Jessenitz potash and rock salt mine
| Jessenitz potash and rock salt mine | |||
|---|---|---|---|
| General information about the mine | |||
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| other names | Duke Regent Jessenitz shaft | ||
| Mining technology | Roof chamber construction | ||
| Funding / total | 1,396,813 t of potash and rock salt | ||
| Information about the mining company | |||
| Operating company | Mecklenburgische Kali-Salzwerke Jessenitz | ||
| Employees | up to 450 | ||
| Start of operation | 1886 | ||
| End of operation | 1912 | ||
| Successor use | Storage / parking lot | ||
| Funded raw materials | |||
| Degradation of | Potash / rock salt | ||
| Degradation of | Rock salt | ||
| Geographical location | |||
| Coordinates | 53 ° 16 '49.3 " N , 11 ° 6' 24.4" E | ||
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| Location | Jessenitz | ||
| local community | Lübheen | ||
| District ( NUTS3 ) | Ludwigslust-Parchim | ||
| country | State of Mecklenburg-Western Pomerania | ||
| Country | Germany | ||
| District | North German Potash District (Mecklenburg) | ||
The potash and rock salt mine Jessenitz is a former potash mine in Lübtheener district Jessenitz. From 1900 to 1912, 1.4 million tons of rock and potash salts were mined here.
prehistory
In 1861 chemical factories in the Staßfurt area, which were called "impure", succeeded in sinking the shafts of the Heydt / von Manteuffel found originally only for the extraction of rock salt to enrich the weak brine of the Staßfurt saline for a technical To make use usable. It had become possible to dissolve the potassium chloride (KCl) contained in these salts and to market it as fertilizer salt in agriculture. The discovery of these potash salt finds - the “Staßfurter Berggeschrey ” - also stimulated the search for such salt deposits in Mecklenburg. Here, in the Grand Duchy of Mecklenburg-Schwerin , salt mining had meanwhile been nationalized by the “State Ordinance of May 16, 1879”. Only the landowner of the Jessenitz manor was exempt from this by a relevant decree. The first search drilling began on September 11, 1882 and found rock salt at a depth of 258.7 m and potash salts at a depth of 270.7 m. This borehole was ceased in rock salt on May 10, 1883 at a depth of 372.7 m. A second core drilling 350 m south of the first opened up potash and rock salts from a depth of 260.5 m in 1886. When the gypsum cap was encountered at a depth of only 36 m with further flat bores west of the connecting line between the two bores, the starting point for the Jessenitz shaft was found.
Financial and business relations
- Mecklenburgische Kalisalzwerke Jessenitz Aktiengesellschaft, Jessenitz near Lübenheen.
- Owner: the above stock company.
- Board of Directors: Bergdirektor Kulle, Factory Director Carl Ludwig Reimer , Director Fehlhaber in Jessenitz.
- Share capital: 5,000,000 Mk.
- Enclosure: "Duke Regent" in Jessenitz.
- Number of bays: 2.
- Average production per day: 500 t of potash salts.
- Processing plants: 1 raw salt mill, 1 chlorinated potassium factory and a sulphate factory.
- Production in 1905: 6326 tons of potassium chloride, 9653 tons of sulphates, 2584 tons of fertilizer salts, 1314 tons of block gravel, 23 504 tons of kainite and sylvinite , 1069 tons of carnallite and mountain gravel.
- Railway station: Jessenitz.
- Post and telegraph station: Jessenitz mine (Mecklenburg).
- Telephone connection: Amt Lübenheen No. 1.
- Siding to Jessenitz station.
- Operations management: Mountain director Kulle and factory director Carl Ludwig Reimer . Operations manager : Obersteiger Starke.
- Average number of workers: 450 men. Member of the Kali Syndicate .
Processing plants
At the beginning of 1902, the company's own chlorinated potassium factory started its work with a processing capacity of 250 t / day. The equipment was supplied by the Staßfurt company G. Sauerbrey. The average number of employees in the factory was 120; In the mine there were up to 330. The factory wastewater was fed directly to the Elde via a 14 km long pipeline.
Geological and hydrogeological conditions
The starting point of the shaft is on the southwest flank of the NW-SE trending salt dome Lübenheen-Jessenitz. This saline structure sits on an approx. 17 km long and approx. 10 km wide northwest-facing salt foot.
The breakthrough of the salt dome happened about 100 million years ago in the Alb . The further rise of the salt took place about 55 million years ago in the Tertiary and its main development phase is dated to the Oligocene (about 25 million years ago) and Neogene (about 5 million years ago). The rise in terrain over the salt dome indicates recent ascent movements.
The deep boreholes sunk on the salt dome as well as the excavations in the Jessenitz mine itself and those of the Friedrich Franz Lübheen potash and rock salt mine about two kilometers away do not allow sufficient clarification of the geological structure of the salt structure. Pleistocene and tertiary strata (less than a million years old) form the overburden above the salt dome. The Pleistocene (approx. 10,000 years ago), which consists of yellow sands and gravel , follows under about 2 m of fine yellowish heather sand, which is often merged into dunes and crossed by boggy lowlands . In places, these several meters thick are boulder clay layers and those with coarse pebbles underlain. This non-cohesive and cohesive rocks reach up to 40 m in thickness .
So-called pinges , which are caused by leaching in the salt mountains, by crevasses in the gypsum hat above, as well as by saline-tectonic disturbances, lie in a wide, NW-SE running zone above the salt dome and make its course transparent on the surface. The most important ones are the 6.4 hectare Probst Jesar See , the Great and Small Sarm near Trebs and the so-called Kirchenversunk near Volzrade . Other small pings are in the Kamdohl forest area.
Tertiary deposits are present as clays , mica and glauconite sands as well as “earthy” lignite . On the flanks of the salt dome, the Tertiary reaches down to a depth of 550 m.
The developed saline can generally be broken down as follows:
- Leine series with the main anhydrite, mostly fissured, up to 120 m thick and the gray salt clay up to 2 m thick .
- Staßfurt series with the fissured deck anhydrite leading to gaps, up to 110 m thick.
- Reddish brown to greyish white capstone salt (up to 250 m thick).
- Hang-end group of the Staßfurt potash seam, partially formed as a pure white carnallite (5 m thick; in compression zones up to 50 m)
- Lying group of the Staßfurt potash seam made of red carnallite (10 m thick; up to 60 m in compression zones). Both groups are separated by an approximately 8 m thick rock salt intermediate.
The salt layers are steep to almost vertical. Bends, tapers and wedges of stratified members indicate strong tectonic movements. Dry as well as caustic and gas-filled fissures have already been encountered by the deep drilling. The main faults run partially into the overburden, but are cut off and protected against the surface water by cement or the recompressed clay.
The valley sand area between Sude and Rögnitz is generally rich in water. The groundwater level in the area of the shaft attachment point is about 5 m below the ground; the direction of flow of the groundwater is generally west to southwest. The cavernous to fissured leaching area above the salt structure, the so-called gypsum hat or caprock, is highly saltwater-bearing from a depth of around 150 m. The water inflow during the lowering of the shaft sometimes exceeded 40 m 3 per minute and, as described below, caused considerable sinking difficulties.
The shaft construction
It was known that the surface loose sediments were highly water-bearing. This also indicated the presence of the water-filled pinges. In 1886, for example, the mining and metallurgical engineer Friedrich Hermann Poetsch was commissioned to dig a shaft with a diameter of 5 m clear width to a depth of 80 m near Jessenitz using the freezing shaft method. This method was patented by Poetsch in 1883 as a "method to sink shafts in water-rich and floating mountains safely, vertically and cheaply".
In March 1888, the first wedge bed was laid at a depth of 75 m, in the area of slightly to moderately fissured plaster, and segments with a diameter of 5 m were installed up to the base of the wall . In May 1889 the second wedge bed was laid at a depth of 89 m because after the frost wall had thawed, inflows of approx. 20 l / min emerged from the first wedge bed. However, these were sealed off with the second set of segments from 89 to 75 m. The further sinking up to 130 m and the lining of the shaft wall with segments (third set of segments from 130 to 89 m) took place until the summer of 1889. A pre-drilling on the shaft bottom showed that one had to be prepared for further fissured, water-bearing rock layers. The mining company decided - because all the equipment for the freezing process was still on site - to expand the bottom of the shaft a little in order to drill eight new freeze boreholes on its wall at regular intervals to a depth of 175 m. After completion, they were piped with a diameter of 171 mm and a pipe wall thickness of 10 mm. It was possible to build a frost wall in a relatively short time; however, in view of the high mineralization and pressures of the strata waters, it turned out to be permeable (January 1890). Thanks to powerful pumps, it was possible to bring the shaft down to a depth of 150 m and to introduce a provisional expansion of U-iron rings and wooden cladding. Nevertheless, the increasing inflows of more than 40 m 3 / min were not controllable in the long run, so that the shaft finally drowned in February 1890.
In August 1892, preparations began for further deepening the shaft using the Kind Chaudron method . The drilling method, named after its inventors, the mining engineers Karl Kind and Joseph Chaudron, was developed around 1850 and allowed shafts up to 4.40 m in diameter to be drilled in dead water and made watertight. At the time, this sinking method had not yet been tried and tested in salt mining.
Since a drill with a diameter of 4.10 m weighs over 25 tons , a stable derrick had to be built first. At the same time, the bottom of the shaft was filled with a concrete layer 12.5 m thick. This towered over the uppermost water-bearing gypsum gap by about 7 m. After three months of waiting time for the setting and hardening of Betonplombe shaft Jessenitz could again gesümpft be. All bulky parts were removed from the shaft and the tubbing column was completed down to a depth of 137.3 m. The recovery of the freezing pipes failed because they were jammed too tightly by falling down and drilling mud. Attempts to solve this by drilling around were also unsuccessful. The boring again led to inflows of uncontrollable magnitudes, as a result of which the shaft drowned again. And so the freezing pipes and some work platforms had to be drilled and these parts had to be laboriously recovered using catching tools and the use of divers. The drilling was entrusted to the factory administration of Haniel & Lueg under the direction of the drilling engineer Berghaus. Since the upper tubbing part of the shaft had a diameter of 5 m, a clear width of 4.10 m was chosen for the further shaft section. After many more difficulties (zerbohrt u. A. Had stuck freeze pipes and their parts salvaged linkage breaks, deviation of the wellbore from the perpendicular, leaks of Moss Bank, Zerbohren a cast-iron Küvelagenbodens in conjunction with laborious fishing operations, etc.) was finally on February 2, 1900, the shaft dry (depth 346 m).
On October 18, 1900, the shaft was christened in the presence of the regent Duke Johann Albrecht von Mecklenburg-Schwerin . Later the shaft was digged up to 603.53 m and covered with brick masonry.
The salt production
Alignment
The complex formation of the salt deposit was studied by the tailgating of test tracks and horizontal drilling. On the 400-m- sole to the shaft 17 meters west was a 50 m thick bearing white Carnallitits. This was also demonstrated on the 430, 470 and 500 m levels that were driven later. However, no extraction took place on these soles. The 500 m level served as the weather sole . When they were driven, an 83 m thick potash seam was found north of the shaft. The 600 m level served as the main conveyor line. From a die south of the shaft and two blind shafts to the north of it , the 700 and 800 m levels and several floor levels were applied.
contraption
Cross-passages and routes with a width of 2.5–4.0 m and a height of 2.0–3.0 m were driven depending on requirements and local conditions.
Dismantling
Salt production took place in both the northern and southern Schachtfelde, but only below the 500 m level. Mining was carried out using the conventional roof chamber construction method. The quarries , which were started from the 604 m level, were usually 20 m wide. Safety pillars 10 m wide were left between these and the striking and cross-cutting stretches . The excavation heights reached up to 70 m, since any levitation was not added to the floor levels, which were laid out at intervals of 8 m. Presumably these mines were mixed with low-quality rock salt, residues from the potash factory and sand. It is noteworthy that a safety pillar around the shaft tube was not established, so that the excavations were brought up to 35 m from the shaft. The excavations of the 700 m level were also 20 m wide, up to 25 m long and up to 24 m high.
The evaluation of the seamless production statistics shows a total production of 1,396,812.736 t of potash salts. This corresponds to a cavity volume of approx. 780,000 m 3 . In addition, according to the mine workings, there are about 60,000 m 3 of cavities on routes, dies and blind shafts, so that the total volume of the pit is around 840,000 m 3 . Quantitative information on the backfill introduced is missing, so the air-filled pit cavity that was present at the time the pit system was drowned cannot be precisely defined.
The drowning of the mine
Already in 1902 a leaching point was found on the 542 m level, in a steeply upright carnallite layer about 150 m north of the shaft, in the horizontal section of the backfill section leading to mining 5 north. The added solutions were saturated; their amount was a few liters per minute. At other points in the same stratigraphic area between the 542 and 584 m levels, more or less saturated salt solutions emerged. Some of these dried up after a short time.
Further lye inflows were noticed from 1906 in mining 3a of the 584 m level and from 1910 also in mining 2 north of the 576 m level. At the beginning of June 1912, a sudden sharp increase in the filling of the lye on the 542 m level was noticed. Most of these salt solutions were pumped into trucks and brought to the surface. The smaller part eventually flowed over the 676 m level and specially laid pipelines to the 700 m level, so that it could also be transported above ground from here by trolley.
Along with these increased inflows, crackling noises were also noticed in the area between the 542 and 600 m levels. Later, from around June 5, 1912, even thunder-like blows were registered in the mountains with subsequent crackling. The investigations of the solutions showed a steady decrease in the magnesium chloride content from initially around 350 g / l to only 56 g / l with an increase in the sodium chloride content from 80 g / l to around 280 g / l. The origin of these solutions from the leaching area of the salt dome was thus proven beyond doubt. This was also confirmed by observations of the water levels in the surrounding waters (Probst-Jesarer See, Großer Sarm) and the wells. The management realized that the inflows could not be controlled in the long run and decided to abandon the mine building below 500 m. From here on, the shaft was intact and dry, and mining was to be continued from here.
But this hope was not fulfilled. On the afternoon of June 24, 1912, the inflows increased so much that the entire mine was drowned within a few hours. In the shaft itself, the water level leveled out at a depth of around 38 m.
Various plans to regain the eligibility for funding or at least to continue operating the potash factory have been drawn up. For example, the shaft was to be swamped to a depth of 400 m, after a concrete plug had been installed, and the deposit was to be approached again at a depth of approx. 380 m in a south-easterly direction. The further brining of the salt deposit through the drowned shaft was also discussed. Until mid-June 1912, 300–400 m 3 of brine were pumped out and processed in the factory every day . However, the mining authority prohibited this work for safety reasons.
The Jessenitz shaft was partially filled with sand and covered with a concrete slab (see photo on the left).
The safekeeping of the shaft tube
After the Jessenitz mine suddenly drowned, on February 18, 1914, the Hagenow Mining Authority ordered the Herzog-Regent mine to be backfilled. In 1916, the above-ground structures were demolished by the "Westphalian iron dismantling and demolition company" from Dortmund. The "Deutsche Futterwerke GmbH Jessenitz", which acquired the land, filled the shaft tube of the Herzog-Regent shaft with sand from the area up to 223.5 m below ground. This work was finished on August 25, 1916. The follow-up inspection carried out by the responsible Oberbergamt Halle on September 3rd showed a fill level at a depth of 235.7 m.
The shaft opening was secured at the beginning of November 1916 by a reinforced concrete ceiling with field rail reinforcement, a sand fill of 1.6 m and a ceiling made of T-iron, NP40, with concrete caps and a standpipe of 100 mm diameter.
The Geology Department of the Schwerin District Council commissioned the "VEB Schachtbau Nordhausen" with a letter dated October 5, 1983 to carry out a new shaft head protection or cover for the shaft tube of the Jessenitz shaft. In 1981, the cover installed after the Jessenitz mine had been drowned out (see illustration on the right) because the intention was to build an artificial final depth in the shaft and then - as successfully carried out in the Friedrich Franz Lübenheen shaft - a lignite filter ash suspension bring in. After some financial / technical considerations, at the end of 1985 a 10 m × 10 m large reinforced concrete slab, resting on a separate ring foundation , was finally poured. The weather channel was previously filled with lean concrete. The cover plate received a control opening 0.6 m in diameter. Public safety was ensured by a 25 m × 25 m barrier (fence made of wire netting and lockable gate). The mining authorities ordered a safety radius of 25 m around the shaft tube.
As a result of a renewed assessment of mining damage, it was recommended that the shaft be completely backfilled. The corresponding execution planning provided for the filling of the remaining cavity using a cohesive filling material with good flow behavior in the pumping process. In the period from January to May 2000, the existing manhole closures (the manhole cover and the reinforced concrete slab which fell in 1985 at a depth of 20 m) were first drilled through and two backfill pipes were installed.
Starting at a depth of 215.5 m, a dam building material was first installed over a length of around 10 m. Subsequently, further dam building material (e.g. LWM-HS B5, determined strengths of up to 12.8 MN / m²) and two cement bridges were installed in several sections. Continuous monitoring of the filling level in the entire shaft as well as a balance of the quantities of the building material brought in and the salt solutions pumped out of the shaft at the same time proved that this was completely filled. A concrete seal, which was inserted below the existing manhole cover, formed the end. The backfilling work was thus completed and the shaft - insofar as it was under the condition found - secured in accordance with the safekeeping guidelines. The use of the area close to the shaft as a parking and / or storage space was approved. The shaft safety area continues to be 25 m × 25 m around the shaft attachment point.
Abseufschacht Jessenitz II
After drowning the shaft Jessenitz the management intended, as the mountain prerogatives , that the legitimate deplete area was large enough m southeast about 750 new slot called Volzrade or Jessenitz II Lower accommodate. The sinking of the foreshaft had already started here in 1911. This stood at 4.5 m in the area of the groundwater level with a diameter of 10 m in bolt shot timber. However, since with the final decision of the distribution office for the potash industry of October 22, 1912 in accordance with Section 17 (2) of the Potash Act of July 1, 1912, the plant was classified as permanently incapable of delivery and lost its sales quota, work on the Volzrade mine was also finally stopped and the shaft filled with sand.
Individual evidence
- ^ Taken from: Yearbook of the German Brown Coal, Hard Coal and Potash Industry 1907. Wilhelm Knapp published in Halle aS, 1907.
- ↑ Hydraulically setting dry mortar for filling cavities; supplied by the Hagenow concrete plant in various mixtures of fillers such as B. sand and gravel and binders. (DM 1.25 HS, compressive strength 2.5 MN / m² )
- ↑ Martin Froben et al .: 20 years of the Stralsund Mining Authority. (PDF, 4.7 MB) 1990-2010. Bergamt Stralsund, p. 51 , accessed on February 25, 2016 .
literature
- Günter Pinzke: The sinking of the Jessenitz shaft in Mecklenburg. In: Leaves on the cultural and regional history in Mecklenburg-Western Pomerania (Hrsg.): Stier and Greif . 20th year, pages 62–74, 2010.
- 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, 2012th
- Günter Pinzke: The salt mines of Mecklenburg . 1st edition. Books on Demand, Norderstedt 2014, ISBN 978-3-7357-7441-5 .
- Günter Pinzke: Mining damage analysis of the Mecklenburg potash salt works Jessenitz . Ed .: Council of the District of Schwerin, Geology Department. 1981 (unpublished report).
- Ullrich: The water ingress into the shafts of the Jessenitz and Friedrich Franz potash works in Mecklenburg . In: Kali magazine . 12th year, no. 6 , 1918, pp. 90-95 .
- ERCOSPLAN GmbH (Ed.): Study to evaluate the Herzog-Regent shaft, Jessenitz, with regard to possible damaging effects on the environment . Erfurt 1997 (unpublished).
- ERCOSPLAN GmbH (Ed.): Analysis of mining damage including the development of a proposed solution for the safekeeping of the Herzog-Regent Jessenitz shaft . Erfurt 1999 (unpublished).
- ERCOSPLAN GmbH (Ed.): Execution planning for the safekeeping of the Herzog-Regent shaft, Jessenitz . Erfurt 1999 (unpublished).
- Thomas Reuter: The shafts of potash mining in Germany . In: Stadtverwaltung Sondershausen (ed.): SONDERSHÄUSER HEFTE on the history of the potash industry . No. 13 . City administration Sondershausen, Department of Culture, Sondershausen 2009, ISBN 978-3-9811062-3-7 , p. 106 .
Web links
- Photos from the Duke Regent shaft
- Lars Baumgarten: Germany's potash and rock salt pits. 7.2 Duke Regent and Jessenitz II. Accessed December 9, 2013 (photos, coordinates).
- Old mining in Mecklenburg-Western Pomerania. Günter Pinzke, accessed on May 10, 2016 (documentation).