Cement companies put up capacities in excess of demand in anticipation of increased consumption of cement on account of expected hike in government spending, which did not materialize. N. A. Viswanathan, Secretary General, Cement Manufacturers’ Association dwells on the issues dogging the cement industry and spells out what needs to be done by the government to tackle these issues.Cement industry, which has a direct co-relation of 1.1 to 1.2 with GDP, plays a pivotal role in the infrastructure development of the country. Buoyed with various infrastructure policies and schemes of the government, particularly after 1982 (partial decontrol) of cement, this industry had added substantial cement capacities year-after-year, much ahead of the actual cement demand taking place. However, the overall slowdown in the economy at 6.5 per cent in FY12, which further contracted to 5.3 per cent in the Apr-Jun quarter of 2012, one of the lowest in nine years, resulting in dampening construction activities, weakening of the rupee value against dollar and higher interest rates of borrowings, to quote a few, have made a severe dent on the growth of the cement industry, from an average growth of around 10 per cent in the last couple of years to a low growth of 5 per cent in FY11 and 6.3 per cent in FY12 respectively. For no fault of theirs, the cement industry has recently been criticised and also harshly penalised for under-utilising the cement capacity, without appreciating the ground realities and the factors which have contributed to reduced capacity utilisation. Today, because of the huge mismatch between demand and supply of cement, the country is having about 93 million tonnes of excess cement capacity created after making colossal investments. To revive the economy from its present slackening mode, it is now imperative for the government to enh-a-nce cement demand by taking some positive and concrete policy measures.The backgroundThough the cement industry has been in existence since 1914, appreciable growth in the cement production has been witnessed only after the introduction of partial decontrol in 1982 culminating in total decontrol in 1989 and delicensing in 1991. With the implementation of liberalisation policies of the government in 1991 followed by government’s thrust on infrastructure development in the country, the pace of the growth of the cement industry has been unprecedented.Exponential GrowthThe burgeoning growth of the industry can be gauged from the fact that for creating the first 100 million tonnes capacity, prior to partial decontrol era, the industry took 83 long years, whereas to reach the second and third 100 million tonnes mark, the period had substantially shrunk to 11 years and less than 4 years, respectively (see chart). Cement capacity which was 64.55 million tonnes in 1990-91 reached 340.44 million tonnes in 2011-12. Similarly, cement production went up from 48.90 million tonnes to 247.32 million tonnes during the same period.World Class IndustryIndia is the second largest cement producing country in the world, next only to China both in quality and technology. It produces about 7 per cent of the global production. In 2010, world production of cement was 3294 million tonnes. It is a matter of concern that even after attaining the second position, our per capita cement consumption is very low at 180 kg., which is much below the global average of 450 kg. (see table).Per capita consumption of cement is accepted as an important index of the country’s economic growth. Hence, there is enough potential to enhance our per capita cement consumption to match with the world average.With the adoption of massive modernisation and assimilation of state-of-the-art technology, Indian cement plants are today most energy-efficient and environment-friendly and are comparable to the best in the world in all respects, whether it is kiln size, technology, energy consumption or environment-friendliness. Industry has progressively reduced its energy consumption from 800-900 kwh/tonne clinker in 80s to 650-750 kwh/tonne clinker now. Similarly, power consumption registered a remarkable improvement from 105-115 kwh/tonne cement to 70-90 kwh/tonne cement during the said period. Presently, about 99 per cent of the total capacity in the industry is based on modern and environment-friendly dry process technology. Cement industry has now been making sincere efforts to utilise waste heat recovery in the plants.Problems plaguing the industryThere are a number of constraints and bottlenecks which are hindering the growth of this core sector industry. A few of the major concerns of the industry are discussed below:Excess cement capacity: Cement industry has been experiencing glut situation as there has been mammoth mismatch between cement demand and its supply. The industry had created the capacity on the back of government’s projection of potential cement demand arising out of the thrust given for infrastructure development in the country and the allocation of funds earmarked for the purpose. However, the cement demand, as projected, has not materialised, despite the capacity having been created well in advance after making huge investments.Acute shortage of coal: Coal is one of the major raw materials needed by the industry both in the manufacturing of cement and also for generating power. In the last couple of years, there has been a steep drop in the supply of linked coal to the cement industry from 70 per cent in FY04 to almost 39 per cent now, mainly due to diversion of coal to the power sector. Cement companies, therefore, have perforce to resort to either open market purchase or imported coal which works out to nearly 2 to 2.5 times higher than the domestic price or use of the alternate fuel like pet coke, lignite, etc. which also adds up significantly to the additional cost of production. What is worse, new capacities are not being given any coal under the Linkage Scheme and therefore there is a real fear that the shortage of the main fuel, with no assurance of its availability in future, may actually hamper the required capacity additions for future build up. With the increasing cost of coal and other input materials such as diesel, etc. the production cost of cement has gone up significantly.Inadequate availability of wagons: Rail is the ideal mode of transportation for cement industry. However, it has always been plagued by the short supply of wagons, particularly during the peak period. In addition to this, infrastructure constraints and also not factoring the points of view of the cement industry, which is one of its largest consumers, in the policies of the railways have been hampering the planned movement of cement to the consumption centres, adversely impacting the production schedule and also increasing the overall transportation cost of cement. Rail share for cement which was 53 per cent a couple of years back has come down to 35 per cent now, which is a matter of great concern both to the cement industry and the railways.Cement highly taxed: Although cement is a high volume low value product, it is one of the highly taxed commodities (60 per cent of the ex-factory price), even more than luxury goods. This is exclusive of the freight transportation, which is about 20 per cent of the operating cost. The levies and taxes on cement in India are far higher compared to those in the countries of Asia-Pacific region or even compared to the developing economies like Pakistan and Sri Lanka. Cement and steel are two major materials needed for construction of any infrastructure. However, it is ironic that the rate of VAT charged on cement and steel differs vastly. While the value-added tax (VAT) on steel is only four per cent, it is 12.5 per cent on cement/clinker which goes up to even 15 per cent in some of the states.Steep fall in cement exports: With the high incidence of government levies, infrastructure constraints at ports and the regulatory policies of the government providing encouragement for import of cement with nil custom duty, the export of cement and clinker from India has been steadily and continuously declining from 9 million tonnes in FY07 to 3.5 million tonnes in FY12, despite the fact that Indian cement industry is presently having the substantial excess capacity of cement and clinker.Use of fly ash unviable: Cement industry’s initiative and investment to the tune of more than Rs 1000 crore for effectively utilizing the industrial waste fly ash, which was otherwise posing a nuisance as a health hazard, has helped the thermal power plants in addressing and tackling the menace of fly ash related health and environmental hazards. However, power plants which had been earlier supplying fly ash to the cement industry free of cost have for the last couple of years, as per the order of the Ministry of Environment and Forests, started charging for fly ash from November 2009. The order has also made it mandatory for the cement plants having captive power plants to supply 20 per cent of the fly ash generated as free of cost to the small scale brick manufacturers, etc. within the vicinity of 100 kms of their plants. Both these have severely impacted the production cost of cement and also seriously threatened the fly ash recycling potential in the country.XII Plan – cement demand projectionsAs per the report submitted to the Planning Commission recently by the Working Group on Cement Industry for XIIth Plan, the country’s cement production and capacity is estimated to surge from 247.32 million tonnes and 340.44 million tonnes respectively in FY12 to 407.4 million tonnes and 479.3 million tonnes respectively by FY17.Future OutlookThe slackening economy will take at least one or two years to bounce back to its earlier level. This would, as a thumb rule, apply to the cement industry also. Since India has been emerging as one of the fastest growing economies in the world, the future outlook for cement looks to be bright, provided government formulates facilitating growth oriented policies so that our per capita cement consumption matches with at least with some of the developing economies.Measures for stimulating cement demandIt is imperative to bring back this core cement industry on higher and faster growth trajectory by revival of cement demand through faster growth of infrastructure sector, including roads, ports, airports, housing, irrigation projects, and so on. This would be possible particularly by bringing out more encouraging schemes for affordable housing with income tax relief and by constructing long-lasting cement concrete roads and adopting cement concrete canal lining to conserve 50 per cent precious water that presently seeps through our unlined canals. Water thus saved can be effectively utilized for our agriculture and other needs. The government’s long cherished ‘dream’ to provide ‘world-class standard roads’ can be fulfilled only if cement concrete roads and white topping (a technology on which a concrete layer is laid on the existing bitumen road) are adopted in the country on a larger scale. It is a well-established fact that cement concrete roads are long-lasting, maintenance-free for 30-40 years and today, in most of the cases, are even economical than bitumen roads in the construction stage itself and are, therefore, much-needed for the exponential growth of our economy. Further, cement roads can simultaneously resolve, without entailing any extra financial cost, a number of national issues and problems the government is grappling to find solutions even after spending thousands of crores of rupees every year. The problems which would be addressed are – (a) conservation of diesel and petrol up to 14 per cent as heavy load carriers consume less fuel on concrete roads than while plying on bitumen roads (b) preservation of precious foreign exchange being spent on the import of bitumen used in the construction of roads (c) utilization of fly ash up to 35 per cent, disposal of which is a nuisance and health hazard (d) conservation of 10 per cent electricity used for the street lights (e) protection of our quarries and mines and above all (f) generation of substantial downstream employment.Coal supply and wagon availability to the cement industry, which have become very acute and uncertain in the recent past, needs to be assured on a consistent and regular basis to the cement industry to facilitate it to meet the projected cement demand of the country.Further, the government needs to initiate certain measures in the form of providing tax incentive to the industry, reduce the overall tax value on the commodity and phase out cross subsidy on electricity, diesel and railway freight in a gradual manner. The government can also consider classifying cement as "Declared Goods" like steel having a uniform VAT rate of 4 per cent throughout the country. The overall taxation value on cement can be brought down to a level of 20-25 per cent of ex-works selling price from the current level.Tax incentive should also be pro-vided by the government for pro-moting blended cement in the larger interest of mineral conservation, waste utilization and bringing down carbon emission.Above all, level playing field needs to be provided to the domestic manufacturers to encourage cement and clinker exports by re-imposing custom duty on cement, which is nil at present. Additionally, Ready Mix Concrete (RMC) needs to be encouraged leading to bulk supply of cement and consequent reduction in pack-aging cost.It is a matter of record that even during the worst phase of economic slow-down, the Indian cement industry has surprised the economy watchers by its pace of sustained growth bucking the general trend of negative or slow growth of economy and the industry sector. It is, therefore, not too optimistic to presume that if the suggested measures are implemented, the cement industry will not only become a leader amongst the various sectors of the industry but will also emerge as a showpiece of model infrastructural growth contributing, in turn, to economic growth.

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Concrete

Refractory demands in our kiln have changed

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4 days ago

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February 20, 2026

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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.

Concrete

Digital supply chain visibility is critical

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4 days ago

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February 20, 2026

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MSR Kali Prasad, Chief Digital and Information Officer, Shree Cement, discusses how data, discipline and scale are turning Industry 4.0 into everyday business reality.

Over the past five years, digitalisation in Indian cement manufacturing has moved decisively beyond experimentation. Today, it is a strategic lever for cost control, operational resilience and sustainability. In this interview, MSR Kali Prasad, Chief Digital and Information Officer, Shree Cement, explains how integrated digital foundations, advanced analytics and real-time visibility are helping deliver measurable business outcomes.

How has digitalisation moved from pilot projects to core strategy in Indian cement manufacturing over the past five years?
Digitalisation in Indian cement has evolved from isolated pilot initiatives into a core business strategy because outcomes are now measurable, repeatable and scalable. The key shift has been the move away from standalone solutions toward an integrated digital foundation built on standardised processes, governed data and enterprise platforms that can be deployed consistently across plants and functions.
At Shree Cement, this transition has been very pragmatic. The early phase focused on visibility through dashboards, reporting, and digitisation of critical workflows. Over time, this has progressed into enterprise-level analytics and decision support across manufacturing and the supply chain,
with clear outcomes in cost optimisation, margin protection and revenue improvement through enhanced customer experience.
Equally important, digital is no longer the responsibility of a single function. It is embedded into day-to-day operations across planning, production, maintenance, despatch and customer servicing, supported by enterprise systems, Industrial Internet of Things (IIoT) data platforms, and a structured approach to change management.

Which digital interventions are delivering the highest ROI across mining, production and logistics today?
In a capital- and cost-intensive sector like cement, the highest returns come from digital interventions that directly reduce unit costs or unlock latent capacity without significant capex.
Supply chain and planning (advanced analytics): Tools for demand forecasting, S&OP, network optimisation and scheduling deliver strong returns by lowering logistics costs, improving service levels, and aligning production with demand in a fragmented and regionally diverse market.
Mining (fleet and productivity analytics): Data-led mine planning, fleet analytics, despatch discipline, and idle-time reduction improve fuel efficiency and equipment utilisation, generating meaningful savings in a cost-heavy operation.
Manufacturing (APC and process analytics): Advanced Process Control, mill optimisation, and variability reduction improve thermal and electrical efficiency, stabilise quality and reduce rework and unplanned stoppages.
Customer experience and revenue enablement (digital platforms): Dealer and retailer apps, order visibility and digitally enabled technical services improve ease of doing business and responsiveness. We are also empowering channel partners with transparent, real-time information on schemes, including eligibility, utilisation status and actionable recommendations, which improves channel satisfaction and market execution while supporting revenue growth.
Overall, while Artificial Intelligence (AI) and IIoT are powerful enablers, it is advanced analytics anchored in strong processes that typically delivers the fastest and most reliable ROI.

How is real-time data helping plants shift from reactive maintenance to predictive and prescriptive operations?
Real-time and near real-time data is driving a more proactive and disciplined maintenance culture, beginning with visibility and progressively moving toward prediction and prescription.
At Shree Cement, we have implemented a robust SAP Plant Maintenance framework to standardise maintenance workflows. This is complemented by IIoT-driven condition monitoring, ensuring consistent capture of equipment health indicators such as vibration, temperature, load, operating patterns and alarms.
Real-time visibility enables early detection of abnormal conditions, allowing teams to intervene before failures occur. As data quality improves and failure histories become structured, predictive models can anticipate likely failure modes and recommend timely interventions, improving MTBF and reducing downtime. Over time, these insights will evolve into prescriptive actions, including spares readiness, maintenance scheduling, and operating parameter adjustments, enabling reliability optimisation with minimal disruption.
A critical success factor is adoption. Predictive insights deliver value only when they are embedded into daily workflows, roles and accountability structures. Without this, they remain insights without action.

In a cost-sensitive market like India, how do cement companies balance digital investment with price competitiveness?
In India’s intensely competitive cement market, digital investments must be tightly linked to tangible business outcomes, particularly cost reduction, service improvement, and faster decision-making.
This balance is achieved by prioritising high-impact use cases such as planning efficiency, logistics optimisation, asset reliability, and process stability, all of which typically deliver quick payback. Equally important is building scalable and governed digital foundations that reduce the marginal cost of rolling out new use cases across plants.
Digitally enabled order management, live despatch visibility, and channel partner platforms also improve customer centricity while controlling cost-to-serve, allowing service levels to improve without proportionate increases in headcount or overheads.
In essence, the most effective digital investments do not add cost. They protect margins by reducing variability, improving planning accuracy, and strengthening execution discipline.

How is digitalisation enabling measurable reductions in energy consumption, emissions, and overall carbon footprint?
Digitalisation plays a pivotal role in improving energy efficiency, reducing emissions and lowering overall carbon intensity.
Real-time monitoring and analytics enable near real-time tracking of energy consumption and critical operating parameters, allowing inefficiencies to be identified quickly and corrective actions to be implemented. Centralised data consolidation across plants enables benchmarking, accelerates best-practice adoption, and drives consistent improvements in energy performance.
Improved asset reliability through predictive maintenance reduces unplanned downtime and process instability, directly lowering energy losses. Digital platforms also support more effective planning and control of renewable energy sources and waste heat recovery systems, reducing dependence on fossil fuels.
Most importantly, digitalisation enables sustainability progress to be tracked with greater accuracy and consistency, supporting long-term ESG commitments.

What role does digital supply chain visibility play in managing demand volatility and regional market dynamics in India?
Digital supply chain visibility is critical in India, where demand is highly regional, seasonality is pronounced, and logistics constraints can shift rapidly.
At Shree Cement, planning operates across multiple horizons. Annual planning focuses on capacity, network footprint and medium-term demand. Monthly S&OP aligns demand, production and logistics, while daily scheduling drives execution-level decisions on despatch, sourcing and prioritisation.
As digital maturity increases, this structure is being augmented by central command-and-control capabilities that manage exceptions such as plant constraints, demand spikes, route disruptions and order prioritisation. Planning is also shifting from aggregated averages to granular, cost-to-serve and exception-based decision-making, improving responsiveness, lowering logistics costs and strengthening service reliability.

How prepared is the current workforce for Industry 4.0, and what reskilling strategies are proving most effective?
Workforce preparedness for Industry 4.0 is improving, though the primary challenge lies in scaling capabilities consistently across diverse roles.
The most effective approach is to define capability requirements by role and tailor enablement accordingly. Senior leadership focuses on digital literacy for governance, investment prioritisation, and value tracking. Middle management is enabled to use analytics for execution discipline and adoption. Frontline sales and service teams benefit from
mobile-first tools and KPI-driven workflows, while shop-floor and plant teams focus on data-driven operations, APC usage, maintenance discipline, safety and quality routines.
Personalised, role-based learning paths, supported by on-ground champions and a clear articulation of practical benefits, drive adoption far more effectively than generic training programmes.

Which emerging digital technologies will fundamentally reshape cement manufacturing in the next decade?
AI and GenAI are expected to have the most significant impact, particularly when combined with connected operations and disciplined processes.
Key technologies likely to reshape the sector include GenAI and agentic AI for faster root-cause analysis, knowledge access, and standardisation of best practices; industrial foundation models that learn patterns across large sensor datasets; digital twins that allow simulation of process changes before implementation; and increasingly autonomous control systems that integrate sensors, AI, and APC to maintain stability with minimal manual intervention.
Over time, this will enable more centralised monitoring and management of plant operations, supported by strong processes, training and capability-building.

Concrete

Cement Additives for Improved Grinding Efficiency

Published

4 days ago

on

February 20, 2026

By

admin

Shreesh A Khadilkar discusses how advanced additive formulations allow customised, high-performance and niche cements—offering benefits while supporting blended cements and long-term cost and carbon reduction.

Cement additives are chemicals (inorganic and organic) added in small amounts (0.01 per cent to 0.2 per cent by weight) during cement grinding. Their main job? Reduce agglomeration, prevent pack-set, and keep the mill running smoother. Thus, these additions primarily improve, mill thru-puts, achieve lower clinker factor in blended cements PPC/PSC/PCC. Additionally, these additives improve concrete performance of cements or even for specific special premium cements with special USPs like lower setting times or for reduced water permeability in the resultant cement mortars and concrete (water repellent /permeation resistant cements), corrosion resistance etc.
The cement additives are materials which could be further differentiated as:

Grinding aids:
• Bottlenecks in cement grinding capacity, such materials can enhance throughputs
• Low specific electrical energy consumption during cement grinding
• Reduce “Pack set” problem and improve powder flowability

Quality improvers:
• Opportunity for further clinker factor reduction
• Solution for delayed cement setting or strength development issues at early or later ages.

Others: materials which are used for specific special cements with niche properties as discussed in the subsequent pages.
When cement additives are used as grinding aids or quality improvers, in general the additives reduce the inter-particle forces; reduce coating over grinding media and mill internals. Due to creation of like charges on cement particles, there is decreased agglomeration, much improved flowability, higher generation of fines better dispersion of particles in separator feed and reduction of mill filling level (decrease of residence time). However, in VRM grinding; actions need to be taken to have stable bed formation on the table.
It has been reported in literature and also substantiated by a number of detailed evaluations of different cement additive formulations in market, that the cement additive formulations are a combination of different chemical compounds, typically composed of:

Accelerator/s for the hydration reaction of cements which are dependent on the acceleration effect desired in mortar compressive strengths at early or later ages, the choice of the materials is also dependent on clinker quality and blending components (flyash / slag) or a mix of both.
Water reducer / workability / wet-ability enhancer, which would show impact on the resultant cement mortars and concrete. Some of the compounds (retarders) like polysaccharide derivatives, gluconates etc., show an initial retarding action towards hydration which result in reducing the water requirements for the cements thus act as water reducers, or it could be some appropriate polymeric molecules which show improved wet-ability and reduce water demand. These are selected based on the mineral component and type of cements (PPC/PSC /PCC).
Grinding aids: Compounds that work as Grinding Aid i.e. which would enhance Mill thru-put on one hand as well as would increase the early strengths due to the higher fines generation/ or activation of cement components. These compounds could be like alkanol-amines such as TIPA, DEIPA, TEA etc. or could be compounds like glycols and other poly-ols, depending on whether it is OPC or PPC or PSC or PCC manufacture.

Mechanism of action — Step By Step—

Reduce Agglomeration, Cement particles get electrostatically charged during grinding, stick together, form “flocs”, block mill efficiency, waste energy. Grinding aid molecules adsorb onto particle surfaces, neutralise charge, prevent re-agglomeration.
Improve Powder Flowability, Adsorbed molecules create a lubricating layer, particles slide past each other easier, better mill throughput, less “dead zone” buildup.
Also reduces caking on mill liners, diaphragms, and separator screens, less downtime for cleaning.
Enhance Grinding Efficiency (Finer Product Faster), By preventing agglomeration, particles stay dispersed more surface area exposed to grinding media, finer grind achieved with same energy input, Or: same fineness achieved with less energy, huge savings.
Example:
• Without aid ? 3500 cm²/g Blaine needs 40 kWh/ton
• With use of optimum grinding aid same fineness at 32 kWh/ton 20 per cent energy savings
Reduce Pack Set and Silo Caking Grinding aids (GA) inhibit hydration of free lime (CaO) during storage prevents premature hardening or “pack set” in silos. especially critical in humid climates or with high free lime clinker.
It may be stated here that Overdosing of GA can cause: – Foaming in mill (especially with glycols) reduces grinding efficiency, retardation of cement setting (especially with amines/acids), odor issues (in indoor mills) – Corrosion of mill components (if acidic aids used improperly)
The best practice to optimise use of GA is Start with 0.02 per cent to 0.05 per cent dosage test fineness, flow, and set time adjust up/down. Due to static charge of particles, the sample may stick to the sides of sampler pipe and so sampling need to be properly done.
Depending on type of cements i.e. OPC, PPC, PSC, PCC, the grinding aids combinations need to be optimised, a typical Poly carboxylate ether also could be a part of the combo grinding aids

Cement additives for niche properties of the cement in concrete.
The cement additives can also be tailor made to create specific niche properties in cements, OPC, PPC, PSC and PCC to create premium or special brands. The special niche properties of the cement being its additional USP of such cement products, and are useful for customers to build a durable concrete structure with increased service life.

Such properties could be:
• Additives for improved concrete performance of cements, high early strength in PPC/PSC/PCC, much reduced water demand in cement, cements with improved slump retentivity in concrete, self-compacting, self levelling in concrete, cements with improved adhesion property of the cement mortar
• Water repellence / water proofing, permeability resistance in mortars and concrete.
• Biocidal cement
• Photo catalytic cements
• Cements with negligible ASR reactions etc.

Additives for cements for improved concrete performance
High early strengths: Use of accelerators. These are chemical compounds which enhance the degree of hydration of cement. These can include setting or hardening accelerators depending on whether their action occurs in the plastic or hardened state respectively. Thus, the setting accelerators reduce the setting time, whereas the hardening accelerators increase the early age strengths. The setting accelerators act during the initial minutes of the cement hydration, whereas the hardening accelerators act mainly during the initial days of hydration.
Chloride salts are the best in class. However, use of chloride salts as hardening accelerators are strongly discouraged for their action in promoting the corrosion of rebar, thus, chloride-free accelerators are preferred. The hardening accelerators could be combinations of compounds like nitrate, nitrite and thiocyanate salts of alkali or alkaline earth metals or thiosulphate, formate, and alkanol amines depending on the cement types.
However, especially in blended cements (PPC/PSC/PCC the increased early strengths invariably decrease the 28 day strengths. These aspects lead to creating combo additives along with organic polymers to achieve improved early strengths as well as either same or marginally improved 28 days strengths with reduced clinker factor in the blended cement, special OPC with reduced admixture requirements. With use of appropriate combination of inorganic and organic additives we could create an OPC with substantially reduced water demand or improved slump retentivity. Use of such an OPC would show exceptional concrete performance in high grade concretes as it would exhibit lower admixture requirements in High Grade Concretes.
PPC with OPC like properties: With the above concept we could have a PPC, having higher percentage flyash, with a combo cement additive which would have with concrete performance similar to OPC in say M40/M50 concrete. Such a PPC would produce a high-strength PPC concrete (= 60 MPa @ 28d) + improved workability, durability and sustainability.
Another interesting aspect could also be of using ultrafine fine flyash /ultrafine slags as additions in OPC/PPC/PSC for achieving lower clinker factor as well as to achieve improved later age strengths with or without a combo cement additive.
The initial adhesion property at sites of especially PPC/PSC/PCC based mortars can be improved through use of appropriate organic polymers addition during the manufacture of these cements. Such cements would have a better adhesion property for plastering/brick bonding etc., as it has much lower rebound loss of their mortars in such applications.
It is needless to mention here that with use of additives, we could also have cement with viscosity modifying cement additives, for self-compaction and self-leveling concrete performance.
Use of Phosphogypsum retards the setting time of cements, we can use additive different additive combos to overcome retardation and improve the 1 day strengths of the cements and concretes.

About the author:
Shreesh Khadilkar, Consultant & Advisor, Former Director Quality & Product Development, ACC, a seasoned consultant and advisor, brings over 37 years of experience in cement manufacturing, having held leadership roles in R&D and product development at ACC Ltd. With deep expertise in innovative cement concepts, he is dedicated to sharing his knowledge and improving the performance of cement plants globally.

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