Lübenheen potash and rock salt mine
| Potash and rock salt mine Friedrich Franz Lübenheen | |||
|---|---|---|---|
| General information about the mine | |||
| Information about the mining company | |||
| Operating company | Mecklenburg trade union "Friedrich Franz" | ||
| Employees | up to 400 | ||
| Start of operation | December 23, 1895 | ||
| End of operation | December 9, 1916 | ||
| Successor use | different users of the daily interface until today | ||
| Funded raw materials | |||
| Degradation of | Potash and rock salt | ||
| Geographical location | |||
| Coordinates | 53 ° 17 '59.6 " N , 11 ° 5' 59.7" E | ||
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| Location | In the urban area of Lübenheen | ||
| local community | Lübheen | ||
| District ( NUTS3 ) | Ludwigslust-Parchim | ||
| country | State of Mecklenburg-Western Pomerania | ||
| Country | Germany | ||
| District | North German Potash District (Mecklenburg) | ||
Friedrich Franz shaft is a former potash shaft in the town of Lübenheen in the Ludwigslust-Parchim district in Mecklenburg-Western Pomerania . Salty water from the subsoil of the gypsum quarry in Lübenheen as well as the traditions of the former Saline Conow gave rise to exploratory drilling within the gypsum quarry. These provided evidence of rock salt ; in later boreholes also of potash salts within the so-called Staßfurt Formation ( Perm , Zechstein ). The sinking of the shaft on the floor of the gypsum quarry that had been in operation until then, about 15 m below the natural terrain, began on December 23, 1895. In 1899 a bronze bust was made by the sculptor Hugo Berwald in honor of the patron saint and Grand Duke Friedrich Franz III, who died in 1897 . of Mecklenburg-Schwerin was solemnly unveiled on a granite base in Lübheen near the Friedrich-Franz-Schacht. In 1936 this monument was moved to the Ludwigslust Palace Park . It has survived there. Enormous difficulties with water inflows meant that the sinking (with interruptions) took around 18 years to complete. The rock and potash mining began on December 11, 1905. The potash salts were further processed in a separate factory on the mine site. The entry of daily watering, initially saturated even in the form of solutions, it was observed in 1905 on the 430-m- sole . Even sophisticated barricade measures could not prevent the mine from drowning within a few hours on the night of December 9, 1916. All fixtures and fittings remained in the shaft. In 1981 the shaft tube with lignite filter ash suspension in connection with cement bridges was finally kept .
prehistory
By chance, a chunk of plaster was found in 1823 on the outskirts of the town of Lübenheen. Soon after, drilling revealed that there was a large deposit of gypsum here. Burnt gypsum, especially as a building material for plastering work , from a gypsum works built in Lübheen found huge sales. As the quarry penetrated into the depths, the pit water that was sitting there became increasingly salty. The assumption that rock salt is lying under the gypsum was confirmed by a shallow drilling. This find was the basis for a report by Clausthal miner Ottiliae , in which he recommended the sinking of a 1000-foot bore. Drilling engineer Stoz from Stuttgart drilled through 1879 in his 1516.86 meckl . Foot (441.4 m) deep hole 150 m of rock salt. This result was sensational, as it was previously assumed that salt deposits could only be found in the Magdeburg-Halberstadt basin. Further systematic drilling later confirmed the existence of the Lübenheen-Jessenitz salt dome, on which the Jessenitz and Lübenheen mines were set up.
Details on the geology and hydrogeology of the salt deposit can be found here .
Financial and business relations
- Mecklenburg trade union "Friedrich Franz in Lübenheen.
- Owner: the above union.
- Management board and operations management: Mine director, Bergassessor Baer, factory director Dr. Ehrhardt, both in Lübenheen.
- Number of kuxe : 1000.
- Total capital 9,215,000 Mk., Loan 2,500,000 Mk.
- Funding per day: 500 t.
- Processing plants: Potassium chlorine and sulphate factory, in operation since May 1906.
- Railway, post and telegraph station: Lübenheen i. M.
- Telephone connection: Amt Lübenheen No. 2.
- Siding to station Lübtheen iM
- Manager : A. Hoffmann in Lübenheen i. M.
- Average number of workers: 430 men. Member of the Kali Syndicate.
Taken from: Yearbook of the German Brown Coal, Hard Coal and Potash Industry 1907. Wilhelm Knapp publisher in Halle aS, 1907.
The shaft construction
Sinking of the Friedrich Franz shaft began on December 23, 1895. After considerable difficulties due to water or salt solutions from the cavernous or fissured caprock (= gypsum hat), the sinking was stopped by hand at a depth of 35 m and the shaft was further sunk using the Kind-Chaudron shaft drilling method. After many difficulties - the hardness of the rock resulted in numerous drill and rod breaks as well as deviations of the drilling shaft from the vertical - on July 5, 1902, the lowering of the cistern cylinder from 3.60 m clear width to 242 m depth was successful . Leaks in the so-called Moosbüchse forced further drilling of the shaft to a depth of 99 m. The new Küvellage with a clear width of 3.0 m was cast with magnesia cement. But it was also unsuccessful because water inflows penetrated the head of the new Küvelage at a depth of 222 m. After placing nine segment rings, each 1.5 m high, on the basin layer and pouring the annular space with Portland cement , the water seal was achieved. Further sinking was done by hand in the original diameter of 3.6 m clear width. On September 2, 1905, the 430 m level and the following year the 500 m level was shot . The 600 m level was reached with a blind shaft . The further digging of the main shaft to the final depth of 618 m began towards the end of 1911 with a rectangular cross-section of 3 × 4 m and ended in 1913.
| Depth | shape | diameter | expansion |
|---|---|---|---|
| 0-208.5 | round | 3.60 m | Iron Küvelage |
| 208.5-222.0 | round | 3.00 m | German segments |
| 222.0-299.0 | round | 3.00 m | Iron Küvelage |
| 299.0-391.84 | round | 3.60 m | German segments |
| 391.84-518.0 | round | 3.60 m | Masonry, one-stone |
| 518.0-618.0 | rectangular | 3 × 4 m | without expansion |
Removal and installation, dismantling and relocation processes
Even before the shaft was completed (1913), the 430 m level (1st level) was shot on September 2, 1905 and the 500 m level (2nd level) the following year. The 600 m level was accessed via a blind shaft . The 43 m level, like all civil engineering levels and essential exploratory stretches in profile 4 m wide and 2-3 m high, examined the salt store over a wide area. In 1908, about 280 m west of the production shaft, test cross passage 2 was driven south to the opposing saddle wing. At a distance of approx. 310 m he found an 8 m thick hard salt deposit of high quality (up to 20% K 2 O), which was also dismantled.
The drives on the 500 and 600 m level in the north-east and north-facing direction were only used for further exploration of the deposit ; there was no dismantling here.
For rock salt extraction - partly for sale, but also as backfill material - a total of five so-called mountain mills were set up. Four of them at the level of the 500 m level, one on the II. A level. They were all in the Na2. Their dimensions were 20 m wide, 80 m long and 10 m high.
It is not certain whether the carnallite and hard salt mining were offset at all, and if so, to what extent. The otherwise usual introduction of rock salt and boiler house ashes from above ground into the empty pits need not have been done here in full, because the former, water-filled gypsum quarry was filled in for a long time during the operating period of the mine.
Manufacturing processing
The "Geological Passport of the Southwest Mecklenburg Potash Salt Deposits, Geological State Institute Rostock 1950" shows that the material to be conveyed was processed in a crude salt mill with three grinding systems and a chlorinated potassium factory. One of the grinding systems was used to process factory salt, a second to manufacture the "Kainit" brand and the third to grind rock salt. Each system had a capacity of up to 45 t / h. The factory produced up to 500 t / d of potassium chloride and high-percentage fertilizer salt as well as larger quantities of sulfuric acid salts. Rock salt, chlorine magnesium, block kieserite, bromine and probably also Epsom salt were produced as by-products. The final liquor from the factory was conveyed to the Elbe through a 17 km long cast iron pipeline. The necessary wastewater concession was unlimited.
The sinking of the mine
After only eleven years of operation, considerable caustic inflows near the shaft on the 430 m level heralded the end of mining activity. These tributaries came from a porous, Langbeinitic - Sylvinitic transition layer from the older rock salt to the lying in the Staßfurt seam about four meters below the lower potash deposit . All attempts to shut off or seal off the tributaries were unsuccessful despite considerable expenditure and engineering services. At the beginning of December 1916, it was decided to give up the mine building below the 430 m level. A concrete plug was installed in the shaft tube from a depth of 410 to 384 meters, which reached 7.8 meters into the tubbing column above . For control purposes, a pipe tour - a pipe standing vertically in the water - was placed in this. On the night of December 8th to 9th, 1916, strong subterranean noises were heard in the town of Lübenheen and the surrounding area. The following day at 11 a.m. the water level in the shaft was already 50 meters deep. In addition to ground movements, the sinking of the groundwater by up to two meters was also observed. The water level in Probst Jesar See, about 1.5 kilometers away (caused by a sinkhole) fell by about 10 centimeters. The total unmoved pit void volume is approximately 320,000 m 3 .
The day surface was closed with a concrete slab with an inserted plumbing tube. A brick edging with a closed roof and a lockable access door was built above it.
The safekeeping of the shaft tube
After the daytime facilities were demolished, the shaft was covered with a cover. Subsequently, the mine Lübenheen remained until the 1970s, i. H. almost unnoticed over a period of almost 50 years. An industrial company was established on the former factory site. The official measures to monitor and secure the mining facilities were limited to a few controls of the water level and the shaft cover. In order to avert threats to public safety, a safety area of 25 m was designated, within which building and / or use was prohibited. The decreed safety area was ultimately also the reason to deal with the mine again from the mid-1970s. At this point in time, the local vehicle factory intended to significantly expand its production capacity. The areas provided for this also included the shaft security area that was previously closed. As a result of the mine damage analysis, it was recommended to completely fill the accessible part of the shaft tube.
Up to this point in time, planned backfilling of old potash shafts that had been filled with solutions had only been carried out in individual cases, so that there was little knowledge of suitable building materials and installation technologies. In addition, during the GDR era only limited economic and technological resources were available for such shaft storage . Based on the experience from the deep drilling sector and the securing of objects in the civil engineering sector, a safekeeping concept was drawn up which, for the first time in potash and rock salt mining, provided for backfilling the shaft using lignite filter ash (BFA) .
This offset work took place in 1980. The drill cores obtained from the offset column then confirmed the projected strength parameters. A major investment measure in the years 2008/09 envisaged using the immediate shaft area as well. This required a reassessment of the custody at the time. To determine the rock mechanical input parameters of the BFA backfill and the top hat rock , in 2008 a core drill was carried out in the BFA backfill column of the shaft tube (down to a depth of 79 m) and in the top hat rock in the immediate vicinity of the shaft (down to a depth of 209 m ) and determined the corresponding strength parameters from the core material. As the comparison with the values determined in 1981 for this BFA backfill shows, there is no loss of strength of this material over secular (long) periods under the conditions prevailing in the manhole. With the performed numerical investigations can stability probably both in the area of the shaft tube and present in the area of mine field or may be incurred Subrosionskavernen be computationally busy and the backfilling of the shaft tube with BFA over a period of 200 years.
literature
- o. V. Acta concerning the operation of the mine in Lübenheen , holdings of mining office 51 to 59. LHA MV Schwerin
- E. Geinitz: The salt mine "Friedrich-Franz" in Lübenheen. Archive no. Mklbg. f. IV 1263, Wissenschaftl. Schwerin General Library, 1906.
- Ullrich: The water ingress into the shafts of the Jessenitz and Friedrich Franz potash works in Mecklenburg. Kali magazine, 12th year, issue 6, pp. 90–95, 1918.
- Günter Pinzke: The salt production in southwest Mecklenburg - geology and development of the deposits; an outline of mining history. Part 2: Search, exploration and development of new salt deposits: the potash and rock salt mines Jessenitz, Lübheen and Conow. In: Association of Friends of Art and Culture in Mining e. V. (Ed.): THE ANSCHNITT . 64th volume, No. 2 -3, pages 76-92, 2012.
- G. Pinzke, A. Jockel: Retrospective on the safekeeping of the old potash shaft Friedrich Franz, Lübenheen, Mecklenburg, with lignite filter ash and its safety assessment after 30 years. "World of Mining" magazine, 5/2010
Individual evidence
- ↑ The lake in Probst-Jesar, a pinge. Retrieved June 5, 2013 .
- ↑ G. Pinzke: mining damage analysis of the potash and rock salt mine "Friedrich Franz" in Lübenheen , LUNG MV, archive no. KA 0016, 1979
Web links
- Günter Pinzke, Andreas Jockel: Retrospective on the safekeeping of the old potash shaft Friedrich Franz, Lübenheen, Mecklenburg, with lignite filter ash and its safety assessment after 30 years. (PDF; 3.3 MB) In: World of Mining. October 2010, pp. 282-294 , accessed January 26, 2011 .
- Günter Pinzke: The salt mines of Mecklenburg . 1st edition. Books on Demand, Norderstedt 2014, ISBN 978-3-7357-7441-5 .
- Martin Froben et al .: 20 years of the Stralsund Mining Authority. (PDF) 1990-2010. Stralsund Mining Authority, accessed on January 26, 2011 .
- Photos from the Lübenheen shaft
- Lars Baumgarten: Germany's potash and rock salt pits. 7.1 Friedrich-Franz. Retrieved December 9, 2013 (photos, coordinates).
- Günter Pinzke: Old mining in Mecklenburg-Western Pomerania. Retrieved May 10, 2016 (documentation).