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Fig. 1. Vogelsberger Basaltwerk in south-western Germany produces gravel, stone, sand and other raw materials primarily used as aggregate for asphalt and concrete. Photo: Sandvik

At the heart of the process

Basalt production has increased by 20 % since Vogelsberger Basaltwerk modernized its processing plant by installing a new high-reduction secondary crusher.

60 km northeast of Frankfurt in south-western Germany, Vogelsberger Basaltwerk GmbH & Co. KG (VBW) extracts basalt from a 19 million year old formation beneath the Vogelsberg mountain range, Central Europe’s largest contiguous volcanic region (Figure 1). VBW produces gravel, stone, sand and other raw materials primarily used as aggregate for asphalt and concrete. As demand for the company’s basalt products has increased over the years, so have the strains on its all-important processing plant.

After more than 30 years of secondary stage service, VBW’s S1650 cone crusher had reached its capacity limits by 2016. Managing Director Bernd Krempel and -Dieter Pracht, operations manager for VBW, researched a replacement with a higher reduction ratio, a crusher that would not only increase capacity but also improve product quality.

VBW initially intended to replace the outdated S1650 with a Sandvik CH-series cone crusher, which would have required a reduction in both feed size and overall throughput.

Sandvik soon announced the launch of Sandvik CS550, and the new crusher’s design immediately impressed Krempel and Pracht. “It’s basically a hybrid of assessed models, a flat cone crusher and gyratory crusher,” Krempel says. Capable of operating at higher pressures than other Sandvik CS-series crushers and featuring proven components from Sandvik CH-series models, Sandvik CS550 seemed to be the ideal solution for VBW.

Sandvik ran process simulations in September 2016 with its PlantDesigner software, using VBW’s real-life figures for work index, basalt moisture, bulk density and clay percentage. “That simulation process was very important for us,” Krempel says. “The competence of our contacts at the company helped convince us.”

Despite having been convinced of the new crusher’s suitability for his operation, Krempel admits he still had nerves about being the first Sandvik CS550 user. VBW commissioned its Sandvik CS550 in February 2017 and soon saw a notable increase in the plant’s throughput capacity (Figure 2).

Fig. 2. Vogelsberger Basaltwerk commissioned its Sandvik CS550 in February 2017 and soon saw a notable increase in the plant’s throughput capacity. Photo: Sandvik

“The biggest advantage, and the one we hoped to have, is the high reduction ratio, and the smoother running of the process,” Pracht says. “We can now achieve higher performance with the downstream pressure because we have less return flow. And in contrast to competitors’ products, it has the largest possible intake.” Less recirculation resulted in reduced wear and less downtime.

“The costs fell, both with the actual crusher and with the downstream components like our gyratory crusher for producing double-broken chippings,” Krempel says. “Because we’re able to supply it with smaller pieces, the costs in wear and in electricity have significantly decreased,” he says.

Sandvik CS550 features a redesigned crushing chamber to ensure improved product quality. VBW feeds 250 to 300 t/h of 250 to 350 mm primary crushed material into the crusher’s C-chamber intake. More than 80 % is processed to VBW’s preferred particle size of < 32 mm.

Pracht says Sandvik CS550’s control system has major advantages over its retired predecessor. It only takes a few simple steps to adjust the crusher to different grain sizes. “Compared to the old crusher, we now have much more flexibility,” he says. “We can adjust our processes more quickly to meet the needs of our clients and to meet demand. We bought the CS550 in order to produce finer aggregates. But at the press of a button, we can adjust the cone, and we have coarser material immediately. There is nothing better on the market right now.”

After more than two years of operation, the crusher’s reliability remains as vital for VBW as its productivity.

With its Sandvik CS550 at the center of a more productive processing plant, VBW has shifted its focus to exploring other potential optimization opportunities. Its primary crusher, e. g., can barely keep the new Sandvik crusher 50 % fed despite operating at its performance limits.

Despite the primary stage bottleneck, VBW has increased basalt production by 20 % since installing Sandvik CS550, even operating the crusher at the smallest possible throw of 24 mm.

Further information:
Sandvik Mining & Rock Technology