Rastenberg potash plant
| Rastenberg potash plant | |||
|---|---|---|---|
| General information about the mine | |||
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| other names | Rastenberg union | ||
| Mining technology | Chamber construction | ||
| Information about the mining company | |||
| Employees | 400 (in 1914) | ||
| Start of operation | January 24, 1910 | ||
| End of operation | April 1, 1925 | ||
| Successor use | no | ||
| Funded raw materials | |||
| Degradation of | Potash salt | ||
| Mightiness | up to approx. 50 m | ||
| Greatest depth | 659 m | ||
| Geographical location | |||
| Coordinates | 51 ° 11 '50 " N , 11 ° 27' 14" E | ||
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| Location | Billroda | ||
| local community | fin | ||
| District ( NUTS3 ) | Burgenland district | ||
| country | State of Saxony-Anhalt | ||
| Country | Germany | ||
| District | Magdeburg-Halberstädter Mulde | ||
The potash Rastenberg was a mine of potash with connected fertilizer plant at Billroda in Saxony-Anhalt ( Burgenlandkreis ). In connection with the end of the German potash monopoly after the First World War and the endeavor to fundamentally reorganize and rationalize the potash industry, which was reflected in the so-called decommissioning ordinance of July 18, 1919, operations ceased in 1925. Devil's time: 1907–1909 (659 m) ; Shaft diameter 5.25 m; open pit cavities: approx. 200,000 m³.
Geological and hydrogeological reservoir conditions
Geological and geological assessment
The deposit is located on the southwest flank of the Herzyn streaking Roßleben saddle (Hercynian or Hercynian refers to the direction of strike of a mountain range in NW-SE direction in geology ); it lies geologically in the Magdeburg-Halberstädter Mulde . The shaft was set up in the middle red sandstone. The figure below on the right provides information about the strata penetrated. With the exception of the uppermost Zechsteinletten and the border anhydrite, the sequence of layers shows the complete Zechstein profile on the Roßlebener Sattel. The potash deposit is limited in the northeast by the leaching of the potash seam emanating from the saddle core. The former Burggraf / Bernsdorf potash mine is located approx. 2.5 km between this leaching boundary and the Rastenberg mine. The disused Richard / Reichskrone mine is located around 5 km to the north . In the west and southwest of the Bad Bibra field there are hard salt reserves worth building . In the southwest, the Finns fault is to be understood as a natural limitation, as the potash deposit continues at a greater depth beyond . The Finn fault falls to NE, was encountered in the Mühltal borehole at 280-300 m and is likely to have come closer to the mine workings up to the level of the potash deposit. The former Finne mines were only mined insignificantly and the areas blocked by mine fields are small in relation to the total potash deposit on the southwest flank of the Roßlebener saddle. By Auffahrungen a flat mounted in the rule was Carnallititlager with an average content of 9-10% K 2 O, and thicknesses between 25 and 50 m encountered. For the most part, only the upper part was worth building. In the lying area of the carnallitite , hard salt lenses appeared to a lesser extent, from which up to 7000 tons of hard salt were extracted annually. No information is available about thicknesses and qualities. In the south-western approach, the camp is said to have already been more severely disturbed by the influence of the Finns fault.
Hydrogeological information
As on all Finne works, the red sandstone in the Rastenberg shaft also carries a lot of water. During the sinking work, water inflows of up to 3.5 m³ / min occurred at a depth of 230–240 m at a depth of up to 1.5 m³ / min. For this reason, more than 250 m shaft tubes in the red sandstone were built with segments . There is no information on the use of lye for the main anhydrite . Most likely, however, it was drilled through dry, as masonry was set as an extension . There is no concrete information about liquor inflows in the mine field . In a letter from the potash engineering office to the Roßleben potash works on October 4, 1956, it says u. a .: “As far as we know, the decommissioning of the Rastenberg plant in 1925 was not only due to the lack of a hard salt deposit worth building and the low K 2 O content of carnallitite (9-10%), but also the fact that In contrast to the neighboring Burggraf-Bernsdorf mine, Rastenberg suffered from lye inflows. After the closure, significant water inflows from the shaft tube found access to the mine workings, as can be seen from the sound of water hitting the shaft tube, which has been observed for decades ” . According to this representation, there should have been liquor inflow points in the pit field. It is certain that it was mainly the water from the eaves that drowned the pit after it was closed . To what extent lye inflows from the mine field were involved can no longer be determined today. The destruction associated with the Finn fault also includes its particular hydrogeological hazard.
The shaft construction
The Rastenberg shaft cut through the sequence of layers listed on the right. The sinking of the Rastenberg shaft with a final diameter of 5.25 m took place from 1907 to 1909. The hanging lawn was at + 301.85 m above sea level. NN . On April 5, 1909, the potash deposit was encountered at a depth of 594 m and then drilled through to a thickness of approx. 50 m. The shaft depth is 659 m.
| Depth 0 - 34 m | Masonry |
|---|---|
| Depth 34 - 311 m | German segments |
| Depth 311 - 659 m | Masonry |
After completion of the production shaft, filling points were set to the north-west and south-east. From these, a weather and conveyor bed were driven forward. On January 24, 1910, the extraction of potash salts began. The so-called two-shaft question was to be resolved by a connecting route with the Prussian Burggraf union. However, with the approval of the responsible mining authority in Apolda, construction was abandoned.
Removal and installation, dismantling and relocation processes
The dismantling was carried out using the chamber construction method. The length of the mining chambers was up to 180 m in the northern construction site and up to 128 m in the south (mining 1). The width of the excavation chambers was generally 10 m. The pier width in the northern mining field was initially 7 m, later 10 m without exception. In the approx. 45 m thick carnallitite camp, several levels were driven on top of each other, the distance between them fluctuating between 7 and 11 m. From the existing crack system it is not clear whether the excavation height extended over several partial levels or whether a suspension was built between each level. The 603, 614 and 649 m level were used as conveyor levels. From the levels in between (621, 628 and 636 m level), it was presumably conveyed via the existing braking mountains to the next lower level. 8 overhocks were probably only used for driving and weather control . Around half of the excavations were moved. Presumably, the backfill material used was mainly factory residues and brought into the pit by hand. Documentation on the technology and the density of the offset application is not available. The calculation of the remaining open cavity on the basis of the existing cracks remains imprecise, as there is no information about the height of the excavation chambers. Assuming an average height of 3 m, a rough calculation results in the following values:
- open cavity excavations: 120,000 m³
- open cavity routes: 80,000 m³
Total: 200,000 m³
After the closure in 1925, most of the residue dump was moved to the mine workings and the shaft was sunk to a depth of 100 m with the rest . Soundings showed that the material gradually subsided until it remained constant at a depth of approx. 450 m. A liquor level formed over the backfill material. On November 20, 1941, it was found that gas smelling of oil was escaping from the ventilation pipe of the manhole cover with a strong hissing sound. The origin and cause of these gases could not be determined beyond doubt. Leaching by fresh water does not necessarily have to be the cause of the sudden escape of gas; the gas can also have made its way through the backfill material if there is sufficient pressure, or fissures opened up through subsidence in the hanging wall of the store, on which the gas made its way to the shaft tube found.
The financial and business situation
The company's economic history
Founded on June 12, 1896 as the "Rastenberg" potash drilling company, it changed into the "Rastenberg" union on December 10, 1906 . This union was entered in the commercial register at the Buttstädt District Court on September 3, 1907. The number of Kuxe was 1000 at the beginning; the trade union meeting of June 29, 1920 decided to increase the number of Kux from 1000 to 3000 pieces; of these were sufficient until the merger in 1253.
On the subject of the company it says: " Exploitation of the after the drilling and lending contract of 23/24. October 1905 in connection with the assignment contract of November 13, 1906 on the part of the grand-ducal Saxony-Weimar government of the trade union Rastenberg to be granted permission to plant and operate a salt or. Potash mine in the Rastenberg district under the rights and obligations arising from the intended contract; Speculation and acquisition of other mines , as well as participation in other mines; Manufacture of plants and operation of companies that aim to exploit the aforementioned authorizations and mines and to utilize their products, as well as participation in such plants or companies; Use and exploitation of self-obtained or otherwise acquired mine products, as well as participation in companies that aim for such use or exploitation ”. On November 25, 1910, the union had concluded a contract with Heldburg AG , according to which it sells all surface and underground facilities , while simultaneously granting all rights, concessions, etc. for the period from January 1, 1911 to March 31, 1912 leased this for 600,000 M / a. The tenant then also acquired all 1000 Kuxe of the Rastenberg union. From January 1, 1913, the company was run for the account of the Rastenberg union.
The union had joined the potash indicator through a provisional contract and was accordingly included in the list of supplying and quota plants when the Reichskaligesetz was passed on May 25, 1910 . At that time , the same was 11.6300 thousandths as for all plants that were provisionally affiliated to the syndicate . The sales quota was initially (December 31, 1924) 4.5362 thousandths; ultimately (from October 1932) 4.2665 thousandths. On May 17, 1924, the trade union assembly resolved to shut down the plant until December 31, 1953 in accordance with Section 83a of the Act on the Regulation of the Potash Industry of July 18, 1919. After the backfilling work prescribed by the mining authorities had been carried out, the Rastenberg mine was shut down on April 1, 1925. In 1925, the potash inspection agency gave the union a participation rate of 95% of the average participation of all potash plants.
The trades' meeting on December 12, 1928 decided the assets of the union as a whole excluding the liquidation with effect from 1 January 1928 in the way of fusion to the Kruger Hall AG (in Burbach-Kaliwerke to transfer AG, Magdeburg). In exchange, the trades received per Kuxe nom. 1200 shares with dividend coupon from January 1, 1928.
The chronology of the company's development 1908–1914
- 1908: Shaft in the process of sinking, shaft approx. 200 m deep. Average number of workers: 150 men. Chairman of the Mine Board : Dr. H. de Neufville. Plant management: Director, mining engineer W. Berkenkamp. Operator: mining engineer Paul Hermann.
- 1909: Shaft approx. 280 m deep. Average number of workers: 150 men. Chairman of the Mine Board: Dr. H. de Neufville. Plant management: Director, mining engineer W. Berkenkamp. Operator: mining engineer Paul Hermann. Surface systems under construction.
- 1910: The shaft is completely sunk. Average number of workers: 150 men. The expansion of the shaft will be finished by the end of the year. The daytime facilities (chlorine potassium factory, mill, etc.) are almost complete. Chairman of the Mine Board: Dr. H. de Neufville. Plant management: Director, mining engineer W. Berkenkamp. Operator: mining engineer Paul Hermann.
- 1911: Fixture works are carried out underground. The daytime facilities are completed. Average number of workers: 150 men. Operations manager: Dipl.-Bergingenieur Fritz Schnadt.
- 1912: The plant is in full operation. Average number of workers: 350 men. Plant management: Director, mining engineer W. Berkenkamp. Operations manager: Dipl.-Bergingenieur Fritz Schnadt.
- 1913: The plant is in full operation. Average number of workers: 350 men. Plant management: Director, mining engineer W. Berkenkamp. Operator: Lehmann.
- 1914: The plant is in full operation. Average number of workers: 400 men. Administration: Factory Director Dr. Sundmacher, authorized officer W. Bunzel. Operator: Lehmann.
The product sales
The raw potash salts delivered by light rail from the neighboring Burggraf and Bernsdorf unions were also processed in the day-to-day manufacturing facilities of the Rastenberg potash plant. Here are some sales figures:
| product | 1917 | 1918 | 1919 | 1920 |
|---|---|---|---|---|
| Carnallite | 16 | - | 261 | - |
| Cainite | 8th | 7944 | 4182 | 763 |
| Fertilizer salt 20s | - | 10011 | 572 | 2713 |
| Fertilizer salt 30s | - | 517 | - | - |
| Fertilizer salt 40s | 86054 | 25917 | 22164 | 25755 |
| Potash fertilizer 38 | 4295 | - | - | - |
| Potassium chloride | 10245 | 56403 | 49511 | 57255 |
| Sulfur. Potash | 7152 | 346 | 503 | 6165 |
| Sulfur. Potash magnesia | 6303 | 5839 | 2011 | 4697 |
| total | 114073 | 106977 | 79204 | 97348 |
In 1921, including sales for the Bernsdorf and Burggraf plants, 123,060 dz K 2 O and 45,090 kg of bromine were sold (Bernsdorf and Burggraf sales 13,335 dz K 2 O), in 1922 122,043 dz K 2 O, in 1923 83,672 dz K 2 O, in 1924 37,339 dz K 2 O and in 1925 only 1,807 dz K 2 O.
The former sewage concession
Following approval of the union's application for expansion, the discharge of final caustic into the Ilm was permitted to the extent that the chlorine content of the water did not exceed 550 mg per liter. The wastewater temperature could not exceed 65 degrees. At the mean water level of the Ilm, this limited amount of wastewater corresponded to a daily processing of approx. 16,000 dz carnallite.
Current condition (2011)
The mining facilities have belonged to the Burbach Group since the closure in 1925. Since January 1, 1955, they were owned by the former VEB Kaliwerk "Heinrich Rau" (shaft tube with a parcel of 345 m²) or from January 1, 1970 of VEB Kombinat Kali, operation Südharz. Since the GDR's safekeeping order of October 10, 1971 (GDR GBl. II No. 73), the council of the Halle district has been responsible for a large number of old potash pits, so-called “pits of old mining without legal successors ”. With the accession of the GDR to the area of application of the Basic Law, the Rastenberg mine was regarded as a "decommissioned installation of a mining operation for which a legal successor does not exist or can no longer be determined". In place of the councils of the districts, the respective state governments acted until the relevant regulatory authority regulations were issued (for the state of Saxony-Anhalt : Law on Public Safety and Order of the State of Saxony-Anhalt (SOG LSA) in the version published on 23 September 2003 ( GVBl. LSA p. 214), last amended on May 18, 2010 (GVBl. LSA p. 340)). Thus, the Rastenberg mine is up to now the responsibility of the municipality in terms of the duty of care for the purpose of averting danger.
These and many other potash and rock salt mines that were closed at the time require continuous monitoring. Critical indications for the necessity of special care for the Rastenberg mine are a gas leak that occurred in 1941, the ingress of water from leaky areas of the shaft lining, which has been audible for decades, and the mineralization of the water or solutions drawn from the shaft tube (including 1969, 1978). As a result of an extensive investigation of the shaft tube in 1978, the responsible mining authority established a safety area that was still in force to date. So far, no special incidents have occurred during the official observations and measurements. To ensure public safety, the existing so-called "Orlas lock" above the unprotected shaft tube was replaced by a new cover in the form of a reinforced concrete slab (see illustration). The manhole cover is fenced in with a chain link fence.
swell
- J. Mossner (Hrsg.): Handbook of the potash mines, salt pans and deep drilling companies. Finanz-Verlag, Berlin 1936.
- Nagel, Lobert, Schwarzer: Mining damage analysis of the mine of the Rastenberg union near Billroda, Nebra district. Roßleben, August 1970.
- G. Pinzke: Expert opinion on the assessment of the mining and public safety of selected potash pits without legal successors on the territory of the Halle district. Assessment. Council of the District of Schwerin, Dept. Geology 1979, Archives of the LAGB Saxony-Anhalt.
- o. V .: Yearbook of the German Lignite, Hard Coal and Potash Industry. XIVth year, Verlag von Wilhelm Knapp, Halle (Saale) 1914.
