The white mountains of the Werra Valley turn green

During the processing of crude salts extracted underground, large volumes of residues are inevitably produced due to their natural composition. These solid salt residues are deposited in tailings piles. If precipitation falls on the tailings pile, saline waters - so- called tailings pile waters - are generated, which are continuously collected and properly disposed of. By completely covering the tailings piles, the tailings pile waters are significantly reduced in the long term.

In spring, K+S had already announced the covering and greening of the potash tailings pile at the Neuhof-Ellers plant. “By covering all tailings piles, we will make a major contribution to a lasting reduction in the environmental impact associated with potash production in the Werra-Fulda region,” says K+S Chairman of the Board of Executive Directors Dr. Burkhard Lohr. Covering the tailings piles is also an important aspect of the Weser River Basin Community's catalog of measures as it will improve the condition of the Werra and Weser rivers in the long term. “After we stopped injecting saline water into deep rock strata at the end of 2021, we are once again keeping our word and proving that K+S is the pioneer of environmentally friendly and sustainable mining,” says Lohr.

The tailings pile covers are also an important component in securing the future of the Werra plant - with potash production that, as things stand at present, will last until the 2060s. “We want to secure domestic raw material extraction and therefore jobs as well as apprenticeships in the long term. The prerequisite for this is resource-conserving mining with modern processing and sustainable disposal methods,” says K+S Plant Manager Martin Ebeling.

“We have been developing different methods of tailings pile covering since the 1980s to sustainably reduce the amount of tailings pile water. These have been tested in pilot projects and implemented on some existing tailings piles - adapted to the respective site conditions,” explains Benedikt Kalbhenn, K+S Project Manager for Tailings Pile Covering. For the Werra plant, a combination of different technical variants represents the solution that is optimally adapted to the site and is the most sustainable. Benedikt Kalbhenn explains the way the tailings pile covering works as follows: “The covering prevents precipitation from entering into contact with the tailings pile body made of salt residue. Instead, the rainwater is temporarily stored or can evaporate directly on the surface of the tailings pile, which is later covered with vegetation.” For this purpose, K+S is using soil material specific to the site; correspondingly, delivery traffic is being kept to an absolute minimum.

The Kassel Regional Council as the responsible supervisory authority has approved the application for the plateau cover in Hattorf, and the neighboring municipalities have also given their consent. Following the start of construction on the tailings pile top in Hattorf, the second step should be the start of construction in Wintershall this year. “The covering of the sides will only take place at a later point in time. There are separate permit procedures to be completed,” says K+S Project Manager Kalbhenn, giving an outlook. “We will inform the public about the current status in good time and get them on board right from the start,” he promises.

“By permanently covering the two tailings piles, we are minimising perpetual burdens and long-term consequences for future generations and the Company. The vegetated tailings piles ultimately fit into the landscape,” says Plant Manager Martin Ebeling. He also points out that the plant wants to use the newly created green spaces on the top to reduce the plant's CO2 output and also promote the creation of biotopes.

Read the article online at: https://www.worldfertilizer.com/potash/22072022/the-white-mountains-of-the-werra-valley-turn-green/