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AAC production in cement plant

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Cement companies can manufacture AAC blocks and can compete with stand alone AAC units in the country.
The raw materials required for AAC production are readily available in any cement manufacturing plant. The process does not require installation of a steam boiler or a power plant and can utilise the waste-heat from the clinker cooler exhaust gases for steam curing of aerated concrete. The method also earns carbon credits not only for the green product being made, but also for waste-heat utilisation. Although, there are more than 35 standalone AAC manufacturing units in India, very limited attempts have been made to manufacture AAC by the cement plants. One reason behind this is the lack of awareness about the new technologies that were developed recently in this field. DS Venkatesh elaborates on the technology offered by Cemeng for AAC production in a cement plant.

What is AAC
AAC is lightweight autoclaved aerated concrete, which is completely cured, inert and stable form of calcium silicate hydrate. It is a structural material, approximately one quarter in weight of the conventional concrete. It is composed of minute cells/air pockets, which give the material its lightweight and high thermal insulation characteristics. It is available as blocks and as pre-cast reinforced units for building floors, roofs, walls and lintels.

Raw material
Raw materials for AAC vary with the manufacturer and the location. The kinds of materials that could be used are detailed in the ASTM C1386 specifications. They include some, or all, of the following: fine silica sand; Class F fly ash; hydraulic cements; calcined lime; gypsum; expansive agents such as finely ground aluminium powder or paste; and water.

AAC is produced by mixing quartz sand and/or pulverised fly ash (PFA), lime, cement, gypsum/anhydrite, water and aluminium and is hardened by steam-curing in autoclaves. The silica is obtained from silica sand, fly ash (PFA), crushed silica rock and/or stone. It is possible to obtain silica as a by-product coming from other processes such as foundry sand or burgee from glass grinding; although, it can be used only if the levels of alkali or other impurities are not too high. The calcium is obtained from quick lime, hydrated lime and cement. Gypsum acts as a catalyst and enhances the properties of AAC. Careful regulation of the amount of aluminium powder gives accurate control over the density of the final product.

Cement with the least per cent of clinker would be the cheapest and suitable, e.g., Portland limestone cement. If milling of siliceous material is required, Cemeng suggests grinding of a composite mix of siliceous materials together with cement clinker, lime and gypsum/anhydrous. The ground material can be stored in a single bin. It also eliminates the need for multiple handling of individual constituents and weigh batchers. Cemeng employs a PSRG mill function in open circuit to produce the desired fineness of the composite mix.

Process flow
Cemeng has simplified the process flow to minimise the number of equipment and material handling requirements in mini AAC plants. The process gets rid of ?wet cutting? the green cake as it is possible only if the plant is involved in exclusive production of smaller blocks. Other AAC products with or without reinforcement certainly require ?dry milling? of cured cakes for profiling. Cemeng moulds for AAC are wheel-mounted units with a base plate and sliding sidewalls. There is no need for rotation or dismantling and re-assembling of side plates. Loaded moulds are transferred directly into the autoclaves for steam curing. Cemeng autoclaves generate the required steam in the autoclave itself. Separate boiler is not required. For mini AAC plants, Cemeng suggests after-cutting/milling of cured blocks for economic benefits.

The important unit operations involved in AAC production are gravimetric proportioning and mixing of constituents with water to form the slurry. This is followed with secondary mixing with expansive agents, pouring the slurry into casting moulds and then allowing sufficient time for initial hydration. Once the material is hydrated it gains enough strength to support its own weight and can undergo de-moulding/cutting. The cakes are then transferred into autoclave for high pressure steam curing. Once cooled, the autoclaved blocks are ready for after-cutting/milling as per the required profile. The AAC cost depends mainly on the cost of mineral binders and the expansive agents used. The cost of silica can vary from location to location.

Cement plant and Cemeng mini AAC production line
Cemeng mini AAC production line can be installed in an existing cement plant. Cement plants are already processing and handling both siliceous and mineral binder constituents, except for lime and sand. Also, ground raw meal, preheater ESP dust, pre-calcined meal from bottom most stage of preheater can partially or wholly replace lime. Sand may be replaced by ground slag and cinder. Clinker dust from cooler ESP and gypsum can replace cement. Besides, clinker cooler exhaust air may be effectively utilised for production of steam required for autoclaving, thus eliminating the need for a separate boiler set up.

AAC production capacity, on a thumb rule basis, can be considered as twenty cubic meter per day for every 100 tpd production capacity of the clinkerisation unit. This is based on steam production using gases only from the from clinker cooler exhaust.

Manufacturing process
To make AAC, sand is ground to the required fineness in a ball mill and is stored along with other raw materials. The raw materials are then batched by weight and are delivered to the mixer. Measured amounts of water and expansive agent is added to the mixer to prepare a cementitious slurry.

Preparation of slurry
Slurry preparation is a batch process. When AAC is being made from dry constituents, Cemeng employs separate weighbin augur dosers for each constituent the Cemeng weighbin augur doser, which uses a combination of weight and volumetric filling. A vertical auger looks like a corkscrew. The auger rotates in the hopper filled with lose powder. As it turns, it drives the powder through the bottom of the hopper into a narrow tube, where the powder is drawn down by a turning screw. The auger runs through the narrow tube, creating a tight fit. As the screw turns, it pulls the prescribed amount of powder down the tube. The agitator keeps the feed flowing to the centre of the auger. You can control the amount of powder delivered by setting the number of revolution made by the auger.

The augur screw discharges into a tubular disc conveyor for conveying and transferring directly into the AAC mixer. Subsequently, aluminium paste is added, secondary mixing is carried out and the final slurry is discharged into the AAC moulds.

Casting in moulds
Steel moulds are prepared to receive fresh AAC. If reinforced AAC panels are to be produced, steel reinforcing cages are secured within the moulds. After mixing, the slurry is poured into the moulds. The expansive agent creates small, finely dispersed voids in the fresh mixture, which increases the volume by about 50 per cent within three hours. The moulding of AAC in the mould box, holding for initial strength and de-moulding prior to autoclaving is an important step in reducing the material handling. Conventionally, the base of the moulds-box and three sides are welded together with only one side plate of mountable type. This calls for mould rotation to load the green mould on to the mountable side plate.

Cemeng moulds for AAC are trolley-mounted units with a base plate and sliding sidewalls. During casting, the sidewalls are slided inwards to form a box holding the slurry. The sidewalls keep space all around the green cake for the passage of steam. No rotation or dismantling of the side plates and reassembling are required. After curing in autoclaves, the cake is picked up by a grab and is transferred to the trolley.

Cemeng also offers ?FlexiMold? wherein rectangular shaped pre-stitched permeable cloth bags with open top are held at the base of the trolley. The flexibag is filled half with slurry and the top half is left empty to allow for expansion. As the green cake attains strength, it attains the shape of the flexibag. The telescopic brackets are then lowered. The bracket is held in its lowest position when the trolley is moved into the autoclave. The green cake along with FlexiMold is left undisturbed. After curing, the trolley is moved out and the cured cake in the moulding bag is lifted and transferred to storage. FlexiMold serves as a protective cover for cured block and it is also disposable. The size of the green cake can be set as required and several green cakes can be mounted on a single trolley.

Autoclaving
Autoclaving is steam curing at high temperature and pressure. It is required to achieve the desired structural properties and dimensional stability. The chemical reactions that produce the final calcium silicate hydrate structure happen in the autoclave. The process takes about eight to 12 hours under pressure of about 174 psi (12 bar) and a temperature of about 360?F (180?C), depending on the grade of material produced. Preferably, two autoclaves are used with the casting and precuring section in between. The mixing station is located near the discharge end of the autoclave. The thermic fluid reservoir is located at the feed end of the autoclave. This permits the precuring shed to store the cast moulds for the required duration. The waste heat from grate cooler exhaust is utilised for the heating the thermic fluid in a simple heat exchanger. It is estimated that at least 350-400 kg/hr of steam could be generated per 100 tpd production capacity of clinkerisation unit. To initiate the curing cycle, the thermic fluid, heated to 205?C, is passed through the coils in the reservoir at the bottom of each autoclave to generate steam. The hot steam pressure rises up to 1.75Mpa.

After-cutting/milling of cured AAC Blocks
Steam cured AAC blocks can be transported directly to the marketing yards. After-cutting can be carried out by the stockists or at the construction site itself. Existing granite/stone cutting and polishing units at different cities in the marketing zone can be used to saw the AAC blocks to the required size/dimensions. It is always possible to saw cut the large size AAC blocks to the required size at the construction site. Any broken pieces could be used as lightweight filler, thus nothing is wasted.

Conclusion
Every cement plant has to take green initiatives to safeguard sustainability. Using waste-heat for steam generation is highly cost effective and adds to the profits of AAC production. Besides, the plant will also be a captive consumer of cement. Every cement plant can produce AAC at considerably lower cost and can compete with standalone AAC units. AAC products can save time, labour, cement and sand during construction.

References
Eco-Care Building products: www.primeaac.com
Raw material formulae: Dearye Brick machine
Silica, calcium joined in premium products, by Sandy Herod Pit and Quarry Dec 1987 Pg.72 – 74
Brick manufacture in a Cement Plant by DS Venkatesh, Cemtec Engineering, Secunderabad. Indian Cement Review May 1989, Pages ICR-19 to ICR-25 Green Concrete by Yuvraj Patil, Flycrete. Indian Cement Review, May 2014 ?Let us employ PSRG Milling Technology? by DS Venkatesh, Indian Cement Industry Desk Book, March 2014. www.victoryenergy.com

DS Venkatesh,
Freelance Industrial Consultant
Email: dsvenkatesh40@gmail.com
Former CEO and Director of Cemtec Engineering at Secunderabad, DS Venkatesh is currently working as a freelance industrial consultant. He started as a Design Engineer at ACC and later had a long stint at Holtec-India holding several responsible positions. He has been one of the lead consultants to many rotary based mini cement plants and expansions.

DS Venkatesh has provided technical know-how, design and manufacturing drawings for cement production machinery to many Indian machinery manufacturers. Re-engineering and retrofitting of plant/machinery for enhanced productivity is his forte. His work has helped in enhancement of PSRG milling technology applied in media grinding.

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Economy & Market

SEW-EURODRIVE India Opens Drive Technology Centre in Chennai

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The new facility strengthens SEW-EURODRIVE India’s manufacturing, assembly and service capabilities

SEW-EURODRIVE India has inaugurated a new Drive Technology Centre (DTC) in Chennai, marking a significant expansion of its manufacturing and service infrastructure in South India. The facility is positioned to enhance the company’s responsiveness and long-term support capabilities for customers across southern and eastern regions of the country.

Built across 12.27 acres, the facility includes a 21,350-square-metre assembly and service setup designed to support future industrial growth, evolving application requirements and capacity expansion. The centre reflects the company’s long-term strategy in India, combining global engineering practices with local manufacturing and service capabilities.

The new facility has been developed in line with green building standards and incorporates sustainable features such as natural daylight utilisation, solar power generation and rainwater harvesting systems. The company has also implemented energy-efficient construction and advanced climate control systems that help reduce shopfloor temperatures by up to 3°C, improving production stability, product quality and working conditions.

A key highlight of the centre is the 15,000-square-metre assembly shop, which features digitisation-ready assembly cells based on a single-piece flow manufacturing concept. The facility also houses SEW-EURODRIVE India’s first semi-automated painting booth, aimed at ensuring uniform surface finish and improving production throughput.

With the commissioning of the Chennai Drive Technology Centre, SEW-EURODRIVE India continues to strengthen its manufacturing footprint and reinforces its long-term commitment to supporting industrial growth and automation development in India.

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Concrete

Material Flow Efficiency

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We explore how material handling systems are becoming strategic assets in cement plants, enabling efficient movement of raw materials, clinker and finished cement. Advanced conveying, automation and digital technologies are improving plant productivity while supporting energy efficiency and sustainability goals.

Material handling systems form the operational backbone of cement plants, enabling the efficient movement of raw materials, clinker and finished cement across complex production networks. With India’s cement industry producing over 391 million tonnes of cement in FY2024 and possessing an installed capacity of around 668 mtpa, according to the CRISIL Research Industry Report, 2025, efficient material logistics have become critical to maintaining plant productivity and cost competitiveness. At the same time, cement production is highly energy intensive and contributes around 7 per cent to
8 per cent of global CO2 emissions, making efficient material flow and logistics optimisation essential for reducing operational inefficiencies and emissions states the International Energy Agency Cement Technology Roadmap, 2023. As plants scale capacity and integrate digital technologies, modern material handling systems, ranging from automated conveyors to intelligent stockyards, are increasingly recognised as strategic assets that influence plant stability, energy efficiency and environmental performance.

Strategic role of material handling
Material handling is no longer viewed as a secondary utility within cement plants; it is now recognised as a strategic system that directly influences production efficiency and process stability.
Cement manufacturing involves the continuous movement of large volumes of limestone, clay, additives, clinker and finished cement across multiple production stages. Even minor disruptions in conveying systems or storage infrastructure can lead to kiln feed fluctuations, production delays and significant financial losses. According to Indian Cement Industry Operational Benchmarking Study, 2024, unplanned downtime in large integrated cement plants can cost between Rs.15–20 lakh per hour, highlighting the economic importance of reliable material handling systems.
Modern cement plants are therefore investing in advanced mechanical handling systems designed for high throughput and operational reliability. Large integrated plants can process over 10,000 tonnes per day of clinker, requiring highly efficient conveying systems and automated stockyards to maintain continuous material flow, suggests the International Cement Review Industry Analysis, 2024. Efficient material handling also reduces spillage, minimises dust emissions and improves workplace safety. As cement plants become larger and more technologically advanced, the role of material handling is evolving from simple transport infrastructure to a critical operational system that supports both productivity and sustainability.

From quarry to plant
The transport of raw materials from quarry to processing plant represents one of the most energy-intensive stages of cement production. Traditionally, limestone and other raw materials were transported using diesel-powered trucks, which resulted in high fuel consumption, dust generation and increased operational costs. However, modern plants are increasingly adopting long-distance belt conveyors and pipe conveyors as a more efficient alternative. These systems allow continuous material transport over distances of 10–15 kilometres, significantly reducing fuel consumption and operating costs while improving environmental performance, states the FLSmidth Cement Industry Technology Report, 2024.
Milind Khangan, Marketing Manager, Vertex Market Research & Consulting, says, “Efficient and enclosed handling of fine materials such as cement, fly ash and slag requires modern pneumatic conveying systems. By optimising the air-to-material ratio, these systems can reduce energy consumption by 10 per cent to 15 per cent while ensuring smooth material flow. Closed-loop conveying further minimises dust loading and improves the performance of bag filters, supporting cleaner plant operations. In addition, flow-regulated conveying lines help prevent clogging and maintain reliable dispatch performance. Overall, automation in pneumatic conveying delivers immediate operational benefits, including improved equipment uptime, lower energy use, reduced material spillage and more stable kiln and mill performance.”
Pipe conveyor systems are particularly gaining traction because they provide a completely enclosed transport system that prevents material spillage and dust emissions. According to global cement engineering studies, conveyor-based transport can reduce energy consumption by up to 30 per cent compared to truck haulage, while also improving operational reliability. Several cement plants in India have already implemented such systems to stabilise quarry-to-plant logistics while reducing carbon emissions associated with diesel transport.

Stockyard management and homogenisation
Stockyards play a critical role in maintaining raw material consistency and stabilising kiln feed quality. Modern cement plants use advanced stacker and reclaimer systems to ensure efficient storage and blending of raw materials before they enter the grinding and pyroprocessing stages. Automated stacking methods such as chevron or windrow stacking enable uniform distribution of materials, while bridge-type or portal reclaimers ensure consistent extraction during kiln feed preparation. These systems are essential for maintaining stable chemical composition of raw meal, which directly influences kiln efficiency and clinker quality. The Cement Plant Operations Handbook, 2024 indicates that advanced homogenisation systems can reduce raw mix variability by up to 50 per cent, significantly improving kiln stability and energy efficiency. Integrated stockyard management systems also incorporate sensors for monitoring bulk density, moisture levels and stockpile volumes, enabling real-time control over material blending processes.

Clinker and cement conveying technologies
Once clinker is produced in the kiln, it must be efficiently transported to storage silos and subsequently to grinding and packing units. Modern cement plants rely on high-capacity belt conveyors, bucket elevators and pneumatic conveying systems to manage this stage of material flow. Steel-cord belt bucket elevators are now capable of lifting materials to heights exceeding 120 metres with capacities reaching 1,500 tonnes per hour, making them suitable for large-scale clinker production lines, states the European Cement Engineering Association Technical Paper, 2023.
For fine materials such as cement, fly ash and slag, pneumatic conveying systems provide a reliable and dust-free solution. These systems transport powdered materials using controlled airflow, ensuring enclosed and contamination-free movement between grinding units, silos and packing stations. Optimised pneumatic systems can reduce energy consumption by 10 per cent to 15 per cent compared to older conveying technologies, while also improving plant cleanliness and environmental compliance, according to the Global Cement Technology Review, 2024.

Automation and digitalisation
Digitalisation is transforming material handling systems by introducing real-time monitoring, predictive maintenance and automated control. Advanced sensors and Industrial Internet of Things (IIoT) platforms enable plant operators to track conveyor health, stockpile levels and equipment performance in real time. Predictive maintenance systems analyse vibration patterns, temperature fluctuations and equipment load data to detect potential failures before they occur. According to McKinsey’s Industry 4.0 Manufacturing Report, 2023, for heavy industries, digital monitoring and predictive maintenance technologies can reduce equipment downtime by up to 30 per cent and increase productivity by 10 per cent to 15 per cent. Digital control centres also integrate data from conveyors, stacker reclaimers and dispatch systems, enabling centralised management of material flows from quarry to dispatch.

Handling of AFR
The growing adoption of Alternative Fuels and Raw Materials (AFR) has introduced new challenges and opportunities for material handling systems in cement plants. AFR materials such as refuse-derived fuel (RDF), biomass and industrial waste often have irregular particle sizes, variable moisture content and lower bulk density compared to conventional fuels. As a result, specialised storage, dosing and feeding systems are required to ensure consistent kiln combustion. According to the Cement Sector Decarbonisation Roadmap published by NITI Aayog in 2026, increasing the use of AFR could enable India’s cement sector to achieve thermal substitution rates of around 20 per cent in the coming decades. To support this transition, plants are investing in automated receiving stations, shredding units, drying systems and precision dosing equipment to stabilise AFR supply and combustion performance.

Energy efficiency and dust control
Material handling systems also play a crucial role in improving plant energy efficiency and environmental performance. Modern conveyor systems equipped with variable speed drives and energy-efficient motors can significantly reduce electricity consumption. Permanent magnet motors used in conveyor drives can deliver 8 per cent to 12 per cent energy savings compared to conventional induction motors, improving overall plant energy efficiency according to the IEA Industrial Energy Efficiency Study, 2023. Dust control is another major concern in cement plants, particularly during material transfer and storage operations. Enclosed conveyors, dust extraction systems and advanced bag filters are widely used to minimise particulate emissions and improve workplace safety.

Future trends in material handling
The future of material handling in cement plants will be shaped by automation, digitalisation and sustainability considerations. Emerging technologies such as AI-driven logistics optimisation, autonomous mobile equipment and digital twins are expected to further improve plant efficiency and operational visibility. Digital twin models allow engineers to simulate material flow patterns, optimise stockyard operations and predict equipment performance under different operating conditions. According to the International Energy Agency Digitalisation and Energy Report, 2024, the adoption of advanced digital technologies could improve industrial energy efficiency by up to 20 per cent in heavy industries such as cement manufacturing. As cement plants expand capacity and adopt low-carbon technologies, intelligent material handling systems will play a critical role in maintaining productivity and reducing environmental impact.

Conclusion
Material handling systems have evolved from basic transport infrastructure into strategic operational systems that directly influence plant efficiency, reliability and sustainability. From quarry transport and automated stockyards to digital dispatch platforms and advanced conveying technologies, modern material handling solutions enable cement plants to manage large production volumes while maintaining process stability.
As India’s cement industry continues to expand to meet infrastructure and urban development demands, investments in advanced material handling technologies will become increasingly important. By integrating automation, digital monitoring and energy-efficient systems, cement manufacturers can improve operational performance while supporting the industry’s long-term sustainability and decarbonisation goals.

  • Kanika Mathur

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Concrete

Modernise to Optimise

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Cement plant modernisation is reshaping the industry through upgrades in
kilns, energy systems, digitalisation, AFR integration and advanced material
handling. We explore these technologies that improve efficiency, reduce
emissions, strengthen competitiveness, while preparing the industry for India’s
next phase of infrastructure growth.

India’s cement industry, the world’s second-largest, is undergoing a rapid transformation driven by infrastructure demand, decarbonisation targets and technological advancement. The sector’s installed capacity stood at approximately 668 million tonnes per annum (mtpa) in FY2025 and is projected to reach 915–925 mtap by 2030, supported by large-scale capacity expansions and infrastructure investment cycles, suggests CRISIL Intelligence Industry Report, 2025. At the same time, cement production remains highly energy intensive and contributes about 6 per cent to 7 per cent of India’s total greenhouse gas emissions, making efficiency improvements and modernisation critical for long-term sustainability as stated in CareEdge ESG Research, 2025. As a result, cement manufacturers are investing in advanced kiln technologies, digital monitoring systems, waste heat recovery, alternative fuels, and modern material handling infrastructure to enhance productivity while aligning with global decarbonisation pathways.

Need for modernisation
The need for plant modernisation is closely linked to the sector’s rapid capacity expansion and rising operational complexity. India’s installed cement capacity has grown significantly in the last decade and is expected to exceed 900 mtpa by 2030, driven by demand from housing, infrastructure and urban development projects, as per the CRISIL Intelligence Industry Report, 2025. However, increasing scale also places pressure on energy efficiency, logistics, and production stability. The report also suggests that the cement plants must upgrade equipment and processes to operate at higher utilisation rates, which are projected to reach 75 per cent to 77 per cent by the end of the decade, compared to around 72 per cent to 74 per cent in FY2026.
Environmental imperatives are another major driver of modernisation. Cement manufacturing is responsible for a significant share of industrial emissions because clinker production requires high-temperature processes that depend heavily on fossil fuels. According to CareEdge ESG research, the cement sector contributes 6–7 per cent of India’s total greenhouse gas emissions, with approximately 97 per cent of emissions arising from direct fuel combustion and process emissions in kilns. Consequently, plant modernisation initiatives now focus not only on productivity improvements but also on reducing emissions intensity, energy consumption, and reliance on conventional fuels.
“One of the most impactful upgrades implemented at Shree Cement in the last five years has been the adoption of advanced data management platforms that provide real-time visibility across major process areas. This digital advancement has strengthened plant automation by enabling faster and more accurate responses to process variations while improving the reliability of control loops. Real-time dashboards, integrated analytics and automated alerts now support quicker, data-driven decision-making, helping optimise kiln and mill performance, improve energy control and detect deviations early. By consolidating data from multiple systems into a unified digital environment, the company has enhanced operational consistency, reduced downtime and improved both productivity and compliance. This shift towards intelligent automation and real-time data management has become a key driver of operational excellence and future-ready plant management,” says Satish Maheshwari, Chief Manufacturing Officer, Shree Cement.

Kiln and pyroprocessing upgradation
The kiln remains the technological heart of cement manufacturing, and modernisation efforts often begin with upgrades to pyroprocessing systems. Many older plants in India operate with four- or five-stage preheaters, while modern plants increasingly adopt six-stage preheater and pre-calciner systems that significantly improve heat efficiency and clinker output. These systems enhance heat transfer, reduce fuel consumption, and stabilise kiln operations under high throughput conditions.
Professor Procyon Mukherjee suggests, “Cement manufacturing is, at its core, a thermal process. The rotary kiln and calciner together account for energy consumption and emissions. The theoretical thermal requirement for clinker production is around 1700–1800 MJ per tonne, yet real-world plants often operate far above this benchmark due to inefficiencies in combustion, heat recovery and material flow. Modernisation, therefore, must begin with the
kiln system, and not peripheral automation or
isolated upgrades. The shift from wet to dry process kilns, combined with multi-stage preheaters and precalciners, has already delivered step-change improvements, making dry kilns nearly 50 per cent more energy efficient.”
Recent investment programmes across the industry have included kiln cooler upgrades, advanced burners, and improved refractory materials designed to increase operational reliability and reduce specific heat consumption. Such upgrades are essential because cement production remains highly energy intensive, and continuous efficiency improvements are required to meet global decarbonisation targets. According to the International Energy Agency (IEA) Cement Tracking Report, 2023, the cement sector must achieve annual emissions intensity reductions of around 4 per cent through 2030 to align with global net-zero scenarios.

Energy efficiency and WHRS
Energy efficiency remains one of the most important areas of modernisation in cement manufacturing, given the sector’s heavy reliance on thermal and electrical energy. Modern plants deploy advanced process controls, efficient grinding systems, and improved combustion technologies to reduce specific energy consumption. The adoption of energy-efficient technologies is particularly important in India, where energy costs account for a large share of production expenses. As demand grows and plants expand capacity, improving energy performance becomes essential to maintain competitiveness.
Waste Heat Recovery Systems (WHRS) have emerged as a key solution for improving plant energy efficiency. During cement production, large volumes of high-temperature gases are released from kilns and coolers. WHRS technology captures this waste heat and converts it into electricity, thereby reducing reliance on external power sources. According to energy benchmarking studies for the Indian cement industry, installed waste heat recovery capacity in the sector has reached approximately 840 MW, with an additional potential of around 500 MW states the Green Business Centre, Energy Benchmarking Report, 2023. Several leading producers have already implemented large WHRS installations; for example, UltraTech Cement has deployed systems with around 121 MW of waste heat recovery capacity, reducing carbon emissions by nearly 0.5 million tonnes annually according to the Energy Alternatives India Case Study, 2024.

Integration of AFR
The integration of Alternative Fuels and Raw Materials (AFR) is another critical dimension of cement plant modernisation. AFR refers to the use of industrial waste, biomass, refuse-derived fuel (RDF), and other non-fossil materials as substitutes for conventional fuels such as coal and petcoke. Increasing the use of AFR helps reduce fossil fuel consumption while simultaneously addressing waste management challenges. According to the NITI Aayog Decarbonisation Roadmap, 2026, scaling the use of RDF and other alternative fuels could enable the sector to achieve thermal substitution rates of around 20 per cent in the coming decades.
However, integrating AFR requires significant plant modifications and operational adjustments. Waste-derived fuels often have inconsistent calorific values, higher moisture content, and heterogeneous physical properties compared to traditional fuels. As a result, modern plants invest in advanced fuel preparation systems, dedicated feeding equipment, and automated dosing technologies to ensure stable kiln operation. These upgrades allow plants to maintain consistent clinker quality while increasing the share of alternative fuels in their energy mix.

Digitalisation and smart plant operations
Digitalisation is rapidly transforming cement plant operations by enabling data-driven decision-making and predictive maintenance. Industry 4.0 technologies such as IoT sensors, artificial intelligence (AI), and advanced analytics are now used to monitor equipment performance, optimise process parameters, and anticipate maintenance requirements. These digital tools enable plant operators to detect early signs of equipment failure, minimise unplanned downtime, and improve operational efficiency. Predictive maintenance systems, for example, analyse vibration, temperature, and acoustic signals from rotating equipment to identify potential faults
before they escalate into major breakdowns. Digital twins and integrated control systems further allow operators to simulate plant performance under different scenarios and optimise production strategies. Such technologies are becoming increasingly important as cement plants operate at larger scales and higher levels of process complexity.
Maheshwari also adds, “Plant modernisation is also increasingly central to the global competitiveness of Indian cement manufacturers. As cost pressures rise across energy, logistics and regulatory compliance, modern plants offer the structural efficiency required to operate reliably and competitively over the long term. Technologies such as AI-driven Advanced Process Control (APC) integrated with real-time data systems are emerging as essential investments for the future. These platforms use predictive algorithms, machine learning and live process inputs to optimise kiln, mill and utility operations with greater precision than traditional control systems. By continuously analysing variations in feed chemistry, temperature profiles, energy demand and equipment behaviour, APC enables stable operations, lower specific energy consumption, reduced emissions and improved product consistency. As regulatory expectations tighten and plants pursue higher efficiency with lower carbon intensity, AI-enabled APC will play a crucial role in strengthening automation, enhancing decision-making and ensuring long-term operational resilience.”

Modern material handling and logistics
Material handling systems play a critical role in ensuring smooth plant operations and efficient logistics. Modern cement plants rely on advanced conveying systems, automated stockyards, and digital dispatch platforms to manage the movement of raw materials, clinker, and finished cement. Long-distance belt conveyors and pipe conveyors are increasingly replacing truck-based transport between quarries and plants, reducing fuel consumption, dust emissions, and operational costs. Automated stacker-reclaimers ensure consistent blending of raw materials,
which improves kiln stability and clinker quality. Meanwhile, advanced packing and dispatch systems equipped with high-speed rotary packers and robotic palletisers enhance throughput and reduce manual labour. These technologies allow cement plants to optimise logistics efficiency while supporting higher production capacities.

Emission control and environmental compliance
Environmental compliance has become a central focus of cement plant modernisation as regulators and investors place greater emphasis on sustainability performance. Modern plants deploy advanced emission control technologies such as high-efficiency bag filters, electrostatic precipitators, and selective non-catalytic reduction systems to reduce particulate matter and nitrogen oxide emissions.
Sine Bogh Skaarup, Vice President, Head of Green Innovation and R&D, Fuller Technologies says, “One of our key focus areas is decarbonisation. We help cement producers reduce CO2 and overall carbon emissions. We offer alternative fuel solutions and calcined clay technologies to enable the production of LC3 cement, which play a significant role in decarbonising the cement industry. By combining alternative fuels and calcined clay solutions, CO2 emissions can be reduced by up to 50 per cent, making this a highly impactful approach for sustainable cement production.”
Continuous emission monitoring systems are increasingly used to track environmental performance in real time and ensure compliance with regulatory standards. In addition to air pollution control, cement companies are also investing in water recycling systems, renewable energy integration, and carbon reduction initiatives. These measures are essential for aligning the sector with national climate goals and improving the environmental footprint of
cement manufacturing.

Economic benefits and future outlook
Beyond environmental and operational advantages, cement plant modernisation also delivers significant economic benefits. Energy efficiency improvements, digital process optimisation, and advanced material handling systems reduce operating costs and improve asset utilisation. Waste heat recovery and alternative fuels help lower fuel expenditure and reduce exposure to volatile fossil fuel markets. As the industry expands capacity to meet growing demand, modernised plants are better positioned to achieve higher productivity and maintain profitability. The long-term outlook for the sector remains positive, with India expected to continue large-scale infrastructure investments in roads, housing, railways, and urban development.
Milan R Trivedi, Vice President – Projects, Prod & QC, MR, Shree Digvijay Cement, says, “The main focus in case of modernisation projects drives through the investment decision, which is mainly based on IRR and impact on overall efficiency improvement, cost optimisation and improvement in reliability. However, there are certain modernisation, which has high impact on environmental impact, statutory requirements, etc. has higher priority irrespective of ROI or payback period.”
“The energy efficiency and reliability investment projects generally provide fast return on investment whereas strategic, digitalisation and environmental investment projects provide long term and compounded benefits. Typical modernisation investment projects are decided with IRR of about > 20 per cent, payback period of typically 2-3 years for fast-track projects,” he adds.
In this context, modernisation will remain a key strategic priority for cement manufacturers seeking to maintain competitiveness in an increasingly sustainability-focused market.

Conclusion
The modernisation of cement plants is no longer a purely technical upgrade but a strategic transformation that reshapes how the industry operates. As India’s cement sector expands capacity toward the next growth cycle, improvements in energy efficiency, digitalisation, alternative fuels and advanced logistics will determine the competitiveness of individual plants. Modern technologies allow producers to operate at higher productivity levels while simultaneously reducing energy consumption and emissions intensity.
Looking ahead, the pace of technological adoption will play a decisive role in shaping the future of
the cement industry. Companies that successfully integrate modern equipment, digital systems, and sustainable production practices will be better positioned to meet rising infrastructure demand while aligning with global climate commitments. In this evolving landscape, plant modernisation stands as the cornerstone of both operational excellence and environmental responsibility.

  • Kanika Mathur

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