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Amazing Advancements In Additive Processing

Published by , Senior Editor
World Cement,


Chris Every, Coomtech Limited, discusses the potential for the cement industry to further reduce its emissions through advancing their additive processing capabilities and practices.

Globally, the cementitious industries have committed to, and embarked on, hugely significant investments in practical actions to reduce emissions from the cement production process. The impact of these changes will be felt throughout the full range of downstream construction materials reliant on it.

As a result of being amongst the world’s most consumed materials, after water, and fundamental to the infrastructure and the built environment, cement production represents a significant share of global emissions. The natural human drive to maintain living standards, and indeed improve them, means the conflicting interests of decarbonising while protecting growth create a huge technical challenge for the industry which has taken up the task of overcoming its emissions problems in all areas.

Putting this dilemma into perspective, 75% of the global infrastructure required by 2050 is yet to be built. Coomtech Clean Technologies is already involved in some projects in these target areas, but it is becoming irrefutable that the cement industry is increasingly (and rightly), looking for a holistic approach to carbon reduction in all areas to meet international targets for limiting its carbon intensity and with it, climate change.

One significant consequence of this is for the growing drive in the industry to draw from an ever-widening range of new raw materials to replace traditional high-carbon clinker-based cement while maintaining the quality of the end product. However, some areas of support for the industry are well behind the technological advances, especially in the areas of industry and governmental standards. To achieve the environmental goals that have been set, this part of the industry must also adapt to future conditions and facilitate the introduction of green cements and downstream products, enabling the creation of new capabilities with appropriate standards in order to match the needs of the industry to grow on the green path towards carbon zero.

Were this article being written a year ago, the drive for low-carbon production would have been ample subject matter, but the geopolitical instability in Europe has forced the cement industry to face the issue of soaring energy costs and availability challenges with traditional energy sources. The drive to reduce emissions is, of course, the right objective for the sake of the industry, but a global energy crisis has added an entirely new layer of complexity to achieving these vital goals.

The scale of the emissions problem for the industry is widely commented on. Cement is one of seven recognised industry sectors given the ‘hard to abate’ label, and among them it is generally accepted to be the single largest contributor.

So, why be concerned about the other ‘hard to abate’ sectors? The answer lies in the impact of what is being done right now by seeking out and integrating new materials into the cement mix and its downstream use. At present, it is possible to trace materials being experimented with or already utilised from at least four of the other ‘hard to abate’ sectors. The current drive for emissions reductions in the cement industry is enabling wins for those other sectors by reducing their carbon footprint as well as enhancing their reputation at the same time. Overall, the impact of these new materials is relatively small, though clearly time and the gradual acceptance of standards etc., will all play their part in establishing the rate at which a positive impact occurs.

Recently, the respected American journal Nature published an article on this replacement process which concluded that: “[C]ement substitution with secondary materials can reduce global annual CO2 emissions by 1.3 gigatons.” However, this is an evaluation of the direct impact of replacement additives in cement clinker to reduce emissions and does not account for the full environmental footprint of the preparation and delivery of these new additives.

Time is against these efforts and therefore while these new materials can come into play over time, thier handling and preparation present a substantial further opportunity to minimise emissions. Reducing the environmental cost of the additive processing chain and augmenting the positive environmental impact of the material replacement itself is a significant contribution to meeting these targets.

The most significant area to address is the traditional cost of thermally drying these materials to meet the specifications required for either blending into cement at manufacture or blending it at the final stage of preparation according to specific customer applications.

It is estimated that annual global cement production is currently 4.4 billion t. Additives can be introduced at varying percentages whilst maintaining the integrity of the cement mix, but assuming that the average accepted maximum for pulverised fuel ash (PFA) in the industry is 35%, this equates to a potential 1.54 billion tpy of additive materials.

There are already several familiar materials mentioned here, but the wide variety being considered will also demand flexibility in processing practices, in pre-preparation, and in the way they are obtained and applied, with some cases requiring co-blending in the same final mix. Similarly critical will be the way energy is used during this process.


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Read the article online at: https://www.worldcement.com/special-reports/22022023/amazing-advancements-in-additive-processing/

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