirge Mts.) | 1948–1950 | vein | ? | 5.4 | 0.0 | 0.0 | 0.0 | 5.4 | |
| NW-Saxony | exploration area | volcanic | 0.0 | 0.0 | 0.0 | 6,660.0 | 6,660.0 | 6,660.0 | W, REE, Nb, Ta, phosphate |
| Kyhna-Schenkenberg | exploration area | volcanic | 0.0 | 0.0 | 0.0 | 2,500.0 | 2,500.0 | 2,500.0 | |
| Werben | exploration area | volcanic | 0.0 | 0.0 | 0.0 | 2,500.0 | 2,500.0 | 2,500.0 | |
| Serbitz | exploration area | volcanic | 0.0 | 0.0 | 0.0 | 1,000.0 | 1,000.0 | 1,000.0 | |
| "southern mineralisation" | exploration area | volcanic | 0.0 | 0.0 | 0.0 | 660.0 | 660.0 | 660.0 | |
| Hauptmannsgrün-Neumark (Vogtland Mts.) | exploration area | blackshale | 0.0 | 0.0 | 0.0 | 2,270.0 | 2,270.0 | 2,270.0 | |
| Erzgebirge Mts. and Vogtland Mts. | exploration area | vein | 0.0 | 0.0 | 0.0 | 11,200.0 | 11,200.0 | 11,200.0 | |
| NW-part Pöhla | exploration area | vein | 0.0 | 0.0 | 0.0 | 6,050.0 | 6,050.0 | 6,050.0 | |
| central Erzgebirge Mts. | exploration area | vein | 0.0 | 0.0 | 0.0 | 2,384.0 | 2,384.0 | 2,384.0 | |
| western Erzgebirge Mts. (excluding Schlema and Pöhla) | exploration area | vein | 0.0 | 0.0 | 0.0 | 1,471.0 | 1,471.0 | 1,471.0 | |
| eastern Erzgebirge Mts. | exploration area | vein | 0.0 | 0.0 | 0.0 | 1,295.0 | 1,295.0 | 1,295.0 | |
| Rudolstadt (southern Thuringia) | exploration area | blackshale | 0.0 | 0.0 | 0.0 | 1,300.0 | 1,300.0 | 1,300.0 | |
| Wismut total to 1990 | 1947–1990 | / | ca. 230,000 | 251,510.0 | 57,922.0 | 74,078.0 | 132,000.0 | 383,510.0 | Sn, W, Zn, Fe, Cu, Bi, Co, Ni, Ag, As, In, Cd, REE; Nb; Ta, phosphate, barite, fluorite |
See also
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- List of uranium mines
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