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At the Carrière de Saint-Colombe (CMSE) quarry, near Perpignan in the south of France, Colas relies on the BHS rotor impact mill of type RPMF to extract even more valuable fine sand for asphalt production. When crushed down to a fine particle size, the material is particularly suitable as a component of asphalt mixtures. As a major international player in road construction, Colas needs the raw material for its own asphalt production site and has been using the quarry as a mining and production site since the early 1990s.

Since then, the company has made many investments into the technology used at the quarry. In order to increase the sand extraction in terms of quality and quantity, Colas decided to add another stage to the crushing process. “The target was to crush the non-valuable grain sizes of limestone 3/6 mm and 6/12 mm to produce fine sand with grain size 0/3 mm in high quantity”, explains the customer.

For this crushing step, Colas turned to BHS-Sonthofen. Alexandre Bernabé, the sales manager for the French market at BHS-Sonthofen, says: “Together with the customer, we carried out several tests with the original material at the test center in Sonthofen. This helped us find out how the machine must be configured and what performance we can actually achieve with our crushing mill.”

Unique crushing technology for high-quality sand

Colas opted for the rotor impact mill of type RPMF 1516 with its unique operating principle – a high-performance crusher with a vertical shaft. The machine is suitable for crushing all low to moderately abrasive minerals and is therefore used predominantly in the production of sand for the concrete, asphalt and dry mortar industries. The machine enables Colas to achieve a high reduction ratio and excellent particle shape.

“With its crushing principle, the RPMF really stands out from competition. Besides particle shape, the high productivity in the manufacturing of fine materials was another main argument for Colas to choose this machine,” Alexandre Bernabé comments. “Compared to other crushing technologies such as rotary mills, the ratio of tons and kilowatt is superior. For instance, we reach 50 tons per hour on average compared to 10-20 tons per hour with different technologies that consume much more power.”

By regularly changing the direction of rotation, Colas achieves uniform wear of all wear parts. With the effective dedusting system, the operator can also easily control the wear of the machine and keep it as even as possible. The result, in percentage terms, is a higher proportion of fine sand. While grain size of the input material is 3/6 mm and 6/12 mm, the grain size of output is 0/3 mm with a high share of grains smaller than 1 mm.

“Production has been running for some time, as the machine was put into operation in December 2017”, Alexandre Bernabé says. “The customer is very satisfied with the result and we are very pleased to have been able to help the Colas Group successfully implement this new crushing step.”