As the European first industrial-scale flash calciner to enter operation, Vicat’s Argilor facility is pioneering the shift to lower-carbon cement. Using local clay sources and innovative processing technology, the French materials company Vicat leads in activated clay-based cement that helps meet France’s RE2020 building regulations.

Solid foundation for innovation

Vicat is a long-standing family-run company founded in 1853 with operations in 12 countries and 16 integrated cement plants with a production capacity of 40 million tonnes of cement per year. It has the stated intention of upholding its legacy in the cement and construction business, with decarbonisation the inevitable next step in its journey and has committed to reach carbon neutrality by 2050 on its full value chain.

As widely recognised in the cement industry, reaching zero emissions will require carbon capture in the long-term. However, other incremental technologies are available in the shorter term with fewer obstacles to overcome. Vicat has decided to implement these with the Argilor project so that it can start offering alternative products to the market more quickly.

Vicat built the Argilor activated clay production facility with a 120,000 tonnes per annum (ktpa) capacity in its Xeuilley cement plant in northeast France. It is the European first industrial-scale flash calciner, an industrial furnace that rapidly heats, dehydrates (or ‘calcines’) and cools clay in a matter of seconds to create a pure and highly reactive activated clay.

This activated clay can be used as a substitute for the carbon-intensive cement component clinker, reducing the amount needed and, by doing so, avoiding the emissions of close to 50 ktpa of CO2 at the facility. Vicat has a target of 25% net CO2 reduction per tonne of cement from a 2015 baseline across the group by 2030.

For Vicat, activated clay is a highly promising Supplementary Cementitious Material (SCM) to partially substitute clinker as it is widely available and provides good concrete performance when used at high rates.

Knock-on effects of evolving adjacent industries

Looking ahead, Vicat could see that as coal power plants decline and as the steel industry evolves from thermal to electric, there would be global shortages of fly ash (from coal) and blast furnace slag (from steel), the conventional additive materials that can be used alongside clinker to make cement. At the same time, demand for cement from around the world is increasing. Raw limestone is the most well-known substitute.

Cluster development model

Since entering the aluminium industry in 2001 in Shandong Province, China Hongqiao’s cluster
approach, as a core business model, co-locates suppliers and customers near smelters,
allowing direct delivery of hot molten aluminium to customers and eliminating the need for
casting and remelting. This further reduces energy use and cuts emissions. The combined
Shandong and Yunnan operations deliver over 90% of smelter production as hot molten metal.
The Yunnan complexes replicate this model, fostering industrial synergies and enabling rapid
growth of downstream operations.

Affordable SCM for today’s challenges

The French RE2020 building regulation introduced in 2020 acted as a strong driver for establishing the project. By setting maximum limits on embedded carbon emissions in new buildings, RE2020 was designed to incrementally promote the use of low-carbon materials and a decarbonised construction industry.

Thanks to this, Vicat was sufficiently confident in the project’s viability and that the French market would turn to cleaner construction materials to remain compliant. The company noticed supportive market signals even before the regulation entered into force in early 2022, as customers started requesting lower-carbon alternatives.

The project was only possible because the clay found at the nearby Xeuilley quarry is of high enough quality to turn into activated clay. If the company had to open another dedicated quarry in France, it would have taken up to 10 years of permitting process – or 15 years if it were in Switzerland.

Thanks to locally-sourced clay that is less energy-intensive to process than clinker, the company became able to offer low-carbon cement blends at a comparable price, creating the right solution for the right market at the right time.

Building confidence in flash calciner technology

Argilor’s flash calciner is a new technology for the production of activated clays in large quantities (they have been producing activated clay using a rotary kiln in Brazil since 2009) and as the name suggests, speeds up production time. Vicat sought out an equipment supplier with deep production expertise that, together with internal know-how, enabled them to optimise the process.

Many pilot tests on a smaller scale were needed to give confidence in the technology, to ensure that the resulting clay would meet the quality specifications and to meet the target clinker substitution levels set internally.

In addition to dealing with the risk of a new technology, using alternative fuels to run the equipment is another innovation that Vicat has successfully managed.

Securing investment – €60 m – was also a critical step for Vicat. A public grant of around €13 m from the French Agency for the environment (France 2030 mechanism) partly relieved the burden, while the rest of the investment was borne by the company. The shareholder structure (which is largely family-controlled), coupled with a strong vision, played a role in driving the internal decision for this project.

Standards remain a barrier

Additionally, slow evolution of the cement standard EN 197-1 – which specifies the composition of cement, including authorised proportions of clinker, activated clay and limestone – has hampered the introduction of blended cement containing activated clay to the market.

It was eventually revised in May 2021 to allow new low-carbon cements with activated clay, but still prevents higher clinker substitution rates (above 50%) with limestone and activated clay. Standards are still a barrier to the introduction of activated clay cement in certain countries, such as in Egypt, where Vicat operates one integrated plant.

Learnings from global projects

Besides Argilor, Vicat has been running an activated clay production facility in Brazil based on rotary kiln technology since 2009.

Rotary kilns and flash calciners are the two main options for producing activated clay, with the tried-and-tested rotary approach also useful in repurposing existing clinker kilns while flash calciners tend to activate clay more efficiently.