The potash plant "Glückauf" Sondershausen in the Kyffhäuserkreis in Thuringia is the oldest still traceable potash mine in the world and is considered the eleventh German potash mine. Currently it serves as an adventure mine and rock salt extraction. The deposit covers an area of over 23 km². The factory construction and the bore of the first shaft began in 1893, the first camp find of Carnallitit / Kaliflöz Staßfurt (K2) was already in May 1892 by the entrepreneur Heinrich Brügmann from Brünninghausen near Dortmund. Already in December 1891 he found a massive rock salt deposit during a test drilling. The location Sondershausen developed into the potash combine of the GDR. 96 years, until 1991, potash salt was mined here. At the time of closure almost 3,000 people worked at the Sondershausen site. In 1995, the Glückauf Sondershausen Development and Backup Company mbH (GSES GmbH) was founded, which from then on took care of the misalignment and in 2011 employed about 230 people. Since 2006, 200,000 t of rock salt have been extracted each year as road salt for winter maintenance.
Overall, the factory promoted between 1896 and 1991 110 million tons of crude salt. In 1989 alone, a flow of 2.3 million tonnes was produced. The potash salt was mainly processed into fertilizer in its own factory.