The process is based on an innovative grinding technology applied for the first time in Europe for recycling. The new plant combines a variable pressure grinding system (Metso HRC 8 TM crusher) with an airflow system (Metso Air Classifier AC30), separating and recovering the cement paste during the crushing operation without grinding the original aggregate. Isolating very fine materials with a high concentration of cement in demolition concrete provides carbon-free additions to manufacturing new cements.
The plant was built in Saint-Laurent-de-Mure in France and taken into operation in September 2023. The plant will serve as a pilot to deploy this equipment in France from 2024.
Full solution from Metso
Metso has executed a complete scope for Lafarge, including flow sheet definition, mechanical and electrical engineering, all equipment and miscellaneous items manufacturing, site assembly supervision, electrical and automation hardware and software, and all documentation.
The plant consists of two independent lines: the first line takes the concrete demolition waste feed, 8/30mm, into the HRC 8 TM that separates the aggregates from the cement paste and creates the final products. The second line is fed with the produced feed, creating the final products.
In addition to the supply of high-quality recycled aggregates for manufacturing new low-carbon concrete, the new installation also meets another essential transformation need for ecological construction: the production of recycled and decarbonised cement.
Cement’s fines, which in a classic crushing process remain attached to the sand, are becoming a sought-after alternative source material to supplement clinker, thus reducing their share in the final composition of the cement and reducing its carbon weight.
Commitment to circular economy
Firmly committed to circular construction, Lafarge continues to innovate to expand the use of demolition materials to manufacture new products. The application of ECOCycle technology in the Saint-Laurent-de-Mure recycling installation will make it possible to both increase the quality of recycled aggregates to promote their reuse in concrete and to recover demolition materials that can be re-injected into the cement manufacturing process with a reduced carbon footprint.
According to the Recybeton organisation, 80% of deconstructed concrete is already reused in France today, primarily in various road applications like pavement underlays. By choosing upcycling and reintroducing these demolition concretes into the cement and concrete manufacturing chain, Lafarge can increase demolition material value and advance its circular ambition.
“The development of circulars is a major pillar of our strategy. This new Lafarge granulates production unit is a decisive step in developing the reuse of demolition materials by utilising all the value they have to offer,” says François Petry, Managing Director, Lafarge France. “Recovering the fines from crushed concrete to reuse them as a carbon-free addition to the cement process is a first in Europe and a giant step forward in the ecological project of building the city of tomorrow with the materials of the city of yesterday.”
Complete plant design and construction by Metso in five months
After a commercial agreement was signed with the sales team in March 2023, Metso's Aggregate Systems group managed to meet the challenge of completing the installation in five months, meeting Lafarge's target date of a start-up before August 4th, 2023.
This results from an excellent project set-up with optimised engineering resources, a network of highly efficient suppliers and an experienced site team.
“Metso's experts completed this project in record time, smoothly and seamlessly. Good collaboration between the teams made this challenge possible,” concludes Olivier Marbec, Head of Aggregates Operation, Lafarge France.
Read about Metso's PrimeSite™ - tailored crushing and screening plants.
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