Navigating the Depths: A Conveying Challenge Underground

The region around Bernburg, Germany, has been dominated by mining since the Middle Ages. Generations of miners have been working here over centuries, extracting salt from the rich deposits deep underground. And when one seam is completely mined out, they move on to the next one, leaving behind caves, tunnels and shafts. For K+S, an experienced and responsible operator with a strong sense of tradition and future orientation, managing open voids is a demanding yet solvable task – as a specialist company, K+S is fully aware of the importance of stability and safety and acts with foresight. To manage this, the internationally oriented raw materials company gradually fills these voids with crushed mineral backfill materials – from larger rocks to smaller pebbles to fine dust.

But that also comes with issues: how to efficiently, automatically and cleanly move up to 200 metric tons of backfill material per hour from a shaft to a silo – through narrow, twisting tunnels, steep inclines and sharp bends, without kicking up dust, spilling loads or requiring frequent maintenance. Until now, conventional conveyor belts have been used for this task. While they have performed reliably, they have reached their limits in terms of efficiency and workplace ergonomics.

Faced with this challenge, the experienced and solutions-oriented team at K+S turned to Continental, known for its ability to tackle complex bulk material handling and conveying issues underground. After a detailed analysis that included tunnel layouts, material behavior and power requirements, our conveying experts recommended a cutting-edge solution: the Sicon conveyor system.

A turn-key underground installation

This innovative Sicon conveyor system encloses material in a closed pouch belt that only opens at loading and discharge points. Capable of navigating curves with radii as tight as 0.6 meters and handling inclines of up to 35°, the Sicon system eliminated the need for multiple transition points – dramatically reducing dust, noise and maintenance. The project involved a 430-meter-long conveyor route with a 50-meter elevation change and three tight bends – 76 degrees, 32 degrees and 78 degrees respectively – within the confined spaces of an underground mine. Our team provided a complete turn-key solution: design, delivery, steel support structure and full electrical installation.

A unique aspect of the installation was logistics. The 900-meter-long Sicon belt had to be packed in custom crates and lowered through an existing mine shaft. Underground, a tailor-made ceiling-mounted support structure was installed to keep the belt path clear and stable.

Exceptional coordination between K+S, Continental and multiple sub-suppliers ensured that everything was delivered and assembled with the highest precision. By September 2024, the entire system was installed, tested during a month-long trial phase, and successfully commissioned in October.

“This was a challenging project with tough conditions underground, but we are very proud that the benefits of switching to the Sicon conveyor system were detectable immediately,” explains Alexander Ginzel, who led the project from Continental’s side. “We could reduce dust and spillage at critical transfer points, improved the air quality and working conditions underground, lowered the noise levels and streamlined the material flow which improved operational reliability and reduced truck dependency.”

"For us at K+S, the safety, reliability and efficiency of our underground operations are top priorities. The implementation of the Sicon system marks a significant step forward in optimizing our backfill logistics. It not only improves working conditions for our teams underground but also demonstrates what’s possible when strong partners work hand in hand to develop tailored, forward-looking solutions." — Dorothee Telaar, Plant Manager Bernburg, K+S Minerals and Agriculture GmbH

While this project focused on installation, we also support our customers with long-term maintenance and service contracts, ensuring systems operate at peak performance. With this project, though, we were able to reaffirm our reputation as an innovator in the field of closed conveyor systems. From concept to commissioning, our hands-on approach and dedication to tailored engineering solutions continue to push the boundaries of what is possible in bulk material conveying.