Morgenstern pit

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Morgenstern pit
General information about the mine
Morgenstern pit 4.JPG
The last remaining building in the mine
Mining technology Opencast mining , magazine construction , expansion mining
Funding / year up to 372,400 t
Funding / total 4.14 million tons of iron ore
Information about the mining company
Operating company Barbara Erzbergbau AG
Employees up to 225 (in 1954)
Start of operation 1938
End of operation March 31, 1963
Successor use landfill
Funded raw materials
Degradation of Brown iron stone
Greatest depth 309 m
Geographical location
Coordinates 51 ° 58 ′ 18 ″  N , 10 ° 27 ′ 5 ″  E Coordinates: 51 ° 58 ′ 18 ″  N , 10 ° 27 ′ 5 ″  E
Morgenstern pit (Lower Saxony)
Morgenstern pit
Location of the Morgenstern pit
Location Klein Döhren
local community Liebenburg
District ( NUTS3 ) Goslar
country State of Lower Saxony
Country Germany
District Peine-Salzgitter area

The Morgenstern mine is a closed, smaller iron ore mine on the eastern flank of the southern Salzgitter ridge . The mining facilities are located directly on the road from the Goslar district of Hahndorf to Klein Döhren , municipality of Liebenburg in the district of Goslar ( Lower Saxony ) near the so-called Ohlei .

The mine last operated by Barbara Erzbergbau AG dismantled a rubble ore deposit of the Lower Cretaceous in opencast and underground mining between 1938 and 1963 and belonged to the Peine-Salzgitter district .

After its closure, the former open-cast mine served as a household waste and rubble dump for several years .

geology

The creation of the ore deposits of the Morgenstern mine

The formation of the camps proceeded like that of the other deposits in the Salzgitter area : the coastline of the Lower Cretaceous Sea was in the area of ​​the Salzgitter ridge. In the area of decaying marine organisms dissolved in water iron compounds could very well precipitate , forming so-called Toneisenstein- geodes . These were preferentially deposited in natural depressions near the coast due to the sea surf. Due to the weathering processes after the water withdrew, they disintegrated into numerous rubble. During subsequent floods, iron oolites were deposited in the same place . The originally flat deposits (also called ore ponds ) that were created in this way were disturbed and erected over the course of millions of years by tectonic processes and / or rising salt domes.

Geographical location and extent

The ore deposit of the mine is on the eastern flank of the Salzgitter ridge. It forms the geological continuation of the Georg-Friedrich deposit to the west of it and was originally connected to it via the removed saddle of Döhrenhausen . The striking length of the camp is 450 to 500 meters. It falls to the east at 27 gon . The thickness of the ore body, which consists of several layers, is 25 meters at the outcrop , increases to 40 meters at depth and then decreases to 15 meters to the south. From top to bottom is the upper bank of the main bearing (1.5 to 5.5 m thick) by a deaf Sanderzlager ( slope repository ) and a sandy, slightly mineralized clay agent covers. After an intermediate means , the 8.5 to 21-meter-thick lower bench is located under the upper bench , which is separated from the lying one by marl clay stones .

mineralogy

The ore from the Morgenstern mine consisted of brown iron debris in a sandy-clay binder. The grain size increased with increasing depth. The mean composition of the ore was between 25 and 30% Fe , 26 to 31% SiO 2 , 9 to 12% Al 2 O 3 and 3 to 5% CaO .

History and technology

Predecessor mining

In 1845, scraped the miner Heinrich Christian Brand in Bad Grund on behalf of Altenau- Lerbacher -Eisenhütte for iron ore and discovered on the eastern flank of the Salzgitter ridge at Klein Döhren an ore deposit. Only after many years of negotiations was he awarded the Morgenstern mine on March 22, 1859, and the Consolidation field a year later . In 1865 Wilhelmshütte from Bornum acquired the mine fields, which it sold to Carlshütte AG from Delligsen in 1890 . Finally came Berechtsame after conversion into a square field of 2.2 square kilometers in 1909 in the possession of the OHG Max Meyer stone of Hannover , without it ever came to a recording of a mining operation. The Morgenstern union was founded in Hanover in 1922 and the Salzgitter union finally took over the extraction rights in 1935. The Salzgitter union was held by the raw materials companies of the United Steelworks AG (VESTAG), Dortmund .

The earliest mining disruption of the camp Morgenstern took place in 1923 to 1925 than that of the Ilseder hut pre exaggerated Schroeder tunnel suffered due the ore deposits in the Ohlei.

Start of mining and operation of the Morgenstern mine from 1937 to 1963

After the National Socialist rulers exerted pressure on the German steel companies as part of their four-year plan , VESTAG also began research and exploration work in the Morgenstern field . Initially, a total of 9 exploratory boreholes were drilled from 1937 onwards . At the same time, the Ilseder Hütte also examined the deposit north and south of the field of what would later become the Morgenstern mine. In addition to boreholes, a 720 m long cross passage from the Schroeder tunnel to the south was driven in 1938 , the so-called Ohleistrecke .

Mining began in an open pit as early as 1938 . To apply this came the so-called Trichterbau , wherein the ore an embankment into a Schrapperrinne down shot was. The scraper conveyed the ore into roller holes , from which it was drawn off over the first underground excavation level in mining vehicles . After the Morgenstern shaft in the lying area of the deposit was sunk from 1938 to 1939 , the open-cast ore above it was lifted to the surface again. The shaft initially had a timber construction , was 2.3 meters by 4 meters in cross-section and 185 meters deep. Four civil engineering layers (45, 85, 135 and 184 m depth) were placed and prepared at the Morgenstern shaft . In addition, there were several tons of daily heaps in the ore deposit . Underground mining began in 1941 in the magazine construction . In this chamber construction method the losgeschossene remained debris until full Auserzung lie in the excavation chamber and served as exhibition space for Hauer in drilling and shooting. The chamber was then pulled empty via roller holes at the lower end of the chamber and a scraper section below.

From 1938 to 1940, the necessary daytime facilities such as wash houses , workshops, shaft hall and administration, as well as ore processing, were built above ground . During processing, the ore was enriched in so-called refining works to a concentrate with 34 to 36% Fe, 22 to 23% SiO 2 , 7 to 7.5% Al 2 O 3 and about 4% CaO. A mud pond served to settle the mud-shaped mountains . Compared with its sister mines and especially with the mines of the Reichswerke in the northern Salzgitter area, the structural and mechanical equipment of the Morgenstern mine was rather modest.

Between 1939 and 1942, around 50,000 tons of ore were mined by an average of 130 miners each year. In 1943 over 100,000 tons were produced and in 1944 the mine reached a temporary high point with 184,000 tons and almost 200 employees, as operations had to be closed in the spring of 1945 as a result of the end of the war and the German surrender .

In the spring of 1946, mining operations were resumed with a workforce of just over 100. First, the distances from the mud is washed up had to be free, because the pit during standstill due to lack of drainage was drowned. From an initial 60,000 tonnes per year, production rose in the first post-war years to 220,000 tonnes by 1950. Despite the shortage of materials and labor, this was due to the great demand for reconstruction. In 1949, the Morgenstern shaft was enlarged to a diameter of 4 meters by 4 meters and lined up .

On March 18, 1953, Barbara Erzbergbau GmbH, based in Siegen, took over the mine as the legal successor to the raw materials operations of the United Steelworks. At this point in time the annual output was already well over 300,000 tons. In 1954 the minable ore reserves in the open pit were exhausted and this was abandoned. However , this could be completely compensated for by rationalization measures in underground mining, especially by converting to floating expansion . In 1957, the highest production ever achieved was 372,400 tons. The highest level of personnel was in 1954 at 225 miners and then the team became steadily smaller due to the progressive improvement and consolidation of the operational processes. In 1956, for example, processing was shut down and the raw ore was transported via a 3.3 km long Lorean cable car to the neighboring Fortuna mine in Groß Döhren , where it was sent for processing there.

The German iron and steel industry had a high demand for raw materials in the second half of the 1950s. On the other hand, the inferior domestic ores, to which above all the acidic and iron-poor Salzgitter ore belonged, came under pressure from imports of iron ore from abroad. That is why the Morgenstern mine was merged with the Fortuna mine in 1960 to form the Fortuna-Morgenstern composite mine . On the newly excavated 5th underground level ( substation construction ) in 309 meters underground, Morgenstern was connected to the new main production shaft Fortuna 2 via a 3.7 km long connecting section . A new central processing facility was set up on Fortuna, which processed the ores from all three pits of Barbara in the southern Salzgitter area. Production in the Morgenstern shaft was discontinued. As a business division of Fortuna, between 1961 and 1962 around 240,000 tonnes were mined in the Morgenstern field until operations ceased on March 31, 1963 for economic reasons. The Morgenstern shaft was backfilled in 1964.

Re-use as a garbage dump for the district of Goslar from 1976 to 1993

As early as 1955, when the mine was in operation, household waste is said to have been deposited in the open pit in a disordered manner . From 1963 to 1968, the Florentz couple used the former mining facilities as a disposal company for chemical waste . Barrels and other containers were improperly thrown into the open pit and even liquids were dumped there . Since the operators committed suicide in 1968, the details have remained in the dark to this day. For security reasons, the district had a fence built in 1970. On November 22nd, 1970, a major fire occurred in the barrel storage facility within the opencast mine , which could not be finally extinguished until January 1971.

Despite this previous history, the district of Goslar, as a municipal waste disposal company, had the suitability of the former Morgenstern opencast mine checked as a domestic waste dump in 1972. After corresponding positive reports from commissioned specialists, the district of Goslar leased the grounds of the Florentz company and the Morgenstern mine from the state of Lower Saxony. After completion of the planning approval procedure on January 30, 1976, the district began to prepare the site and operated the waste disposal facility on its own until the landfill space was exhausted in 1993. The combined building of the former shaft hoisting facilities and pre-shredding served as a depot.

After the landfill was closed, follow-up work has been carried out in the form of groundwater monitoring. Among other things, the water level in the Fortuna 2 shaft and the Morgenstern pit are measured monthly.

Current condition

Landfill during masking work

The colliery site of the Morgenstern pit is located east of the district road on a plateau. Of the day-to-day facilities of the mine, only the combined operating building that previously housed the shaft and the conveying facilities remains. The outlets for the hoist ropes and the covered recess for the headframe are reminiscent of the building's former function.

Instead of the cut in the opencast mine, the garbage dump rises east of the Zechenplatz. To the south of it is the still existing Morgenstern pond.

Measures to cover the household waste dump have been carried out by specialist companies since around October 2017. These measures are carried out with soil, foil and topsoil, among other things. Measures for surface water drainage and collection are also carried out. The measures are expected to be completed by the end of 2018.

literature

  • Rainer Slotta : Technical monuments in the Federal Republic of Germany - Volume 5, Part 1: The iron ore mining . German Mining Museum, Bochum 1986, p. 169-183 .
  • Heinrich Korthöber et al .: Mining in Salzgitter . the history of mining and the life of miners from the beginning to the present. In: Archives of the City of Salzgitter (Ed.): Contributions to the city's history . 1st edition. tape 13 . Appelhans, Salzgitter 1997, ISBN 3-930292-05-X , p. 304-310 .
  • Manfred Watzlawik et al .: Fortuna, Morgenstern, Georg-Friedrich . History and stories of ore mining near Döhren. Ed .: Döhrener Mining Working Group. 1st edition. Self-published, Groß-Döhren 1983.
  • Heinz Kolbe: The history of iron ore mining in Salzgitter: The exploration history of the plants south and north of the Salzgitter urban area . In: Geschichtsverein Salzgitter eV (Ed.): Salzgitter Yearbook 1984, Volume 3 . Salzgitter 1984, p. 25-27 .

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