Bismuth object 02
The object 02 was a retrieval object and as an independent structural unit within the Wismut AG / Wismut reports directly to the head office. The mine field of object 02 in the Oberschlema area had an area of approx. 6 km² and was developed through a total of 5 tunnels, 29 shafts and 20 blind shafts on 26 levels . Three levels (-630-m-, -675-m- and -720-m-level) were developed from Niederschlema. The greatest depth in the mine field was reached at about −374 m above sea level on the −720 m level. This corresponds to a total depth, based on the zero point of the Marx-Semler-Stollnsohle , of 704 m. All depth information in + m or −m was based on the level of the Marx-Semler-Stolln. The 330 m above sea level The measuring point established for this purpose lies between the light holes 12a and 14a, directly below the Oberschlema train station. Up to 25,000 people were employed at the same time in property 02. The total production of uranium between 1946 and 1959 was 7,822 t.
geology
The Oberschlema deposit is part of the Schneeberg-Schlema-Alberoda ore field and is located at the intersection of the WSW-ENE running Lößnitz - Zwönitzer and the NW-SE-striking Gera - Jachymov fault zone. The Oberschlema deposit is bounded in the south by the granite from Gleesberg and Aue, in the north by the outer contour of the Kontakthof, in the east by the administrative boundary of the NW trending fault Schwerin and in the west by the northwest trending fault Roter Kamm .
In the Lößnitz-Zwönitzer-Zwischenmulde, Silurian - Devonian rocks are embedded in Ordovician slate . The dark schists, dark mica rocks, metadiabase and skarns occurring here form the so-called productive series, in which around 95 percent of the uranium reserves of the deposit were concentrated. The productive series is located within the approximately 1 km thick contact zone of the Auer granite intruded into the slate complex and was changed by this contact metamorphic . The rocks of the productive series are located in two troughs at the Marx-Semler-Sole level. The southern hollow with a thickness of about 500 m and the northern hollow with a thickness of about 180 m. The rocks of the southern hollow dip at an angle of 45 ° to the NW. The southern hollow is cut off from the underlying granite in the area of the −720 m level. Some of the veins continued into the granite, but became numb there. The north trough is a little steeper than the south trough and is only formed on the −240 m level between the faults Sieg and Schwerin and wedges completely out just below this level.
The main structure of the NW fault, which runs along the course of the Lößnitz-Zwönitzer-Zwischenmulde, reaches a length of approx. 2.5 km with a thickness of up to 10 m and belongs to the system of morning corridors . This system also includes the main tunnel on which the Marx-Semler tunnel was excavated . The dip of the gears is between 45 ° and 65 °.
The duct structures occurring in the course of the Gera-Jachymov fault zone reach lengths of up to 3 km and a thickness of up to several meters. The dip of the aisles is between 50 ° and 90 °. The main representatives are the structures of the flat corridors Schwerin, Sieg, Bergmanns Hoffnung and Roter Kamm . Other important passages are the Gleesberg , Johannes , Bocksloch and Anatoli passages .
In addition to the flat dikes in the main strike direction, there are also late dikes with the strike direction WNW. Their length is several 100 m with a vertical extension of up to 500 m. The dip is between 70 ° and 90 ° with a thickness between 0.5 m and 1 m. Well-known courses here are the Baryt , Oschatz , Sophie and Fern courses .
The duct system of the NNW-trending flat ducts is weak. Their length is up to 100 m with a vertical extension of several hundred meters. The dip is between 60 ° and 75 °. This passage system includes z. B. the aisles Plauen , Oschatz IV and Sangu .
Standing tunnels (strike direction NE) play no role for the deposit. Their length is up to 2 km with a thickness of up to 10 m. Well-known courses are dynamo and central disturbance .
Noble quartz formation (eq formation)
This formation was only found in the shaft field of shaft 67 and near the granite in the central field. The corridors are made of quartz . The mineralization with wolframite , scheelite and molybdenite found in these veins was not worth building.
Gravelly lead formation (kb formation)
This formation occurred on the NW and ENE trending corridors. The corridors consist mainly of quartz, fluorite or chlorite . The mineralization of these veins consists of chalcopyrite , sphalerite , arsenopyrite , galena , pyrite , bornite and tennantite . Buildable concentrations of lead, zinc and copper ores, which were also extracted, were found here only in isolated cases. These passages were mainly to be found in the northwest district. The most famous courses are Torgau and Zambezi .
Comb quartz calcite pitchblende formation (kku formation)
This formation was encountered on all veins of the deposit. The veins consist mainly of quartz, fluorite and calcite. The mineralization of these veins consists of pitchblende, coffinite , chalcopyrite, pyrite, galena, sphalerite, hematite , lepidocrocite and lollingite and was representative of the primary uranium mineralization of the deposit. In some cases, the pitchblende was completely displaced by coffinite (e.g. in the puzzle corridor ). This formation also formed independent passages in the Oberschlema deposit.
Magnesium carbonate pitchblende formation (mgu formation)
This formation is the main uranium carrier of the deposit. It was created through a metasomatic transformation of the corridors of the kku formation. The courses consist mainly of dolomite and black fluorite (stink spar). The mineralization of the veins consists of pitchblende, chalcopyrite, hematite, lepidocrocite, clausthalite , umangite, naumannite, tennantite, bornite, chalcosine and marcasite .
Bismuth-cobalt-nickel formation (BiCoNi formation)
The BiCoNi formation , although spread over the entire deposit, is only of secondary importance. The corridors consist of dolomite, quartz, fluorite, barite and calcite. In the vicinity of the granite and in the area of the Red Ridge, the quartz filling of the corridors predominated. The mineralization of the veins consists predominantly of solid bismuth , skutterudite , rammelsbergite , safflorite , nickeline , lollingite, chalcopyrite, pitchblende, sphalerite, bismuthinite , coffinite and solid silver and arsenic . As a special form, for example, arsenic with ingrown silver appeared on the Mercury corridor .
Silver sulphide arsenide formation (ags formation)
The mineralization of the ags formation is of only minor importance within the Oberschlema deposit. Often this formation occurs as a younger formation in the corridors of the BiCoNi formation. The mineralization of these calcite and barite veins consists of cullet cobalt (native arsenic), lollingite, proustite , argentite , native silver, pyrite, marcasite, chalcopyrite, pyrargyrite , argentopyrite , xanthocone and realgar .
Iron-manganese formation (e-formation)
This formation occurs mainly in the Oberschlema area. The veins consist of brownish-red quartz and the mineralization predominantly of hematite. Manganese ores such as psilomelan and pyrolusite have also occurred locally . The most famous gears of the e-formation are Roter Kamm, Sieg, Bergmanns Hoffnung, Plauen and Gang X.
The Oberschlema deposit, with an explored reserve of approx. 9,000 tons of uranium, was the second largest ore deposit in Wismut.
The uranium ore thickness in the ore-bearing veins ranged between 0.5 cm and 3 cm. In some corridors, however, the thickness reached a few decimeters, in extreme cases even between 1 m and 4 m. The density of veins in the central area was extremely high with 4 veins over a length of 10 m. The ore output between the Marx-Semler level and the −330 m level was fairly constant between 14 and 19 t / m depth. The highest output took place on the −210 m level with a depth of 19.8 t / m. Due to the wedge-out of the deposit in the depth, the output sank and was 0.3 t / m on the −630 m level.
In addition to uranium, the "minor ores" found in the corridors were also extracted from 1957 onwards, if the building was suitable. The ores of the BiCoNi formation were mined here. These are cobalt ores (main components skutterudite and safflorite), nickel ores (main components nickel linine, rammelsbergite and nickel skutterudite ) and bismuth ores (main component native bismuth). During this time 62 tons of cobalt , 13 tons of nickel and 11 tons of bismuth were probably extracted. The building-worthy distribution of these ores began on the −420 m level. They were dismantled in the Kobalt and Sophie corridors.
After mining ceased in 1961, around 200 tons of uranium, 29 tons of cobalt, 318 tons of nickel and 276 tons of bismuth remained in the deposit.
The naming of the veins was obviously not subject to any uniform regulation. On the upper soles, the aisles were often only numbered, e.g. B. 6, 16 or 25. The fact that there were obviously no limits to the imagination at the beginning of the mines is shown by gang names such as dream, riddle, sniffing, forgetfulness, courage, regular law, tulip and blondika. Animal lovers could also immortalize themselves with gang names such as gemsbok, bat, stork, tit, peacock, fish, falcon, cricket and fox. In addition to women's names such as Tatjana, Anita, Olga, Heidi, Helene and Sophia, there are also corridors with names such as Little Red Riding Hood , Lohengrin , Carmen , Siegfried , Nibelungen and Mona Lisa on the lower soles .
Administrative development
The first inspection of the Schneeberger Revier took place on August 1, 1945. On September 14, 1945 the 9th Administration of the Ministry of Interior of the USSR formed the Geological Group (Геологопоисковая Партия). The investigation of the Schneeberg deposit was carried out by the Saxon ore prospecting group (Саксонская Рудно-Поисковая Партия) . The research work of the Saxon ore search group began in September 1945 and was carried out by them until March 16, 1946. The investigation was then continued by the Saxon Extraction and Exploration Group (Саксонская Промышленно-Разведочная Разведочная Разведочная Партия) from April 4, 1946, retroactively to April 1, 1946 extended from Schneeberg to the Oberschlema area.
With the Council of Ministers resolution No. 9372 of July 29, 1946, the Saxon Extraction and Exploration Group was renamed the Saxon Mining Administration of the Ministry of the Interior of the USSR with field post number 27304 of the Red Army . After the discovery of seven ore-bearing tunnels in the Oberschlema study area, the Saxon Mining Administration founded object 02 in October. The seat of the property management was in the Kurhotel Schlema. Property 02 included the parts of the Schneeberg, Oberschlema and Niederschlema deposits.
On April 1, 1947, the Schneeberg deposit was spun off from property 02 and became an independent property as property 03 .
On May 30, 1947, the facilities of object 02 were transferred to Soviet property on the basis of order no. 113 of the SMA Saxony . After the Wismut AG branch was entered in the commercial register in Aue on July 2, 1947, property 02 was placed directly under the Wismut headquarters.
After the discovery of new uranium deposits in the Niederschlema area by object 21, object 09 was founded at the turn of the year 1948/49 . The object 09 then took over the district of Niederschlema with the shafts 13, 13 bis , 38, 66, 128, 170 and 186 from the object 02. Until the end of 1948 all the shafts of the object were independent units. In 1949 there was an initial concentration of the shaft systems , in which several shafts were combined into shaft fields. The shaft fields 4 (shafts 4, 7, 14, 14 bis and 88), 6 (shafts 6, 16 and 280), 6 bis (shafts 6 bis , 6 c and 7 bis ), 12 (shafts 12, 27, 35 and 127), 15 (slots 5, 5 bis , 8, 15, 15 bis and 256) and 64 (slots 64 and 259). Shafts 63/63 bis , 65 and 67 still existed as independent shaft systems . The resulting shaft fields were divided into several districts. Northwest area (bay 12), west (bay 67), south (bay 65) and central area (bay 4, 6, 6 bis , 15 and 64).
In addition to these districts, there was also district 501, which was mainly occupied with the investigation and utilization of old dumps (tipping over). From 1951 the term Schachtfeld was replaced by the term Schachtverwaltung and the mining area was restructured. The shaft administrations 4 (shafts 7, 14, 14 bis and 309), 6 (shafts 6, 6 c , 16 and 280), 6 bis (shafts 6 bis and 7 bis ), 12 (shafts 12, 27, 127, 310 and 311), 15 (shafts 5, 8, 15, 15 bis and 256) and 64 (64 and 259) as well as the independent shafts 65 and 67. A further concentration took place in 1954 when the shaft management 64 was merged with the shaft management 6 to . The shafts 309, 310 and 311 were administratively assigned to the object 09 from 1955.
In the years 1956/57 various shaft administrations were merged. Shaft management 6 and 64 were assigned to shaft management 4 and shaft management 15 to shaft management 12. In 1958, shaft management 12 took over the shafts of shaft management 4 that were still producing.
In addition to the shaft management facilities, object 02 also included object 99 (blue color processing plant, closed in 1957), the test mine, the central workshop, a drilling department and the chemical / geophysical laboratory.
By order of the general management of Wismut No. 149 of March 21, 1958, on April 1, 1958, property 02 was closed and shaft management 12 was assigned to property 09 as the last producing shaft management.
Mining operation
Alignment, fixture and removal
The Oberschlema deposit went unnoticed for a long time, although the Neustädtler Bergrat Schulze in an expert opinion of February 18, 1924 on discoveries of pitchblende, zeunerite , uranium ocher and uranium mica during the excavations in the area between the 13th and 15th light hole of the Marx-Semler-Adit in the Years 1909 to 1913. After Friedrich Schumacher (Director of the Geological Institute of the Bergakademie Freiberg), Bergdirektor Willy Rumscheidt and Colonel Professor Kreiter (Head of the Soviet Geological Commission) visited the Schneeberger Revier on August 1, 1945, Friedrich Schumacher and the physicist Carl Friedrich Gustav Aeckerlein ( Head of the Radium Institute of the Bergakademie Freiberg ) presented a report on October 8, 1945, which showed a reserve of 10 t of uranium for the Schneeberger Revier.
On the orders of Captain Regens, the Russian city commander of Schneeberg, the mining of BiCoNi ores in the Schneeberg district was resumed in September 1945. Work began with a workforce of 93 men in the area of the Weißer Hirsch (shaft 3) and Ritterschacht (shaft 9) pits. The shaft of the Weißer Hirsch mine was swamped and reconstructed between November 1945 and early summer 1946 up to the 155 Lachter route.
The first investigations for uranium by Soviet geologists in the area of the Marx-Semler-Stolln took place in early 1946 through some of the accessible light holes (1, 2, 6, 9, 13 and 15). The passable pit length of the Marx-Semler-Stolln at that time was 4250 m. Exact results of the investigations are not known. It can be assumed, however, that they did not find anything in the examined area.
In August 1946 the first mining work began. In the Schlema area, trenches with a depth of 2 to 3 meters and a length of 50 meters were dug by Soviet pioneers and German workers. If radioactive anomalies were found, these were examined with trial digs. The underground work began in the same period. Via the light hole 15, the examination of the corridors already known in 1913 (Riedel Flacher, Heinrich Flacher, Emanitions Flacher, Johannes Flacher, Radium Flacher, Gleesberg Flacher, Jung König David Flacher, Wolfgang Flacher, Marien Flacher, Corridor 26b, Friedrich Flacher and St. Bartholomäus Flacher).
At the same time, the Gallus tunnel on Hammerberg, which is still partially passable, was examined as a + 30 m bottom with the designation Shaft 4 and the pitch cover located there was removed immediately. The Gallus tunnel was further exposed via a second mouth hole in the basement of the residential building of the Enders medical practice in Oberschlemaer Mühlenstraße.
A new building worthiness assessment revealed a reserve of 710 t of uranium for the mine field known as Schneeberg Ost. In November / December 1946, the digging of shafts 5, 6, 7 and 14 began. Most of the work was carried out by external companies (e.g. W. Wagner GmbH from Essen). In 1946 a total of 10 uranium ore-bearing tunnels were developed and 9.7 t of uranium were mined from the + 30 m level.
Since the area of the Schlema radium bath was now in the restricted area of mining, the spa operation for foreign guests was closed on November 15, 1946 according to a Russian order, but continued for locals, miners and Soviet troops.
In August 1946, the Schneeberg mining industry was subordinated to the Saxon Mining Administration. The mining of BiCoNi ores in the Schneeberger ore field was continued until October 1946 and finally stopped after the last 123 tons of BiCoNi ore had been extracted. At the same time, the opening of the Siebenschlehen (shaft 10), Neujahr (shaft 11) and Beust (shaft 24) shafts began.
In 1947, the digging of shafts 8, 12, 13 bis , 14 bis , 16, 27 and 38, as well as the excavation of shaft 35 began. The shafts 5, 6 and 7 were put into production. In addition, the Bocksloch adit (shaft 88) was opened up and taken down. The object 11 took over all sinking and fixture work. Object 11 was founded in the first quarter of 1947 and probably goes back to the Wagner company, which has carried out this work so far. At the end of 1947, the first shafts reached the −60 m level. The mining moved on the levels + 60-m, + 30-m, Marx-Semler and −30-m and the number of prospective veins had risen to 57. In 1947, 74 t of uranium were mined and the open pit length reached 30 km by the end of the year. The number of employees had risen to 6,000 by the end of the year. The Marx-Semler-sole was the largest sole of the property with an extension of 6.3 km².
On April 1, 1947, the Schneeberg deposit was spun off as an independent property 03 from property 02.
In 1948, the digging of shafts 5 bis , 6 bis , 63, 64, 65, 66, 67, 125 and 127, as well as the jacking and excavation of shafts 170, 174 and 13, 63 bis (Green Shield), 128 and 172.
Shafts 8, 12, 13 bis , 14, 27, 35, 38, 67, 127, 128, 170, 172 and 174 were put into production. The levels + 90-m and -60-m were taken down.
As the mining progressed, the bottom of the Marx-Semler-Stolln was partially destroyed and the pit water from the Schneeberger Revier (approx. 550 m³ / h) fell into the lower pit, from which it was pumped back to the level of the Marx-Semler- Stollns had to be lifted. In order to keep the mine water out of the Schneeberger Revier, a dam gate was installed between the 15th and 16th light hole of the Marx-Semler-Stolln. The water that accumulates behind it was diverted into the Schlemabach via a pump system or pumped into the elevated tanks on the Gleesberg in order to be used as process water by the Wismut.
The protection zones established by the Wismut in the area of the sources of the radium bath on the Radium Flachen and the Heinrich Flachen were lifted and these areas were included in the mining. The breakdowns, e.g. B. on the Falke corridor, were sometimes only 5 m below the lawn in the area of the Kurhaus. Object 02, with 149.3 t of uranium, held first place in the Wismut production statistics in 1948 and employed around 9,000 people.
In 1949, the depths of shafts 7 bis , 27 a , 186, 256, 259 and 280 began. Between the −120 m level and the −180 m level, the sinking work began on the blind shafts 271, 272, 273 and 274 At the beginning of 1949, the newly built object 09 in Niederschlema-Alberoda was attached to shafts 38, 66 and 186 and in the middle of the year, shafts 13, 13 to 128 and 170 were added. The 50 m deep Heinrichgesenk on the Heinrich Flachen, was cut as shaft 6c from the Marx-Semler bottom to the surface and sunk further down to the −360 m bottom. Shafts 5 bis , 6 bis , 14 bis , 16, 63, 63 bis , 64 and 65 were put into production and floors −90 and −120 were dismantled. Above all on the Marx-Semler-Sole, the device and the dismantling were advanced. Alignment began on the −180 m level via shafts 5, 6, 7, 8 and 14. Annual production was 417.6 t of uranium. The intensive mining under the center of Oberschlema leads to the first irregular subsidence on the surface.
In 1950 the depth of blind shaft 338 began from the −180 m level to the −300 m level and of the blind shaft 339 from the −180 m level to the –420 m level. Outside the actual deposit, the drilling of shafts 309, 310 and 311 began.
Shaft 311 was the first shaft within property 02 to have a steel conveyor frame and shafts 6 c , 7 bis and 256 and blind shafts 271, 272, 273 and 274 were transferred to production. Mining reached levels −150 m and −180 m, and in the northwest field, mining began on the + 30 m level and the Marx-Semler level. Mining on the +90 m level was discontinued. Alignment on the −210 m level began via shaft 6 c . Alignment also began on the −240 m level via shafts 5, 6, 7, 8, 14, 16, 27, 64 and 127 and on the −300 m level via shafts 14 bis , 16 and 127 The exploratory shafts 63, 63 bis , 172 and 174 were written off due to a lack of recoverable supplies. With the progressive degradation, the subsidence on the surface increases. The decrease was 22 cm per year. Due to the near-surface mining, there were repeated penetrations after days. With 619 t uranium, object 02 reached about 50 percent of the total production of the bismuth.
In 1951 the weather shaft 125 and the blind shaft 338 went into operation and mining began on the levels −210-m and −240-m. The −240 m level had an extension of 3.1 km² and was expanded to become the main production level, as the small hoisting machines (TM 23) of most of the shafts were only suitable up to a depth of 300 m. In the north-west field, mining began on levels −30 m and −60 m. In this year, the removal of backfill masses from the blocks that had already been dismantled also began in order to win over those with displaced aches and pains in the first few years due to a lack of processing capacity. The excavation blocks that had been emptied were not relocated, which had a serious impact on the stability of the mine and led to a further lowering of the earth's surface and open breaks. Production reached 756.3 tons of uranium in 1951. As a result of penetrations from the near-surface quarries to the surface of the earth, the Schlemabach repeatedly pours into the mine building. To prevent this, 400 m of the Schlemabach were led in wooden floodlights. The subsidence reached up to 36 cm in 1951 and in some cases led to severe building damage. As a result of the mining damage, the evacuation of the residents of Oberschlemas began on November 22, 1951.
In 1952 the depth of shaft 15 bis began . The depth of blind shaft 27 to from −180 m level to −585 m level, of blind shaft 359 from −240 m level to −300 m level and of blind shaft 5 I from the −240 m level to −360 m level. Shafts 15 bis , 259 and 309 as well as the blind shaft 339 went into operation. The mining reached levels –270-m, -300-m and -330-m. In the northwest field, mining began on the −90 m level and the −120 m level. On the −330 m level, the alignment began via the blind shaft 5 I and on the −360 m level via the shafts 6c , 14 bis , 16, 127, 256 and the blind shaft 339. This was done to expand the supply base Object 09 Parts of the pit field of shaft 64. With a production of 864.8 t of uranium, Object 02 was still at the top of the Wismut production statistics, even if its share of the total production had fallen to 36 percent. At the end of the year, 16,052 people were employed in the property. The planned demolition of the town center of Oberschlema began on October 17th. On the Reichsbahn line to Schneeberg, too, after the track bed was lowered by one meter, passenger traffic was discontinued from April 7, 1952, and freight traffic from August 1, 1952. The subsidence reached 67 cm in 1952. To prevent the Schlemabach from constantly breaking into the mine workings, the Wismut asked the community to relocate the creek. Work on this began in November 1952.
In 1953, the digging of blind shafts 5 III, 64 II, IV and 27 V from the −240 m level drove the development of the deeper levels. The blind shafts 5 III and 64 II reached up to the −420 m level, the blind shaft IV up to the −480 m level and the blind shaft 27 V up to the −540 m level. The shafts 280 and 311 as well as the blind shafts 5 I and 359 went into operation. While the levels −360-m and −390-m were being mined, the device of the −390-m level began via the blind shaft 339 and the device of the −420 m level via the shaft 280 and the blind shaft 339 . Shaft 12 was written off and mining began in the north-west field at the −150 m level. In 1953, the ore production reached 974.1 t of uranium and the subsidence at the earth's surface was up to 49 cm.
In 1954, the sinking of blind shafts 125 bis , 4 and 6 began from the −180 m level. The weather blind shaft 125 bis reached the −240 m level and the blind shafts 4 and 6 reached the −360 m level. The blind shaft 9 was sunk from the −240 m level to the –360 m level. Shaft 310 and blind shafts 125 bis , 5 III, 64 II, IV and 9 went into operation. The levels −420-m and −450-m went into operation. The installation of the −450 m level began via shafts 280 and 310 and the installation of the −480 m level via the blind shafts 27 bis , IV and 27 V. After the beginning of the demolition of the town center of Oberschlema, dismantling began resumed the already closed corridors and partially reached to the surface of the earth. In the northwest field, mining reached the −180 m level. Due to the wedging of the productive layers, this part of the deposit ends at this depth. Mining no longer took place below this level and mining on the −150 m level was also discontinued. The shafts 14 and 14 bis went out of operation due to total deformation of the shaft tube and the shafts 310 and 311 took over their tasks. The subsidence reached this year up to 93 cm. With a production of 987.6 t uranium, the highest level in the production of object 02 was reached.
In 1955, blind shafts 27 bis , 27 V, 4 and 6 went into operation. Mining on the −480 m level has started. The bottom only had an extension of 0.6 km². The installation of the -510 m level was started via the blind shaft 27 bis and the installation of the level -540 m via the blind shafts 27 bis and 27 V. Mining on the +60 m level was discontinued. In the northwest field, mining on the + 30 m level was stopped. The shaft 256 had to be abandoned because of the total deformation of the shaft tube. The subsidence reached this year the record value of up to 113 cm. The uranium production showed a downward trend at 982.3 t.
In 1956, the sinking of the weather blind shafts WI began from the −360 m level to the -540 m level and W III from the −480 m level to the −540 m level. Shaft W III went into operation that same year. Mining reached the −510 m level and the installation of the −585 m level began via blind shaft 27 bis . Shafts 15 bis , 16 and blind shaft 6 were written off due to the discontinuation of mining. The mining in the west, north-west and south fields was stopped. The limited perspectives for continuing the object became increasingly visible. The ground subsidence was up to 101 cm. In some places the greatest reductions reached a total of 5 m. The recovery still reached 939.9 tons of uranium.
In 1957 the weather blind shaft WI went into operation. Mining reached the −540-m level, while mining was stopped on the −180-m, −210-m and −450-m levels. Shafts 6c , 8 and 65 as well as blind shafts 64 II and 5 III were written off due to the discontinuation of mining. The subsidence was reduced due to the sharp decline in mining and only reached 42 cm. With an annual production of 678.4 t of uranium, the object reached only 10 percent of the total production of Wismut in 1957.
In 1958, by order of the General Management Wismut (order no. 149 of March 21, 1958), property 02 was closed with effect from April 1. The shafts that were still in production were combined into shaft management 12 and attached to object 09. Mining began on the −585 m level. The shafts 5, 6 bis and the weather blind shaft W III have been written off. The subsidence decreased to about 11 cm. The production for the year 1958 is shown with 370.2 t uranium.
In the Oberschlema deposit, around 2020 km of expansion and equipment pits had been excavated by 1958. The resulting excavation cavity is approx. 5.07 million m³ and the deduction of backfill from the excavation blocks amounts to about 1.35 million m³. A total of 7,822 t of uranium was mined. In the near-surface areas of the central area, around 200 t of uranium remained, which could no longer be mined due to the heavy erosion.
The object 09 continued the dismantling work started by the object 02. In the course of geological exploration work, there was an increase in the ore reserves on the levels −510-m and −540-m. The levels -630-m and -675-m were driven from Niederschlema and the resources encountered were mined. The excavation of the −720 m level once again penetrated the entire deposit complex from the Oberschlema to the "Red Ridge". During this excavation, however, no passages worth building were encountered, as the deposit here is finally cut off by the underlying granite. In 1959, shafts 7, 15, 64, 67, 125 and blind shaft VI were written off due to the discontinuation of mining.
After the progress of the final mining and robbery work, shaft 259 was written off in 1960 and shafts 280 and 309 in 1961.
After the mine drainage system was converted, shafts 6 (1964), 27 (1968) and 7 bis (1970) were written off. Shaft 310, which served as a weather shaft for the Niederschlemaer Revier, was also written off in 1970.
In 1968, a final investigation was carried out for ores in the blue color works safety pillar, but it ended with negative results.
In 1980, shaft 15 IIbis was sunk in order to achieve permanent access to the pumps at the Dammtor on the Marx-Semler-Stolln .
Used conveyor technology
The first shafts in the area were light holes 13 (shaft 13) and 15 (shaft 15) of the Marx-Semler-Stolln. Due to their clear cross-section of 5.3 m² and 3.8 m², it was only possible to convey with a bucket. A track laid in 1909 (probably 300 mm gauge) already existed between the two light holes. The bucket conveyance at shaft 13 was initially operated with an electric reel. With this reel, 200 kg could be conveyed from a depth of 40 m at a speed of 1 m / s. Shaft 15 was expanded quickly because it was still conveyed using a hand reel. After the installation of a hoisting machine, shaft 15 was the first eligible shaft.
The first new shafts were sunk at the end of 1946, initially by hand. The resulting mass was shoveled up by miners over the individual shaft platforms. Apart from a few exceptions (e.g. shaft 14 to 14.8 m² in cross-section), the shafts were designed as type projects. The newly sunk shafts 6, 7 and 5 bis had a clear cross-section of 5.9 m², while shafts 5, 8 and 16 had a clear cross-section of 7.5 m². Depending on the intended use, the cross-sections varied from 1948 between 8.80 m² (shafts 63, 64, 65, 259 and 7 bis ) or 12.00 m² (shafts 67 and 127). Due to the wooden headframes and the TM 23 type hoisting machines used at the beginning, the final depth of these shafts was a maximum of 300 m with a maximum conveying speed of 5 m / s with a hunt in the conveyor frame .
In the early years, Hunte in the form of front or side tippers were used for horizontal conveyance. This hunt had a volume of 0.44 m³ and a track width of 600 mm. The driveways had a cross-section of 3.5 m² to 5 m² up to the −330 m level. In the first few years, filling the hunt and transporting it through the mine was mostly done with pure muscle power. In shaft 4 (Gallus Tolln) horses were also used for long-distance transport. Battery locomotives of the type EGS Karlik , which were built from 1947 by the Bleichert Transportanlagenfabrik of the AG “Transmasch” Leipzig , were probably used as a means of traction during this period . The battery locomotive weighed 2.2 tons and had a pulling force of 2 kN at a top speed of 5.9 km / h.
Starting in 1949, manual filling of the Hunte was gradually replaced by the use of the first PML 3 throwing shovel loader . Probably also from 1949 the first battery locomotives of the Metallist type from the BBA Aue were used. This battery locomotive weighed 2.9 tons and had a pulling force of 2.1 kN at a top speed of 6 km / h. With its narrow width of 780 mm and a negotiable curve radius of 5 m, it was ideally suited for small track cross-sections and tight curve radii. Similarly, larger hunts with a volume of 0.63 m³ were used, which increased the conveying capacity rapidly.
With the further exploration of the deposit and the knowledge gained from it about its depth, some of the shafts were sunk further and equipped with new hoisting machines. For example, shafts 14 bis , 16, 64 and 127 received more powerful hoists and shafts 14 bis , 67 and 127 were equipped with 2 drum hoists.
In 1949/50, the depth of 5 new large shafts began, the clear cross-sections of which were between 16 m² and 17 m². Despite their size, like all other shafts, they were sunk with a rectangular cross-section and provided with a bolt shot support. The shafts 309, 310 and 311 were sunk outside the central deposit area, probably in order not to endanger the new shafts by the beginning deformation. The shafts 256, 280 and 310 each had two hoisting machines and the shafts 309 and 311 had three hoisting machines.
Instead of the previously usual wooden headframes, these shafts now have steel headframes . Shaft 280 was given a two-storey solid wall double bracing frame. Shaft 310 was equipped with a two-storey full-wall double gantry and two Koepe machines for extraction. Each of these shafts had a skip conveyor and shafts 256, 280 and 311 also had a rack conveyor .
The blind shafts sunk in the same period of time had a clear cross-section of 8.8 m² and were designed for one-day rack conveyance with a hunt. The blind shafts I, II and III, sunk in 1953 with a clear cross-section of 12 m², conveyed via skip systems, while the conveyance via the blind shafts IV and V, each sunk in 1953 with a clear cross-section of 13.5 m², each with a hoisting machine and one-day rack funding for a hunt took place.
With the introduction of the new loading and transport technology (e.g. throwing shovel loader PM 17 or PML 63 and the Akkulok Metallist) underground, larger profiles were now necessary in the driveways of the routes. In 1954 they reached 7.5 m² on the −450 m level.
Weather management
In addition to the on-site fresh air supply, the aim of the ventilation is to remove the dusts and aerosols generated in the mine and, in uranium mining, to reduce radon pollution for the miners. When it comes to ventilation, a distinction is made between main weather management via stationary main pit ventilators on the shafts and special ventilation with the aid of portable ventilators for ventilating the drive-up and work locations.
In the early years of uranium mining, the mine workings could hardly be ventilated in a targeted manner. The natural flow of weather due to temperature differences was mainly used. The existing compressed air was used to ventilate the workplaces after the blasting. The legal basis at this time was the general mountain police regulations for the state of Saxony of September 27, 1929 and the resulting safety regulations for weather management and firedamp as well as light and lamp management from 1932.
From 1949 onwards, the Wismut AG issued the first safety regulations, in which a fresh weather quantity of 3 m 3 / min fresh weather was required for every worker working on the most busy shift at the same time . This regulation also applied to the horses used, for which 6 m 3 / min were required. In order to meet these regulations, the establishment of a weather service was started in 1949. To ensure the Sonderbewetterung spot was Lutten made of cardboard with a diameter from 20 to 30 cm and blowing fans used with an output of 3 kW.
The first statutory regulations of the GDR on technical safety and occupational health and safety in ore mining, which also regulated the requirements for ventilation, were issued on December 30, 1952. A general rethinking of the necessary construction of a central ventilation system did not take place until after the mine fire on July 16, 1955 at the −480 m level in the filling area of the blind shaft 208 bis . 33 miners were killed.
Probably the first pure weather shaft in object 02 was shaft 125, which was sunk from 1948 and had a cross-section of 5.1 m². Connected to shaft 125 were the levels +60 m, + 30 m, Marx-Semler, −30 m, −60 m, −90 m, −120 m, −150 m and −180- m. The −180 m level was only reached in 1951. Shaft 27a, which was sunk in 1949 and branched off from shaft 27 on the +60 m level, was obviously also used as a weather shaft.
In 1954, from the −180 m level to the −210 m level to the −240 m level, the weather shaft 125 bis was sunk. After the mine fire of July 16, 1955, the WI and W III weather shafts were sunk in 1956. The weather shaft WI with a cross-section of 12 m² was located in the eastern part of the mining area and was sunk from the −360 m level to the −540 m level. Connected to the shaft were the levels −390-m, −420-m, −450-m, −480-m and −510-m. The weather shaft W III with a cross section of 6.4 m² connected the levels −480-m, −510-m and −540-m.
Shaft 125, which was sunk between 1948 and 1951, went out of service in 1958/59 due to total deformation of the shaft tube and was backfilled in 1959. Shaft 309, which also served as a weather shaft for the −630 m level, was dropped in 1961. Shaft 310, which was sunk as a production shaft between 1950 and 1954, was used as a weather shaft from 1955 to 1969.
Immediately after the end of the mining work, all mine workings that were located below the Marx-Semler-Sohle and penetrated into the Niederschlema-Alberoda deposit were hermetically sealed by bricking up the routes and sealing them with a bitumen emulsion . Ventilation of these pit areas therefore no longer had to take place.
Drainage
When the mining began, the problem of water solution also had to be faced. The Marx-Semler-Stolln, through which approx. 550 m 3 / h of pit water was released from the Schneeberger Revier and which at the same time drained the Schlemaer Revier, was in the beginning also used as the main mine for all transports and expanded accordingly with electrical and compressed air lines . Time and again, disruptions during transport (e.g. overturned hounds) resulted in restrictions in the water solution. In addition, the water from the levels -30-m and -60-m excavated in 1947 was raised to the level of Marx-Semler-Stolln, so that it soon reached its capacity limit. In order to relieve the Marx-Semler-Stolln, a dam gate was built into the tunnel in 1947 between light holes 15 and 16, which was supposed to keep the pit water from the Schneeberger Revier away from the mine workings of object 02. The water accumulating behind the dam was pumped above ground into the Schlemabach using an underground pumping system and discharged there. The pumping station installed on the Marx-Semler-Stollnsohle was able to lift 1950 m 3 / h of water. Due to the independence of the 22 manholes by the end of 1948, the drainage was also carried out independently. It was only with the concentration of the pits in 1949 and the excavation of the −240 m level as the main production level in 1950 that the first main water retention systems were set up at shaft 6 and shaft 27. The pumping station on the hopper 6 was in a position 750 m 3 / h through the shaft 7 up to pump in the canopy of the Schlema stream. The normal amount of water here was approx. 210 m 3 / h. This also included the pit water from shaft 65 on the −120 m level, which first fell to the −240 m level, continued to flow to shaft 6 and was then lifted via the pumping station there. The pumping station at shaft 27 had a capacity of 501 m 3 / h of water. The inflow of pit water was around 190 m 3 / h. After several days the water was pumped into the wood floodlight of the Silberbach and drained there. This pumping station was also used to remove the water from shaft 67 on the −120 m level and the water from shaft 259 on the −240 m level.
When the −360 m level was excavated in 1952, a pumping station with a capacity of 468 m 3 / h was also set up at shaft 16 to lift the water to the pumping station at shaft 6 at the −240 m level . The normal amount of water here was around 70 m 3 / h.
When the −420 m level was excavated in 1952, a pumping station with an unknown capacity was also built at shaft 280. The amount of water here was approx. 44 m 3 / h.
In 1954, excavation of the −480 m level began. A pumping station with a capacity of 377 m 3 / h was then installed at blind shaft 27 bis . This made the pumping station built in 1952 at shaft 280 superfluous and the resulting pit water was lifted to the pumping station at shaft 27 to the −240 m level.
With the excavation of -540 m level in 1955 and the -585-m level in 1956 with the slot 27 were to two pumping stations with a capacity of 120 m 3 / installed h, the resulting mine water to the pumping station at the shaft 27 raised to the −240 m level.
The pit water from shaft 127 fell via blind shaft 339 from the −360 m level to the −420 m level and from here on via the blind shaft 280b is to the −540 m level. From there, the pit water was lifted by the pumping station at shaft 38 down to the −240 m level to the pumping station at shaft 38, and from there it was pumped above ground into the Schlemabach.
With the scheduled cessation of mining in the Oberschlema district by 1961, it became necessary to restructure the entire drainage system. In the third quarter of 1960, after the commissioning of the new main drainage system on the -546 m level, work began on shaft 38 to gradually shut down and dismantle the existing pumping stations. In order to ensure the undisturbed inflow of the pit water to shaft 38, downpipes were installed in the shafts and extra water channels were created on the feed lines for the pit water. The pumping station at shaft 6 was probably shut down in 1964 and the pumping station at shaft 27 in 1968. Shaft 7 bis was used to control the main water line to shaft 38 until 1970. The output of the pumping station at shaft 15 bis was, most likely in 1959, increased to 5860 m 3 / h. In order to have permanent access to this pumping station, shaft 15II bis was sunk in 1980 to replace shaft 15 bis, which was backfilled in 1959 . Until then, access was only possible via the pipe shaft at the pump station.
After the renovation of the Marx-Semler-Stolln, the Dammtor, built in 1947, was opened in 2010. Since the Marx-Semler-Stolln was no longer suitable for permanent water dissolution due to the ongoing ground movement in the deformation area, the excavation of a tunnel break ("southern break") south of the deformation area began in July 2011 by Wismut GmbH. The break begins at light hole 14 and ends in the area of the König-David- Schacht in the already existing bypass of the Marx-Semler-Stolln from the year 1822.
Dump management
At the beginning of the mining work, the mountain masses from the excavation, alignment and excavation were dumped directly at the respective shafts onto the areas between the houses of Oberschlema. The available space was quickly exhausted and so one was forced to transport the mountain masses away by truck. This problem had already become so acute in early 1947 that the first general director of Wismut AG, Michail Mitrofanowitsch Malzew , dealt with it personally. The project for the construction of a cable car was examined in order to tilt the mountain masses on Gleesberg or Hammerberg. However, this project failed because of the steep slope angles of both mountain slopes. Alternatively, the Silberbachtal should be filled in, but this project was also discarded for no real reason, certainly in ignorance of the size of the deposit and the mountain masses still to be expected.
At this point in time the daily production was approx. 1000 m³ of mountain mass. In the further course of the mining work, the mountain masses from the shafts in the place were brought to the edge of Oberschlema by means of conveyor bridges. As early as 1947, the tailings from shaft 15 were transported over a conveyor bridge to the dump in shaft 5. Shafts 6, 6 bis , 6 c , 7 and 7 bis conveyed over a common conveyor bridge to a heap that was above today's Markus-Semmler-Straße. Parts of this dump served as a dam for the sludge pond for the uranium processing of object 99. From 1948, shafts 14 and 14 bis conveyed to the Hammerberg dump via a terraconic. The shaft 65 conveyed its mountain mass to a dump, which was located above today's market passage. However, these measures were not enough to remove the resulting mountain masses from the place. In the meantime, a dump had been built up at the goat drag between Schneeberg and Oberschlema. The mountain masses were transported to the dump using a steam locomotive-operated field railway or mine locomotives. Another dump was created on the concert square of the spa park.
At the end of 1949, the construction of a heap railway (900 mm) operated by steam locomotive began. The partly double-track Haldenbahn reached a length of 8 km. The depot was located between shafts 256 and 280. The Haldenbahn drove from shafts 5/15 to shaft 256 further into the Silberbachtal to shafts 16, 27 and 127. From there the route led along the Hammerberg and the high bunkers of the shafts 280 and 8/14/14 to . The mountain masses along the Hammerberg up to the Schafberg on the Niederschlemaer Flur were tilted. The Hammerberghalde extends over a distance of 1.5 km on the Hammerberg as a slope filling. On the Schafberg it was raised in the area of shaft 382 as a flat and table dump. At the shafts 12, 63, 63 bis , 64, 67 and 127 located a little outside Oberschlemas , the mountain masses were heaped up over terraconic plants to form pointed cone heaps. At the shafts 259, 309, 310 and 311, which were sunk in the 1950s, the mountain masses were heaped up via terraconic systems to form pointed cone heaps.
The heap created at the goat drag was cleared again in 1950 and taken to the Hammerberghalde with the heap railway. After the cessation of mining, the dumps were rehabilitated for the first time in the 1960s. The dumps in the former town center were leveled together with the remaining building remains. The Hammerberghalde was covered with alluvial sand after 1962 and planted with pine trees. The heap of shaft 65 was flattened and planted in 1963/64. The day breaks occurring in the deformation area were filled with existing dump material. The material from the heap of shaft 6 was used to cover the sludge settling basin of the treatment. Then the rest of the dump area was flattened and reforested. From the mid-1960s, dump material was processed into gravel and sold within the GDR (e.g. for the construction of the Rostock overseas port). The dump of shaft 65 was removed for this purpose. From 1975 the dump material from shafts 127 and 311 was also processed into ballast in a crusher system at shaft 127.
After 1990 the deformation area was covered with a layer of heaps up to 10 m thick and the new spa park was built on top of it. In the course of the renovation work by WISMUT GmbH, almost all of the dumps have been renovated to date. With the exception of arsenic, the metal content of the seepage water discharged from the heaps is below the current legal limit values. Since the limit value for arsenic is only partially and slightly exceeded, there is currently no need for additional water treatment.
Mountain damage
Due to the sometimes ruthless and near-surface mining, in some areas there was sometimes severe damage to buildings due to subsidence.
On the instruction of the Prime Minister of the GDR , Otto Grotewohl , on September 10, 1951, a “special commissioner for the settlement of settlement issues in the Saxon ore mining areas” was founded. The aim was to relocate the population from the subsidence areas. The legal basis for this was the “Ordinance for the Execution of the General Mining Act” of the Kingdom of Saxony of August 31, 1910. The resettlement of the population of Oberschlema began on November 22, 1951. A total of 203 houses with 1711 inhabitants were affected. The resettlement also affected 58 companies and 19 public institutions. At this point the subsidence had already reached 68 cm in places.
The demolition of the town center of Oberschlema began immediately after the resettlement was completed on May 20, 1952. In April 1952, Wismut had already started demolishing 14 houses it owned without a permit. The scheduled demolition work did not begin until October 17, 1952. Since the community was overwhelmed with this task, it transferred the work to the VEB Bergungsbetrieb Berlin . The demolition of the houses was carried out with the aim of completely reusing the recovered building materials. Gas and water pipes, power lines and the paving of the streets were also recycled where possible. Even trees and bushes were recovered in the spring of 1953. From the end of 1954, VEB Baubetrieb Chemnitz took over the further demolition work. The demolition of the houses in the Oberschlema municipality was completed in the spring of 1958.
In addition to the subsidence, the penetrations to the surface and the quarries were another problem caused by mining. Again and again the Schlemabach and also the Silberbach poured through these openings into the mine building. As early as 1951, 400 m of the Schlemabach and the entire lower reaches of the Silberbach were routed in wooden floodlights to prevent uncontrolled water entry. The raft ditch in the southern area was repeatedly buried by rolling heaps of heaps. The water overflowing as a result also penetrated the mine workings.
The raft ditch was used sporadically as a service water dispenser for ore processing and for the discharge of the waste water produced during processing. During a storm on August 31, 1951, the raft ditch overflowed, penetrated the mine workings and also flooded Oberschlema station. As with the slippery slope of the settling tank of the treatment in 1948, also reached on 31 August 1951 of radioactive sludge in the Floßgraben and the flooded land.
In order to prevent further water ingress into the mine workings, the community began, at the request of Wismut, in November 1952 with the reallocation of the Schlemabach. Over a length of 3 km between the "Brückenhof" (now Kobaltstrasse 27) in Schneeberg and Lichtloch 13 in Niederschlema, a new stream bed was built that led the Schlemabach around the mining area. At the end of 1953, the work was completed. The water from the raft ditch was then channeled into the new Schlemabach stream.
The Silberbach was also enclosed in a concrete corset in 1954/55 and the lower course of the stream was relocated in the area of shaft 280.
After the town center was demolished, the wooden floodlights in the subsidence area were relocated to guide the Schlemabach on Friedensstrasse in 1954/55 in order to prevent the brook from sinking further. After the mining work was completed, the Schlemabach in the area of the blue paint works was finally enclosed in a concrete corset.
Although the subsidence subsided very quickly after the mining was stopped, the number of open-day quarries increased. For safety reasons, the 23.4 hectare deformation area was completely cordoned off with barbed wire and barriers in 1959.
The greatest depression is on the northern edge of today's spa gardens at 50 ° 36 ′ 11.5 ″ N , 12 ° 39 ′ 40.9 ″ E and was 6 m.
literature
- Werner Runge: Chronicle of the bismuth . Ed .: Wismut GmbH. Self-published, Chemnitz 1999 (CD).
- Axel Hiller, Werner Schuppan: Geology and uranium mining in the Schlema-Alberoda district . Mining monograph (= mining in Saxony . Volume 14 ). State Office for Environment, Agriculture and Geology [LfUG], Freiberg 2008, ISBN 978-3-9811421-3-6 , urn : nbn: de: bsz: 14-qucosa-78919 .
- Rainer Bode: Rope ride . Ed .: SDAG Wismut, Chemnitz. Bode-Verlag, Haltern 1990, ISBN 3-925094-40-7 .
- Oliver Titzmann: Radium bath Oberschlema . Kurgesellschaft mbH Schlema, Schlema 2003.
- Yearbook for mining and metallurgy in the Kingdom of Saxony. 1873 to 1917.
- Yearbook for mining and metallurgy in Saxony 1918 to 1934.