In a first for the UK cement industry, Cookstown-based CEMCOR has successfully completed extensive production trials of CalcinX, a low-carbon cement product set to reshape the construction materials market. Representing a major step in the race to decarbonize concrete, CalcinX builds on the company’s earlier pledge to invest over £6 million in ESG-focused upgrades and stands poised to offer developers, precast manufacturers, and the broader construction sector an efficient path to lowering embodied carbon.

Context: Decarbonizing Concrete

Cement production is widely recognized as a major contributor to global greenhouse gas emissions, largely due to the high temperatures required to produce conventional clinker. As climate imperatives intensify, the construction industry faces growing scrutiny over its carbon footprint, prompting a search for alternatives that reduce emissions without sacrificing structural integrity or performance. Calcined clay has emerged as a leading contender in this area, offering a lower-carbon route compared to traditional processes.

“While our existing product range is well established in the market, at CEMCOR we are always looking to the future to develop innovative products which can help our customers to achieve their own sustainability goals,” said David Millar, Managing Director, CEMCOR. “CalcinX will enhance our current product range, allowing us to develop a range of low carbon cement products for a wide range of applications. CalcinX further enhances our commitment to invest in sustainable outputs and to protect the environment around us following other significant investments over the last 3 years. The development to date of CalcinX is a significant milestone not only for CEMCOR but also the wider industry and we are delighted to have partnered with two valued customers in Tobermore and Moore Concrete in this process.”

The Journey to CalcinX

Shortly after CEMCOR’s inception in early 2022, the company embarked on an ambitious research and development project, led by Dr. Allistair Wilkinson, Technical and Innovation Manager. The goal: to harness calcined clay—heat-treated clay that can serve as a critical partial replacement for conventional clinker. Compared with Portland cement, calcined clay requires lower firing temperatures, curbing both energy use and carbon emissions.

During 2022, the team focused on pinpointing suitable raw materials from existing quarry operations. Through lab analysis and pilot-scale experimentation, they determined the optimal clay blend that would deliver high reactivity and consistent performance. The first major milestone came in March 2023, when CEMCOR conducted a calcination trial using its Lepol kiln system technology—an approach now unique to Cookstown in the local cement industry.

Multiple Trials, One Breakthrough

Building on that initial run, CEMCOR completed a second, extended trial in May 2023, producing over 1,200 tonnes of calcined clay. During this phase, engineers fine-tuned the calcination parameters to reduce firing temperatures further while maximizing reactivity. The company also performed grinding trials with the existing cement mills, resulting in two new low-carbon solutions:

1. CalcinX – A supplementary cementitious material (SCM) that end users, such as concrete producers, can blend with their own Portland cement to achieve targeted performance and carbon reduction.
2. CEM IV/B-Q Cement – A specially formulated blend containing less than 50% clinker and up to 50% CalcinX, drastically lowering embodied CO2 compared to conventional CEM I.

To date, CEMCOR has produced more than 3,000 tonnes of CalcinX across these trials, marking a critical step toward scaling up commercial production.

Industry Collaboration

A hallmark of the CalcinX development process is CEMCOR’s partnership with Tobermore and Moore Concrete, both of which tested the new material in their respective operations:

• Tobermore used up to 50% CalcinX as a CEM II replacement in a variety of paving products.
• Moore Concrete similarly employed up to 50% CalcinX to substitute CEM I in demonstration precast concrete units.

Both companies have provided encouraging feedback, reinforcing confidence that CalcinX is compatible with full-scale, real-world manufacturing conditions.

“Tobermore is absolutely delighted to be working alongside CEMCOR on this exciting project. We have trialled CalcinX in a number of products across our extensive range and are really pleased with the results,” said David Henderson, Managing Director, Tobermore.

“We are excited to work with CEMCOR as they release their CalcinX cement replacement and have been greatly encouraged by our initial production with the material. We are delighted to be so closely linked with CEMCOR’s innovation providing a market ready reduced carbon cement replacement,” added Wilbert Moore, Managing Director, Moore Concrete.

Innovate UK Funding and Academic Insight

The technical backbone of CalcinX has been strengthened through a collaboration with Queen’s University Belfast, facilitated by Innovate UK funding under the “Contracts for Innovation: Decarbonising Concrete” program. This partnership focuses on process optimization, material characterization, and further refinement of the calcination approach. By linking academic expertise with industrial-scale trials, CEMCOR aims to accelerate the rollout of its low-carbon cement solutions.

Why Calcined Clay Matters

Calcined clay-based materials are gaining momentum as a versatile decarbonization tool for several reasons:

1. Reduced Energy Demand: Clinker typically requires temperatures of around 1,450°C. Calcined clay, by contrast, can be processed at lower temperatures, resulting in significant energy savings.
2. Lower CO2 Emissions: The primary driver of cement’s carbon footprint is the release of CO2 from limestone calcination. Partial or substantial replacement of clinker with calcined clay reduces that chemical reaction.
3. Preservation of Resources: Traditional clinker production consumes high-grade limestone, a finite resource. Utilizing locally sourced clays lessens the strain on such resources, aligning with circular economy principles.
4. Versatile Applications: Calcined clay can be adapted for a variety of cement formulations, from partial supplements to near 50/50 blends, enabling flexibility in application across different concrete products.

Looking Ahead

CEMCOR’s successful trials place it at the forefront of low-carbon cement technologies in the UK—a milestone with potential reverberations for the entire construction sector. The shift to green solutions has accelerated in recent years, driven by legislative pressure, investor demands, and client preferences for more sustainable materials. CalcinX enters the market at a time when net-zero building standards are quickly evolving, offering a robust path to cut emissions without compromising performance.

With more than 3,000 tonnes of CalcinX already produced, the next steps involve fine-tuning for specific applications, scaling to meet market demand, and ensuring that developers and contractors can seamlessly integrate the product into existing supply chains. As CEMCOR continues to invest in ESG-focused upgrades, the company’s track record suggests that CalcinX may not only solve pressing environmental challenges but also prove commercially viable.

For the UK cement industry, long criticized for its high carbon output, projects like CalcinX signal a decisive turn. By leveraging local raw materials, forging academic partnerships, and collaborating directly with manufacturers, CEMCOR exemplifies how innovation can propel the industry toward a low-carbon future—helping to build the foundations of sustainable infrastructure, one bag of cement at a time.