Economy & Market

Indian Cement Industry: The year gone by and the challenges ahead

Published

14 years ago

December 31, 2011

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Though the year 2011 has been bumpy for the Indian cement sector, demand growth for the sector is likely to bounce back given the positive outlook of the general construction and infrastructure sector. The main impediments which have impacted the industry are the recent devaluation of the rupee and bank funding becoming costlier for the industry. This has led to a rise in import & input costs for the company in the form of freight and logistics cost. Read on to know the journey of the Indian Cement industry in the current scenarioIndia is the second largest producer of cement in the world after China and the Indian cement industry has seen a tremendous boom during the last few years in sync with the booming Indian economy. However, the fiscal 2011-12 saw the Indian economy suffering a setback due to an increase in inflation, spiking interest rates and a surge in the prices of commodities and fuels alongwith a devalued rupee. A lull has also been observed in the country’s housing sector, which accounts for over 60-70 percent of the country’s cement demand.Pervasion of a negative sentiment in the Indian Economy :As per the monthly "Economic Watch for November 2011" brought out by the Federation of Indian Chambers of Commerce and Industry (FICCI), the country’s economic growth is expected to slump to 6.6-6.8 percent in the financial year 2011-12. This projection by the industry’s apex body comes in the wake of the Indian government having lowered the country’s GDP growth forecast from the originally projected 9 percent to 7.25-7.75 percent. A poor performance by the mining, manufacturing and capital goods sectors resulted in a 5.1 percent on year contraction in the country’s industrial production in October in over two years. The growth of India’s GDP in the July-September quarter was pegged at 6.9 percent, the lowest in two years on account of the weak global fundamentals and a tight monetary policy by the government. The export sector is also likely to witness a moderation given the bearish fundamentals gripping the world economy. The situation has been complicated further by a widening trade deficit in the current fiscal. Exports for the April-November period increased by 33.2 percent on year to $ 192.7 billion while imports rose by 30.2 percent on year to $ 309.5 billion.A gloom has also been witnessed in the investment climate of the country with a slowdown in the housing and construction industry, which are critical demand drivers for the cement industry. This view was further emphasized by Jayram Nambiar, Ex Managing Director, Pfeiffer India Pvt Ltd who stated, "there has been a substantial reduction in private investments in major capital projects in 2011. There has been low government expenditure on public projects and a fall in investment levels in the housing and construction industry. The cement industry is unlikely to see a revival in demand to the tune of 8-9 percent for some time."Indian Cement Industry : The year that wasThe negative sentiment in the economy has also found its reverberations in the cement sector.Jayram Nambiar, Ex Managing Director-Pfeiffer India Pvt Ltd has concurred "as per a report by the CMA, the country produced 98.81 mt of cement in April-October 2011 which is only 1.2 percent higher than 96.75 mt produced in 2010. A slowdown in demand for cement has been noticed from the housing industry and if the trend continues, the annual growth in demand for cement will remain in the range of 3 per cent on a year on year basis , in 2011-12". The year 2011 also witnessed low cement capacity utilizations compounded by a fall in capacity additions. It was further observed that inspite of an oversupply situation, increased cost of inputs such as fuel and commodities led to a rise in prices of cement across India. Commenting on the capacity parameters for the cement industry, Umesh Shrivastava, Executive Chairman, Holtec Consulting Private Limited stated, "the average capacity utilization, over the year is likely to be in the range of 70-75 percent, which despite being low, is pegged at a level higher than the breakeven point of 50 percent. A slowdown has also been observed in capacity additions, with only 12-13 mtpa of capacity commissioned till now. A capacity addition of around 30 mtpa was expected to come onstream in the period April 1, 2011-31 March 2012." The industry was expecting the installation of around 15-20 mtpa of capacity in 2011. However, a difference in value perceptions between prospective sellers and buyers led to the prospect remaining unrealized. As compared to a peak cycle witnessed during FY 2007-08, cement industry utilization rates witnessed a downslide in FY 2011-12. Commenting on this aspect, Sumit Banerjee, Vice Chairman, Reliance Cementation augured, "the cement sector is cyclical in nature and continues to witness peak and trough cycles. Following a peak capacity utilization rate of 98 percent in FY08, the industry witnessed a down cycle with utilization rate falling to 74 percent in FY 2011-12. Hopefully, this should be the bottom of the cycle with the utilization rate expected to record an improvement to 76 percent in FY 2012-13 and further to 79 percent in FY 2013-14."A moderate 3.1 percent year on year growth in dispatches was recorded by the Indian cement industry in FY 2011-12, following a year on year increase of 4.5 percent in FY 2010-11. The bleak scenario was a result of muted demand, especially in the Southern Indian state of Andhra Pradesh due to political instability. Demand growth for cement in fiscal 2011-12 was expected to remain lower at 4.5 percent due to a slowdown in the economy, sluggish growth in infrastructure and real estate projects and a low momentum in government sponsored housing and irrigation schemes.Cost pressures also added to the woes of the cement industry in this fiscal. There was a rise in limestone mining costs due to a hike in prices of diesel in June 2011. Heavy monsoons in the coal mining areas also forced cement companies to import coal at inflated price levels due to a fall in the value of the rupee. High input costs coupled with a fall in demand led to a pressure on the margins of companies. Commenting on the cost factor, Sumit Banerjee, Vice Chairman, Reliance Cementation said, "severe pressure has been exerted over cement production costs over the last two years. The underlying reason behind the same was an increase in costs incurred on raw material, fuel and power, and freight costs which account for around 70 percent of the overall costs for the manufacture of cement. This has affected the operating margin of the industry, which has gone down significantly inspite of higher cement prices."The year can also be noted for technological developments which included waste heat recovery systems and utilization of lower grades of limestone for making clinker. Positive moves were also witnessed on the part of stronger players in the domestic cement arena who tried to establish production capacities outside India and acquire sources for solid fuel.The road aheadThe future largely appears bleak for the cement industry in the fiscal 2012-13 due to prevalent weak economic fundamentals. Commenting on the adversities likely to be faced by the industry, Jayram Nambiar, Ex Managing Director, Pfeiffer India Pvt Ltd said, "looking ahead, the economic scenario the world over and in India is anti growth and the worst is yet to come. The problem in India has been compounded by the current unfavorable political climate. The coming general election is unlikely to lead to the emergence of a strong political party or coalition. The growth levels of 2008-09 are not likely to be witnessed over the next two years. The period is also likely to be tough for the cement industry. The industry will have to deal with problems like rising energy costs compounded with the depreciation of the rupee, higher freight and distribution costs and low price realizations due to weak demand." These problems shall further be exacerbated by a rise in labour costs due to inflationary trends and a rise in the cost of living index. However, price levels for cement cannot be expected to increase much due to high unutilized capacity far in excess of demand likely to prevail in 2012 and 2013. However, it should be noted that additional cement capacity of 20 million mtpa is being implemented and will be commissioned in 2012. If sufficient demand exists, a capacity utilisation of more than 85 percent is easily achievable. The weak economic climate will also have an impact on smaller cement producers and their operations, leading to a spate of consolidations. Concurring on this issue, Nambiar reiterated, "presently, 35 percent of the cement production capacity is in the hands of smaller producers for whom the future will be one of tribulation due to unfavourable economic conditions. The next two years will see a period of consolidation in the industry with the smaller players withdrawing from the industry by selling out to the financially stronger cement producers. Their share of the total cement capacity can be expected to increase to over 70 percent by 2014."Being a huge country, there will be a difference in the region wise demand for cement in the country which is broadly divided into the western, eastern, northern and southern regions. Elaborating on this aspect, Sumit Banerjee, Vice Chairman, Reliance Cementation stated, "demand for cement in the South is expected to go southward by 4 percent in FY2011-12, display lower than average growth at 5 percent in FY2012-13 and bounce back sharply in FY2013-14. A rise in growth will be witnessed by the Eastern and Central regions from the lower than average levels of 6 percent in FY2011-12 to 9 percent in FY2013-14. Demand for cement in the Northern region is expected to remain in the range of 7-9 percent while the Western region will show demand in the 10 percent range till FY2013-14."Reiterating on the capacity utilization differentials across different regions, Banerjee stated, "a moderation is expected to set in the average industry capacity utilization rate to 76 percent in FY2012-13 from 79 percent in FGY2010-11 before showing an upward curve to 79 percent in FY2013-14. The highest capacity utilization rates are likely to be witnessed by the Eastern and Northern regions at 90 percent levels in FY2012-13 while higher capacity additions could lead to a fall in capacity utilizations in Central India. Utilization rates are also likely to be impacted in the Western region due to pressure exerted on account of cement supply from Southern India."The industry is also optimistic that demand for cement will surge in the near future through the revival of economic activity by the government especially through investment in infrastructure projects. Expressing confidence that the government will initiate the demand push process, Umesh Shrivastav, Executive Chairman, Holtec Consulting Private Limited stated, "following the slump of 2011, demand for cement is likely to see a recovery process and will touch levels of 6-8 percent in 2012. The increase in growth will be triggered by the government’s drive to revive economic activity by initiating investment in infrastructure projects. A correction is foreseen in interest rates and improved regulation as regards land acquisition and environmental clearance leading to revival of several on-hold projects. Cement prices are likely to maintain an upward curve due to increasing production and ownership costs alongwith lower capacity utilizations."Challenges & Opportunities for Indian Cement Industry during 2012 onwards:The forthcoming year 2012 for the Cement Industry is likely to see more of consolidation but lower growth rate. The challenges and opportunities may be summarized as follows:??Extraordinary delay in mining lease sanction and delay in land acquisition & MoEF clearance.??Non availability of domestic coal clubbed with poor quality. Hence, industry has to depend upon high cost imported coal. ??Depreciation of Indian currency has further increased the cost of imported coal, Fuel, Gypsum & other raw materials.??Continuous hike in power tariff, due to increase in coal cost & cross subsidy. Though captive power plant appear to be a part solution, but CPP is again depending upon coal supply linkage, which is uncertain.??On top of it, total taxation including excise, VAT, royalty and cross subsidy amounts to approx. 39 – 40% of Ex-works sales realization. Cement being mass consuming item, such high taxation needs re-visit.??Low packing rate and low level of dispatches leading to IR – Labor issues as per the applicable rules & norms of wage board.??Cement Plant being a capital intensive unit, high interest cost is another disincentive for fresh investment in the sector.??Reduced spending on Government Projects and Slow down in infrastructure investment is another cause of worry for fresh investment.Some of the Indian Economy Strong Points & Stimulators relating to Cement Industry??Growing population of currently 1.2 billion with increasing spending power??Government pursuing structural reforms, facilitating pan-Asian trade, increasing FDI inflows??Recent push at Prime Minister’s level for large infrastructure projects such as Highways, Roads, Ports, Railways, Power, Housing, etc. ??Requirement of Accelerated industrialization to cater to infrastructure and consumer markets??India’s economic growth based on reforms and economic liberalization likely to sustain on long term basis.Measures to be implemented for stimulating cement demand:In order to stimulate demand in an already sagging industry, 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 supportive components. The government can also consider classifying cement as "Declared Goods" like steel having a uniform VAT rate of 4 percent throughout the country. To throw light on the matter further, P.K.Ghosh, Chairman, Ercom Engineers Pvt Ltd Ercom Group said, "the overall taxation value on cement can be brought down to a level of 20-25 percent of ex-works selling price from the current level. Tax incentive should be provided by the government for promoting blended cement in the larger interest of mineral conservation, waste utilization and bringing down carbon emission. Cross subsidy burden on electricity, diesel and railway freight should be phased out in a gradual manner. The supply of superior quality coal should be increased through merchant mining in private sector. Companies who have been allotted captive coal blocks should be asked to increase production for selling in the open market."Cement manufacturers need to maximize production of blended cement by utilizing industrial waste like fly ash and slag for conserving mineral resources. The current average blending ratio in the country is pegged at approximately 27 percent which needs to be increased to 40 percent over the next 4-5 years. High energy consuming old and inefficient equipment needs to be replaced with modern equipment for optimizing and minimizing energy consumption alongwith increasing capacity. The industry needs to adopt the latest technology for Green Cement grinding for reducing clinker consumption and deriving benefits of carbon credits. Ready Mix Concrete (RMC) business may be promoted by cement companies or small companies should be encouraged to undertake RMC business at various locations, leading to bulk supply of cement and consequent reduction in packaging cost.ConclusionIn a nutshell, the government needs to support the cement industry in reviving its fortune through initiatives like reducing tax burden, providing incentives and ensuring availability of superior quality coal.

Concrete

Refractory demands in our kiln have changed

Published

3 days ago

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

Published

3 days ago

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

3 days ago

February 20, 2026

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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.