The Stentenberg quarry is located in a hilly forested area east of Cologne and already has a long history as a well-known producer of high-quality aggregates. For over 50 years, the hilly benches have been extracted down, creating a green-colored pond at the bottom.
Already in the 1950s, Clemens used several MK series jaw crushers from Metso. The main end-products crushed are screened of hard and homogenous, PSV 59-rated, high-quality greywacke. The end products of Clemens fulfill even the strictest quality requirements and are suited as valuable aggregates for concrete, asphalt and road base materials.
The Clemens quarry operations were bought by the Dutch company Van Niewport 11 years ago. A new expansion currently under way is widening the quarry face even further, securing full operational life for several decades to come. The average daily production is about 4,000 tons, working in one shift.
Three Metso jaws take care of primary crushing
After Udo Noss joined Clemens as Quarry Manager four years ago, the quarry has been modernized by adding new crushers to the process.
A Nordberg C106 was the first Metso C series jaw crusher to be installed to the stationary process. It was soon followed by the bigger C120 jaw model. The latest purchase, the brand new C150 jaw, was installed in May 2014.
Today, all blasted, 0–1,000-mm-sized boulders pass through the C150 primary jaw, operated at a 250-mm closed side setting. After the primary crushing, the aggregates are screened and conveyed to an intermediate storage.
The further processing is executed using two different production lines. The “Edelsplitt” line starts with the C120 jaw crusher, followed by other crushers and screens, including Metso’s smallest GP100 cone crusher. From this line, the highest quality “Edelsplitt” grades with excellent cubicity are produced. The second line starts with Metso’s C106 jaw crusher and produces different-sized aggregates grades.
"We want to ensure the quality"