Jens Mose and John Terembula, Product Line Management, FLSmidth A/S, introduce the type and availability of supplementary cementitious materials (SCMs) in this first part of a three-part article about the potential to increase the use of SCMs to reduce carbon emissions from cement manufacture. You will find parts two and three in the September and October issues of Indian Cement Review.
While much has been done to reduce emissions from cement production, the calcination of limestone is still a major contributor of harmful pollutants and must be addressed if cement manufacturers are to meet their sustainability targets. Fortunately, a number of supplementary cementitious materials (SCM) are available, which enable cement manufacturers to replace clinker and thus reduce CO2 emissions. However, adoption of these SCMs varies widely on a regional basis. In India and Brazil, for example, it is common to use fly ash and slag to reduce the clinker factor to as little as 65 per cent. In the US, however, the clinker factor remains high at around 95 per cent. Worldwide, according to the Climate Technology Centre and Network, the ‘average clinker/cement ratio is about 0.81, with the balance comprising gypsum and additives such as blast furnace slag, fly ash, and natural pozzolana.’ The UNEP-sponsored white paper ‘Eco-efficient cements: Potential economically viable solutions for a low-CO2 cement-based materials industry’ suggests a reasonable worldwide average of 0.60 is achievable by 2050. But how do we get to this figure? With many decades’ experience grinding a wide range of different materials in vertical roller mills, ball mills and hydraulic roller presses, FLSmidth is in a position to share our knowhow to help the industry make strides in reducing its carbon footprint.
Types of SCMs SCMs include both naturally occurring materials and byproducts of other industrial processes. The Global Cement and Concrete Association (GCCA) groups SCMs according to how they harden : hydraulic SCMs harden in the presence of water (like Portland cement) and include granulated blast furnace slag (GBFS) and burnt shale oil. Pozzolanic materials require the additional presence of dissolved calcium hydroxide (Ca(OH)2) – a byproduct of the hydration of Portland cement – in order to harden. These include fly ash, silica fume, calcined clays, burnt rice husk and natural pozzolans. Hydraulic cements have a higher early age strength, while pozzolans continue to gain strength for a longer period, giving a higher long-term concrete strength. Both have been proven in construction applications. Limestone is not classified as either hydraulic or pozzolanic but also contributes to the hardening of concrete, putting it in an SCM category all of its own.
Table 1: Common types of SCMs
Find parts two and three of this article in the September and October issues of Indian Cement Review: Part 2: Equipment selection for SCM grinding, Indian Cement Review, September 2023 Part 3: Expanding SCM use in the future, Indian Cement Review, October 2023
Andhra Pradesh Education and IT Minister Nara Lokesh on Wednesday laid the foundation stone for the Line-2 expansion of Dalmia Bharat Cement at Chinnakomerla village in Mylavaram Mandal in Kadapa district. The project carries an investment of Rs 31 billion (bn) and is slated for completion by the third quarter of the financial year 2028. The expansion is intended to boost industrial growth and employment generation across the Rayalaseema region.
Once commissioned, the Kadapa facility will become Dalmia Bharat’s largest integrated cement manufacturing ecosystem in southern India, creating over 1,000 direct and indirect jobs and opening new business avenues for regional micro, small and medium enterprises and transport operators. Lokesh said the expansion signalled growing corporate confidence in the state and reflected the practical ease of doing business that secured repeat investment.
He placed the project within the government’s wider economic targets and recalled the Yuvagalam padayatra commitment to generate two million (mn) jobs within five years, noting that the state would cultivate talent while industry created opportunities. Lokesh highlighted Andhra Pradesh’s competitive pursuit of major manufacturing accounts, mentioning past successes and a personal initiative to engage global investors when persuading them to anchor expansion in the state.
The plant will leverage Kadapa’s abundant limestone reserves to scale production and sustainability. Clinker capacity is planned to rise from two point five million tonnes per annum (mn tpa) to six point one mn tpa, while overall cement output will increase from three point six mn tpa to nine point six mn tpa. The unit is designed to operate on over eighty per cent renewable energy and deploy waste heat recovery, zero liquid discharge, water recycling and advanced AI systems to optimise efficiency. Industries Minister TG Bharat, BC Welfare Minister S. Savitha and Jammalamadugu MLA C. Adinarayana Reddy attended the ceremony.
HDFC Securities has said the cement industry is unlikely to register a sequential increase in prices in Q2 FY27 as monsoon-related demand moderation coincides with rising fuel and packaging costs that will squeeze margins. The brokerage observed that price gains remained modest, with increases of two to three per cent quarter-on-quarter across regions, and noted subdued offtake in May with improvement in June as a delayed monsoon supported construction activity. The brokerage added that modest pricing gains so far have been insufficient to offset the input cost escalation.
The report stated that input cost pressures intensified in Q1 FY27 owing to the West Asia conflict, which pushed up coal and pet coke prices and is expected to keep fuel costs elevated, with a likely peak in Q2 FY27. It assessed that total variable costs, including packing, could rise by around Rs 150 per t quarter-on-quarter and that lower offtake and seasonal operating deleverage could further raise operating expenditure by about Rs 50 per t quarter-on-quarter.
Overall, cement prices were estimated to remain flat in Q2 FY27 as monsoon-led demand weakness offsets limited upside in realisation, and rising fuel costs alongside seasonal deleverage were expected to compress industry margins by over Rs 100 per t quarter-on-quarter to below Rs 880 per t. The brokerage indicated that the combined impact of energy inflation and higher packing expenditure would be the principal drivers of margin contraction in the near term. HDFC Securities projected a recovery in margins in H2 FY27 should the West Asia turmoil subside and energy and packing costs cool off.
The brokerage expressed optimism on long-term demand fundamentals and said improving realisation together with an anticipated cost cool-off should support a margin rebound from H2 FY27 onward, underpinning favourable industry prospects over the medium term. Its outlook rests on monsoon normalisation and a decline in imported fuel prices in the second half of the fiscal year.
Dalmia Bharat Limited recently laid the foundation stone for its second manufacturing unit at Kadapa in Andhra Pradesh. The company will invest Rs 31 billion in developing the next-generation integrated cement manufacturing facility.
The foundation-laying ceremony was attended by Nara Lokesh, Andhra Pradesh Minister for Information Technology, Electronics and Communications, Real-Time Governance and Human Resources Development, along with Puneet Dalmia, Managing Director and Chief Executive Officer, Dalmia Bharat, senior government officials and company representatives.
Scheduled to be commissioned by the third quarter of FY28, the Kadapa unit will become Dalmia Bharat’s largest integrated manufacturing facility in southern India. It will have a clinker production capacity of 6.1 million tonnes per annum and a cement manufacturing capacity of 9.6 million tonnes per annum.
The facility is designed to produce what the company describes as one of the world’s greenest cements. It is also expected to generate approximately 1,000 direct and indirect employment opportunities while supporting local MSMEs, transporters, contractors and service providers.
Lokesh said the investment reflected Dalmia Bharat’s confidence in Andhra Pradesh and aligned with the state’s objective of promoting sustainable industrialisation, job creation and technology-led economic growth.
Puneet Dalmia said the project represented the company’s long-term vision of developing low-carbon cement manufacturing assets. He added that the facility would establish new benchmarks in operational efficiency and sustainability while supporting India’s infrastructure and environmental goals.
Dalmia Bharat will also expand its regional community development programmes in education, healthcare, skill development and welfare through its DIKSHa and Gram Parivartan initiatives.
The company currently has an installed cement manufacturing capacity of 54.7 million tonnes across 19 manufacturing units in 12 states. It is also the first cement company globally to commit to the RE100, EP100 and EV100 initiatives.