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Economy & Market

Advances in Cement Analysis

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Though Blaine analysis is a time tested method of measuring fineness of cement. Today Laser Diffraction technology scores over it mainly due to more accurate and real time measurement. Dr. Michael Caves, India ? Business Development Manager of Malvern AIMIL explains the advantages of laser based particle size analysers.

The final steps in cement manufacturing involve grinding (milling) and blending in order to produce the fine powder that is recognizable as cement. Every step in the manufacture of cement is checked by frequent physical tests, as is finished product, to ensure that it complies with all necessary specifications. Cement is ground to a particular fineness since the influence of particle size on the kinetics of cement hydration and development of strength is well known. A reduction in median particle size generally produces a higher compressive strength. Consequently the fineness of Portland cements has been increased over the years to improve properties such as higher early strengths. Nevertheless, other effects of increased fineness, such as higher water demands and more rapid heat generation in the concrete cannot be ignored. Despite the availability of instrumental methods of measuring particle size distributions, the classical method of air permeametry remains.

Understanding Blaine
Many plants control cement fineness using an air permeability apparatus to measure the Blaine number, a parameter related to the cement particle size. The Blaine surface area measurement has been used since the 1940s to determine cement quality and despite its longevity the limitations of this off-line technique are widely recognized. It is slow and suffers from poor reproducibility, which can lead to significant errors, including unnecessary or inaccurate changes to the classifier speed. Blaine analysis measures the specific surface area of a sample, the surface area per unit mass. Finer particle sizes have higher specific surface area: more area per unit mass, so Blaine is an indirect measure of particle size.

But, Blaine delivers just a single averaged figure. Figure 1 shows analysis of 2 cement samples using a Malvern Mastersizer Laser Diffraction system. Sample 2 contains more fines than sample 1 but also more coarse material. These two differences cancel each other out so average specific surface area remains the same, illustrating why two quite different samples can have the same Blaine. The more important question is ?do we need to know about the difference indicated by the particle size distribution??

Size Distribution Measurements
However two cement samples with identical Blaine figures can show different particle size distributions when measured by laser diffraction. Should we classify these two cements as different or the same?

For answers, we need to look at how the data are used. Cement manufacturers measure Blaine to quantify product quality. The hydration speed of cement particles is a function of particle size and determines the strength of the set cement. Generally, finer particles hydrate more quickly, giving greater strength, and within certain limits finer cement is better cement.

Returning to our samples, these materials will behave differently when used. Very fine cement particles, in the 2 – 3 micron range can cause exothermic cracking. Conversely particles over 50 microns may not hydrate, compromising product strength. Sample 1 contains less of both types of particles and consequently is a superior cement, even though Blaine ranks it the same as sample 2. So, the size distribution data are most certainly relevant.

Switching to laser diffraction
The practicalities of switching to laser diffraction are equally compelling. Laser diffraction, however, is fast and automated. In the lab this means greater productivity and better reproducibility. For processing it means on-line instrumentation and real-time measurement.

Malvern Mastersizer 3000 (Figure 2), which has a measurement range of 0.01 to 3500 microns, is an essential component of a high-quality cement laboratory. Finished products, as well as replacement material such as fly ash and blast furnace slag and fuels, have varying size distributions and so behavioral understanding and prediction requires Mastersizer analysis.

A vital element in successful laser diffraction particle size analysis is ensuring that samples are dispersed properly. In cement manufacture it is the primary particle size of a sample that is most usually the parameter of interest, rather than the size of any agglomerated material present. When using laser diffraction, samples can be dispersed and measured wet in the form of a suspension, or as dry powders. Dry dispersion, using dry compressed air, has a number of advantages, not least its obvious suitability for water sensitive material such as cement. It also avoids the need for solvent based dispersants and is rapid, thus increasing instrument productivity. The dry dispersion accessory, Aero S, available with Mastersizer 3000 has modular dispersion nozzles with different impaction surfaces. Keeping in mind that flow of abrasive material like cement for a prolonged period of time can cause damage to metal surfaces, there are options available for ceramic coated flow paths. It is worth highlighting the value of considering an analyzer that can switch easily between different samples with a minimum of fuss. Being able to change between different types of samples without fear of cross contamination, or to move simply or quickly from dry to wet measurement (or vice versa) as required, can make a real difference to analytical productivity, helping to maximize the return of investment in the system.

Finally, another important reason to switch to laser diffraction is the possibilities the technique offers for on-line analysis. Insitec systems deliver fully automated real-time analysis of cement particle size distribution from 0.1 to 2500 microns and can be configured to suit practically every process.

Conclusion
Whilst traditional Blaine measurements have served the cement industry well since the development of the Blaine method in the 1940s, the efficiency and quality of production of modern cements can be improved greatly by using Laser Diffraction technology. Efficient data acquisition, adaptable methods, and information-rich data explain the increasing use of the Malvern Mastersizer 3000 and Insitec range of systems in cement production around the world.

For more details, pls contact: Malvern Aimil Instruments Pvt. Ltd. Tel : 011-30810244 Fax : 011-26950011, Email : delhi@aimil.com

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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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