Ore mine Grund
| Ore mine Grund | |||
|---|---|---|---|
| General information about the mine | |||
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| Mining technology | Ridge construction | ||
| Funding / year | 300,000 t | ||
| Funding / total | 16 million tons of metal ore | ||
| Information about the mining company | |||
| Operating company | Preussag AG Metall | ||
| Employees | 540 (1981) | ||
| Start of operation | before 1564 | ||
| End of operation | 03/28/1992 | ||
| Funded raw materials | |||
| Degradation of | Lead luster , zinc blende , copper pebbles | ||
| Greatest depth | approx. 900 m | ||
| Geographical location | |||
| Coordinates | 51 ° 48 '21 " N , 10 ° 13' 30" E | ||
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| Location | Bad Grund (Harz) | ||
| local community | Bad Grund (Harz) | ||
| District ( NUTS3 ) | Osterode am Harz | ||
| country | State of Lower Saxony | ||
| Country | Germany | ||
| District | Silbernaal-Grund mining inspection | ||
The ore mine reason was a lead - zinc - mine in the mountain town of Bad Grund (Harz) in Harz ( Lower Saxony ). It was the last producing ore mine in the Federal Republic of Germany.
Geology, deposit, mineralogy
The pit fields of the ore mine Grund were on the Silbernaaler , Rosenhöfer and Laubhütter gangway . These parts of the Upper Harz corridor system stretched from the western edge of the Harz near Gittelde to the Clausthal plateau in an east-southeast direction. Faults in the mountains formed a total of seven powerful ore resources, which were the basis of the mine. The most important ores were galena and zinc blende with an average metal content of 10%. From this lead , zinc , copper and silver were extracted.
Pit building
The Grund ore mine consisted of the fields of the pits Help God in the west and Bergwerkwohlfahrt in the east. The mine building was exposed from west to east by the Westschacht ( depth 518 m), the Achenbachschacht (depth 719 m), the Knesebeckschacht (depth 499 m) and the Wiemannsbuchtschacht (depth 761 m). At historical shafts there were u. a. also the Hilfe-Gotteser-Schacht near the Achenbachschachtes and the Medingschacht (depth 517 m) in the Innerstetal. The eastern part of the mine was cut through the Tiefen-Georg tunnel , which begins in the Grundner valley and is completely cut through by the Ernst August tunnel below. The excavations last reached to the 21st level at a depth of 900 m. The main extraction level was the 19th level (approx. 700 m underground).
history
The Grund ore mine was created in 1923 from the merger of the originally independent pits Help God (start of operation in 1831) and Bergwerkwohlfahrt (start of operation in 1819).
Predecessor pits were: Hilff Gots im Grund (first mentioned in 1564), Silberner Nagel (= Silbernaal , 1570–1633), House Braunschweig (1577–1680) and Isaacstanne (1740–1751).
The first extraction shaft of the mine Bergwerkswohlfahrt (later Ostfeld ) was the ( Saigere ) Meding shaft, which was started in 1829 . The original Kehrradförderung gave way to the first electric winder in the Harz Mountains and a steel strut frame in 1902 . The shaft was abandoned and backfilled in 1967 because of the westward migration.
By means of a government initiative, mining , which had come to a standstill on Todtemannberg, was resumed in 1831 by sinking the Hilfe-Gotteser Schachtes.
In 1855 the Knesebeck shaft was sunk . It was initially intended as a light hole for the Ernst August tunnel (construction period 1851 to 1864), but was expanded as a driving and material shaft at the beginning of the 20th century. The drive was given up in 1974 and it then served exclusively as a weather shaft .
The Royal Mining Inspection in Grund was established in 1887 through the merger of the Silbernaal and Sankt Andreasberg inspections .
After its completion in 1907, the Achenbachschacht replaced the Hilfe-Gotteser-Schacht as the modern main production shaft of the Help Gottes mine. He received electrical funding with a steel headframe. From 1931 onwards, all ores from the mine were only conveyed through this shaft and processed centrally by flotation (foam-swimming separation). The miners also drove to work through this shaft .
In 1923 Preussag took over all state mines in the western Harz. The Grund ore mine was created from the pits of the Grund mining inspection.
In 1934 and 1950, other ore materials were discovered in the far west. The mines in the western field of the mine were supplied with fresh weather by the western shaft sunk in 1933 .
In 1951 the Wiemannsbuchtschacht was sunk in the eastern field. From now on, all of the mountains occurring underground were lifted to the surface with a container transport system (Skip). The mine dump was created in the vicinity.
From 1970 to 1973 extensive modernization measures were carried out to increase the output of the mine: the introduction of trackless drilling vehicles for blasting work, diesel-powered loaders for transporting the ore and the mountains, a shuttle train transport between the east and west fields with large conveyor vehicles and an increase in processing capacity .
In 1976 the Achenbachschacht received a new, modern headframe with solid wall struts made of box profiles, and the hoisting machine was modernized. From 1978 onwards, mining was carried out with self-hardening backfill. The annual output was increased from 260,000 t to 450,000 t of raw ore.
Despite all rationalization efforts, the production was stopped on March 28, 1992 because of the further decline in metal prices on the world market. Around 200 miners lost their jobs. After the cessation of operations, the mechanical equipment was dismantled and the vehicles were removed from the pit. The dewatering was discontinued, so that today the pit is full of water below the Ernst-August-Stollen level. When the Achenbach shaft was backfilled in 2002, the last access to the mine was closed.
In total, around 16 million tons of ore were mined in the Grund ore mine and 1 million tons of lead, 700,000 tons of zinc and 2,500 tons of silver were extracted from it.
With its closure, the Upper Harz mining industry came to an end after 450 years.
Ore stage from the Grund ore mine
Headframe of the Meding shaft from 1902
Headframe of the Achenbach shaft (status 2009)
Mining museum at the Knesebeck shaft
Wiemannsbucht mine (photo 2014)
Headframe of the Wiemannsbucht mine (photo 2014)
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Technical monuments, traces
The development of the Wiemannsbucht pits (located in the forest at the entrance to the town), Knesebeck (above the town center) and Achenbach ( Am Taubenborn ) has been preserved to this day and the headframes are still upright as a landmark and in memory of the mining industry.
A mining museum has been set up at the Knesebeckschacht : In the mining museum "Schachtanlage Knesebeck" , also Mining Museum Knesebeckschacht or Mining Museum Bad Grund , the buildings, the machines and technical systems, underground vehicles, some of the breakers and the wheel rooms of the original mining can be visited. The landmark of the facility is the 47 meter high hydro compressor tower, which can be seen from afar.
The headframe and other operating buildings of the Meding shaft still stand in the Innerstetal. However, the facilities are in poor condition. The associated electric hoisting machine is one of the oldest of its kind in Germany and is exhibited in the German Mining Museum in Bochum .
literature
- Preussag AG Metall (publisher): 1931 - 1981 Pit Help of God . Goslar 1981
- Torsten Schröpfer: Treasure trove - interesting facts about the West Harz mining and metallurgy . Clausthal-Zellerfeld 2000, ISBN 3-923605-08-0
- Herbert Sperling, Dieter Stoppel: Course map of the Upper Harz. Monographs of the German lead-zinc deposits, Volume 3.Swisserbeard, Stuttgart 1981