Concrete

Revealing the numbers behind calcined clay

Published

4 years ago

December 21, 2021

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Clay is a naturally occurring material found almost everywhere around the world with the potential to replace 30 per cent of the energy intensive clinker. But how does the calculations look in terms of fuel- and power consumption. We did the math.

One of the great benefits of calcined clay is that it activates at a much lower temperature than that required to make clinker. With temperatures of 750 to 850˚C instead of 1,400 to 1,500˚C and much lower costs for grinding and handling, you gain significant fuel and power savings – 30 per cent and 40 per cent, respectively – when comparing the operating cost to make 1 tonne of clay versus 1 tonne of clinker. While this is obviously a great result for the environment, it also makes for much lower operating costs, enabling you to achieve a reduced cost per tonne of cement.

Table 1 shows typical values for a direct comparison between traditional OPC (95 per cent clinker and 5 per cent gypsum) and LC3, a cement made of 50 per cent clinker, 15 per cent limestone, 30 per cent activated clay and 5 per cent gypsum. The impact is clear: 40 per cent lower CO2 emissions per tonne of cement. That is without considering the further reductions you could gain if you also switched to more environmentally friendly fuels.

Table 1

You’ll note that Table 1 also references the fact that by halving clinker content, you could double cement production. This would certainly be a driver for cement manufacturers seeking to increase productivity. However, even where extra capacity is not required, the benefits are incredibly valuable. A more efficient, more environmentally friendly process – working smarter, not harder.

Managing the risks of a new investment

With any new technology, there will always be some hesitation. Being an early adopter carries risks as well as benefits. But having dedicated ourselves to MissionZero – equipping the cement industry with the means to achieve net zero emissions by 2030 – we want to give cement manufacturers the confidence that they are investing in solutions that will work for them. That’s why we set up a pilot plant in our test facility in Denmark, specifically dedicated to calcined clay.

Here, we can carry out full chemistry and mineralogical testing of your clay source, as well as a clay reactivity analysis. We can also put your clay through our pilot test system, including crushing/drying, calcining, colour control, strength testing, etc. to show that the clay will meet the strength and colour requirements of a blended cement for ultimate peace of mind before making an investment.

This facility was instrumental in the decision by French cement manufacturer Ciment Vicat to invest in a 525 tpd clay calcination plant, which will be built in France. Citing increasing demand for sustainable cements as one of their main drivers, Ciment Vicat approached us with the project knowing we had the ability to confirm the suitability of their locally available clay source. We tested 5 tonnes of clay and were able to give them the reassurance they needed to proceed with the investment.

“With the results from the pilot studies at FLSmidth’s test facilities, we are confident that this technology will provide a truly environmentally-friendly alternative, enabling us to reduce CO2 emissions by 16 per cent compared to our existing cement products as soon as the site is commissioned in 2023, and perhaps even more than that in the future,” says Renaud Claie, Project Director at Vicat Group. Leadership like this is so important to moving the industry forward. Where one global leader moves, others will follow. We congratulate Ciment Vicat on their initiative and commitment to their sustainability goals.

One decade to make a difference

Calcined clay is a stable, widely available resource that slots in easily to the existing cement manufacturing process. It requires new but familiar technologies. It produces a different but equally high-quality cement product, at a lower cost, using less energy and less fuel. It has the potential to dramatically reduce the cement industry’s environmental impact.

What are we waiting for? FLSmidth is ready to assist with your clay calcination plans and to help answer any questions or concerns you might have. This is our decade to make a difference. We can reduce the pressure on our industry and on our planet by moving the cement industry over to a more environmentally friendly cement product as standard.

Concrete

Gautam Adani Inspects Godda 2,300 MW Power Plant

Inspection follows MP request and points to cement plan

Published

12 hours ago

February 26, 2026

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Gautam Adani visited Godda on Sunday to carry out a first inspection of the power plant in the district, where electricity generation of 2,300 megawatts (MW) is being undertaken through five units. The visit involved a walkthrough of production areas and technical installations and included meetings with senior plant executives. The inspection was described by officials as focused on operational readiness and optimisation of output.

Officials said the establishment of the plant followed a request from the local member of parliament, who provided cooperation during project development, and indicated that plans to establish a cement plant in Godda are likely to materialise soon. The electricity produced at the facility is currently being supplied to Bangladesh, and officials confirmed that the possibility of exporting power to other neighbouring countries is under consideration. Company representatives indicated that the project aims to balance regional energy demand with commercial export obligations.

During the review of all units, plant leadership set out steps to accelerate commissioning and enhance maintenance regimes to ensure sustained generation. The commissioning of the power plant has already been credited with contributing significantly to the development of Godda, and the proposed cement plant is expected to add industrial capacity and create large-scale employment in the region. Local authorities are monitoring progress with a view to aligning infrastructure improvements and workforce development.

Stakeholders expect the visit to accelerate operational momentum at the site and to clarify timelines for further investment and local supply arrangements. The inspection was followed by technical briefings and an internal review of safety and environmental practices to support reliable operations. Officials said subsequent measures will focus on connectivity, logistics and community engagement to ensure the project delivers intended economic benefits.

Concrete

Govt Exempts Tailings Recycling In Mines From Fresh Green Clearance

Move aims to streamline mining waste management

Published

12 hours ago

February 26, 2026

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The central government has exempted tailings recycling in mines from the requirement of a fresh environmental clearance, citing an effort to streamline approvals and promote resource efficiency.

The decision is intended to simplify regulatory procedures for operators seeking to process existing mine waste for recovery of minerals and other materials.

Officials indicated that the move should reduce administrative delays while maintaining compliance with existing safeguards.

Authorities said existing environmental safeguards would continue to apply to recycling operations.

Tailings recycling refers to the recovery of valuable materials from the fine waste generated by mining operations and the subsequent reprocessing of material to reduce the volume stored in tailings facilities.

Advocates argue that recycling can recover metals and minerals, lower the demand for new ore extraction and reduce the footprint of waste storage.

The policy change is expected to encourage the adoption of technologies that convert legacy waste into usable inputs for industry.

The mining industry welcomed the exemption as a way to accelerate projects and improve economics, while environmental groups urged robust conditions to prevent adverse impacts.

Conservation organisations stressed the importance of rigorous monitoring, independent audits and clear standards for waste handling and water management.

Regulators are likely to frame the exemption with specific compliance requirements to balance economic and environmental objectives.

Industry sources indicated that the move could attract investment in processing plants and associated infrastructure.

The change may prompt states and permitting authorities to update their frameworks to reflect the central clearance position and to clarify oversight roles.

Observers noted that effective implementation will depend on transparent reporting, enforcement capacity and investment in rehabilitation of legacy sites.

The long term outcome will hinge on whether recycling reduces the environmental risks associated with tailings while supporting a circular approach in the mining sector.

Stakeholders called for clear timelines for compliance.

Concrete

Cement Demand Revives As Prices Decline In Q3 FY26

Nuvama reports improved volume growth after price correction

Published

2 days ago

February 24, 2026

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A report by Nuvama Financial Services (Nuvama) said cement sector demand revived in the third quarter of fiscal year twenty twenty six as prices declined, supporting volume growth across regions. The note indicated that sequential price correction helped replenish demand that had been subdued by elevated pricing earlier in the year. Nuvama quantified the price decline as a sequential correction that varied across states and segments, facilitating restocking by merchants and traders.

The report suggested that improved affordability after the price correction encouraged housing and infrastructure activity, with developers and contractors adjusting procurement plans. It added that regional dynamics varied, with some markets showing faster recovery while others remained reliant on seasonal construction cycles. Housing demand was driven by both affordable and mid segment projects, while infrastructure segment recovery was contingent on timely execution of public works.

Analysts at Nuvama assessed that the price moderation eased inventory pressures for manufacturers and distributors and supported margin stabilisation at several producers. Demand improvement was visible in both urban and rural segments, although the pace of recovery differed by state and trade channel. Producers were seen balancing price realisations with volume targets and managing input cost volatility through operational efficiencies.

The report recommended that investors monitor volumes and realisations closely as market equilibrium emerges in the coming quarters, noting that sustainability of recovery would depend on monsoon patterns and government infrastructure outlays. Overall, the assessment pointed to a cautiously optimistic outlook for the cement industry as price correction translated into tangible volume gains. Market participants were advised to track early signs of demand broadening beyond core construction hubs to assess the depth of the rebound.