First published in the September 2015 issue of Quarry Management as ’On the Front Line’
Three Metso jaw crushers operate at one hundred percent efficiency at the Clemens Stentenberg quarry in Germany
The Clemens Stentenberg quarry in Germany has been in operation for more than 50 years, and its long history carries a lot of valuable insight. For example, the quarry has one basic rule when ordering crushers: Only choose crushers that can be operated at 100% efficiency from day one, without any rebuilds.
‘After using three different-sized Metso Nordberg C-series jaw crushers in our quarry, nobody needs to convince me that Metso actually have the best jaw crushers in the marketplace,’ said quarry manager Udo Noss of Schotterwerk Clemens GmbH & Co. KG, as he summarized his experience with Metso’s jaw crusher range.
The Stentenberg quarry, located in Gummersbach, uses Nordberg C106, C120 and C150 jaw crushers in the production of the site’s high-quality, cubical greywacke aggregate products. Moreover, Clemens are the first customers in Germany – and one of the first worldwide – to run the all-new Nordberg C150 jaw crusher.
After more than 500,000 tonnes crushed, the company’s feedback on the new C150 is very positive. ‘We have not encountered any extra service breaks and we are producing in excess of 400 tonnes/h in continuous operation. Actually, the jaw could do even more, but we have to restrict production because of our conveying capacity,’ said Mr Noss.
The Stentenberg quarry is located east of Cologne and already has a long history as a well-known source of high-quality aggregates. Even as far back as the 1950s, Clemens used several MK-series jaw crushers from Metso to crush the quarry’s hard and homogenous 59 PSV greywacke. The end products from Clemens fulfil the strictest quality requirements and are well suited for use in concrete and asphalt, and as roadbase materials.
The Clemens quarry operations were bought by Dutch company Van Niewport 11 years ago, and expansion of the site is currently under way, widening the quarry face even further and securing
the operational life of the site for several decades to come. Average daily production is about 4,000 tonnes, working a single shift.
After Udo Noss joined Clemens as quarry manager four years ago, the quarry was modernized by adding new crushers to the process. A Nordberg C106 was the first Metso C-series jaw crusher to be installed in the stationary process, and 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 boulders up to 1,000mm in size pass through the C150 primary jaw, which operates at a 250mm closed-side setting. After primary crushing, the aggregates are screened and conveyed to intermediate storage.
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 a range of different aggregate sizes.
‘Because of today’s competition, we want to ensure the quality and cubicity of the end products we produce. For our quarry, we require crushers that can be operated at 100% efficiency from day-one without any rebuilds,’ stressed Mr Noss.
‘One way to keep our quality high is to invest in state-of-the-art equipment. We are fully convinced that Metso make the best jaws in the world. We also believe in keeping the amount of unnecessary fines as low as possible with the GP100 cone.’
The new Nordberg C150 jaw crusher can be fitted with either one- or two-piece wear parts, with even wear achieved by turning the parts and thus adding to wear part lifetime. After 500,000 tonnes, no turning or changing of wear parts has been required so far, and no actual wear is yet visible.
‘With hard but not too abrasive greywacke as our rock type, we estimate that we’ll crush up to 2 million tonnes with the same wear parts,’ Mr Noss concluded.
- Subscribe to Quarry Management, the monthly journal for the mineral products industry, to read articles before they appear on Agg-Net.com