K+S Kali GmbH is a mining corporation with the emphasis on potash and salt mining. At two sites, the existing production plant was expanded, the strict environmental protection standards to reduce the salt content primarily in the Werra River were met, and the purity of the salt mined also appreciably boosted. To this end, K+S developed new plant technology that constitutes significant innovations as regards both the dry and the wet salt desalination systems and thus could be considered key to keeping the locations in operation.

The measure at the Heringen facility involved demolition and subsequent rebuilding of a section of one of the plants during ongoing operations and also construction of a new evaporation plant (EDA Kainit), the latter being erected in the shortest time possible on an extremely confined site. The Kainite facility stands on deep bored piles between the existing foundations and is braced by a 35-metre-high stairwell core built in advance using a slipform construction method. The main construction work entailed classic heavy steelwork.

The expansion at the Hattorf facility hinged on substantial investments in improving water protection. An existing hall was expanded by a 104-metre-long and 55-metre-high new construction. Again, not interrupting ongoing operations and a very confined site spelled a particular challenge. The extension building rests on deep bored piles and is likewise a heavy steel structure with a reinforced concrete elevator and stairwell tower built using a slipform construction method in advance.

Design and construction monitoring operations required close dovetailing of building technology and plant engineering for both projects.