Carrière du Boulonnais, France's largest open-pit quarry  

Before a quarry can be operated, an operating permit must first be obtained by prefectural decree. This is followed by seven stages, beginning with the preparation of the deposit by removing topsoil and sterile material to expose the limestone roof. These excavated materials are then stored for use in the redevelopment of the quarry. Next, blasting is carried out to break up and remove the rock face.  

The Ferques quarry manufactures its own explosives and, with its blasting experts, carries out two to three blasts per day to extract up to 35,000 tons of rock daily. This highly sensitive operation is subject to strict safety protocols and rigorous administrative monitoring. 

The stones are then loaded and transported by dump trucks to the processing facilities to be used in the manufacture of various materials. The manufacturing process consists of several stages : crushing ( fragmentation or grinding), screening (for material classification), and handling by conveyor belts. 

The aggregates obtained are then transported either to storage areas by truck or to silos at the recomposition plant, where they are mixed according to our customers' specific recipes.  

Sales are made automatically into the hopper in the transport container destined for the end customer.
The site has a large storage capacity of 400,000 tons.

The Ferques quarry is also equipped with a unique, high-performance washing facility. This facility produces a unique washed sand with a grain size of 0/4 mm and 7% fines, as well as washed gravel that meets the requirements for concrete applications and civil engineering structures.