The analytical techniques that can improve sustainability in cement manufacturing

Concrete is one of the most common construction materials used today. However, markets and regulatory bodies are increasingly advocating for more sustainable cement, a key component of concrete. Decreasing CO₂ emissions during production is one solution – so how can manufacturers achieve this?

A better understanding of raw material, clinker, and cement mineralogical compositions during production is one way to improve the sustainability and cost-efficiency of the process. That’s because these characteristics correlate to the physical and mechanical properties of the resulting cement. With deeper insights into cement chemistry at the atomic level, manufacturers can therefore optimize their processes and minimize waste.

Here’s how X-ray diffraction (XRD) can provide these insights – and some of the instruments we offer for this analysis. This is the first in a series of blogs on our toolbox of analytical techniques for cement production, so stay tuned!

Key quality and performance parameters in cement production

Mineralogical composition refers to the elements present in cement raw materials and how they are organized into crystalline phases.  To create more sustainable cement, producers aim to use more and more supplementary cementitious materials (SCMs) as alternatives to clinker, the manufacture of which results in most of the emissions of the cement production process.

SCMs are typically upcycled waste and by-products from other industrial processes such as clays, fly ash, slag, and silica fume.  As a result, their mineralogical composition is highly variable. By screening the mineralogical composition of each batch of SCMs, manufacturers ensure the right mix of mineral phases enters the process, optimizing reactivity, minimizing waste and ensuring consistent output quality.

Another property manufacturers can monitor is the type and abundance of mineralogical phases of clinker, which significantly impacts the cement’s final properties. Controlling the mineralogy of the raw mix, the clinker, and the SCMs enables manufacturers to create the right cement, one that complies with their quality specifications.

Indeed, most natural and new alternative materials used in cement production are polycrystalline mixtures, meaning that the atoms they’re composed of pack in a variety of structures. The number and characteristics of these structures determine the reactivity of the intermediate compounds such as the raw mix, the clinker and the SCMs, and define the properties of the produced cement – for example, its setting time, water consumption, and 28-day strength.

By monitoring mineralogical structures at multiple steps of the production process, manufacturers can produce cement with the desired properties much more reliably and in a more eco-friendly way, enabling larger-scale sustainable cement production.

Multipurpose, user-friendly solutions for mineralogical composition and crystallinity analysis

XRD is one of the most popular techniques for quick, reliable mineralogical composition and crystalline structure screenings in the cement industry. XRD instruments use X-rays to probe the distances between atoms. The measured distances can then be compared with database values of the various mineral components. This enables the quantity of crystalline structures and their type to be identified while requiring little to no sample preparation, and without destroying the sample – which can even be returned to the process line. It is also increasingly used to characterize alternative fuels and amorphous phases in green blended cement and other more sustainable cement.

Malvern Panalytical’s XRD instruments for cement applications – the floor-standing Empyrean and the compact Aeris Cement– are designed to further support the fast, simple, and flexible analysis provided by this technique:

The Empyrean: Ideal for research

• Highest data quality on every sample: The collection of sample stages and optical components for Empyrean allows applications to be made in various ways: if the need for a certain application increases, data quality and throughput time can be improved by adding dedicated modules.
• Multipurpose: It’s easy to add new applications to an Empyrean system, making it ideal for meeting your future requirements.
• Customizable: Got concepts for new sample holders and stages, optical modules, or analytical techniques? We’re here to help – discuss your requirements with your local sales representative or submit a request if you need a dedicated solution for your diffraction research.

The Aeris: Ideal for process analysis

• Plug-and-play simplicity: With its intuitive interface, pre-loaded measurement programs, and easy automation, the Aeris Cement provides rapid and accurate results directly in your LIMS.
• Future-proof: Its modular design makes optimal upgrades and additions a breeze, ensuring peace of mind for the future. The Rietveld software solution is easy to update in order to analyze new alternative raw materials, additives, or new green cements.
• Compact and fast: Aeris’ unique compact design guarantees optimal data quality, with no compromise on speed of measurement and with the lowest cost of ownership on the market. As we say at Malvern Panalytical, we’re big on small!

To learn more about Malvern Panalytical’s suite of analytical instruments for building materials applications, please visit our building materials webpage or download our analytical toolbox brochure.

Plus, stay tuned for our next blog on elemental composition analysis!