Connect with us

Economy & Market

Prioritise durability—use premium basic bricks

Published

on

Shares

Sunil Kumar Gupta, Chief Project Officer, Star Cement, discusses how evolving refractory technologies and smarter pyro-processing strategies are redefining performance, durability and cost efficiency.

In recent years, increase in use of alternative fuels, volatile operating conditions and tighter thermal-efficiency targets have reshaped how kilns and preheater lines are designed, lined and monitored. In this interview, Sunil Kumar Gupta shares with how these innovations are strengthening uptime, clinker quality and the future-readiness of India’s pyro-processing systems.

How have refractory demands changed in your kiln and pyro-processing line over the last five years?
Over the past five years, the operational demands on kiln and pyro-processing refractories have intensified, driven by higher kiln throughput and more impact on volume requirements, more stringent thermal-efficiency targets, and the accelerated adoption of alternative fuels (AFR) and mine life- day by day it’s a big challenge.
These factors have necessitated a shift away from conventional alumina-based brick systems toward engineered basic refractories, spinel-forming linings, and high-performance monolithic materials capable of withstanding greater thermal fluctuation, mechanical stress, and chemical attack.

What is the biggest refractory-related challenges you face in preheater, calciner and cooler zones?
Every zone has its own challenges:
A. Preheater
B. Calciner
C. Cooler

A. Preheater

  • Fluctuating feed chemistry increases coating instability and causes lining erosion.
  • High-speed gas streams and dust-laden environments accelerate abrasion, especially around bends and risers.

B. Calciner

  • AFR combustion introduces reducing conditions and alkali–sulphur interactions, which attack conventional refractories.
  • Localised hotspots form due to fuel injection patterns, leading to thermal shock and micro-cracking.

C. Cooler

  • Clinker breakage patterns cause heavy mechanical wear near the bull nose and in the tertiary
    air duct.
  • Modern coolers operate with rapid thermal cycles, which stresses monolithics and metallic anchors.
    The overarching challenge is selecting materials that balance chemical resistance, thermal shock capability, and mechanical strength under constantly changing process conditions.
    With the kiln, we are facing the problem of frequent breakdowns of the kiln bricks, specifically in the burning zone. So far, we were using high alumina but now we are planning to go with basic bricks to have more reliability and the longer operation duration of the kiln.

How do you evaluate and select refractory partners for long-term performance and life-cycle cost?
We evaluate the refractive suppliers based on the following four aspects:
A. Technical Capability
B. Engineering and Design Support
C. Life-Cycle Economics
D. Partner Support and Collaboration
Selecting a refractory partner is not simply a materials purchase, it’s a strategic procurement decision that directly affects plant uptime, process stability, and long-term operating cost. An effective evaluation approach should consider below pillars:

A. Technical Capability
The refractory supplier must demonstrate strong materials performance backed by reliable laboratory testing and consistent production quality. Key technical criteria include:

  • Cold Crushing Strength (CCS), abrasion and erosion resistance-Indicates mechanical durability against clinker dust, gas flow, and material movement.
  • Chemical resistance and corrosion testing-Confirms the refractory’s ability to withstand alkali attack, clinker phases, alkali sulphates/chlorides, and reducing/oxidizing atmospheres.
  • Thermal shock resistance and spalling index-Evaluates resistance to rapid temperature changes and cycling—critical in cement kilns, coolers, risers, and cyclones.
  • Density and porosity consistency across batches-Ensures uniform behavior in service and
    reduces the risk of localized weaknesses or premature failures.
  • PCE (Pyrometric Cone Equivalent) testing-Measures refractoriness—the temperature at which the refractory begins to soften under its own weight—ensuring suitability for high-temperature zones.

B. Engineering and Design Support
A strong partner provides engineering expertise that prevents failures before they occur.
This includes:

  • Proper lining design and zoning
  • Thermal calculations, heat loss modeling, and expansion joint design
  • Wear-profile analysis and historical performance audits and installation specifications

Engineering support directly influences service life, coating stability, and thermal efficiency.

C. Life-Cycle Economics
Assess the total cost of ownership rather than just initial material costs. This includes installation expenses, refractory maintenance frequency, downtime costs during replacement or repair, and energy efficiency improvements. Refractory partners who provide detailed life cycle cost analysis and emphasise value over initial price help optimise long-term operational costs. Transparent communication about the refractory’s expected service life and maintenance needs is crucial for selecting partners focused on minimizing life-cycle cost.

D. Partner Support and Collaboration
Select refractory partners who offer technical support, expert consultation, and a collaborative approach to tailor solutions. Partners committed to understanding your specific operational conditions, providing training, and proactively addressing performance issues tend to enhance overall refractory service life and reliability.

Can you share a recent instance where improved refractory selection enhanced uptime or clinker quality?
We recently deployed magnesium–iron spindle bricks, which perform exceptionally well across burning, pre-burning and post-burning zones. Their coating-friendly behaviour in the burning zone improves brick life, while their high density in other zones allows stable operation with minimal coating.
By combining coating bricks in the burning zone with non-coating bricks elsewhere, we avoided issues like excessive coating near the tyre area, which can push the kiln into reduction conditions and affect clinker quality. Modern burners with short, hot flames and lower primary air have also helped stabilise coating and heat distribution.
Overall, optimised brick selection paired with the right burner design has improved uptime, reduced wear and delivered more consistent clinker quality.

Use of advanced spinel bricks in kiln linings:

  • One 2025 case study described how a cement plant replaced its conventional magnesia-chrome refractory lining in a large dry-process rotary kiln with Magnesium Iron Spinel Brick (and in some cases synthetic magnesium-iron-aluminum spinel) for the kiln’s hot zones.
  • After the switch, the plant saw its kiln-lining life extended by over 20 to 30% compared to previous linings — raising lining life from the typical ~8 to 9 months to ~12 to 15+ months without relining.
  • This led to a significant reduction in unplanned shutdowns (fewer relining, fewer maintenance events), improving overall operational uptime.
  • Because the refractory was more chemically and thermally stable under high temperature and corrosive conditions, the kiln could maintain a more stable thermal profile, which supports consistent clinker formation and improved clinker quality (more uniform mineralogy, less variation due to thermal or chemical stress).

How is the increased use of alternative fuels impacting refractory behaviour in your pyro-line?
Usage of alternative fuels has adverse effect on refractory behaviour in the pyro-line:

A. Higher chemical attack
Alternative fuels (RDF/SRF, biomass, sludge, waste oils) introduce more alkalis, chlorides, and sulphur, cause corrosion of basic bricks, softening of castable, and loss of lining in kiln inlet, riser, and calciner and leads to unstable coating and accelerated wear.

B. More aggressive ash chemistry
AF ash often contains reactive SiO2, Fe2O3, CaO, metals, increases abrasion in kiln inlet and preheater and Generates slag and fluxing reactions that weaken MgO-based bricks.

C. Higher thermal instability
AFs vary in moisture and calorific value, as a result it results in less predictable combustion, produces temperature swings, spalling, microcracks and falling rings and creates hot spots due to irregular flame shape.

D. Changed coating behaviour
AF-related chemistry modifies coating growth and stability. More volatile coating exposes burning zone bricks and overcoating or build-ups in inlet and riser resulting in mechanical damage and choking.

What are plants doing to counter it:

  • Switching to MgO–spinel bricks and alkali-/chloride-resistant castables.
  • Adding SiC or abrasion-resistant linings in high-velocity or high-ash zones.
  • Improving burner control, AF dosing, and raw mix balancing.
  • Using sacrificial layers, redesigned anchors, and better insulation to protect main linings.What role does digital monitoring or thermal profiling play in your refractory maintenance strategy?
    Thermal profiling and digital monitoring have become essential predictive-maintenance tools for managing kiln and preheater performance. Online shell scanners now provide continuous thermography from inlet to outlet, helping teams assess coating behaviour and refractory health. Drone-based thermography is gaining popularity because it captures hotspots in areas manual checks cannot reach, especially inside cyclones and the calciner during shutdowns. Alongside kiln and cooler cameras, emerging instruments such as cooler-bed thickness sensors further optimise operation. Together, these technologies deliver better KPIs, more stable coating and improved refractory life.

    A. Kiln Shell Temperature Monitoring (IR scanners and cameras)
    Continuous kiln shell scanning identifies:

  • Hot spots signaling refractory thinning or brick loss
  • Misalignment, ovality, and ring formation through temperature pattern changes
  • Overloaded or under-performing burners by observing flame/heat profile
  • This allows maintenance teams to plan brick patching or section repairs before a shell deformation or blowout occurs.

B. Cooler Monitoring (grate cooler and tertiary air duct)
Thermal sensors and camera systems help:

  • Spot grate cooler hot spots that indicate coating issues or refractory wear
  • Track TA duct temperatures to avoid thermal shock or lining scouring
  • Maintain proper heat recovery efficiency, which directly impacts refractory life
  • Digital data ensures that refractory life is maximised by maintaining stable thermal conditions.

How do you balance cost, durability and installation speed when planning refractory shutdowns?
Balancing cost, durability and installation speed in cement plant refractory shutdowns is challenging because each section of the process line has different wear mechanisms, temperature profiles and maintenance needs. The strategy below is designed specifically for cement kilns, preheaters, calciners, coolers, riser ducts and cyclones:

A. Kiln burning zone: Prioritise durability—use premium basic bricks. They are more expensive and slower to install, but failures here are extremely costly.
B. Transition zone, calciner and riser ducts: Prioritise speed and cost—use gunning castable and lower-grade bricks. These provide fast installation, are economical, and offer adequate durability for these areas.
C. Cyclones and high-wear areas: Use low-cement castable combined with precast blocks to achieve a balance of durability and installation efficiency.
D. Cooler: Use precast shapes in the hot zones and abrasion-resistant castable elsewhere. The bottom (impact) area is especially critical and requires high-wear-resistant castable.
Use precast blocks to save time as and when justified and use conventional castable in areas
where cost and installation time are lower priorities. Always base decisions on life-cycle cost, not just material price.

Which refractory or pyroprocessing innovations will transform Indian cement operations?
The refractory and pyroprocessing landscape for cement plants in India (and globally) is evolving — and several innovations are taking shape that could significantly transform how cement operations are run: improving durability, lowering energy usage, cutting downtime, and boosting sustainability. Here are the key innovations likely to shape the future of cement-plant refractories and pyro-processing — along with what they mean for Indian operations.
A. Advanced refractory materials: Nano-engineered, spinel-rich, alkali-resistant bricks and ULCC/LCC castable for longer life and fewer shutdowns.
B. Precast and fast-install solutions: Precast blocks, engineered shapes, and fast-dry castable to reduce shutdown time and improve reliability.
C. Digitalisation and predictive monitoring: Kiln shell scanners, thermal imaging, IoT sensors, digital twins and AI-based kiln control for early detection and optimised operation.
D. Refractory recycling and low-carbon materials: Circular-economy reuse of spent refractories and development of low-CO2 refractory mixes.
E. Fuel-flexible and sustainable pyro-processing: Refractories and kiln designs adapted for alternative fuels (RDF, biomass), higher AF substitution, and eventually hybrid/electric kiln concepts.

Together, these innovations will help Indian plants achieve higher thermal efficiency, lower CO2 intensity, and more stable running conditions.

Economy & Market

Smart Pumping for Rock Blasting

Published

on

By

Shares

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

Continue Reading

Concrete

Digital process control is transforming grinding

Published

on

By

Shares

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.

Continue Reading

Concrete

Refractory demands in our kiln have changed

Published

on

By

Shares

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.

Continue Reading

Trending News

SUBSCRIBE TO THE NEWSLETTER

 

Don't miss out on valuable insights and opportunities to connect with like minded professionals.

 


    This will close in 0 seconds