While carbon capture (CCS) projects in Europe are being paused one after another, another decarbonisation route is quietly being deployed: replacing a portion of clinker with calcined clay. In early September 2026, Holcim launched the country's first calcined clay production line at its Čížkovice plant in the Czech Republic; in spring 2026, Schwenk's meca-clay installation at Allmendingen in Germany entered into operation. The equipment to be procured for this route is very specific: calcination units, mills, heat exchangers, and conveying equipment.

The following facts are as of 27 October 2026, with sources listed at the end of the text. The opinion section is separately indicated.

Why It Can Reduce Carbon

Most of the carbon dioxide in cement comes from clinker. The method for calcined clay is to heat clay to a lower temperature, then grind it finely, to replace a portion of clinker in cement. Holcim states that the Čížkovice line can reduce the carbon footprint of cement by around 30% compared to ordinary CEM I (OPC) cement, without compromising performance [Source 1]. Fives states that lowering the clinker ratio using calcined clay and other materials can reduce CO₂ emissions from the cement manufacturing process by 40% [Source 4]. The two figures use different scopes (one is product carbon footprint, the other is manufacturing process emissions) and cannot be directly compared.

AUMUND's material gives the common LC3 mix proportions: around 50% clinker, 30% calcined clay, 15% limestone, and 5% gypsum, whereas clinker in ordinary Portland cement accounts for around 95% [Source 13].

Descriptive materials for the EU Innovation Fund's LCSCM project mention that the EU's target is to reduce the clinker-to-cement ratio from 77% to 60% by 2035, and state that there is an annual shortfall of around 40 million tonnes of low-carbon supplementary cementitious materials [Source 9].