After 120 years, potash mining ended
Potash production at the Sigmundshall plant will end on 21 December 2018. After almost 120 years of potash mining, the economically recoverable deposits have been exhausted and work between 1,100 and 1,400 meters deep pushed people and technology to their limits.
In addition to the necessary safety work, which will take several years to complete, K+S would like to develop the site into an innovation center for testing and establishing new business segments.
Our certificates at the Sigmundshall location
Our products are certified according to international standards and norms. Here you can find our current certificates.
ISO 50001 Certificate
ISO 9001 Certificate
ISO 9001 Certificate
Certificate Qualified Waste Management
The history of the Sigmundshall plant
With its 120-year history, Sigmundshall is not only a reflection of current events, but also illustrates the turbulent development of German potash mining.
1898 - Sigmundshall shaft is drilled in the middle of the "potash boom" of the late 19th century. It is one of more than 200 potash shafts in the German Reich.
1906 - Construction of the potash factory and start of fertilizer production
1913 - The Weser shaft in Altenhagen is drilled and connected to the Sigmundshall mine in 1914. Potash mining at "Gebrück" (approx. 1920s).
1933 - Closure of the plant within the framework of state control of production
1949 - Resumption of production as a replacement for lost potash plants in Central Germany
1960 - Start of molten salt production for metallurgical applications
1965-1969 - Drilling of the Kolenfeld shaft and extension of the Kolenfeld shaft to a weather and material shaft
End of the 1960s - Introduction of trackless winding machines and rapid mechanization of extraction work.
At the end of the 1970s - performance increase of the line conveyance by large-capacity wagons. Annual production exceeds 2 million tonnes (1979).
1992 - Construction of a plant for the recycling of aluminum salt slags (REKAL)
The Husum shaft project northwest of the Steinhuder Meer is abandoned because the reunification had fundamentally changed the structure of the German potash industry.
1995 - Start of tailing pile coverage with REKAL residue and greening
1997 - Reached 1,400 meters
1999 - Construction of a new production line for the manufacture of fertilizer specialties based on hard salt/Kieserite
2001 - Start of Kieserite production and use of the Staßfurt seam (hard salt) as an additional crude salt base, thus extending operating life
2003 - Annual production for the first time exceeds 3 million tonnes
2007 - Introduction of series construction machines for line haulage in mine operations
2014 - The extraction of crude salt is almost exclusively shifted to the 1,150 to 1,400 meter level. Temperatures of up to 50 °C prevail there.
November 2017 - The K+S Board of Executive Directors decides to discontinue salt production and potash production at the end of 2018, as economic operation is no longer possible. The employees affected by the closure were offered new jobs at other company sites.
Dec. 21, 2018 - Potash production at the Sigmundshall plant ends with the production of the "last ton". Between 1904 and 2018, a total of about 130 million tonnes of crude salt were extracted from the Bokeloh salt dome and processed into fertilizers and industrial products.
from 2019 - The site will be developed into an innovation center for testing and setting up new business activities.
The REKAL plant will continue to produce to the same extent as before; the recycling waste generated there will continue to cover the tailings pile. The greening of the tailings piles is to be completed by approx. 2037.
The mine will be secured and prepared for the subsequent flooding, which is required for disused salt mines in Lower Saxony.
K+S is continuing the ongoing training of industrial mechanics, electronic technicians and chemical technicians and will also hire nine new trainees in 2019 to cover its own demand for qualified specialists. From 2020, only the apprenticeship of chemical technicians will be continued.