Lafarge Canada and TransAlta agree on new project : Repurposing fly ash for cement production

In an effort to reduce their carbon footprint as well as a large waste stream, Lafarge Canada and TransAlta Corporation agreed to advance low-carbon concrete projects in Alberta. The newest project will repurpose landfilled fly ash, a waste product from TransAlta’s Canadian coal-fired electricity operations west of Edmonton, which ended in 2021. The ash will be used to replace cement in concrete manufacturing. The project received $15 million from the Government of Alberta through Emissions Reduction Alberta (ERA), which invests the revenues from the carbon price paid by large final emitters to accelerate the development and adoption of innovative clean technology solutions.

“There is great potential in repurposing materials across the construction value chain. Transforming landfilled material, such as fly ash, into a usable product for construction, is a win-win solution for all of us,” said Brad Kohl, President and CEO, Lafarge Canada (West).

“Using fly ash to make concrete creates a valuable opportunity to recycle one of the largest waste streams in North America. It’s a great complement to the zero-emissions electricity we are currently providing to Lafarge from our wind platform in Alberta,” said Blain van Melle, TransAlta Corporation’s Executive Vice President, Alberta Business.

Landfilled fly ash must first go through a beneficiation process in order to be used in concrete. The project will utilize the Ash-TEK Ponded Ash Beneficiation System (PABS) technology, which consistently produced high-quality ash during trials and proved to have a low carbon footprint and an economical operating cost. Lafarge will deploy this unique approach to the process, removing moisture from the ash, milling it, and removing excess carbon, ensuring that it meets regulatory standards and market expectations.

Geocycle, a leading provider of sustainable waste management services worldwide, and Lafarge’s subsidiary in Canada, will also join the initiative. The organization brings experience in managing millions of tonnes of fly ash in the U.S. “Landfilled fly ash sometimes has too much carbon, which affects how much air there is in the concrete. Once we can treat and separate that carbon, then the fly ash is ready to be used (up to 25% standard replacement) in place of cement,” commented Sophie Wu, Head of Geocycle, North America.

Although the role of fly ash in concrete manufacturing isn’t new, the technology for beneficiation is highly exact and specialized. “We recognize that seizing opportunities to optimize cement is a key part of our CO2 reduction strategy,” said Kohl. “Thinking outside the box is a part of how we do business.”