Lower CO₂ emissions (>30%)
Lower capital & operating costs
Quality product with cement-grey color
High system availability
Proven at industrial scale
Abundant resources. Significant clinker reduction. Lower costs. With 56% of cement's CO₂ tied to limestone calcination in clinker production, reducing the clinker factor is the single biggest lever for emissions reduction. As a supplementary cementitious material (SCM), calcined clay can replace up to 40% of clinker - driving high-quality, low-carbon cement at lower cost. It's effective. It's sustainable. And it's available worldwide.
But unlocking that potential at industrial scale is not straightforward. It demands precise thermal activation technology, reliable color control, and deep process expertise - and the margin for error is thin.
That's where Fuller comes in. With proven flash calcination technology, reliable color control, and a comprehensive lab-to-plant pathway backed by long-term service expertise, we give cement producers the confidence to invest - and the results to prove it. We're not planning for scale. We're already there - and just getting started.
Why is industrial-scale clay calcination still rare, given its proven benefits? Because most producers face a web of interconnected challenges: clay variability from deposit to deposit, color control that makes or breaks market acceptance, energy efficiency that determines your business case, and emission limits that vary by region. Get any one wrong, and the project stalls.
Controlled calcination for Fuller means an integrated calciner system where every component - from dryer crusher to cooling cyclones - is engineered to work together. Consistent activation. Permanent color control. Maximum heat recuperation. Reliable strength development. Full regulatory compliance.
It also means providing a clear pathway from initial clay testing through to full-scale production - whether you're evaluating calcined clay for the first time or ready to commission your plant.
Whatever your starting point, we've built the system - and the expertise - to make it work.
Our clay calciner design is based on years of research and development, backed by extensive process expertise to optimize clinker substitution while maintaining cement quality. The key: heating clay to its activation temperature destroys the crystalline structure, creating an amorphous, highly pozzolanic material with high surface area - ideal for clinker replacement. Our system is engineered to hit that activation window precisely, every time. The result: a highly consistent product that enables higher clinker substitution rates than kiln-produced alternatives.
The process begins with the dryer crusher, specially designed for clays with up to 40% moisture content. Using hot waste gases from the preheater, it dries and crushes in one operation. Material then enters the 2-stage preheater/calciner, where clay is activated under tightly controlled conditions - delivering consistent product quality and reliable emission control. After calcination, the clay passes through a dedicated reducing zone where red hematite is converted to grey magnetite, then through cooling cyclones where our patented air-quench process locks in the cement-grey color permanently while recovering heat back into the system.
Fresh Clay Feed
The system accepts a wide range of clay types and mineralogies with up to 40% moisture content - providing flexibility to source from local deposits. Clay availability worldwide is one of calcined clay's strongest advantages over traditional SCMs.
Preheater Cyclones:
2-stage preheater/calciner where clay is activated under tightly controlled conditions. A cyclone at the calciner outlet separates gas and material. Tight process control delivers consistent activation - resulting in uniform product quality and reliable emission control.
Fuel Input
Any traditional fuel type used in a clinker system – as well as most waste and alternative fuels - can be fired in the calciner, reducing both carbon footprint and operating costs.
Reducing Zone
Our patented Greymax™ process transforms red hematite to grey magnetite in a dedicated reducing zone. Oxidizing flash-cooling in the next stage locks in the cement-grey color permanently - a two-step process proven with high-iron and non-kaolinitic clays.
Calcined Clay Product
Highly reactive, amorphous calcined clay with high surface area - ideal for clinker replacement. Because the flash calciner delivers a more consistent product than a kiln, it enables higher substitution rates: up to 40% (or more) clinker replacement while maintaining cement quality.
Dryer Crusher
Specially designed for clays with up to 40% moisture content. Hot waste gases from the preheater dry and crush in one integrated operation, reducing energy consumption from the start.
Cooling Cyclones
Patented atmospheric air-quench cooling serves a dual purpose: it locks in the grey color from the reducing zone while maximizing heat recovery by preheating combustion air for the calciner. The result – cutting energy costs up to 50% compared to clinker production, with no compromise on color.
Fresh Clay Feed
The system accepts a wide range of clay types and mineralogies with up to 40% moisture content - providing flexibility to source from local deposits. Clay availability worldwide is one of calcined clay's strongest advantages over traditional SCMs.
Preheater Cyclones:
2-stage preheater/calciner where clay is activated under tightly controlled conditions. A cyclone at the calciner outlet separates gas and material. Tight process control delivers consistent activation - resulting in uniform product quality and reliable emission control.
Fuel Input
Any traditional fuel type used in a clinker system – as well as most waste and alternative fuels - can be fired in the calciner, reducing both carbon footprint and operating costs.
Reducing Zone
Our patented Greymax™ process transforms red hematite to grey magnetite in a dedicated reducing zone. Oxidizing flash-cooling in the next stage locks in the cement-grey color permanently - a two-step process proven with high-iron and non-kaolinitic clays.
Calcined Clay Product
Highly reactive, amorphous calcined clay with high surface area - ideal for clinker replacement. Because the flash calciner delivers a more consistent product than a kiln, it enables higher substitution rates: up to 40% (or more) clinker replacement while maintaining cement quality.
Dryer Crusher
Specially designed for clays with up to 40% moisture content. Hot waste gases from the preheater dry and crush in one integrated operation, reducing energy consumption from the start.
Cooling Cyclones
Patented atmospheric air-quench cooling serves a dual purpose: it locks in the grey color from the reducing zone while maximizing heat recovery by preheating combustion air for the calciner. The result – cutting energy costs up to 50% compared to clinker production, with no compromise on color.
Our flash calciner delivers precise temperature control, efficient heat exchange, and a more consistent product. The result: highly reactive, amorphous calcined clay with high surface area - enabling up to 40% (or more) clinker substitution. A rotary kiln produces less reactive clay, typically allowing only 15–25% substitution.
Already have an available kiln? A new calciner delivers the best results, but a kiln conversion can reduce your upfront capital cost. We'll help you evaluate the right option for your site.
Permanent Color for Market-Ready Cement
Grey cement is the market standard. But calcined clay naturally turns red from iron oxidation to hematite. Our patented Greymax™ process solves this by transforming red hematite to grey magnetite in a dedicated reducing zone, followed by oxidizing flash-cooling that locks in the grey. Proven with high-iron and non-kaolinitic clays - even the most challenging feedstocks.
Maximum Efficiency. Minimum Fuel Costs.
Our patented atmospheric air-quench cooling maximizes heat recovery by preheating combustion air for the calciner - without compromising color or incurring water-quenching losses. Hot waste gases dry incoming clay, further enhancing efficiency. The result: energy costs savings up to 50% compared to clinker production.
Any Fuel. Full Flexibility.
Any traditional fuel type used in a clinker system – including most waste and alternative fuels - can be fired in our calciner. The system is designed for full fuel flexibility, accommodating refuse-derived fuels alongside fossil fuels to further reduce carbon footprint and operating costs.
Precise Dosing for the Perfect Mix
Calcined clay, limestone, and clinker are precisely dosed into ball mills using our industry-leading PFISTER® FRW rotor weigh feeders and SLF belt weigh feeders. Accurate proportioning is critical for consistent LC3 product quality and optimized clinker substitution rates.
Expert Process Control at Your Fingertips
Our ECS/ControlCenter empowers operators to manage calcination and deliver consistently high-quality product. Granular parameter views, open programming adjustable to your site, sensor outputs, feedback loops, and trending - data-driven interventions that mitigate issues before they become problems.
Proven Abatement for Full Compliance
Strict emission limits shouldn’t stand in your way. Our proven expertise helps you predict emissions with precision and design the right solution to ensure full compliance with even the strictest regulations.
From clay testing and tailored plant design to installation, commissioning, and long-term support - we optimize your system for maximum substitution rates and minimum OPEX. Once running, our expert service team provides ongoing monitoring, maintenance, and process optimization - with full OEM flowsheet support across every aspect of your process.
With Fuller, you're not just investing in a calcined clay plant - you're gaining a trusted partner for every step of the way.
From initial clay testing through to long-term operational support - comprehensive services across every phase of your calcined clay project.
Pilot plant at Dania (R&D centre) for SCM activation and color control.
Full plant design and commissioning from the OEM team.
Digital tools to keep reliability high and OPEX low - from process control to real-time condition monitoring.
Expert support from the team that designed your equipment. OEM knowledge across every aspect of your process.
Never wait on the parts you need. Tailored packages for your specific equipment and operating conditions.
With Full Chemistry, Mineralogy, and Reactivity Testing & Analysis
Not all clays are equal. A clay's viability as a clinker substitute depends on its chemical and mineralogical content, how amorphous its structure is, particle fineness, strength development, and emissions. Committing capital without confirming these factors is a risk no producer should take. At our Dania R&D centre in Denmark - one of the world's most advanced facilities for raw materials in cement production - we help you confirm that you have a suitable clay source and the right equipment design to process it. Our laboratory services include full chemistry, mineralogical analysis, and clay reactivity testing. A pilot-scale calcination system is also available for full quality and strength testing of the blended cement product. The results go beyond pass or fail - you receive detailed insights to guide your project design and optimize your investment.
Niels Christian Dodensig Lundgaard, Head of Lab and Green Cement Testing
Whether you're evaluating your first clay source or scaling to full commercial production, Fuller has the technology, the testing infrastructure, and the project experience to take you from where you are to where you need to be. The question isn't whether calcined clay already works. It's when you'll start scaling into a low-carbon future.
Our Low Carbon Solutions lead walks through the two-decade journey that brought industrial calcined clay from R&D ambition to two operating plants – Europe's first full-scale clay calciner with Vicat in France, and the world's largest calcined clay installation with CBI Ghana. See the technology, the process choices, the plant layout, and what producers need to settle before committing capital.
1200+TPD
Capacity (400,000+ tpa)
-20%CO2
vs current practices
50%Energy
less than clinker
30%Clinker
Replaced with calcined clay
CBI Ghana, alongside major shareholder Heidelberg Materials, commissioned the world's largest clay flash calciner to reduce dependency on expensive clinker imports. Fuller supplied the complete calcination system - including color control, heat recuperation, precision feeding, process control, and packing.
The plant produces both LC3-45 and LC3-60 cement, crafted with 40-55% locally sourced materials. With process related emissions for the calcined clay of just ~80 kgCO₂/t, equivalent to 90% less than clinker, CBI Ghana's LC3 cements also deliver higher compressive strength from 7 days onwards, with enhanced durability.
Kobby Adams, Commercial Director, CBI Ghana
525TPD
capacity calcined clay
-16%CO2
at plant dispatch
48500 CO2 Saved
tons/year
100%Compliance
strictest EU standards
Fuller delivered Europe's first industrial-scale clay flash calciner installation for Vicat at their Xeuilley plant. The project tackles non-kaolinitic, high-iron smectitic clay - a challenging feedstock requiring Greymax™ color control to achieve consistent cement-grey product.
The installation includes full emission controls (scrubber, RTO, SCR) meeting the strictest EU standards, alternative fuel capability using refuse-derived fuels, and saves 48,500 metric tons of CO₂ annually.
Vicat Project Team
Calcined clay: test before you invest
Testing, testing – how material and pilot scale testing helps confirm clay suitability for eco cement: Fuller experts describe the material testing necessary to determine if a particular clay is suitable to process into eco-friendly cement.
Showcasing what’s possible: clay calcination in Ghana
As the cement rolls out to customers, Fuller Technologies’ Peter Juul Andersen, Steven Miller and Rasmus Franklin Momme describe CBI Ghana’s record-breaking new calcined clay plant.
A First for Europe
Rasmus Franklin Momme - Global Chief Process Engineer, Morten Østergaard - Project Director, and Steven Miller - Global Product Manager, Fuller Technologies, describe the first-of-a-kind installation of the company’s calcined clay technology at Vicat's Xeuilley cement plant in France. This article first appeared in the April 2026 issue of World Cement.
Brochures
REPRINT from International Cement Review, April 2026. Rasmus Franklin Momme, Morten Østergaard and Steven Miller, Fuller Technologies, explore the first-of-its-kind installation of calcined clay technology at Vicat’s Xeuilley Cement Plant in France.
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6.39 MB |
English
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