As one of the biggest aggregates plants in Europe, the new CMGO (Colas) Grand-Champ quarry in Brittany, France, pays special attention to all environmental issues. In addition to investing in the best noise and dust suppression systems and a closed water circuit, every spring the quarry builds a “nesting” sand wall to protect the swallow population in the quarry area.

Chapter One

The results of innovative collaboration

“Our quarry meets all the required environmental regulations. Besides keeping the bird population alive, we carefully restore and plant the old quarry areas after exploiting,” says Médéric d´Aubert, Sites Manager for Carrières et Matériaux du Grand Ouest (CMGO) South Brittany operations.

In addition to the swallows, the bees and frogs in the quarry are also thriving, thanks to the exceptionally low noise and dust emissions. Some buildings are equipped with double-layer insulation for noise reduction. Conveyors are extensively covered, and crushers and dust-laden points feature efficient dust filters.

Our quarry meets all the required environmental regulations. Besides keeping the bird population alive, we carefully restore and plant the old quarry areas after exploiting.
Médéric d´Aubert, Sites Manager for Carrières et Matériaux du Grand Ouest (CMGO) South Brittany operations

Chapter Two

Close cooperation between the customer and supplier

CMGO’s recently opened, two-million-ton per year stationary plant with an hourly capacity of 850 tons of high quality aggregates has been designed in close cooperation with Metso’s process experts from the Systems business line.

The novel process design that Metso’s Systems business line created for the Grand-Champ plant integrates all feeders, crushers, screens and conveyors. It also includes a revolutionary, fully automated truck loading system and electrification engineering. To complete the state-of-the art installation, Metso introduced VisioRock® in the aggregates circuit monitoring for uniform end-product delivery.

Consistency, performance and uptime are the main drivers

Close cooperation between Metso and CMGO began back in 2005.

“We chose Metso for this Grand-Champ project because they could fulfill all the specifications and process engineering that we wanted for the new quarry. Metso has the capacity to work as a full-scale processing expert and technical partner in all related subcontracts, such as automation, and is not just an equipment provider of crushers and screens,” Médéric d´Aubertcomments.

“As our main goals, the consistency and uptime of operations and energy efficiency were crucial for us,” he adds.

Chapter Three

A stationary plant with impressive numbers

The CMGO Grand-Champ quarry, referred to as “Clara” after the former site manager’s granddaughter who was born in 2005, is really a plant with impressive numbers. It was inaugurated in June 2016 and replaces two existing plants: an old plant built in 1973 and a newer, temporary plant built in 2008 to avoid disruption in the day-to-day business while awaiting the new plant.

The new plant is built with 2600 tons of steel to meet a maximum capacity of 2 million tons per year. It includes 2.6 kilometers of separate conveyors and 7500 square meters of building space. The quarry area is built to an area of 140 hectares and has reserves for 40 years of quarrying.

The rock processed is a mylonite type of granite, classified as high-quality material for any demanding usage. The Los Angeles index is 25-30. Some 40% of the end products are used for concrete production, 20% for road construction, and another 40% for other construction-related jobs.

1 instead of 2

One plant replaces two existing plants

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Chapter Four

“We can produce everything our customers need”

When Equipment Director Pascal Trescos of Colas explains the end-product selection of the Grand-Champ quarry, the details come easily:

“Thanks to the new, highly versatile quarry, we can actually produce everything that our customers have a need for. Our basic range is 0-20 mm sized aggregates, of which we can process all necessary grades, for example 0-2 mm, 0-4 mm, 2-4 mm and so on. We are able to make manufactured sand and wash all end products according to the customers’ needs.”

According to Pascal Trescos, the quarry currently produces 1.3-1.5 million tons per year.

“One 8-hour work shift produces one million tons per year, and now we are running it at 1.5 shifts, meaning 12 hour days. When needed, the production can easily be increased to 2 million tons,” Mr. Trescos adds.

We can actually produce everything that our customers have a need for.
Pascal Trescos, Equipment Director of Colas
Full automation, including truck loading, secures efficiency

CMGO Grand-Champ is probably one of the most advanced quarries worldwide with its state-of-the-art automation system created by Metso. The whole quarry can be operated with just two persons, securing efficiency and competitiveness.

CMGO is the first customer globally to use a brand new loading automation system created by Metso and its sub-suppliers.

The new system is based on swipe cards and a laser measuring system. When the driver arrives to the site, he swipes his card, which indicates the end product size he’s requesting to load.

Meanwhile, two scanners precisely measure the volume of his trailer in order to secure the loading amount and properly distribute the material in the trailer.

“This system enables independent loading and a much quicker operation than before. With the new system, up to 30 trucks per hour can be loaded,” Pascal Trescos notes.

Chapter Five

VisioRock® guarantees an accurate setting and the right-sized products

CMGO Grand-Champ is one of the first French quarries to introduce Metso’s innovative VisioRock® aggregates circuit control system. The computer-based system, processing visual information gathered from accurate video cameras placed above the conveyors, has two main purposes.

“We have VisioRock® at our Nordberg® HP Series™ HP500 cone crusher to always secure the precise closed-side setting in the cone crusher. The second task is to detect oversized materials before they pollute the 4-6 mm and 6-10 mm materials for road base materials. We can even use VisioRock® for preventive maintenance to predict the wear of screening media,” Médéric d´Aubert explains.

The VisioRock® system will be expanded this year to also the two tertiary Nordberg® HP Series™ HP6 cone crushers.

First use of VisioRock® in tertiary crushing globally

“For Metso, this will be the first time globally that VisioRock® will be used in tertiary stages in aggregates production. It shows that there is interest in this innovative visual monitoring device in the mining industry,” says Vincent Celsi, Sales Support Manager and Metso’s Project Manager for the showcase Grand-Champ plant project.