Economy & Market

Cement Makers Bullish on FY2019

Published

8 years ago

May 31, 2018

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Cement is never used as cement alone but is always converted to a value-added product in practice. Therefore application of cement becomes extremely important. The cement producers have a dedicated department that looks into the applications of product. Now onwards, we shall try and cover it through a series of articles in a structured way.
India is the second largest cement producer globally and is a vital part of the economic development, providing employment opportunities to more than a million people, directly or indirectly. Since its deregulation in 1982, the Indian cement industry has grown at a tremendous pace attracting huge investments – both from domestic as well as foreign investors. The industry has added over 110 MT of capacity in the last five years.
However, the financial year 2017-18 has been a relatively tough one for the industry due to ban on sand mining, use of pet coke and diminished market concentration of industry leaders. Slower progress in infrastructure projects and low offtake from housing and industrial users also slowed down the growth. A number of foreign players are also eyeing India’s cement sector, owing to high margins and steady demand.Industry structure
The Indian cement industry is dominated by a few companies. The top 20 cement companies account for almost 70 per cent of the total cement production of the country. A total of 210 large cement plants account for a cumulative installed capacity of over 350 MT, with 350 small plants accounting for the rest. Of these 210 large cement plants, 77 are located in the States of Andhra Pradesh, Rajasthan and Tamil Nadu.
Due to increased construction and infrastructural activities, which has led to growth in demand, cement industry has seen major consolidation and large investments in recent years. During the year, UltraTech Cement acquired Jaypee Cement while Orient Cement took over two entities – Bhilai Jaypee Cement and Nigrie Cement grinding unit. An improvement in utilisation rates of the newly-acquired capacities and fresh capacity additions by these players has led to higher volumes.The construction market
India’s construction value of output stands over at Rs 26,500 billion and has been slowly expanding over the years. With value addition close to Rs 10,000 billion, its share in total GDP rose from 5.6 per cent in 1990-91 to over 7.3 per cent in 2017-18. However, the growth of construction activity has slowed down significantly in recent years but picked in 2017-18. The last highest yearly growth of 10.8 per cent was recorded in 2011-12, but thereafter it has not even touched 5 per cent until now. In 2016-17, it is estimated to have increased 1.3 per cent and rebounded to 4.3 per cent in 2017-18. Going ahead, it appears that the growth will remain under 4 per cent, thus will result in slower increase in demand for construction materials including cement. However, the growth will largely depend on the government’s initiative in developing the infrastructure and the process of boosting the housing sector.
In construction, cement is the second largest component, although its value accounts for only 12.5 per cent of total input cost of construction, whereas steel takes away nearly half the cost of inputs. Over Rs 2,100 billion worth of cement is consumed to construct a variety of structures over the past three years. Under this premise, dwelling construction accounts for 27.5 per cent of all construction activity, while another 40 per cent is accounted for non-residential buildings construction. Roads and bridges, which is the major infrastructure component, accounts for just 6.4 per cent of construction. The remaining is other structures and land improvement activity. Thus, housing and commercial construction is the major economic activity and is largely dependent on cement and steel. According to estimates, housing sector accounts for about 67 per cent of the total cement consumption while infrastructure makes up for 13 per cent of the consumption in India.Cement industry performance in 2017-18
Cement production volume in 2017-18 grew 6.3 per cent year-on-year after a decline of 1.2 per cent in 2016-17, for the first time in 15 years as demonetisation reduced demand. The industry with an estimated capacity of about 465 million ton (as of December 2017), saw production grow 3.8 per cent per annum during the period 2012-13 to 2017-18. With no authentic data available on cement consumption or demand, it is assumed in this report, that production will be a proxy to consumption since ending stocks are negligible.
The cement industry witnessed a revival during 2017-18, backed by government spending on infrastructure. Construction of houses under the ‘Housing for All’ scheme and Pradhan Mantri Awas Yojana (PMAY) have been major drivers of demand from the housing segment especially in the rural areas. Infrastructure projects under Bharatmala, Sagarmala and smart cities continued to drive demand from infrastructure segment.
The real estate sector witnessed disruption in the construction and sales activity beginning demonetisation exercise in November 2016. The disruption continued with builders taking a cautious approach to RERA implementation, temporarily halting new sales or construction. Implementation of RERA in May 2017 impacted the demand for cement from real estate segment in first and second quarters of 2017-18.
Cement prices remained range bound in the past four years. They are mainly driven by regional capacity, utilisation levels and demand within the region. The price variation across regions contract when there is steady demand from both retail and institutional cement consumers. Western and eastern regions with favourable demand continue to record higher price for cement.Prospect for 2018-19
Cement demand has a very close linkage with economic growth and government spending. Demand for housing is driven by income growth while infrastructure development largely depends on government expenditure, both state and central. In recent past, demand for cement has remained poor as the economic growth slowed down to less than 7 per cent between 2012-13 and 2016-17 from an average of 9 per cent between 2005-06 and 2010-11 when cement demand had expanded by 8.5 per cent per annum. Considering that economy will grow between 7 to 8.25 per cent in the next five years, the statistical relation between cement demand and economic growth, predicts that cement demand will grow at the rate of 3.6 per cent per annum during the period 2018-23. In 2018-19, demand is expected to rise 3.8 per cent assuming GDP grows 7 per cent and overall construction activity expand 5.2 per cent during the year.
However, large cement companies are bullish on economic growth in 2018-19 and well as on the cement industry. This was largely evident from the developments in the last quarter of 2017-18 and early 2018-19. After a prolonged lull in demand, volume growth picked up pace, buoyed by government spending on infrastructure projects; but prices are far from their historic levels. Cement prices took a hard knock in the seasonally strong March quarter of 2017-18.
Care Ratings observes that demand for cement from housing and real estate sectors is expected to grow by around 7 per cent, and from infrastructure by 8 to 10 per cent. The demand from affordable housing is expected to sustain on the back of the government allocating Rs 6,500 crore for urban housing. Completion of the same would lead to an incremental demand of 1 to 1.5 per cent (3 to 4.5 MT) for cement in 2018-19. Additionally, the monsoon forecasts for the year indicate normal rainfall, which should lead to sustained demand from rural housing segment.
Similarly, infrastructure segment may continue to remain in focus during the year as far as demand for cement is concerned. Development of national highways is expected to contribute 2-3 MT of incremental demand for cement.
Demand from various projects at proposed smart cities and under-construction metro rail projects at various stages of development in 14 cities are some of the projects expected to drive demand for cement during the fiscal 2019. The development of the above-mentioned projects across the geography is expected to improve capacity utilisation of cement plants across the five regions. Election in some of the key states in southern, northern and central regions followed by the general election in 2019 would ensure faster implementation of sanctioned projects. The infrastructure segment is expected to grow by 8-10 per cent, the analysis added.Challenges
Increase in pet coke prices in the global markets and global crude oil price has been leading to increase in domestic diesel prices would impact operating margins of major players during 2018-19.
Availability of sand is a major challenge globally which affects construction activity. India has been facing acute shortage of sand across states especially in northern and southern region. Even though sand seems to be an abundant resource, the availability of sand required for construction is scarce in these regions. Sand is largely illegally mined across many of the states in southern and northern regions, and the respective state governments have been trying to curb the same, in order to boost their tax revenues. This has led to a sudden drop in sand availability for construction.
In 2018-19, capacity addition of around 8-10 MT is expected in eastern and western region. Central, northern and southern regions combined are expected to add about 10-15 MT of production capacity. Revocation of the sand mining ban and acceptance of manufactured sand, popularly known as M-sand in various region, is expected to aid construction activities. It is expected that in order to meet rising demand, cement companies will add 56 million ton capacity over the next three years.
With two major states (Rajasthan and Madhya Pradesh) going into assembly elections followed by general elections in first and second quarters of 2019, the demand from infrastructure and construction is expected to peak in central, eastern and western region. Utilisation in cement capacity across regions is expected to improve during the year to around 67 per cent from 65 per cent in 2017-18.What large companies expect this year to be
ACC expects GDP growth, primarily fueled by consumption, to touch a respectable mark of 7.5 per cent in 2018-19, up from 6.5 per cent in the previous year. Budget initiatives are expected to raise the rural demand and bolster economic growth with initiatives such as Minimum Support Price (MSP) for farmers set at 1.5 times the cost of production, export impetus on agri-produce, increased allocation of Rs 14.4 lakh crore for rural housing and infrastructure and a 26 per cent increase in funding to the Pradhan Mantri Krishi Sinchayee Yojna (PMKSY). Additionally, private consumption expenditure is expected to increase with the implementation of the Seventh Pay Commission hike at the State level.
Demand for cement in 2018-19 is expected to increase from 6-7 per cent with continued government’s focus on rural development, affordable housing, smart cities, as well as infrastructure by laying thrust on construction of cement concrete roads, highways through its "Bharatmala Project", one of the biggest highway construction project. This also includes economic corridors’ development, coastal and port connectivity roads, border and international connectivity roads, expressway etc.
However, the cement industry is grappling with sub-optimal effective capacity utilisation of 70 per cent, with capacity overhang of more than 100 million ton. While cement plants in the northern, central and eastern regions of the country produced at levels above 85-90 per cent of capacity, excess capacity in the southern region has inhibited the industry’s average capacity utilisation. Intense competition and not enough demand pull, will continue to lead to excess capacity in 2018-19. However, this situation is expected to correct itself in 2019 with the increased outlays on housing, infrastructure development and agri-sector initiatives.
The five-fold increase in the outlay on Pradhan Mantri Awas Yojana – Urban (PMAY-U) to Rs31,500 crore, is expected to revive urban housing demand, while generating a 30 per cent share of the overall demand for cement. Infrastructure development outlay for highways, roads and railways has increased by 11 per cent and 22 per cent respectively. This will boost demand for cement from the infrastructure sector, which is estimated to account for 20 per cent of cement demand. A social welfare surcharge of 10 per cent, will replace the existing 3 per cent education cess on customs duty, which will marginally inflate the cost of imported inputs such as petcoke and non-coking coal products.
According to Gujarat Ambuja Cement, 2018-19 will be a year of growth, which has been rightly endorsed by the World Bank. According to the World Bank, when compared to other emerging economies, India has an "enormous growth potential" with the implementation of comprehensive reforms. Key indicators across the economy have shown positive rebounds and there is hope that the upward trajectory will continue in the new fiscal year to help achieve a GDP of +8 per cent for the years to come.
However, it also pointed towards major challenges that can impede cement growth. The industry is dependent on natural resources and is highly energy intensive. Natural resources like limestone, coal and minerals are essential to produce cement. The industry needs to ensure the uninterrupted supply of these materials at an optimum cost and quality, however due to the depletion of reserves, this is becoming challenging. Volatility in the price of coal is also an area of concern for the industry. The quality of raw material additive and mineral gypsum is also depleting.
Nevertheless, with an improvement in the economic scenario, immense potential is being offered to the cement industry by the infrastructural, commercial and housing sectors.
UltraTech Cement is bullish on the growth prospects for the cement industry as the government goes big on roads and metro spendings. Reportedly it said that cement demand in the country could well grow by about 8 per cent in 2018-19, led by government spending on infrastructure. With bulk of demand is being generated from infrastructure spending, roads and metro are driving this growth.Sensitive issues
The government plans banning burning petroleum coke as a fuel nationwide to comply with a Supreme Court request as part of a long-running case to clean the country’s air. A refinery by-product, petroleum coke, or pet coke, is used as a fuel because of its higher energy content than coal, but it releases larger amounts of carbon dioxide and sulphur dioxide, which can cause lung disease and acid rain.
The ongoing consolidation in cement industry has changed the supply dynamics. Competitive intensity remains high as some regional firms are venturing into newer markets and some of them are on a capacity addition spree. So cement makers will be chasing demand growth at the expense of prices. And the trend of depressed prices may not reverse in near term.– NITIN MADKAIKAR

Concrete

Refractory demands in our kiln have changed

Published

4 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

4 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

4 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.