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Clinker factor determines the CO2 footprint of cement

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Manoj Kumar Rustagi, Chief Sustainability and Innovation Office (CSIO), JSW Cement, gives insights into the process of producing blended cement with supplementary cementitious materials for more strength and durability.

What are the core raw materials used in the production of cement?
Cement manufacturing is an energy and resource intensive process. Primary raw material is limestone which is mined, crushed, ground and mixed with bauxite, iron ore and other additives/correctives to make raw meal which is then heated to a temperature as high as ~1400°C in a horizontal kiln. Coal is the primary fuel which provides energy for the combustion process. The hot material is then cooled down to form clinker, an intermediate product for making cement. Clinker is further ground and blended with gypsum (mineral or chemical) to make the final product called ordinary Portland cement (OPC).
When clinker is blended with other supplementary cementitious materials like fly ash or slag or both, the product is known as blended cement.

What are the alternative raw materials that can be used in the production of cement? How does that impact the process of production?
Cement sector accounts for ~7 per cent of global CO2 emissions, and therefore it needs to be aggressive on its decarbonisation strategy wherein one of the primary lever is using alternative raw materials for the production of clinker and supplementary cementitious materials (SCMs) as cement/clinker replacements. Different fine-grained silica, silicate and alumina-silicate materials either natural or synthetic can be used in the final cement product to obtain a new eco-friendly cementitious binder with similar or better properties. The most commonly used SCMs are fly ash, granulated blast furnace slag, natural volcanic pozzolana etc.
When clinker is blended with other supplementary cementitious materials like fly ash, slag or both, products are called Portland Pozzolona Cement (PPC), Portland Slag Cement (PSC) and composite cement (CC) respectively. Blended cement products have a much lower carbon footprint than OPC. Since clinker manufacturing is the phase where most thermal energy is consumed and CO2 is emitted, reducing clinker factor in cement not only results in lowering the process CO2 but also the thermal energy and electrical energy requirements.
There are other alternative raw materials like Spent Pot Liner (SPL), red mud, lime sludge and steel slag, which are used in the clinker manufacturing to reduce consumption of limestone and consequently reducing the process CO2 that comes from limestone calcination.

Can cement maintain its quality standard with inclusion of supplementary raw materials as against limestone?
Yes, blended cement products not only maintain the most quality standards as OPC but also have superior properties in various parameters when compared to conventional OPC. Blended cements are preferred for its late strength, chemical resistance, alkali resistance and for coastal applications and dams and irrigation projects where they are technically most suitable.
The use of SCMs/mineral admixture/blended cements in concrete significantly helps in mitigating the expansion due to alkali silica reaction (ASR), due to the reduction in the availability of alkalis in the pore solution and the refinement of the pore structure. Not only does this reduce maintenance costs of infrastructure such as dams and bridges, but also allows the consumption of local aggregates that may contain deleterious materials. The reduced expansion in SCM-blended structures reduces the risk of expansion and cracking. This pozzolanic reaction also has a beneficial impact on resistance to sulphate attack.
Recently GCCA, India has published a detailed report on Benefits of Blended Cement Products, which has been prepared by NCCBM and reviewed by IIT, Madras, and that captures all the environment and technical benefits.

Explain the impact on carbon emission of the production unit when alternative raw materials are used in various proportions.
In cement manufacturing, CO2 is primarily emitted as a result of the chemical conversion process used in the production of clinker in which limestone (CaCO3) is first converted to lime (CaO) and then to hydraulic compounds. CO2 is also emitted during cement production by fossil fuel (primarily coal) combustion. Thus ~80-85 per cent of the CO2 emissions could be attributed to the production of clinker. This is partly reduced by using alternative raw materials and mineralisers in the raw mix design of clinker.
The amount of clinker in cement, known as clinker factor, determines the CO2 footprint of cement. In OPC, clinker factor is ~90 per cent thus, it has a carbon footprint of around 800 – 850 kg/MT of cement. When clinker is replaced with SCMs, the CO2 emissions are reduced as SCMs don’t have embodied carbon emissions. That is why blended cement have much lower carbon footprint than OPC. Currently in Portland Slag Cement (PSC) production almost 60 to 65 per cent of clinker is replaced with slag which results in ~60 per cent of CO2 footprint and the final carbon footprint is around 300 – 350 kg/MT. Similarly, in PPC where ~35 per cent of clinker is replaced, carbon footprint will be in the range of 500 – 550 kg/MT.

-Kanika Mathur

Concrete

Indian Cement Industry Sees Further Consolidation

Cement industry to face consolidation soon.

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India’s cement sector is set for further consolidation in the near-to-medium term, according to a recent report. With increasing competition, rising input costs, and the need for economies of scale, companies are expected to explore mergers and acquisitions (M&A) to strengthen their market positions. As the industry faces various challenges, including high energy costs and fluctuating demand, consolidation is viewed as a strategic move to drive growth and sustainability.

Key Points:
Market Consolidation: The Indian cement industry has already witnessed significant consolidation over the past few years, with several large firms acquiring smaller players to enhance their market share. The trend is expected to continue, driven by the need to optimize operations, cut costs, and gain better pricing power. Consolidation helps companies to expand their geographic reach and strengthen their portfolios.

Rising Costs and Challenges: One of the primary drivers of consolidation is the rising cost of inputs, particularly energy and raw materials. With costs of coal and petroleum coke (key energy sources for cement production) soaring, companies are looking for ways to maintain profitability. Smaller and medium-sized players, in particular, find it challenging to cope with these rising costs, making them more likely targets for acquisition by larger companies.

Economies of Scale: Larger cement companies benefit from economies of scale, which help them absorb the impact of rising input costs more effectively. Consolidation allows firms to streamline production processes, reduce operational inefficiencies, and invest in advanced technologies that improve productivity. These efficiencies become critical in maintaining competitiveness in an increasingly challenging environment.

M&A Activity: The report highlights the potential for more mergers and acquisitions in the cement sector, particularly among mid-sized and regional players. The Indian cement market, which is highly fragmented, presents numerous opportunities for larger companies to acquire smaller firms and gain a foothold in new markets. M&A activity is expected to accelerate as firms seek growth through strategic alliances and acquisitions.

Regional Focus: Consolidation efforts are likely to be regionally focused, with companies looking to expand their presence in specific geographic areas where demand for cement is strong. Infrastructure development, government projects, and urbanization are driving demand in various parts of the country, making regional expansions an attractive proposition for firms looking to grow.

Impact on Competition: While consolidation may lead to a more concentrated market, it could also intensify competition among the remaining players. Larger firms with more resources and market reach could dominate pricing strategies and influence market dynamics. Smaller firms may either merge or struggle to compete, leading to a reshaping of the competitive landscape.

Demand Outlook: The near-term outlook for the cement industry remains uncertain, with demand being influenced by factors such as construction activity, infrastructure projects, and government initiatives. The report notes that while urban demand is expected to remain stable, rural demand continues to face challenges due to slow construction activities in those areas. However, the long-term outlook remains positive, driven by ongoing infrastructure developments and real estate projects.

Sustainability Focus: Companies are also focusing on sustainability and environmental concerns. Consolidation can provide larger companies with the resources to invest in green technologies and reduce their carbon footprint. This focus on sustainability is becoming increasingly important, with both government regulations and market preferences shifting toward greener production practices.

Conclusion:
The Indian cement industry is poised for further consolidation in the coming years, driven by rising costs, competitive pressures, and the need for economies of scale. M&A activity is likely to accelerate, with larger firms targeting smaller and regional players to strengthen their market presence. While consolidation offers opportunities for growth and efficiency, it could also reshape the competitive landscape and influence pricing dynamics in the sector.

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Concrete

Cement Companies May Roll Back Hike

Cement firms reconsider September price increase.

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Cement companies in India might be forced to reverse the price hikes implemented in September due to weakened demand and pressure from competitive market conditions, according to a report by Nuvama Institutional Equities. The recent price increase, which was expected to improve margins, may not hold as demand falls short of expectations.

Key Points:
Price Hike in September: Cement firms across India increased prices in September, aiming to improve their margins amidst rising input costs. This was seen as a strategic move to stabilize earnings as they were grappling with inflationary pressures on raw materials like coal and pet coke.

Weak Demand and Pressure: However, demand has not surged as expected. In some regions, particularly rural areas, construction activity remains low, which has contributed to the tepid demand for cement. The combination of high prices and low demand may make it difficult for companies to maintain the elevated price levels.

Competitive Market Forces: Cement manufacturers are also under pressure from competitors. Smaller players may keep prices lower to attract buyers, forcing larger companies to consider rolling back the September hikes. The competitive dynamics in regions like South India, where smaller firms are prevalent, are likely to impact larger companies’ pricing strategies.

Nuvama Report Insights: Nuvama Institutional Equities has highlighted that the September price hikes may not be sustainable given current market conditions. According to the report, the demand-supply imbalance and weak construction activities across many states could push cement companies to reconsider their pricing strategies.

Impact on Margins: If companies are compelled to roll back the price hikes, it could hurt their profit margins in the near term. Cement firms had hoped to recover some of their input costs through the price increases, but the competitive landscape and slow demand recovery could negate these gains.

Regional Variations: Price rollback might not be uniform across the country. In regions where infrastructure development is picking up pace, cement prices may hold. Urban areas with ongoing real estate projects and government infrastructure initiatives could see a sustained demand, making price hikes more viable.

Future Outlook: The outlook for the cement sector will largely depend on the pace of recovery in construction activity, particularly in the housing and infrastructure sectors. Any significant recovery in rural demand, which is currently subdued, could also influence whether the price hikes will remain or be rolled back.

Strategic Adjustments: Cement firms may need to adopt a cautious approach in the near term, balancing between maintaining market share and protecting margins. Price adjustments in response to market conditions could become more frequent as companies try to adapt to the fluctuating demand.

Conclusion:
The September price hikes by cement companies may face reversal due to weak demand, competitive pressures, and market dynamics. Nuvama’s report signals that while the increase was aimed at margin recovery, it may not be sustainable, particularly in regions with low demand. The future of cement pricing will depend on construction sector recovery and regional market conditions.

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Concrete

Bridge Collapse Spurs Focus on Stainless Steel

Climate change prompts stainless steel push.

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The Ministry of Road Transport and Highways (MoRTH) is turning its attention to the use of stainless steel in bridge construction to counteract corrosion, an increasing issue linked to climate change. With recent bridge collapses highlighting the vulnerability of existing infrastructure to corrosion and extreme weather events, the ministry is promoting the adoption of durable materials like stainless steel to ensure the longevity and safety of India’s critical transport infrastructure.

Key Points:

Bridge Collapse and Climate Change: Recent incidents of bridge collapses across the country have raised alarm over the durability of current construction materials, with corrosion cited as a leading cause. Climate change, leading to harsher weather patterns and increased moisture levels, has accelerated the deterioration of key infrastructure. This has prompted MoRTH to consider long-term solutions to combat these challenges.

Corrosion: A Growing Concern: Corrosion of structural materials has become a serious issue, particularly in coastal and high-moisture regions. The Ministry has identified the need for a more resilient approach, emphasizing the use of stainless steel, known for its resistance to corrosion. This shift is seen as crucial in ensuring the longevity of India’s bridges and reducing maintenance costs over time.

Stainless Steel for Bridge Construction: Stainless steel, while more expensive initially, offers long-term savings due to its durability and resistance to environmental factors like moisture and salt. The Ministry is advocating for the material’s use in future bridge projects, particularly in areas prone to corrosion. Stainless steel is seen as a solution that can withstand the pressures of both natural elements and increasing traffic loads.

Government’s Proactive Steps: The government, through MoRTH, has started consulting with experts in the field of metallurgy and civil engineering to explore the expanded use of stainless steel. They are considering updates to construction standards and specifications to incorporate this material in new and rehabilitated infrastructure projects.

Economic Considerations: Although the initial investment in stainless steel may be higher than conventional materials, the reduced need for repairs and replacements makes it a cost-effective option in the long run. This approach also aligns with the government’s push for sustainable infrastructure that can withstand the test of time and climate change effects.

Future of Indian Infrastructure: With the push for stronger, more durable infrastructure, the Ministry’s move to adopt stainless steel for bridge construction marks a shift towards building climate-resilient structures. The use of this material is expected to not only enhance the safety and longevity of bridges but also reduce the financial burden on the government for constant repairs.

Industry Perspective: The stainless steel industry sees this shift as an opportunity to expand its market, particularly in the infrastructure sector. Stakeholders are engaging with the government to demonstrate the benefits of stainless steel, advocating for its increased use not just in bridges but across various infrastructure projects.

Conclusion: In response to the growing threat of climate change and its impact on infrastructure, the Ministry of Road Transport and Highways is prioritizing the use of stainless steel in bridge construction to combat corrosion and ensure the long-term durability of critical transport structures.

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