Concrete
Gypsum is used in cement to avoid flash-set
Published
4 years agoon
By
admin
Pradeep Kumar Chouhan – General Manager (QC and Environment), Udaipur Cement Works, sheds light on the role of gypsum and its manufacturing process.
Explain the role of gypsum in the cement manufacturing process.
Gypsum plays an important role in controlling the rate of hardening of the cement. Since it delays the settling of cement, it allows a longer working time, transporting, and placing. If gypsum is not added with a clinker during the cement manufacturing process, then the cement produced will immediately be set in addition to water and masons will not find time to work with it.
Gypsum is colourless, transparent, and naturally occurring in crystalline form as a mineral. It is widely used in our day-to-day life. It is a primary ingredient of toothpaste, used as a colour additive for drugs and cosmetics, as a food additive, plaster for orthopaedic use etc.
Generally, gypsum occurs in nature called mineral gypsum. Another variety of gypsum produced during production of common salt in coastal regions, particularly in Gujarat and Tamil Nadu, is called marine gypsum. Phosphoric Acid plants are important sources of by-product Phosphogypsum. Nowadays, chemical gypsum or synthetic gypsum (SynGyp) are also widely utilised as an alternative source of mineral gypsum for manufacturing of cement. The chemical gypsum or synthetic gypsum are produced from dyes and chemical industries and during flue gas desulphurisation (FGD) for abatement of SO2 pollution from sources like power plant for sulphur dioxide controlling system as an additional pollution control device.
Gypsum (CaSO4.2H2O) added with clinker while grinding in the cement mill to produce finished product i.e., cement.
C3A is the phase with the highest hydration speed
3CaO.Al2 O3 + n H2O fast reactions CAH + profuse exothermic heat
C3A + 6H2O▼ C3AH6
This is controlled by gypsum,
C3A + H2O + CaSO4- C4AS3H12 – C4AS3H32
Chemical reaction in the presence of gypsum is given below
3CaO. Al2O3 + 3CaSO4 . 2H2O + nH2O → 3CaO. Al2 O3 . 3CaSO4 . 32H2O
(Ettringite: calcium tri sulpho aluminate hydrate) + moderate exothermic heat
What proportions of gypsums are added in various types of cements produced? Tell us in detail about the composition and percentage.
Gypsum is normally used in various types of cement to maintain the SO3 in cement as per specification of BIS, based on Purity of Gypsum as CaSO4.2H2O its proportion in cement varies in the tune of 4 to 10 per cent. Limit for SO3 per cent in cement is 3.5 per cent, accordingly based on purity of gypsum as CaSO4.2H2O, proportion of gypsum is as follows:
Tell us about the process of obtaining gypsum by your organisation. What are the key resources utilised?
Udaipur Cement Works Limited (UCWL) is uses two types of gypsum i.e., Mineral and Chemical Gypsum for its cement products (i.e. OPC and PPC).
UCWL procures mineral gypsum from Rajasthan State Mines and Minerals Ltd. (RSMML) through road transportation.
Chemical gypsum generated primarily by dyes manufacturing industries using sulphuric acid in the manufacture of dye intermediates. The waste/effluent containing sulphuric acid is neutralised with limestone to produce large quantities of chemical gypsum in these industries. At present, UCWL procures chemical gypsum from Chemical Industries of Gujarat through road transportation.

Tell us about the key technical feasibility factors that make gypsum viable for mixing with cement?
As I mentioned earlier, gypsum is used in cement to avoid flash-set. In other words, gypsum delays the setting of cement. The main purpose of adding gypsum in the cement is to slow down the hydration process of cement once it is mixed with water. The hydration process starts when water is added into cement. Water reacts with C3A and hardens. This happens in a very short time, which doesn’t allow cement for transporting, mixing, and placing with construction building material and other useful materials. In presence of gypsum in the cement and water is added to it, reaction with C3A particles takes place to form ettringite (calcium tri sulpho aluminate hydrate). This ettringite is initially formed as very fine-grained crystals, which form a coating on the surface of the C3A particles. These crystals are too small to bridge the gaps between the particles of cement. Therefore, the cement mix remains plastic and workable. This is an important role of gypsum for strength, composition and workability of concrete. The gypsum retards the process of hydration, so it is termed as retarding agent of cement.
Clinker, which has all cementitious properties, after mixing of water it gets set quickly without gypsum. To avoid the quick set and give a workability time gypsum is mixed with clinker in the tune of 4 to 9 per cent (based on the purity of gypsum as CaSO4.2H2O). Limit of BIS for initial setting time is above 30 minutes and final setting is less than 600 minutes. Normally, cement is produced having a setting time between 60 to 150 minutes. We can say gypsum is not only a retarding agent of cement but also provides strength and hardness to cement.
What is the preparation or processing required to make gypsum ready to mix with the clinker?
Gypsum is added to the clinker just before the final grinding to make it into the finished product i.e., cement. Gypsum is a hygroscopic material and is sticky in nature. Its composition and physical characteristics vary from region to region in case of mineral gypsum and purity or quality matters for chemical or synthetic gypsum.
Since, gypsum is used as one of the prime materials in cement and due to its hygroscopic nature, it requires proper cover shed to avoid direct sunlight and moisture. Moisture control is one of the complex handling issues for storage of gypsum and to retain its quality. Therefore, gypsum stockpiles should be stored in a building or a storage in a cover shed which is preferably dry, rain proof and moisture proof.
Due to sticky nature, further procedures of handling, loading, conveying and feeding into cement mills require precautions and robust systems to ease this material flow and feed into cement mills for mixing with clinker. There are, however, alternative sources of gypsum available which may be able to partly substitute natural gypsum. Synthetic gypsum can be produced by using limestone powder with sulphuric acid. For making gypsum limestone to be ground at the fineness of 100 – 200 mm.
Dilute sulphuric acid to be added to the limestone powder as per molar ratio of calcium and sulphate to produce CaSO4.2HO. Gases generated during treatment to be handled by suitable pollution control equipment. Produced gypsum is required to be sun dried till moisture is reduced to the level of 10 to 15 per cent. Solar drying method for removal of moisture is one of the best available, less complex, and economical technologies for drying gypsum where solar radiation is high.

How does automation help in obtaining this mineral and increasing productivity
of the unit?
Any kind of possible automation in the manufacturing process will help increase productivity and sustain business. Right now, UCWL does not have any processing unit for manufacturing gypsum.
To bring down moisture in mineral/chemical/synthetic gypsum at desired level, solar drying method can be adopted. If the solar drying system is controlled with a Programmable Logic Controller (PLC) to check and control the indoor temperature and humidity, lower energy cost and higher material drying performance can be obtained through automation.
However, automation of gypsum manufacturing processes helps to increase productivity and availability. During the synthetic gypsum manufacturing, dosing of sulphuric acid with automation will help to maintain the pH of the mix. Mixing and treatment time regulation is required and can be controlled through automation. Fineness of limestone powder can also be controlled for treatment with sulphuric acid.
What are the sustainability measures taken by your organisation in obtaining and processing the desired quality of gypsum?
UCWL started trials of various industrial waste to use as a set retarder for replacement of gypsum. Our organisation is a pioneer in the utilisation of Jarosite in its cement manufacturing process as a partial substitute of gypsum. JK Lakshmi Cement (JKLC) Group’s research and development department is also working on making gypsum from Limestone rejected through screen during the crushing
of limestone.
Does your organisation recycle gypsum? Tell us more about the process.
Since, once gypsum is added to cement it cannot be recycled, however at UCWL, we are using various materials as a set retarder to replace mineral gypsum.
Other industrial wastes like chemical gypsum are used to the tune of 40 to 60 per cent of the total gypsum in place of mineral or marine gypsum. As I said, for the first time in India, UCWL started use of Jarosite (an industrial waste from the zinc industry’s smelting process) as a part replacement of mineral gypsum. Presently 10 per cent of mineral gypsum is replaced by use of Jarosite.
What are the major challenges faced in handling and obtaining gypsum for the manufacturing process?
The cement industry is a major user of gypsum. India’s domestic resources of gypsum are large enough to meet increased demand. Rajasthan has one of the richest sources of mineral gypsum however, it is a limited natural resource in view of increasing demand of the cement industry as a whole. It is also used for the manufacturing of value-added products like POP. Cement industry is also looking for other alternatives i.e., chemical gypsum, POP waste and industrial waste. Consumption and demand of gypsum will also increase by rapid growth of the cement industry, which leads to increased dependence upon alternatives of mineral gypsum viz. synthetic and chemical gypsum to meet cement demand.
There are two ways to obtain gypsum either from natural resources i.e., mineral gypsum and to some extent marine gypsum or chemical or synthetic gypsum generated from dyes and chemical industries and through flue gas desulphurisation (FGD) process.
To obtain mineral gypsum state-of-the-art technology needs to be adopted for the exploitation of deep-seated gypsum. Synthetic gypsum can be manufactured as per specific requirement and quality depends upon purity of lime.
Major challenges during the manufacturing process of Synthetic Gypsum (SynGyp) are as follows.
a) Availability of sulphuric acid, price variation of sulphuric acid as its availability depends on other industries production and consumption. Sulphuric acid is majorly used by fertiliser manufacturing units, hence, during crop seasons availability of sulfuric acid affects badly.
b) Quality of lime w.r.t. purity
c) Maintenance of Process is comparatively higher.
d) Drying of produced gypsum to get desired level of moisture.
e) Safety measures are required due to the use of sulphuric acid.
Nowadays, FGD generated gypsum is getting more attention among industries. High market demand for FGD gypsum is expected to encourage companies to install FGD systems in their power plants. Research shows that more than 85 per cent of FGD systems installed across the globe are wet systems. Rise of the construction industry and agricultural sector is expected to create opportunities for FGD manufacturers over the coming years, which will aid the expansion of synthetic gypsum market size as well.
Through manufacturing of synthetic gypsum, industry can reduce overall environmental impacts and their carbon footprint. This is a win-win situation for both generators as well as users of the synthetic gypsum (SynGyp). SynGyp is the best sustainable alternative for the environment through conservation of mineral gypsum natural deposits.
-Kanika Mathur

Concrete
CarbonStrong Raises Rs 125 Million To Scale Low Carbon Cement Tech
To build capacity of 100,000 tonnes a year
Published
2 days agoon
August 28, 2026By
admin
CarbonStrong has raised Rs 125 million (125 mn) to scale a low carbon cement technology and build commercial production capacity. The startup was founded in 2022 by Harsh Jain and Vikramaditya Singh and has moved from customer trials to plans for industrial supply. The company said its material replaces up to 50 per cent of cement in concrete while reducing costs and improving durability.
CarbonStrong states the product is around 30 per cent cheaper than cement and compatible with existing concrete plants, reducing the need for new equipment and operational disruption. Trials and paid pilots have been conducted in Bengaluru, Hyderabad and Chennai with demonstration projects involving ready-mix firms and precast manufacturers. Compatibility with current workflows forms a central part of the commercial strategy, aiming to ease adoption by builders and contractors.
The funding will support construction of a facility with capacity of up to 100,000 tonnes (100,000 t) a year over the next two years to supply early customers commercially. The firm is also developing materials from steel slag, copper slag and mine tailings to expand its feedstock base, while noting the technical challenge of homogenising different waste streams. Recognition by HCL ClimaForce in 2026 and by the Avaana-Startup India-NITI Aayog AIM Grand Challenge in 2025 has underscored progress.
Industry adoption remains the principal test and will require consistent material performance, supply reliability and competitive economics. CarbonStrong projects the Indian market for cement substitutes could reach Rs 250 billion (250 bn) by 2030 and has set an ambition to produce 10 million tonnes a year by 2035 (10 mn t), a target far above its near term capacity. Moving from pilots to production demands capital, manufacturing discipline and customers willing to specify the material beyond demonstrations. The recent Rs 125 million raise is intended to fund the next phase of scale and to demonstrate that industrial waste can become a dependable input for lower carbon construction.
In a research-backed article, Dr SB Hegde examines why carbon-adjusted profitability and LC3 will decide the next set of winners in cement manufacturing.
The Indian cement industry has achieved world-class operational efficiency through lower specific energy consumption, high plant utilisation and a reduced average clinker factor of approximately 67.5 per cent. These traditional measures of operational excellence remain essential. However, they are no longer sufficient. Carbon now carries a measurable financial cost under India’s Carbon Credit Trading Scheme (CCTS) and under European carbon markets. Future leadership will be defined by carbon-adjusted profitability, the ability to generate strong returns while systematically lowering the carbon intensity of every ton sold.
Limestone calcined clay cement (LC3) offers a practical, scalable pathway to achieve this dual objective. By replacing up to 50 per cent of clinker with calcined clay and limestone, LC3 can reduce CO2 emissions by 30–40 per cent while delivering comparable or superior durability performance.
This article examines the technical foundations of LC3, European industrial practices, the emerging Indian carbon market and a concrete roadmap for Indian companies to embed carbon-adjusted metrics and LC3 into daily operations, incentives and commercial strategy.
Limits of traditional operational excellence
For many years, plant performance has been judged primarily by five indicators: specific heat consumption, specific power consumption, kiln and mill utilisation, clinker factor and overall equipment effectiveness. These metrics drove continuous improvement and helped the industry reduce energy use and increase the share of blended cement. Three structural changes have rendered them incomplete as sole measures of success.
First, carbon now carries a real or opportunity cost. Plants that improve volume or lower cash cost while raising or stagnating emissions intensity create a hidden liability that will surface as CCTS trading matures and as green procurement expands.
Second, lower-carbon products such as LC3 and high-performance blended cements are creating differentiated market segments. Customers in infrastructure, real estate and export-oriented construction are beginning to specify embodied-carbon limits.
Third, investors and lenders increasingly treat carbon intensity as a financial risk factor. Traditional KPIs can mask the divergence between short-term cash profit and long-term carbon-adjusted value.
What is carbon-adjusted profitability?
Carbon-adjusted profitability evaluates normal profit after explicit adjustment for carbon performance. A practical expression is:
Carbon-Adjusted EBITDA = Conventional EBITDA – Carbon Cost + Green Premium Income
Carbon cost may be an internal carbon price, the actual cost of purchasing Carbon Credit Certificates under CCTS, or the opportunity cost of high emissions relative to peers. Green premium income arises when customers pay more for verified lower-carbon cement or when the company sells surplus credits. Tracking both conventional and carbon-adjusted profit side-by-side gives management a clearer picture of value creation under evolving market rules.
Table 1. Traditional KPIs versus Carbon-Adjusted Leadership Metrics
Traditional Focus New Leadership Metric Why It Matters
Specific energy consumption Emissions intensity (kg CO2/t cement) Directly linked to future CCTS and CBAM costs
Kiln utilisation Carbon-adjusted contribution margin Reveals true value of incremental volume
Clinker factor Share of lower-carbon products sold (incl. LC3) Measures commercial success of the transition
Power cost per tonne Effective carbon cost per tonne sold Expose hidden liabilities
Absolute EBITDA Carbon-adjusted EBITDA + green premium Aligning profit with future market reality
LC3: Technical foundations and performance advantages
LC3 is a ternary blended cement that typically combines approximately 50 per cent clinker, 30 per cent calcined clay, 15 per cent limestone and 5 per cent gypsum (the classic LC3-50 formulation). The decisive technical advantage is that clay is calcined at 700–850 °C, far below the 1,450 °C required for clinker production. This lower temperature, together with the substantial reduction in clinker content, delivers CO2 reductions of 30–40 per cent relative to ordinary Portland cement (OPC).
Chemistry is synergistic. Calcined kaolinitic clay (metakaolin) reacts with calcium hydroxide from clinker hydration and with limestone to form additional C-A-S-H gel and carboaluminate phases. These phases densify the microstructure, reduce porosity and improve durability.
Field experience shows superior resistance to chloride ingress, sulphate attack and alkali–silica reaction. Early-age strength can match OPC with high-reactivity clays; later-age strengths routinely meet 42.5 and 52.5 grade requirements.
Importantly, LC3 does not require high-purity kaolin. Clays with 40 per cent or even lower kaolinite content can be activated successfully, expanding raw-material availability across India. Calcination can use adapted rotary kilns or dedicated flash calciners, making the technology compatible with existing plant infrastructure and far less capital-intensive than carbon capture.
Economic analyses show that LC3 can be produced at equal or lower cost than OPC in many locations because of reduced energy demand and cheaper clay. Life-cycle assessments consistently report 30–40 per cent lower embodied CO2 per tonne of cement.
Table 2. Comparative profile: OPC versus LC3-50
Parameter OPC LC3-50
Typical clinker content ~95 per cent ~50 per cent
CO2 emissions (relative) Baseline (≈0.85 t CO2/t cement process + fuel) 30–40 per cent lower
Clay calcination temperature Not applicable 700–850 °C
Key hydration products C-S-H, portlandite, ettringite C-A-S-H + carboaluminates
Chloride & sulphate resistance Good Superior
Production cost potential Baseline Equal or lower in most locations
Infrastructure compatibility Existing High (minor adaptations)
In India, commercial adoption has begun in earnest. JK Cement commenced the first commercial production of LC3 in the Indian subcontinent at its Mangrol plant in Rajasthan in 2025 under BIS standard IS 18189.
By early 2026, approximately 2,000 tonnes had been produced and sold, avoiding an estimated 500 tonnes of CO2. JK Lakshmi Cement followed with commercial launch of its Green PRO LC3 grade from the Jaykaypuram plant. As of mid-2026, two producers are supplying LC3 to the market. The first large-scale infrastructure application is the Noida International Airport (Jewar), where LC3 was used in the runway and a building complex, demonstrating full constructability and performance under demanding conditions. These early volumes are still small relative to national cement demand, but they mark the critical transition from pilot to commercial reality. Companies that scale capacity now will be positioned to capture both CCTS credits and emerging green-procurement demand.
Why the shift is accelerating
According to the World Bank’s State and Trends of Carbon Pricing 2026, direct carbon pricing now covers nearly 30 per cent of global greenhouse-gas emissions and generated more than US$107 billion in public revenue in 2025. The average global carbon price stands at approximately US$21 per tonne, although regional prices vary widely.
In Europe, the EU ETS price has traded near €80–85 per tonen in mid-2026. Free allocation for cement is being withdrawn in parallel with CBAM. European producers therefore face a clear signal: every tonne of avoided CO2 improves both compliance and competitiveness. Holcim has scaled calcined-clay production, including Europe’s first dedicated line at Saint-Pierre-la-Cour (France) and a second line in the Czech Republic (2026). Heidelberg Materials, Cementir (FUTURECEM) and others have commercialised low-clinker calcined-clay blends across multiple markets, showing that carbon-adjusted profitability is already reshaping capital allocation in the world’s most mature carbon market.India’s CCTS is now operational. Binding emission intensity targets apply to 186 cement facilities for FY 2025–26 and FY 2026–27. Average required reductions for integrated plants are modest (around 2.7 per cent by FY 2027), yet the direction is clear.
Trading of Carbon Credit Certificates is expected in the second half of 2026, with early prices likely in the `800–1,500 per tonne range. Plants that outperform targets can sell credits; those that underperform must buy them or face compensation. Cement is well positioned to be a net supplier of credits if clinker factor continues to fall through LC3 and other low-clinker systems.
Way forward for India
India starts from a strong baseline, world-class energy efficiency and a clinker factor already lower than the global average. The next competitive frontier is the deliberate reduction of process emissions through clinker substitution at scale. LC3 is uniquely suited to Indian conditions because suitable clays are widely distributed, the technology fits existing kiln and grinding infrastructure, and the resulting product can meet the performance demands of both infrastructure and building construction.
A practical national pathway contains five interlocking elements:
- Standards and acceptance: Accelerated finalisation and promotion of BIS specifications for calcined-clay and limestone–calcined-clay cements will remove a key barrier to commercial uptake. Alignment with European practice (EN 197-5) can facilitate knowledge transfer and export readiness.
- Supply-chain development: Investment in flash calcination capacity and systematic characterisation of regional clay deposits will secure reliable, low-cost feedstock. Existing rotary kilns can be adapted for initial volumes while dedicated calciners are built.
- Incentive alignment: Part of variable compensation for plant managers, sales teams and senior leadership should be linked to emissions intensity reduction and to the volume of lower-carbon products (including LC3) sold. Without this link, traditional volume and cost targets will continue to dominate behaviour.
- Product-level carbon accounting: Reliable measurement of emissions intensity at the individual cement grade level, supported by third-party verification where required, is essential for both CCTS compliance and credible green claims.
- Demand-side pull: Green public procurement policies that specify maximum embodied-carbon thresholds for major infrastructure projects will create a predictable market for LC3 and other low-carbon cements, accelerating scale and cost reduction.
Companies that treat LC3 as a strategic product line rather than a niche offering will be better positioned to generate surplus Carbon Credit Certificates, capture any emerging green premium, and protect margins as carbon costs rise.
Organisational changes required
Technical capability alone is insufficient. Three organisational shifts are required.
Daily management: Emissions intensity must appear on the same daily and monthly dashboards as heat consumption, power consumption and utilization. Plant reviews should examine both conventional and carbon-adjusted results.
Incentives: A meaningful portion of bonuses for plant heads, technical teams and sales leadership should be tied to lower emissions intensity and successful commercialisation of LC3 and other low-carbon grades.
Commercial approach: Sales teams need clear volume and pricing targets for lower-carbon products, supported by technical service that helps customers specify and place the material correctly. Without commercial pull, excellent technical performance remains under-utilised.
Table 3. Three-stage roadmap to carbon-adjusted profitability
Time Horizon Priority Actions Expected Outcome
Next 12 months Add emissions intensity to plant dashboards; establish internal carbon price; initiate LC3 pilot production and customer trials Visibility and early organisational learning
12–24 months Revise incentive systems; scale LC3 and other low-carbon grades to key accounts; secure third-party verification capability People and sales aligned with carbon goals
24–36 months Embed carbon-adjusted metrics in board reporting and capital allocation; expand calcined-clay capacity Full system integration and competitive advantage
Questions senior leaders should ask
Boards can accelerate the transition by insisting on answers to a short list of questions:
• Is our carbon-adjusted profit improving, stable or declining relative to conventional EBITDA?
• Did recent volume growth improve or worsen our emissions intensity?
• What share of sales already comes from lower-carbon products, including LC3, and what is the trajectory?
• How exposed is our capital expenditure plan to rising carbon costs under CCTS and potential CBAM-related requirements?
• Do our incentive systems still reward only volume and cost, or have they been updated to include carbon performance?
Treating carbon with the same seriousness as energy cost or kiln utilization does not diminish operational excellence; it expands the definition of excellence to match the new competitive reality.
Looking ahead
By 2030 the gap between leading and lagging cement companies will not be decided by who records the lowest specific heat consumption. It will be decided by who delivers the strongest carbon-adjusted profits.
Absolute emissions may still rise as national production grows. That is not the issue. Companies that reduce intensity year after year and successfully sell cleaner products will pull ahead in both domestic and export markets. Those that do not will fall behind, even if their traditional efficiency numbers look strong.
Operational excellence built the Indian cement industry. It remains the foundation. It is no longer the complete picture. Carbon-adjusted profitability is the clearer measure of success.
LC3 is not a distant technology. It is available now. It cuts CO3 by 30–40 per cent, works with existing plants, and is already in commercial production in India. Companies that treat it as a strategic product, not a pilot, will protect their margins and generate tradable credits.
Leaders who act now will place carbon metrics on daily dashboards, link incentives to intensity reduction and LC3 sales, invest in calcined-clay capacity, and build commercial capability to sell lower-carbon products. They will shape the next chapter of the industry.
References
- World Bank. (2026). State and Trends of Carbon Pricing 2026. Washington, DC: World Bank Group.
- International Carbon Action Partnership (ICAP). (2026). India Carbon Credit Trading Scheme – Status and Coverage. Berlin: ICAP.
- Ministry of Environment, Forest and Climate Change / Bureau of Energy Efficiency. (2025). Greenhouse Gases Emission Intensity Target Rules, 2025. New Delhi: Government of India.
- Scrivener, K., Martirena, F., Bishnoi, S., & Maity, S. (2018). Calcined clay limestone cements (LC3). Cement and Concrete Research, 114, 49–56.
- RMI. (2024). The Business Case for LC3. Rocky Mountain Institute.
- European Commission. (2026). EU Emissions Trading System – Allowance Price Data and Free Allocation Phase-out Schedule. Brussels.
- Holcim. (2025–2026). Scaling Calcined Clay for Sustainable Building – Corporate Updates on European and Latin American Capacity. Zurich: Holcim Ltd.
- LC3 Project / EPFL. (2026). LC3 – A Guide to Best Practices for Scalable, Affordable and Sustainable Low-Carbon Building. Lausanne: École Polytechnique Fédérale de Lausanne.
- Business Today / Industry Reports. (2026). First Large-Scale LC3 Application at Noida International Airport, Jewar. New Delhi.
- NITI Aayog / Industry Analyses. (2026). Roadmap and Baseline Performance Indicators for the Indian Cement Sector. New Delhi.
- Springer / Innovative Infrastructure Solutions. (2026). LC3 Systems: A Review of Chemistry, Performance, Durability and Sustainability toward Market Adoption.
- Cementir Holding / Industry Sources. (2025–2026). FUTURECEM and Related Low-Clinker Technologies in Europe.
- Climate Risk Horizons & Independent Analyses. (2026). Assessment of Emission Intensity Targets under India’s CCTS for Cement and Other Hard-to-Abate Sectors.
- GCCA / TERI. (Various years). Decarbonization Roadmaps for the Indian Cement Industry.
- EN 197-5:2021. Cement – Part 5: Portland-composite cement CEM II/C-M and Composite cement CEM VI. European Committee for Standardization.
Concrete
More Oversight Makes Cement Plants Less Safe
Published
2 days agoon
August 28, 2026By
admin
Dijam Panigrahi makes a counterintuitive but data-backed argument that routing every sensor alert through human approval does not make cement plants safer.
India’s cement industry has spent the last two years wiring kilns, mills and coolers with sensors and automated control systems, and the safety case for doing so is strong on paper. Contract workers still make up the majority of the industry’s workforce, and fatal accidents remain a recurring problem. The Indian National Cement Workers Federation has noted that around 83 per cent of workers in the sector hold precarious positions, a fact that resurfaced after an oxygen cylinder explosion killed three contract workers at a plant in Chhattisgarh.
Industry tallies compiled by IndustriALL found cement plants recorded at least seventeen accidents in one year with 21 workers killed, and ten accidents the following year with nine killed, most of them contract staff. Automated monitoring, in theory, closes that gap. A sensor never gets complacent and never skips a check because a shift is short staffed.
However, plants that respond by routing every anomaly reading to a person for approval are quietly building a system that fails the same way understaffing does. When operators receive dozens of flagged deviations a shift, most of them minor, they learn a simple lesson: the fastest way through the queue is to approve without reading closely. The safety benefit disappears, not because the technology failed, but because the humans supervising it adapted to the volume.
Why alerts get ignored
A study cited by manufacturing technology publisher Applied SmartFactory found more than 95 per cent of alarms in a semiconductor fab were low priority, and only about 4 per cent ever triggered an action, with just 100 out of 5,000 alarms accounting for 70 per cent of all alarm activity. The mechanism is the same whether the trigger is a vibration sensor or an AI model flagging a kiln temperature swing. Once the ratio of noise to signal crosses a threshold, workers stop treating the system as a decision aid and start treating it as a formality to clear.
The scale of AI deployment underway makes this more than a theoretical risk. Stanford’s 2026 AI Index Report found organisational adoption of AI has reached 88 per cent, even as documented AI incidents rose to 362 in 2025, up sharply from 233 the year before, according to analysis of the report. The Index also found only about a third of organisations have adopted a formal governance framework, with NIST’s AI Risk Management Framework cited by 33 per cent and ISO/IEC 42001 cited by 36 per cent.
Most manufacturers are deploying monitoring systems faster than they are building the judgment for when a flagged event actually needs a person’s attention. In India, plants run by JK Cement have begun pairing CCTV feeds with AI to define safe zones around heavy machinery, a promising direction that still depends on operators trusting and reading the alerts the system generates.
A three-tier model for cement plant
The fix is not less monitoring or more monitoring. It is classifying decisions by risk and by novelty, rather than treating human oversight as a single switch that is either on or off. A workable model sorts factory floor events into three tiers.
The first tier, proceed, covers deviations the plant has seen before that fall within known safe bounds, such as a kiln feed rate adjustment within an established range. These should run without a stop for approval, because routing them to a person only trains that person to click through.
The second tier, pause, covers events that are unusual but not yet dangerous, such as a vibration reading trending toward a limit or a fuel blend shifting outside its typical mix. These warrant a brief human check before the system proceeds, giving an operator the chance to apply judgment the model does not yet have.
The third tier, escalate, covers events that are both high risk and unfamiliar, such as a pressure reading combined with a temperature spike that has no close precedent in the plant’s history. These should stop the process entirely and require a decision from someone with the authority to shut down a line.
Who should set the threshold
Where these tiers get drawn matters as much as the framework itself. Threshold setting is frequently handed to the vendor supplying the monitoring software or to a plant’s IT department, both of which understand the technology but not the specific tolerances of a given kiln, mill or line. Operations staff, who know that a particular grinding unit runs hotter under monsoon humidity or that a calciner behaves differently after a refractory reline, are better positioned to calibrate what counts as routine on their own equipment.
Handing threshold ownership to operations does not remove IT or vendors from the process, but it puts the calibration decision closest to the people who live with its consequences on the floor.
Signals that oversight is actually working
A few concrete indicators reveal whether a monitoring setup is functioning as intended or simply providing the appearance of safety. The escalation rate over time is the first: a rate that stays flat or climbs slowly as operations mature is healthy, while one that spikes and then falls sharply often means operators have started overriding the system rather than engaging with it. Time to resolution is the second: escalations that take progressively longer to close suggest fatigue or confusion about ownership, not diligence. The third, and most telling, is how accurate the system’s own uncertainty estimates turn out to be, meaning whether events flagged as high risk actually correlated with real incidents, and whether events waved through stayed incident free. A system whose escalations do not track with actual outcomes trains operators toward the same complacency that unmonitored equipment produces.
None of this argues against automation in Indian cement manufacturing, where a labor structure built on contract work and a track record of serious accidents make better monitoring an urgent need. It argues for treating human oversight as a design problem with three distinct settings, rather than a single
dial turned up whenever a plant wants to look safer on paper.
About the author:
Dijam Panigrahi, Co-founder and COO, GridRaster, is a spatial computing platform for industrial enterprises and manufacturers.
CarbonStrong Raises Rs 125 Million To Scale Low Carbon Cement Tech
Protect Your Margins
More Oversight Makes Cement Plants Less Safe
The biggest gap arises from inconsistent leadership
The Future of Vertical Material Handling
CarbonStrong Raises Rs 125 Million To Scale Low Carbon Cement Tech
Protect Your Margins
More Oversight Makes Cement Plants Less Safe
The biggest gap arises from inconsistent leadership

