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Economy & Market

Optimising Cement Grinding

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Kanika Mathur explores the role of grinding aids in enhancing the efficiency and sustainability of cement production by reducing energy consumption, improving particle size distribution, and extending equipment life.

The grinding process is a crucial step in cement production, directly impacting the final quality and efficiency of cement manufacturing. With growing demands for energy efficiency, cost optimisation, and sustainable production, cement manufacturers are continuously seeking ways to improve grinding operations. Grinding aids, introduced into the process, have emerged as an essential component in achieving these objectives by enhancing the efficiency of
grinding mills and improving the performance of cement. This article explores the significance of the grinding process, the challenges faced in cement grinding, and the role of grinding aids in optimising cement manufacturing.

The Importance of the Grinding Process in Cement Manufacturing
Grinding is a fundamental process in cement production, where clinker, gypsum, and other additives are ground into fine powder to create the final product. The fineness of cement particles influences the hydration reaction, strength development, and overall durability of the cement. The efficiency of the grinding process directly affects the energy consumption, production costs, and environmental impact of cement plants.
The grinding process primarily takes place in ball mills, vertical roller mills (VRMs), and roller presses. Each of these grinding technologies has its advantages and limitations, influencing factors such as energy consumption, operational efficiency, and product quality. In recent years, there has been a shift towards more energy-efficient grinding systems, such as VRMs and roller presses, which offer better control over particle size distribution and reduce specific energy consumption.

Grinding Technologies
The grinding process is a critical component of cement manufacturing, influencing energy consumption, production efficiency, and product quality. Traditional ball mills, vertical roller mills (VRMs), and roller presses are the primary grinding technologies used in the industry. While ball mills have been widely used, they are energy-intensive and require frequent maintenance. VRMs and roller presses, on the other hand, offer better energy efficiency and control over particle size distribution, making them attractive alternatives. The shift toward advanced grinding systems has helped cement manufacturers reduce operational costs and improve sustainability.
However, cement grinding presents several challenges, including high energy consumption, inconsistencies in particle size distribution, and equipment wear. Grinding consumes nearly 60 to 70 per cent of a cement plant’s total electricity, making it one of the most energy-intensive processes. Additionally, friction during grinding generates heat, leading to agglomeration and efficiency losses. Optimising grinding operations requires careful control of raw materials, mill performance, and energy inputs to ensure sustainable and cost-effective production.
Ashok Dembla, Director, KhD Humboldt says, “The use of alternative fuels and raw materials (AFR) is continuously evolving within the cement industry. As a machinery supplier, we are adapting to these changes by providing advanced solutions for handling and processing AFR. One of our most significant innovations is the PyroRotor, an equipment designed specifically for feeding up to 85 per cent of alternative fuels into the pyroclone, which is far beyond what conventional methods can achieve. This has greatly enhanced our ability to replace traditional fuels with more sustainable alternatives.”
“In addition, we have developed solutions to address nitrogen oxide (NOx) emissions, a critical environmental concern. Our NOx reduction equipment significantly minimises NOx generation during the production process, helping plants meet stringent regulatory requirements” he adds.
Grinding aids play a vital role in enhancing grinding efficiency by reducing agglomeration, improving dispersion, and minimising energy consumption. Chemical additives such as amine-based compounds, glycols, and organic acids help improve cement properties by ensuring better flowability, reducing coating on mill internals, and extending equipment life. These additives also enhance cement hydration, leading to stronger and more durable concrete. As cement manufacturers seek ways to reduce costs and carbon footprints, grinding aids have become an essential tool in improving overall plant performance.
Looking ahead, the future of grinding in the cement industry will be shaped by advancements in eco-friendly grinding aids, digital process optimisation, and AI-driven automation. Research into bio-based and waste-derived additives is gaining traction, as companies aim to align with global sustainability goals. Additionally, integrating digital technologies into grinding operations will allow real-time monitoring and process control, further enhancing efficiency. By embracing these innovations, the cement industry can achieve greater sustainability, reduce emissions, and enhance profitability while maintaining high-quality production standards.

Challenges in Cement Grinding
Despite advancements in grinding technology, cement manufacturers still face several challenges in optimising the grinding process. Some of the key challenges include:

Energy Consumption: Grinding is an energy-intensive process, accounting for nearly 60 to 70 per cent of the total electricity consumption in a cement plant. The high energy demand for clinker grinding results in increased operational costs and contributes to CO2 emissions. Reducing energy consumption while maintaining cement quality remains a primary goal for manufacturers.
Particle Size Distribution: Achieving the right particle size distribution (PSD) is crucial for cement performance. A well-optimised PSD improves the workability of concrete, enhances strength development, and reduces the risk of segregation. However, variations in raw materials, mill operations, and grinding media can lead to inconsistencies in PSD, affecting the quality of the final product.
Mill Performance and Wear: Grinding equipment is subject to continuous wear and tear due to the abrasive nature of clinker and additives. The efficiency of grinding media, liner design,
and mill internals plays a significant role in optimising mill performance and reducing maintenance costs.
Heat Generation and Agglomeration: During grinding, friction generates heat, which can lead to issues such as agglomeration and coating on grinding media. This reduces the efficiency of the grinding process, requiring additional efforts to control mill temperature and ensure proper dispersion of cement particles.
Dyanesh Wanjale, Managing Director, Gebr. Pfeiffer says, “One of the major challenges we face is the demand for expedited deliveries. While customers often take time to decide on placing orders, once the decision is made, they expect quick deliveries. However, our industry deals with heavy and highly customised machinery that cannot be produced off the shelf. Each piece of equipment is made-to-order based on the client’s unique requirements, which inherently requires time for manufacturing.”
“Another significant challenge comes from competition with Chinese suppliers. While the Indian cement industry traditionally favoured our technology over Chinese alternatives, a few customers have started exploring Chinese vertical roller mills. This is concerning because our German technology offers unmatched quality and longevity. For example, our mills are designed to last over 30 years, providing a long-term solution for customers. In contrast, Chinese equipment often does not offer the same durability or reliability. Despite the cost pressures, we firmly believe that our technology provides superior value in the long run” he adds.

Role of Grinding Aids in Cement Grinding
Grinding aids are chemical additives that are introduced into the grinding process to improve efficiency and performance. These additives work by reducing the surface energy of clinker particles, preventing agglomeration, and enhancing the flowability of the cement powder. Some of the key benefits of grinding aids include:
Enhanced Grinding Efficiency: Grinding aids help in breaking down clinker particles more effectively, reducing the energy required for grinding. This leads to higher mill output, lower specific energy consumption, and improved overall plant performance.
Improved Particle Size Distribution: By minimising agglomeration and promoting dispersion, grinding aids contribute to a more uniform particle size distribution. This results in better cement hydration, improved strength development, and enhanced durability of concrete structures.
Reduction in Coating and Mill Wear: Grinding aids help prevent the accumulation of cement particles on grinding media and mill internals, reducing coating issues. This minimises wear and tear on equipment, leading to lower maintenance costs and extended mill life.
Better Flowability and Handling: Cement produced with grinding aids exhibits improved flow properties, reducing the risk of blockages in silos and conveying systems. This facilitates smoother handling, packaging, and transportation of cement.
“The performance evaluation of grinding aids is crucial in determining their efficiency and overall contribution to cement manufacturing processes. A systematic assessment involves analysing key performance indicators (KPIs) such as energy consumption, mill output, and particle size distribution, while also evaluating their impact on cement hydration, setting time, and compressive strength. These evaluations, carried out both in laboratories and real-world industrial settings, provide critical insights into the effectiveness of grinding aids” says Dr SB Hegde.

Types of Grinding Aids
Grinding aids can be classified into different categories based on their chemical composition
and functionality. The most commonly used grinding aids include:
Amine-Based Grinding Aids: These additives, such as triethanolamine (TEA) and diethanolamine (DEA), enhance the grinding process by reducing surface tension and improving dispersion. They are widely used to improve early strength development and reduce setting time.
Glycol-Based Grinding Aids: Polyethylene glycols (PEG) and ethylene glycols are commonly used to improve mill efficiency and reduce energy consumption. They help in reducing agglomeration and enhancing cement flowability.
Organic Acids and Their Salts: Organic acid-based grinding aids, such as acetic acid and citric acid derivatives, function by modifying surface interactions between clinker particles. They contribute to better particle dispersion and enhanced cement performance.

Advanced Process Control and AI in Grinding Optimisation
The integration of Advanced Process Control (APC) and Artificial Intelligence (AI) in cement grinding has revolutionised the industry by enhancing efficiency, reducing energy consumption, and improving product quality. APC systems use real-time data from sensors to automatically adjust operating parameters, such as mill speed, grinding media distribution, and material flow, ensuring optimal performance. AI-driven predictive analytics further refine this process by identifying patterns and trends, allowing for proactive adjustments that minimise downtime and maximise throughput.
Rajeev Manchanda, Director, Christian Pfieffer says, “Technology plays a vital role in both our operations and those of the cement industry. We have established several collaborations with leading European companies to provide cutting-edge technology and services. These partnerships allow us to offer energy-efficient and environmentally friendly solutions to our clients. For example, we work closely with Semprotect to optimise the calorific value of clinkerisation plants, which significantly reduces coal consumption. By saving coal, we not only cut costs but also contribute to environmental preservation.”
“All our equipment is designed with the primary objectives of saving energy, minimising coal usage, and increasing production efficiency. Our approach involves replacing outdated systems with modern, optimised ones, which have consistently delivered substantial benefits to our clients. These improvements are aligned with our commitment to reducing the industry’s carbon footprint while enhancing operational efficiency” he adds.
One of the key benefits of AI in grinding optimisation is its ability to handle complex variables that affect grinding efficiency, such as raw material variability, feed rate fluctuations, and mill conditions. Machine learning algorithms continuously analyse historical and real-time data to make intelligent decisions, reducing human intervention and improving accuracy. This results in lower specific energy consumption, better particle size distribution, and increased cement strength.

The Future of Grinding Aids and Sustainable Cement Production
With increasing emphasis on sustainability and reducing the environmental impact of cement production, the development of eco-friendly grinding aids is gaining attention. Researchers are exploring bio-based and waste-derived additives that can improve grinding efficiency while minimising the carbon footprint of cement manufacturing. Additionally, advancements in digitalisation and AI-driven process control
systems are expected to further optimise grinding operations, leading to smarter and more sustainable cement production.

Conclusion
The grinding process plays a crucial role in cement manufacturing, influencing energy consumption, production efficiency, and final product quality. While challenges such as energy demand, particle size distribution, and mill performance persist, the use of grinding aids has proven to be an effective strategy in overcoming these obstacles. By enhancing grinding efficiency, improving cement properties, and reducing operational costs, grinding aids contribute significantly to the sustainability and competitiveness of the cement industry. As technology advances, further innovations in grinding aids and process optimisation will continue to shape the future of cement grinding, ensuring a more sustainable and efficient production process.

Economy & Market

Smart Pumping for Rock Blasting

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SEEPEX introduces BN pumps with Smart Joint Access (SJA) to improve efficiency, reliability, and inspection speed in demanding rock blasting operations.
Designed for abrasive and chemical media, the solution supports precise dosing, reduced downtime, and enhanced operational safety.

SEEPEX has introduced BN pumps with Smart Joint Access (SJA), engineered for the reliable and precise transfer of abrasive, corrosive, and chemical media in mining and construction. Designed for rock blasting, the pump features a large inspection opening for quick joint checks, a compact footprint for mobile or skid-mounted installations, and flexible drive and material options for consistent performance and uptime.

“Operators can inspect joints quickly and rely on precise pumping of shear-sensitive and abrasive emulsions,” said Magalie Levray, Global Business Development Manager Mining at SEEPEX. “This is particularly critical in rock blasting, where every borehole counts for productivity.” Industry Context

Rock blasting is essential for extracting hard rock and shaping safe excavation profiles in mining and construction. Accurate and consistent loading of explosive emulsions ensures controlled fragmentation, protects personnel, and maximizes productivity. Even minor deviations in pumping can cause delays or reduce product quality. BN pumps with SJA support routine maintenance and pre-operation checks by allowing fast verification of joint integrity, enabling more efficient operations.

Always Inspection Ready

Smart Joint Access is designed for inspection-friendly operations. The large inspection opening in the suction housing provides direct access to both joints, enabling rapid pre-operation checks while maintaining high operational reliability. Technicians can assess joint condition quickly, supporting continuous, reliable operation.

Key Features

  • Compact Footprint: Fits truck-mounted mobile units, skid-mounted systems, and factory installations.
  • Flexible Drive Options: Compact hydraulic drive or electric drive configurations.
  • Hydraulic Efficiency: Low-displacement design reduces oil requirements and supports low total cost of ownership.
  • Equal Wall Stator Design: Ensures high-pressure performance in a compact footprint.
  • Material Flexibility: Stainless steel or steel housings, chrome-plated rotors, and stators in NBR, EPDM, or FKM.

Operators benefit from shorter inspection cycles, reliable dosing, seamless integration, and fast delivery through framework agreements, helping to maintain uptime in critical rock blasting processes.

Applications – Optimized for Rock Blasting

BN pumps with SJA are designed for mining, tunneling, quarrying, civil works, dam construction, and other sectors requiring precise handling of abrasive or chemical media. They provide robust performance while enabling fast, reliable inspection and maintenance.With SJA, operators can quickly access both joints without disassembly, ensuring emulsions are transferred accurately and consistently. This reduces downtime, preserves product integrity, and supports uniform dosing across multiple bore holes.

With the Smart Joint Access inspection opening, operators can quickly access and assess the condition of both joints without disassembly, enabling immediate verification of pump readiness prior to blast hole loading. This allows operators to confirm that emulsions are transferred accurately and consistently, protecting personnel, minimizing product degradation, and maintaining uniform dosing across multiple bore holes.

The combination of equal wall stator design, compact integration, flexible drives, and progressive cavity pump technology ensures continuous, reliable operation even in space-limited, high-pressure environments.

From Inspection to Operation

A leading explosives provider implemented BN pumps with SJA in open pit and underground operations. By replacing legacy pumps, inspection cycles were significantly shortened, allowing crews to complete pre-operation checks and return mobile units to productive work faster. Direct joint access through SJA enabled immediate verification, consistent emulsion dosing, and reduced downtime caused by joint-related deviations.

“The inspection opening gives immediate confidence that each joint is secure before proceeding to bore holes,” said a site technician. “It allows us to act quickly, keeping blasting schedules on track.”

Framework agreements ensured rapid pump supply and minimal downtime, supporting multi-site operations across continents

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Concrete

Digital process control is transforming grinding

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Satish Maheshwari, Chief Manufacturing Officer, Shree Cement, delves into how digital intelligence is transforming cement grinding into a predictive, stable, and energy-efficient operation.

Grinding sits at the heart of cement manufacturing, accounting for the largest share of electrical energy consumption. In this interview, Satish Maheshwari, Chief Manufacturing Officer, Shree Cement, explains how advanced grinding technologies, data-driven optimisation and process intelligence are transforming mill performance, reducing power consumption and supporting the industry’s decarbonisation goals.

How has the grinding process evolved in Indian cement plants to meet rising efficiency and sustainability expectations?
Over the past decade, Indian cement plants have seen a clear evolution in grinding technology, moving from conventional open-circuit ball mills to high-efficiency closed-circuit systems, Roller Press–Ball Mill combinations and Vertical Roller Mills (VRMs). This shift has been supported by advances in separator design, improved wear-resistant materials, and the growing use of digital process automation. As a result, grinding units today operate as highly controlled manufacturing systems where real-time data, process intelligence and efficient separation work together to deliver stable and predictable performance.
From a sustainability perspective, these developments directly reduce specific power consumption, improve equipment reliability and lower the carbon footprint per tonne of cement produced.

How critical is grinding optimisation in reducing specific power consumption across ball mills and VRMs?
Grinding is the largest consumer of electrical energy in a cement plant, which makes optimisation one of the most effective levers for improving energy efficiency. In ball mill systems, optimisation through correct media selection, charge design, diaphragm configuration, ventilation management and separator tuning can typically deliver power savings of 5 per cent to 8 per cent. In VRMs, fine-tuning airflow balance, grinding pressure, nozzle ring settings, and circulating load can unlock energy reductions in the range of 8 per cent to 12 per cent. Across both systems, sustained operation under stable conditions is critical. Consistency in mill loading and operating parameters improves quality control, reduces wear, and enables long-term energy efficiency, making stability a key operational KPI.

What challenges arise in maintaining consistent cement quality when using alternative raw materials and blended compositions?
The increased use of alternative raw materials and supplementary cementitious materials (SCM) introduces variability in chemistry, moisture, hardness, and loss on ignition. This variability makes it more challenging to maintain consistent fineness, particle size distribution, throughput and downstream performance parameters such as setting time, strength development and workability.
As clinker substitution levels rise, grinding precision becomes increasingly important. Even small improvements in consistency enable higher SCM utilisation without compromising cement performance.
Addressing these challenges requires stronger feed homogenisation, real-time quality monitoring and dynamic adjustment of grinding parameters so that output quality remains stable despite changing input characteristics.

How is digital process control changing the way grinding performance is optimised?
Digital process control is transforming grinding from an operator-dependent activity into a predictive, model-driven operation. Technologies such as online particle size and residue analysers, AI-based optimisation platforms, digital twins for VRMs and Roller Press systems, and advanced process control solutions are redefining how performance is managed.
At the same time, workforce roles are evolving. Operators are increasingly focused on interpreting data trends through digital dashboards and responding proactively rather than relying on manual interventions. Together, these tools improve mill stability, enable faster response to disturbances, maintain consistent fineness, and reduce specific energy consumption while minimising manual effort.

How do you see grinding technologies supporting the industry’s low-clinker and decarbonisation goals?
Modern grinding technologies are central to the industry’s decarbonisation efforts. They enable higher incorporation of SCMs such as fly ash, slag, and limestone, improve particle fineness and reactivity, and reduce overall power consumption. Efficient grinding makes it possible to maintain consistent cement quality at lower clinker factors. Every improvement in energy intensity and particle engineering directly contributes to lower CO2 emissions.
As India moves toward low-carbon construction, precision grinding will remain a foundational capability for delivering sustainable, high-performance cement aligned with national and global climate objectives.

How much potential does grinding optimisation hold for immediate energy
and cost savings?
The potential for near-term savings is substantial. Without major capital investment, most plants can achieve 5 per cent to 15 per cent power reduction through measures such as improving separator efficiency, optimising ventilation, refining media grading, and fine-tuning operating parameters.
With continued capacity expansion across India, advanced optimisation tools will help ensure that productivity gains are not matched by proportional increases in energy demand. Given current power costs, this translates into direct and measurable financial benefits, making grinding optimisation one of the fastest-payback operational initiatives available to cement manufacturers today.

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Concrete

Refractory demands in our kiln have changed

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Radha Singh, Senior Manager (P&Q), Shree Digvijay Cement, points out why performance, predictability and life-cycle value now matter more than routine replacement in cement kilns.

As Indian cement plants push for higher throughput, increased alternative fuel usage and tighter shutdown cycles, refractory performance in kilns and pyro-processing systems is under growing pressure. In this interview, Radha Singh, Senior Manager (P&Q), Shree Digvijay Cement, shares how refractory demands have evolved on the ground and how smarter digital monitoring is improving kiln stability, uptime and clinker quality.

How have refractory demands changed in your kiln and pyro-processing line over the last five years?
Over the last five years, refractory demands in our kiln and pyro line have changed. Earlier, the focus was mostly on standard grades and routine shutdown-based replacement. But now, because of higher production loads, more alternative fuels and raw materials (AFR) usage and greater temperature variation, the expectation from refractory has increased.
In our own case, the current kiln refractory has already completed around 1.5 years, which itself shows how much more we now rely on materials that can handle thermal shock, alkali attack and coating fluctuations. We have moved towards more stable, high-performance linings so that we don’t have to enter the kiln frequently for repairs.
Overall, the shift has been from just ‘installation and run’ to selecting refractories that give longer life, better coating behaviour and more predictable performance under tougher operating conditions.

What are the biggest refractory challenges in the preheater, calciner and cooler zones?
• Preheater: Coating instability, chloride/sulphur cycles and brick erosion.
• Calciner: AFR firing, thermal shock and alkali infiltration.
• Cooler: Severe abrasion, red-river formation and mechanical stress on linings.
Overall, the biggest challenge is maintaining lining stability under highly variable operating conditions.

How do you evaluate and select refractory partners for long-term performance?
In real plant conditions, we don’t select a refractory partner just by looking at price. First, we see their past performance in similar kilns and whether their material has actually survived our operating conditions. We also check how strong their technical support is during shutdowns, because installation quality matters as much as the material itself.
Another key point is how quickly they respond during breakdowns or hot spots. A good partner should be available on short notice. We also look at their failure analysis capability, whether they can explain why a lining failed and suggest improvements.
On top of this, we review the life they delivered in the last few campaigns, their supply reliability and their willingness to offer plant-specific custom solutions instead of generic grades. Only a partner who supports us throughout the life cycle, which includes selection, installation, monitoring and post-failure analysis, fits our long-term requirement.

Can you share a recent example where better refractory selection improved uptime or clinker quality?
Recently, we upgraded to a high-abrasion basic brick at the kiln outlet. Earlier we had frequent chipping and coating loss. With the new lining, thermal stability improved and the coating became much more stable. As a result, our shutdown interval increased and clinker quality remained more consistent. It had a direct impact on our uptime.

How is increased AFR use affecting refractory behaviour?
Increased AFR use is definitely putting more stress on the refractory. The biggest issue we see daily is the rise in chlorine, alkalis and volatiles, which directly attack the lining, especially in the calciner and kiln inlet. AFR firing is also not as stable as conventional fuel, so we face frequent temperature fluctuations, which cause more thermal shock and small cracks in the lining.
Another real problem is coating instability. Some days the coating builds too fast, other days it suddenly drops, and both conditions impact refractory life. We also notice more dust circulation and buildup inside the calciner whenever the AFR mix changes, which again increases erosion.
Because of these practical issues, we have started relying more on alkali-resistant, low-porosity and better thermal shock–resistant materials to handle the additional stress coming from AFR.

What role does digital monitoring or thermal profiling play in your refractory strategy?
Digital tools like kiln shell scanners, IR imaging and thermal profiling help us detect weakening areas much earlier. This reduces unplanned shutdowns, helps identify hotspots accurately and allows us to replace only the critical sections. Overall, our maintenance has shifted from reactive to predictive, improving lining life significantly.

How do you balance cost, durability and installation speed during refractory shutdowns?
We focus on three points:
• Material quality that suits our thermal profile and chemistry.
• Installation speed, in fast turnarounds, we prefer monolithic.
• Life-cycle cost—the cheapest material is not the most economical. We look at durability, future downtime and total cost of ownership.
This balance ensures reliable performance without unnecessary expenditure.

What refractory or pyro-processing innovations could transform Indian cement operations?
Some promising developments include:
• High-performance, low-porosity and nano-bonded refractories
• Precast modular linings to drastically reduce shutdown time
• AI-driven kiln thermal analytics
• Advanced coating management solutions
• More AFR-compatible refractory mixes

These innovations can significantly improve kiln stability, efficiency and maintenance planning across the industry.

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