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Efficient grinding unit selection impacts profitability

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ICR gets Vimal Jain, Director – Technical, HeidelbergCement India, to share his views about the innovations in technology of the grinding process and grinding aids as well as his understanding on how the entire process can be made more energy-efficient and cost-effective.

Explain the grinding process in cement manufacturing.
The grinding process is needed to create surface area for a good chemical reaction and reactivity to occur in cement manufacturing. The grinding process is mainly required for raw material, coal and clinker grinding in the cement manufacturing process.
The process of cement manufacturing involves grinding clinker granules along with blending materials or additives and gypsum to produce a fine powder called cement. Depending on the quality of clinker and type of cement, blending material/gypsum are added in controlled proportion to produce a quality product to meet the prescribed quality as per given codes.
Optimum fineness needs to be found for the type of raw materials, coal, and clinker to avoid over-grinding, which comes with ‘excess energy’ consumption and has a negative impact on quality and cost.
The quality of cement depends on its physical and chemical properties. Technology has advanced over the period and the grinding process can help in augmenting some properties of cement.

Tell us about the equipment used for grinding raw material and clinker.
The main equipment used for grinding raw materials and clinker are categorised based on their size reduction concept and mechanism as,
Ball Mill (BM):
Size reduction mechanism –

  1. Impact: particle breakage by a single rigid force causing fracture.
  2. Attrition or Abrasion: arising from particles scraping against one another or against a
    rigid surface.
    Ball mills are the most widely installed grinding equipment in the cement industry. It consists of a rotating cylinder filled with steel balls that tumble inside the mill, applying impact and friction forces to the clinker particles. For better grinding efficiency, the mill may be operated with one, two or three internal compartments separated by diaphragms that prevent the transfer of the balls between the compartments while allowing the flow of the ground material through the mill.
    Roller Press (RP)
    Size reduction mechanism – Compression: particle disintegration by two rigid forces.
    The roller press has been extensively used as a pre-grinder as well as a stand-alone cement mill. It compresses the material in a gap between two counter-rotating grinding rollers lined with wear-resistant material. The output product contains fine and coarse particles with a large number of cracks and weak points that significantly reduce the energy requirement during the further stage of fine grinding.
    Vertical Roller Mill (VRM)
    Size reduction mechanism –
  3. Compression
  4. Shear or Chipping: produced by fluid or particle-particle interaction.
  5. Attrition or Abrasion
    In a vertical roller mill, two-four rollers turning on their axles press on a rotating grinding table mounted on the yoke of a gearbox. Pressure is exerted hydraulically. This mill also has a built-in high-efficiency separator above the rollers. The vertical roller mills offer high drying capacity, comparatively low energy consumption, and compactness.
    Hybrid Grinding: a combination of Ball Mill with Roller press
    Horo Mill (HM): it is similar to the vertical mill but the roller arrangement differs from VRM.
    In the ball mill, RP and Combined grinding system separation take place outside the grinding mill, whereas in the VRM separation and grinding take place in one system.
    The technologies involved in cement can be classified as per the following:
    Intergrinding: With the intergrinding process, all components of the blended cement are ground together. In that way, the cement is homogenised during the grinding, and at the cement plant only one silo is needed. Because of interactions between the different cement components due to differences in grindability, the PSD of the blended cement and the different components is difficult to control due to differential grindability due to different hardness of materials. Equipment for the inter grindings are Ball mills, roll press/ Pre-grinder + Ball mill, Horo mill, and VRMs.
    Separate grinding: The separate grinding process is grinding the various components separately, storing them, and mixing them according to the desired proportions. This process has several advantages: the PSD of each component and of the blended cement can be controlled according to the components’ hardness and required fineness, and appropriate grinding equipment can be used for each component. But in this case, several silos for storage are needed at the cement plant. Equipment for separate grinding is all the grinding equipment mentioned above, with the use of blenders required to blend the grounded material in the proportion needed for the specific cement product.
    The advantage of separate grinding can be to produce a wide range of cements from one plant.
    Grinding systems are either ‘open circuit’ or ‘closed circuit.’ In an open circuit system, the feed rate of the incoming clinker is adjusted to achieve the desired fineness of the product. In a closed circuit system, coarse particles are separated from the finer product and returned for further grinding.

What are the key functionalities that are looked at while installing a grinding unit in your plant?
The key factors, which shall be carefully considered, include:

  • Product quality requirement: market requirement
  • Machine sizing and layout: investment cost
  • Raw materials quality and characteristics: input materials
  • Mechanical design: maintenance cost and reliability
  • Latest design innovations including high grinding efficiency, energy saving and environmental protection, good quality of finished products, etc., performance improvement
  • On-demand changes: project-specific requirement
  • Product diversification: commercial reasons
  • Capex vs Opex economics: budget
  • Spare part and service availability: after-sales service

What is the contribution of grinding units in making cement-making processes efficient and productive?
The grinding unit plays an important role in making the operation efficient. Approximately 60 per cent of the cement power is absorbed in the grinding circuit, and to be competitive in the market, power cost plays an important role.
It is also observed that particle size distribution is better in the BM compared to other mills considering the product quality requirement.
The following grinding units are involved in cement making process:

  • Raw material grinding: to improve raw meal burning behavior, clinker quality, and kiln output, including thermal energy requirement
  • Coal grinding: better combustion of fuels, improves the flame property, and avoids CO2 generation, including improved burning process
  • Cement grinding: cement hydration, strength development, and water demand

How do grinding units contribute to the profitability of the cement-making process?
The grinding unit contributes to profitability in the following ways:
The electrical energy price is a major contributor to the cost of production. Therefore, producing cement with less energy is becoming a key element of profitability: as the grinding process consumes about 60 per cent of the total plant electrical energy demand and about 20 per cent of cement production variable cost. So efficient grinding unit selection impacts profitability of cement manufacturing. Optimum fineness needs to be found to avoid over grinding and consuming excess energy Final product PSD (particle size distribution) improves quality and profitability. Where two types of cement have identical surface areas, the cement with the narrower PSD will have a higher compressive strength.
Maximum use of low-cost blending materials, technology and layout such that the repairs and maintenance and manpower costs are lower, etc.

What are the materials and equipment that aid in the process of cement grinding?
Grinding Aid (GA):
In the grinding process, agglomeration takes place, due to this grinding efficiency is reduced and the output and quality of product effects. The GA is a very efficient way to avoid the agglomeration mechanism and improve the over-grinding efficiency. Therefore, GA helps to increase the grinding mill output and reduces
the electrical energy consumption, resulting in improving profitability.
Performance Enhancers/Quality Improvers: Due to the quality of raw materials and variation in the burning process, desired clinker phase formation does not take place, which impacts the cement performance, workability, and durability. Therefore, in addition to a grinding aid, additional chemicals are used to improve the cement performance and properties, such as setting time and strength development
Functional Additives: The additive imparts a specific property, such as air entrainment in masonry cement or chromium (VI) reduction.
Supplementary Cementitious Materials (SCM): Supplementary Cementitious Materials (SCMs) are added to cement mixtures for various reasons, including improving durability, decreasing permeability, aiding in pumpability, mitigating alkali reactivity, and improving the overall hardened properties of concrete. This also helps to reduce the carbon dioxide footprint in cement manufacturing. The use of SCMs also reduces the dependency on natural resources and enhances the circular economy.
Equipment: Raw materials storage, dosing station, raw material transport conveyors/elevators, weigh feeders, air separators, baghouse, product transport and storage silos are the key equipment of the grinding units.
Air Separator is one of the vital equipment for grinding systems that plays a significant role in maintaining product quality and increasing the grinding system productivity.
QC Lab: It’s a must for sampling and testing so that consistent quality material is produced and supplied to customers.

How do you ensure standards in the process?
During manufacturing, quality control parameters are established with reference to the national standards, and accordingly, the sampling and testing plan of the company is maintained.
There are very well descriptive quality control and assurance plans at various stages of the manufacturing/operations.
At each of our plants, we have state-of-the-art laboratories to produce quality cement much above the spec from the BIS. We have a very low standard deviation in the finished product that indicates the consistency in the cement. We are certified with applicable ISO standards to ensure that the product supplied is safe, environmentally compliant, and quality consistent.

How often is the same monitored?
Cement manufacturing is a continuous process and monitoring is done in 24×7 mode to ensure cement quality.
The quality control starts from the mine to the cement packing, and there are well-defined testing protocols at a sampling frequency. Plants are equipped with various material feeding and transportation systems to maintain the quality and process.

What challenges do you face in the process of cement grinding?
Availability and economics of outsourced materials are major challenges these days. The key challenges are as follows:

  • Availability of reliable and economical energy sources, power generation is becoming expensive due to increasing fuel prices and quality of fuel.
  • Right quality and Quantity of SCMs (Supplementary Cementitious Materials) are needed to achieve cement quality and also to mitigate the challenges of CO2 reduction in the cement-making process
  • Production of multiple cement types needs more storage facilities and impacts mill performance and product quality
  • SCMs with high moisture content demand drying arrangements resulting in a need for more capital as well as operational expenses.
  • Skilled manpower for operation and maintenance.

What are the innovations you would like to see in the technology of the grinding process and grinding aids?
Innovations play an important role in the cement industry. The quality of the product can be enhanced by adopting the right technology and the optimum key performance indicators for producing a quality product at a competitive price. We would like to see further innovation for:

  • Energy efficient equipment and drives to lower the power consumption
  • Separate grinding of cement to improve product quality and lower power consumption to reduce CO2 emission.
  • New hybrid formulations in grinding aid to improve product quality, specific energy consumption and reduce clinker ratio in cement.
  • Innovation for cement production by substituting max possible clinker incorporation by alternative / lower quality cementitious materials but maintaining the product quality.
  • New wear materials for enhancing the life of wear components to reduce the consumables cost per ton.

Kanika Mathur

Concrete

India’s Steel Imports Drop 34 Per Cent, Exports Rise 25 Per Cent In April–October

Consumption grows despite weak prices and subdued demand

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India’s finished steel imports fell 34.1 per cent year-on-year to 2.5 million tonnes in the first seven months of the financial year, according to government data. Despite the decline, the world’s second-largest crude steel producer remained a net importer of finished steel during the April–October period. The fall in imports came alongside a 7.4 per cent rise in domestic consumption, which reached 92.2 million tonnes.

South Korea emerged as India’s largest source of finished steel imports, supplying 1.4 million tonnes. It was followed by China, Japan and Russia. Although total imports declined sharply, the figures show a continued inflow of foreign steel into the Indian market.

Domestic production remained strong. Finished steel output stood at 91.6 million tonnes for April–October, while crude steel production reached 95.7 million tonnes, underscoring the scale and resilience of India’s steel industry despite external competition.

In contrast to the fall in imports, India’s finished steel exports jumped 25.3 per cent year-on-year to 3.5 million tonnes. Europe was a major destination, with Italy and Belgium leading as top importers of Indian steel, followed by Spain. This highlights the growing global competitiveness of Indian steel in select markets.

The government noted that domestic steel prices have come under pressure due to weak demand and high supply. Trading activity also remained subdued during the festival season. This challenging environment has been particularly difficult for smaller steel producers, as previously reported.

Overall, the combination of declining imports, rising exports and increasing domestic consumption reflects the complex landscape of the Indian steel sector as it navigates muted internal demand and evolving international trade dynamics.

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JK Lakshmi Cement Plans Rs 18.16 Billion Expansion

Firm to boost clinker and grinding capacity in Chhattisgarh

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JK Lakshmi Cement announced on Tuesday that it will invest Rs 18.16 billion to expand its manufacturing operations in Chhattisgarh. The company intends to raise its clinker production capacity by 2.31 million tonnes per annum (MTPA) and its cement grinding capacity by 1.2 MTPA, supported by this proposed investment.

The Memorandum of Understanding for the expansion was signed during the Chhattisgarh Investor Connect event in New Delhi, in the presence of Chief Minister Vishnu Deo Sai. The added capacity will enhance the company’s ability to serve the rapidly growing markets of Eastern and Central India, where demand for building materials remains robust.

The move supports JK Lakshmi Cement’s broader goal of increasing its total capacity to around 30 MTPA in the coming years. Deputy Managing Director Shrivats Singhania said the expansion marks a significant step in the company’s next phase of growth, adding that Chhattisgarh has long been central to its manufacturing strategy.

Over the past decade, JK Lakshmi Cement has contributed to strengthening Chhattisgarh’s industrial landscape since establishing its integrated plant in Durg in 2015. The company has implemented multiple initiatives, including a manufacturing facility with 1.8 MTPA of clinker capacity and 2.7 MTPA of cement capacity, operational upgrades with energy-efficient technology and automation, and logistics improvements through enhanced rail connectivity.

Chhattisgarh continues to show strong economic momentum, making it one of the most promising markets for cement demand, said Arun Shukla, President and Director at JK Lakshmi Cement. The company’s shares closed 0.28 per cent higher at Rs 782.10 on the BSE.

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Balancing Rapid Economic Growth and Climate Action

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Dr Yogendra Kanitkar, VP R&D, and Dr Shirish Kumar Sharma, Assistant Manager R&D, Pi Green Innovations, look at India’s cement industry as it stands at the crossroads of infrastructure expansion and urgent decarbonisation.

The cement industry plays an indispensable role in India’s infrastructure development and economic growth. As the world’s second-largest cement producer after China, India accounts for more than 8 per cent of global cement production, with an output of around 418 million tonnes in 2023–24. It contributes roughly 11 per cent to the input costs of the construction sector, sustains over one million direct jobs, and generates an estimated 20,000 additional downstream jobs for every million tonnes produced. This scale makes cement a critical backbone of the nation’s development. Yet, this vitality comes with a steep environmental price, as cement production contributes nearly 7 per cent of India’s total carbon dioxide (CO2) emissions.
On a global scale, the sector accounts for 8 per cent of anthropogenic CO2 emissions, a figure that underscores the urgency of balancing rapid growth with climate responsibility. A unique challenge lies in the dual nature of cement-related emissions: about 60 per cent stem from calcination of limestone in kilns, while the remaining 40 per cent arise from the combustion of fossil fuels to generate the extreme heat of 1,450°C required for clinker production (TERI 2023; GCCA).
This dilemma is compounded by India’s relatively low per capita consumption of cement at about 300kg per year, compared to the global average of 540kg. The data reveals substantial growth potential as India continues to urbanise and industrialise, yet this projected rise in consumption will inevitably add to greenhouse gas emissions unless urgent measures are taken. The sector is also uniquely constrained by being a high-volume, low-margin business with high capital intensity, leaving limited room to absorb additional costs for decarbonisation technologies.
India has nonetheless made notable progress in improving the carbon efficiency of its cement industry. Between 1996 and 2010, the sector reduced its emissions intensity from 1.12 tonnes of CO2 per ton of cement to 0.719 tonnes—making it one of the most energy-efficient globally. Today, Indian cement plants reach thermal efficiency levels of around 725 kcal/kg of clinker and electrical consumption near 75 kWh per tonne of cement, broadly in line with best global practice (World Cement 2025). However, absolute emissions continue to rise with increasing demand, with the sector emitting around 177 MtCO2 in 2023, about 6 per cent of India’s total fossil fuel and industrial emissions. Without decisive interventions, projections suggest that cement manufacturing emissions in India could rise by 250–500 per cent by mid-century, depending on demand growth (Statista; CEEW).
Recognising this threat, the Government of India has brought the sector under compliance obligations of the Carbon Credit Trading Scheme (CCTS). Cement is one of the designated obligated entities, tasked with meeting aggressive reduction targets over the next two financial years, effectively binding companies to measurable progress toward decarbonisation and creating compliance-driven demand for carbon reduction and trading credits (NITI 2025).
The industry has responded by deploying incremental decarbonisation measures focused on energy efficiency, alternative fuels, and material substitutions. Process optimisation using AI-driven controls and waste heat recovery systems has made many plants among the most efficient worldwide, typically reducing fuel use by 3–8 per cent and cutting emissions by up to 9 per cent. Trials are exploring kiln firing with greener fuels such as hydrogen and natural gas. Limited blends of hydrogen up to 20 per cent are technically feasible, though economics remain unfavourable at present.
Efforts to electrify kilns are gaining international attention. For instance, proprietary technologies have demonstrated the potential of electrified kilns that can reach 1,700°C using renewable electricity, a transformative technology still at the pilot stage. Meanwhile, given that cement manufacturing is also a highly power-intensive industry, several firms are shifting electric grinding operations to renewable energy.
Material substitution represents another key decarbonisation pathway. Blended cements using industrial by-products like fly ash and ground granulated blast furnace slag (GGBS) can significantly reduce the clinker factor, which currently constitutes about 65 per cent in India. GGBS can replace up to 85 per cent of clinker in specific cement grades, though its future availability may fall as steel plants decarbonise and reduce slag generation. Fly ash from coal-fired power stations remains widely used as a low-carbon substitute, but its supply too will shrink as India expands renewable power. Alternative fuels—ranging from biomass to solid waste—further allow reductions in fossil energy dependency, abating up to 24 per cent of emissions according to pilot projects (TERI; CEEW).
Beyond these, Carbon Capture, Utilisation, and Storage (CCUS) technologies are emerging as a critical lever for achieving deep emission cuts, particularly since process emissions are chemically unavoidable. Post-combustion amine scrubbing using solvents like monoethanolamine (MEA) remains the most mature option, with capture efficiencies between 90–99 per cent demonstrated at pilot scale. However, drawbacks include energy penalties that require 15–30 per cent of plant output for solvent regeneration, as well as costs for retrofitting and long-term corrosion management (Heidelberg Materials 2025). Oxyfuel combustion has been tested internationally, producing concentrated CO2-laden flue gas, though the high cost of pure oxygen production impedes deployment in India.
Calcium looping offers another promising pathway, where calcium oxide sorbents absorb CO2 and can be regenerated, but challenges of sorbent degradation and high calcination energy requirements remain barriers (DNV 2024). Experimental approaches like membrane separation and mineral carbonation are advancing in India, with startups piloting systems to mineralise flue gas streams at captive power plants. Besides point-source capture, innovations such as CO2 curing of concrete blocks already show promise, enhancing strength and reducing lifecycle emissions.
Despite progress, several systemic obstacles hinder the mass deployment of CCUS in India’s cement industry. Technology readiness remains a fundamental issue: apart from MEA-based capture, most technologies are not commercially mature in high-volume cement plants. Furthermore, CCUS is costly. Studies by CEEW estimate that achieving net-zero cement in India would require around US$ 334 billion in capital investments and US$ 3 billion annually in operating costs by 2050, potentially raising cement prices between 19–107 per cent. This is particularly problematic for an industry where companies frequently operate at capacity utilisations of only 65–70 per cent and remain locked in fierce price competition (SOIC; CEEW).
Building out transport and storage infrastructure compounds the difficulty, since many cement plants lie far from suitable geological CO2 storage sites. Moreover, retrofitting capture plants onto operational cement production lines adds technical integration struggles, as capture systems must function reliably under the high-particulate and high-temperature environment of cement kilns.
Overcoming these hurdles requires a multi-pronged approach rooted in policy, finance, and global cooperation. Policy support is vital to bridge the cost gap through instruments like production-linked incentives, preferential green cement procurement, tax credits, and carbon pricing mechanisms. Strategic planning to develop shared CO2 transport and storage infrastructure, ideally in industrial clusters, would significantly lower costs and risks. International coordination can also accelerate adoption.
The Global Cement and Concrete Association’s net-zero roadmap provides a collaborative template, while North–South technology transfer offers developing countries access to proven technologies. Financing mechanisms such as blended finance, green bonds tailored for cement decarbonisation and multilateral risk guarantees will reduce capital barriers.
An integrated value-chain approach will be critical. Coordinated development of industrial clusters allows multiple emitters—cement, steel, and chemicals—to share common CO2 infrastructure, enabling economies of scale and lowering unit capture costs. Public–private partnerships can further pool resources to build this ecosystem. Ultimately, decarbonisation is neither optional nor niche for Indian cement. It is an imperative driven by India’s growth trajectory, environmental sustainability commitments, and changing global markets where carbon intensity will define trade competitiveness.
With compliance obligations already mandated under CCTS, the cement industry must accelerate decarbonisation rapidly over the next two years to meet binding reduction targets. The challenge is to balance industrial development with ambitious climate goals, securing both economic resilience and ecological sustainability. The pathway forward depends on decisive governmental support, cross-sectoral innovation, global solidarity, and forward-looking corporate action. The industry’s future lies in reframing decarbonisation not as a burden but as an investment in competitiveness, climate alignment and social responsibility.

References

  • Infomerics, “Indian Cement Industry Outlook 2024,” Nov 2024.
  • TERI & GCCA India, “Decarbonisation Roadmap for the Indian Cement Industry,” 2023.
  • UN Press Release, GA/EF/3516, “Global Resource Efficiency and Cement.”
  • World Cement, “India in Focus: Energy Efficiency Gains,” 2025.
  • Statista, “CO2 Emissions from Cement Manufacturing 2023.”
  • Heidelberg Materials, Press Release, June 18, 2025.
  • CaptureMap, “Cement Carbon Capture Technologies,” 2024.
  • DNV, “Emerging Carbon Capture Techniques in Cement Plants,” 2024.
  • LEILAC Project, News Releases, 2024–25.
  • PMC (NCBI), “Membrane-Based CO2 Capture in Cement Plants,” 2024.
  • Nature, “Carbon Capture Utilization in Cement and Concrete,” 2024.
  • ACS Industrial Engineering & Chemistry Research, “CCUS Integration in Cement Plants,” 2024.
  • CEEW, “How Can India Decarbonise for a Net-Zero Cement Industry?” (2025).
  • SOIC, “India’s Cement Industry Growth Story,” 2025.
  • MDPI, “Processes: Challenges for CCUS Deployment in Cement,” 2024.
  • NITI Aayog, “CCUS in Indian Cement Sector: Policy Gaps & Way Forward,” 2025.

ABOUT THE AUTHOR:
Dr Yogendra Kanitkar, Vice President R&D, Pi Green Innovations, drives sustainable change through advanced CCUS technologies and its pioneering NetZero Machine, delivering real decarbonisation solutions for hard-to-abate sectors.

Dr Shirish Kumar Sharma, Assitant Manager R&D, Pi Green Innovations, specialises in carbon capture, clean energy, and sustainable technologies to advance impactful CO2 reduction solutions.

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