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Cement industry will take a ready-mix concrete route

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– Anil Banchhor,MD and CEO of RDC Concrete

Can you briefly introduce RDC concrete to our readers? Please tell us about your pan India presence and capacity as of March 31, 2021.

RDC concrete is the pioneer of the commercial ready-mix concrete industry in India. The first commercial plant was established in 1993 in Mumbai as a JV between RDC of Singapore and UNITEC developers. The earlier name of the company was Unitech Prefab. In the year 2000, RDC Singapore took over 100 per cent of equity and the name of the company changed to RDC Concrete India. At that time, RDC concrete of Singapore was also having a presence in several other countries like Malaysia, Vietnam, Indonesia, Hongkong, etc.

In the year 2005, Truenorth a PE fund (India value fund) took over RDC, but the name RDC concrete continued as the brand name was strongly associated with quality and service. In the portfolio of Truenorth PE fund, there are about 25 companies from various sectors like cement, aggregates, banking, home financing, technology, logistics, FMCG, pharma, services, etc. RDC concrete has 51 plants across India with a capacity of 25 lac m3 concrete per year.

The year 2020 was critical for every industry. To what extent your business got affected due to the pandemic? How was the recovery?

In our RMC industry, work from home is not possible as all actions happen at factories for production, deliveries, and pumping at the site. When the lockdown was imposed, we kept two batchers within the plant and their job was to keep the equipment in good condition and take dry runs at regular intervals so that we are fully prepared once the lockdown is lifted. We kept a check on the functioning of the plants through video calls. This way, we kept the powder dry and started firing on all cylinders, when lockdown ended.

We did a 20 per cent lower volume in the last financial year as compared to FY 2020, but we were successful in exceeding the EBITDA of the previous year, despite Covid-19. Q1 was a complete washout after the lockdown was imposed after 23rd March. But we were the first to restart plants in Mumbai on 13th April and then all plants opened gradually. Q2 was like breakeven. Q3 and Q4 were really good, and we could produce 17.5 lac m3 concrete. Profitability wise we improved over previous year numbers due to reduction in fixed costs. Our truck hiring model was changed from fixed rental per month to variable model on a km run basis. Also, we were successful in reducing costs such as power, water, wastages, etc on the plant operations level.

What about cash flow?

Cash flow was a matter of concern and we increased focus on collections. Many clients were not paying dues, but we kept on paying our vendors because they have been associated with us for a long time. Slowly all customers started paying in parts, which we kept rotating back in our business.

As a leader how do you keep the morale of the employees high during the pandemic time?

Morale is infectious. If the morale of a leader is high, then the morale of the whole team remains high. The morale of all our business heads was high and this is in our culture. They just do not give instructions, but they lead from the front. When the concrete was required for a government project in Mumbai, our plants were started immediately. Our Mumbai Business head was present at the plant for the smooth delivery of concrete. I remember that this happened on 13th April in the Sakinaka area of Mumbai. This kind of leadership action boosted the morale of the team.

We made an Emergency Response Team called ERT consisting of two people from each city and two people from the head office. The job of ERT was to call every employee at regular intervals for improved communication and to check the well-being of their family members. They provided immediate assistance in case of any hospitalisation.

We also introduced daily health declarations by all employees, including family members, through google form about their health status like temperature, cough, oxygen level to quickly identify issues and to provide immediate support.

We purchased O2 concentrators for each location and kept them in readiness for any emergency requirements. Plants were sanitised regularly. We followed all protocols related to wearing a mask, hand washing, and social distancing. We had taken the Apollo home care package and all employees with families were covered in it. Apollo doctors were calling the patients two times a day through web calls and checking all vital parameters. Medicines, oximeters, thermometers were delivered to their homes regularly. Regular video calls by psychologists and dieticians were arranged for them. As a result, the number of people infected in our company was very low.

We have also given 14 days special leave provision for those who got infected from Corona, apart from 42 days of Earned leave. To my knowledge, no other company from our industry has given such additional leave provision. We did not sack any staff during Covid-19, and no salary deduction was done. We enhanced the life insurance coverage at the beginning of the first Covid impact. At the lower level pay scale, it worked out to be 10 years of CTC and that is quite impactful.

Tell us about your preparedness for the second wave or maybe the subsequent third wave?

Everything was looking good in December-January, and then suddenly the second wave hit India, which was more infectious. Since many SOPs were in place during the first wave of Covid, we simply rolled it out again. We were ready but were only constrained by the government’s orders. Otherwise, our people are geared to work in any wave now. Our Emergency response Team ??RT??strong> swung into action and started enquiring with all staff members to check their well-being and assist, if needed. Our group company Truenoth is having about 25 companies and a network of all HR heads who started regular web meetings for supporting each other. We continued with the Apollo home package.

We also made a list of plasma donors within the company and shared it with other sister companies for any urgent requirements. Additional Covid leave of 14 days is already in place. This was our preparedness for the second wave.

What is the current situation? How many of your plants are functional?

Kerala is fully locked down and no plant is running there. Gurgaon is fully closed too. Few of the cities are having a weekend lockdown and we cannot operate on weekends. Our volume has come down to 40-50 percent of the normal.

Many companies increased their technology penetration during Covid. How has RDC leveraged technology to enhance efficiency and effectiveness?

We already have good technology penetration in RDC. All our plants are online including all incoming material systems and outgoing supplies. Further enhancement was made on the technology during the Covid period, and we were able to reduce the paper consumption significantly.

Earlier, all incoming trucks with raw materials were coming with paper challans and we converted them to e challan with QR code. Hence all points of contact were eliminated, and this helped us in reducing the spread of infection. This led to a drastic reduction in paper consumption. All outgoing delivery challans were converted to e challan for all customers except a few who still wanted paper challans compulsorily. In our industry, people are not very tech-savvy, and many customers still want everything in hard copies. Whereas we do not want any hard copy from any of our vendors.

Our IT penetration has reached all employees. Training is online, the production system is online, logistics is online, all documents are on the server. All employee claim forms and documents were converted to a digital platform including all approvals. Papers have been dispensed with and everything moves electronically by DMS. Another major technology penetration is an e-learning tool called E Diksha. We took advantage of the available time and opportunity to train all staff in plant operations, logistics, quality controls, materials management, and general management programmes through web training.

We also developed interesting business simulation games, which were done completely in-house. These simulation games are for all business managers to sharpen their decision-making skills in a real-life situation. We are the only company in our industry to have such business simulation games. We run business games for three to four quarters and results are declared after every quarter. Feedback is also given, after every quarter, as to what went well and what needs improvement. This has helped significantly in improving leadership skills.

On the technology front, we developed a manless weighbridge based on QR code and RFID. All weighbridges are fitted with three cameras and two RFID readers. The supplier gets material receipt notification with a pdf copy by mail along with six photographs.

We introduced Petro cards issued by oil companies and gave them to transporters. As soon as the diesel is dispensed from petrol pumps through petro card, automatic GRN entry reflects in our ERP. In the plant, we also developed an automated diesel dispensing system with ERP integration. Whatever diesel is drawn, the automatic diesel issue gets recorded in ERP.

All HR-related items have been shifted to zing HR, like KPI, performance review, compensation, leave approvals, salary slips, form 16, mediclaim, etc. Silo stock measurement has also been developed with automation and is being implemented after a successful pilot in three to four plants.

Do you think it is a fallout of the Covid wave or otherwise also you would have persuaded the same this time?

Due to Covid-19, we could get time since all the plants were closed and we could spend some energy on it. The other reason is we always wanted to go paperless. Paper is one cause for spreading infections. We are moving towards paperless RDC.

How do you foresee business in the year 2021-22? Especially taking into account the spread of the 2nd wave of coronavirus and maybe 3rd a little later?

In April, volumes were down by 20 per cent. In May, the business came down by 40 per cent of the normal months. It seems that this will continue in June also. I expect things will start moving upward from July before it reaches normalcy in October. By this time, more vaccinations will happen and infrastructure in hospitals would also improve to a great extent to tackle the third wave. We have tied up with Apollo hospitals for the vaccination of all our staff and their family members. Preparedness of all agencies would be better during the third wave in all cities, and I feel that the impact would be much lower. I am confident that all businesses will bounce back after November, and we will do better than last year.

Give us some idea about the safety aspects of your operations? How do you engage employees in making safety a matter of daily routine? How coronavirus impacted the safety at your plants and offices?

In RDC Concrete, safety is taken as a priority item. Safety Toolbox talk meetings are happening at plants on a daily and weekly basis. Compliance on safety initiatives, hazard identification, and rectification are reviewed on a weekly and monthly basis. We keep on improving safety through various new safety initiatives. We also ensure that the best practice of one plant is replicated in other plants quickly.

KPI of all employees is having 20 per cent weightage on safety. Even the staff at the head office must go to the plant every quarter to complete a safety audit of the plant. We have a quarterly interplant competition on Safety and productivity called ??artaj??and safety has 38 per cent weightage in the competition.

The winning plant is awarded with a rolling trophy with one lac cash award for staff engagement with certificates for all plant staff. Runner up plant gets Rs 50,000 for party or people engagement activities. RDC concrete is the only RMC company which is having such interplant completion on safety and productivity.

The safety officer visits each plant in a year and conducts audits. During this pandemic, video audits are being done. Apart from this, we have internal and external statutory auditors, and they also check safety compliance in the plant and bring out issues if there are any. Safety related to Coronavirus is the most important aspect now. The well-being of employees is the foremost priority at present and not the business. If employees are taken care of, the business will bounce back later. We are taking all precautions for the protection of staff and their family members during this challenging time.

We have tied up with Apollo for vaccination of all staff including their family members. We made vaccination compulsory for each staff member. About 95% of staff including their family members are already vaccinated as of the date.

How do you manage the shortage of sand in making concrete?

River sand is being used mostly in the north and eastern part of India, otherwise in most of the states use of river sand for concrete making is banned. All grades of concrete including high grades up to M120 and high-performance concrete are being produced with crushed sand or manufactured sand. Even concrete structures in coastal zones which are exposed to the extreme weather conditions and durability is foremost important, are being made with crushed sand. In fact, we should not be using river sand at all. Customer acceptance in some locations is a challenge and not the availability of river sand. Slowly all locations are seeing improved customer acceptability.

Normally the river sand is rounded whereas crushed has angular particles which give a kind of harshness to concrete. How is this problem addressed?

With proper proportioning of the ingredients like 10 mm, 20 mm, sand, and the finer material fly ash and cement together should give a cohesive mix of concrete. Let us not forget about the admixtures. Today we get good and consistent quality of admixtures, which helps in producing self-compacting concrete even with crushed sand, which can be used for very thin sections and is easily pourable. All this put together takes care of the angularity of manufactured sand. The manufactured sand produced using a vertical shaft impact (VSI) crusher is much better in shape and angularity. While sourcing the material we make sure that the supplier uses a VSI crusher.

What are the disadvantages of being a non-cement player in concrete business? I agree that being a non-cement RMC player is a challenge but there are opportunities also, which makes us more efficient, more productive, and agile, leading to better service to the customers. Let me admit that the cement and concrete together are a very good combination. However, it does not mean that a non-cement player cannot work. In fact, he can turn it into an opportunity to be a more efficient player, which we are. In fact, all cement players must have concrete as a channel. We had seen in practical terms that in combination, cement EBITDA gets doubled or more than double, if the cement company is having RMC as a channel.

In the last few years, there has been a boom in the RMC industry and the cement consumption through the RMC route is increasing every day. RMC penetration in tier 2 and tier 3 cities are increasing. Headache of manual mixing is a challenge due to the shortage of workers and wastages. Architects are also recommending the use of RMC for better quality and durability of the concrete structure.

Which are the highest-selling grades of concrete for metro work and for real estate? What are the challenges associated with supplying these grades?

For metro jobs, generally, M40 and M30 grades are being used. For the precast segment higher grades like M50 are also being used for early stripping of formwork. In commercial or residential projects, general grades are M40 and M30. For columns, M60 is being used. For high-rise skyscraper projects, we have supplied even M95 grades also in Mumbai and other metro cities.

Quality control on raw materials and the skill set of people are very important for high grades and there is no challenge for us in this regard as our in-house team is quite competent and motivated. We have done many metro captive jobs in many cities and at present, five metro captive jobs are running in different cities. We are also supplying a lot of concrete from commercial plants as well to metro projects. Managing transit mixer truck movement is the only challenge during peak traffic in cities.

What do you see 5 years, 10 years down the line about the ready mixed concrete business? What kind of sophistication do you think can come in?

The RMC industry will keep growing at about 18 to 20 per cent CAGR and more and more cement will move through the ready-mix concrete route. Trade sales will keep on coming down over a period. Because of increased RMC penetration, more cement needs to be delivered in bulk. Cement companies need to create bulk terminals near cities for quicker delivery. Such cement companies would be at an advantage. More penetration will come in tier 2 and 3 cities as the high-rise building construction will increase in such cities apart from metros. Individual house constructions are getting reduced. Builders and developers are launching new projects in tier 2, 3 cities. A lot of commercial complexes, malls are being built. All these constructions are using batching plants with bulk supplies.

At present, there are about 2,500 commercial RMC plants and about 7,000 captive plants of contractors and construction companies. This number will keep on growing and within the next 8-10 years, this number is expected to double. Automation will increase in RMC and more mechanised construction will take place leading to higher productivity per person.

Many cities are having a lot of traffic restrictions for truck movement. So, the time available to service to customers is getting reduced. This will lead to a higher capacity of plants and a higher capacity of transit mixers. At present we use trucks with a capacity of 6-7 cum of concrete that will go to 8-10 cum of concrete. More and more use of concrete pumps will take place. Hence bigger size plants are required in outskirts of the city.

Anil Banchhor is Managing Director and CEO of RDC Concrete. He is a professionally qualified civil engineer. Initially, started from construction and then moved to cement marketing and to ready mixed business. He was associated with ACC, rose to the position of CEO- RMX, and then moved on to RDC concrete.

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Concrete

JSW Cement aims to launch Rs 4,000-crore IPO in Jan 2025

SEBI had put the IPO on hold in September.

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JSW Cement plans to launch its Rs 4,000-crore initial public offering (IPO) in January 2025, according to JSW Group chairman Sajjan Jindal. The Securities and Exchange Board of India (SEBI) had previously paused the IPO in September 2023.

The IPO will consist of two parts: a fresh issue of equity shares worth Rs 2,000 crore and an offer-for-sale (OFS) of Rs 2,000 crore by existing shareholders. Under the OFS, AP Asia Opportunistic Holdings Pte. Ltd and Synergy Metals Investments Holding Ltd will each sell shares worth Rs 937.5 crore, while the State Bank of India (SBI) will divest shares valued at Rs 125 crore.

The company intends to use Rs 800 crore of the proceeds from the fresh issue to help finance the establishment of a new integrated cement plant in Nagaur, Rajasthan. An additional Rs 720 crore will be allocated for debt repayment, with the remaining funds earmarked for general corporate purposes.

JSW Cement, which currently has a manufacturing capacity of 19 million tons per annum (MTPA), aims to increase this to 60 MTPA. Its existing manufacturing units are located in Vijayanagar (Karnataka), Nandyal (Andhra Pradesh), Salboni (West Bengal), Jajpur (Odisha), and Dolvi (Maharashtra). Additionally, through its subsidiary Shiva Cement, the company operates a clinker unit in Odisha.

JSW Group has a diverse business portfolio spanning sectors such as steel, energy, maritime infrastructure, defense, B2B e-commerce, real estate, paints, sports, and venture capital. The group’s last IPO was that of JSW Infra.

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Balancing Demand and Sustainability

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ICR discusses India’s rapid advances in renewable energy, on track to exceed its 2030 targets, even as the rising energy demands challenge complete reliance on sustainable sources.

The cement industry, a cornerstone of infrastructure development, has long been associated with high emissions, particularly of CO2. This sector alone is responsible for approximately 8 per cent of global carbon dioxide emissions, primarily due to the energy-intensive processes of clinker production and calcination. Beyond carbon emissions, cement production also generates particulates, nitrogen oxides (NOx), sulphur oxides (SOx), and other pollutants, contributing to environmental degradation and health risks. With the global push towards sustainable practices and carbon neutrality, addressing emissions in the cement industry has become imperative.
According to Climate Change Performance Index, India ranks 7 in 2024. India receives a high ranking in the GHG Emissions and Energy Use categories, but a medium in Climate Policy and Renewable Energy, as in the previous year. While India is the world’s most populous country, it has relatively low per capita emissions. Data shows that in the per capita GHG category, the country is on track to meet a benchmark of well below 2°C.
India’s situation underscores the complexity of transitioning to sustainable energy systems in the face of rising and fluctuating energy needs. International support is crucial for India to access advanced technologies, financial resources, and best practices that can accelerate its transition to a sustainable energy future. Our analysis shows that with current policies, India will overachieve its conditional NDC targets of achieving 50 per cent non-fossil capacity by 2030, so it could set stronger targets. India has ambitious renewable energy plans as outlined in the National Electricity Plan 2023 (NEP2023) aiming for a share of installed capacity of 57 per cent and 66 per cent in 2026-27 and 2031-32, respectively. Share of renewable energy capacity in India reached 44 per cent, ranked fourth in the world in renewable energy capacity installations in 2023, after China, the US and Germany. The NEP2023 is reflected in the lower bound of our current policy and action pathway.
India has seen a steady increase in renewable energy deployment, including both utility-scale and rooftop solar, leading to the share of coal capacity dropping below 50 per cent for the first time. However, this increase in renewable energy capacity is barely able to keep up with the surging demand. As a result, the electricity generation share of renewable energy, including large hydro, remains at around 18 per cent, showing no improvement since last year. Investment in renewable energy projects in India are projected to increase by over 83 per cent to around USD 16.5 bn in 2024, with fossil fuel companies also diversifying their investments into the renewable sector. Despite this, India has not committed to phasing out coal power or fossil gas.
The National Electricity Plan indicated a temporary halt in coal capacity addition, but current under-construction capacity exceeds the threshold stated in these plans. While new gas power projects have been abandoned, the utilisation of existing gas power plants has increased to meet energy demand driven by severe heat stress.

Understanding Emissions in Cement Production
Primary Sources of Emissions: Cement production emissions stem mainly from three sources: calcination, fuel combustion, and electricity use. During calcination, limestone is heated to produce clinker, releasing CO2 as a by-product. This process alone accounts for roughly 60 per cent of emissions in cement manufacturing. The remaining emissions result from burning fossil fuels in kilns to achieve the high temperatures needed for calcination and from electricity consumption across production stages.
Raju Ramchandran, SVP Manufacturing (Cluster Head – Central), Nuvoco Vistas, says, “We consistently track air emissions from fuel combustion in our cement manufacturing and power generation operations. The burning of fossil fuels releases pollutants such as Oxides of Sulphur (SOx), Oxides of Nitrogen (NOx), and Particulate Matter (PM), which require stringent monitoring.”
“We ensure compliance with regulatory standards by using the Continuous Emission Monitoring System (CEMS) to monitor these emissions. For the FY 23-24, both our stack and fugitive emissions have stayed within the permissible limits set by Pollution Control Boards. Moreover, our ongoing monitoring of fugitive emissions ensures that we meet the prerequisite air quality standards,” he adds.
In addition to CO2, the cement industry releases various pollutants that pose risks to air quality and public health. These include particulate matter, NOx, and SOx, which can lead to respiratory and cardiovascular issues, acid rain, and ecosystem imbalances.
Governments worldwide are setting increasingly stringent regulations to curb industrial emissions. Standards such as the EU Emissions Trading System and India’s National Action Plan on Climate Change encourage cement manufacturers to adopt cleaner technologies. Many countries now impose limits on NOx, SOx and particulate emissions, with the aim of minimising the industry’s environmental impact.

Challenges in Reducing Emissions
High carbon intensity of cement production: Cement’s high carbon intensity largely stems from the chemical reactions involved in transforming limestone into clinker, making emissions difficult to reduce without altering core processes. Additionally, achieving the necessary kiln temperatures requires significant energy, often derived from coal or natural gas.
Operational limitations: Altering the traditional cement production process can compromise the quality and durability of the end product. Adapting existing production lines for lower emissions involves extensive R&D and technical trials to ensure the finished cement meets industry standards.
Financial constraints: The cost of implementing green technology is high, creating economic challenges, particularly for smaller cement manufacturers. Equipment upgrades, energy-efficient kilns, and carbon capture facilities require considerable investment, which many companies find difficult to justify without strong financial incentives.
Balancing market demands and environmental goals: With global infrastructure demands rising, the cement industry faces pressure to meet growing production needs while simultaneously working to reduce emissions. Balancing these competing demands requires innovation, efficient resource management, and support from stakeholders.

Technological Innovations for Emission Reduction
Alternative fuels and energy sources: One of the most effective ways to reduce emissions is by replacing fossil fuels with alternatives like waste-derived fuels, biomass, or biofuels. Some manufacturers are incorporating solar and wind energy to power auxiliary processes, further reducing reliance on traditional energy sources.
Sudhir Pathak, Head- Central Design & Engg (CDE), QA, Green Hydrogen, Hero Future Energies, says, “The cement industry is one of the largest consumers of grid power (Scope 2) and also a guzzler of in-process fossil CO2 (Scopem1) including process-based CO2 through limekilns. Decarbonisation can be achieved only up to 50 per cent to 60 per cent through plain hybrid solar and wind. However, for achieving balance 40 per cent, storage is essential, be it chemical or mechanical. Today, HFE is ready to provide such bespoke storage solutions as is evident through several complex RTC tenders that we have won in the last 6-8 months floated by agencies like SECI, NTPC and SJVN. These include tenders for FDRE projects, peak power, load following, etc. Further, regarding green hydrogen and its derivatives, we are ready to apply these for decarbonising industrial heating and mobility.”
Carbon Capture and Storage (CCS): CCS technology captures emissions at the source, storing CO2 to prevent it from entering the atmosphere. Recent advancements in CCS technology make it a viable option for large-scale cement plants, although high costs and infrastructure requirements remain obstacles to widespread adoption.
Clinker Substitution: Reducing clinker content is a promising method for emission reduction, achieved by using supplementary cementitious materials (SCMs) such as fly ash, slag, and calcined clay. These materials not only reduce CO2 emissions but also enhance the durability and performance of cement. SCMs are gradually becoming industry-standard components, especially in eco-friendly and green cement products.
Rajesh Kumar Nayma, Assistant General Manager – Environment, Wonder Cement, says, “The use of AFR plays a critical role in our strategy to reduce the environmental footprint of cement production. By substituting traditional fossil fuels with waste-derived alternatives like biomass, refuse-derived fuel (RDF) and industrial by-products, we significantly lower CO2 emissions and reduce the demand for natural resources. The utilisation of supplementary cementitious materials (SCMs), such as fly ash, helps in reducing clinker consumption, which is a major source of carbon emissions in cement production. This not only decreases our reliance on energy-intensive processes but also promotes waste recycling and resource efficiency. AFR adoption is an integral part of our commitment to the circular economy, ensuring that we minimise waste and optimise the use of materials throughout the production cycle, ultimately contributing to a more sustainable and eco-friendly cement industry.”
“WCL is exploring transitioning from fossil fuels to cleaner alternatives like biofuels or hydrogen or RDF/plastic waste/other hazardous waste. Till date, 5 per cent TSR has been achieved, while the intent is to achieve more than 20 per cent TSR. WCL is utilising the hazardous and other waste as an alternative fuel or raw material. We have used more than 3 lakh metric tonne of hydrogen waste and other waste in FY-2023-24,” he adds.
Improving energy efficiency is critical for emissions reduction. Technologies like high-efficiency kilns, heat recovery systems, and process optimisation techniques are helping manufacturers achieve more output with less energy. These measures reduce the carbon footprint while lowering operational costs.

The Role of SCMs
SCMs serve as partial replacements for clinker, providing a dual benefit of reduced carbon emissions and improved product resilience. The use of materials like fly ash and slag also helps mitigate industrial waste, contributing to a circular economy. Fly ash, slag, and silica fume are among the most widely used SCMs. Each has unique properties that contribute to cement’s strength, workability, and durability. By incorporating SCMs, manufacturers can produce cement with a lower environmental footprint without compromising quality.
While SCMs are effective, several obstacles hinder their widespread adoption. Supply chain constraints, material variability, and lack of technical standards are challenges that manufacturers face. Additionally, geographic limitations impact access to certain SCMs, creating disparities in their usage across regions.

Policy and Industry Collaboration
Policies play a critical role in driving green transitions within the cement industry. Carbon credits, tax incentives, and funding for R&D are some measures governments have introduced to support emission reduction. India’s Perform, Achieve, and Trade (PAT) scheme is an example of a policy incentivising industrial energy efficiency.
Collaborations between government entities, private corporations, and research institutions foster innovation and accelerate the adoption of sustainable practices. Partnerships can also help address funding gaps, allowing companies to explore new technologies without bearing the full financial burden.
International frameworks such as the Paris Agreement and industry-led efforts like the Global Cement and Concrete Association (GCCA) are setting targets for sustainable cement production. These initiatives encourage the sector to adopt environmentally friendly practices and set a roadmap toward achieving net-zero emissions.

Towards a Net-Zero Future
Reaching net-zero emissions is an ambitious but necessary goal for the cement industry. Realistic targets, set with interim milestones, allow companies to gradually transition to greener processes while maintaining production efficiency. Continued investment in R&D is crucial for discovering new methods of emission reduction. Emerging technologies such as carbon-negative materials, alternative binders, and low-carbon clinkers hold promise for the future, potentially transforming cement production into a more sustainable process.
Increasingly, consumers and investors are prioritising sustainability, placing pressure on companies to reduce their environmental impact. This shift in consumer sentiment is driving the cement industry to adopt green practices and focus on transparency in emissions reporting.

Conclusion
The journey toward reducing environmental impact in the cement industry is complex and multifaceted, requiring a combination of innovation, policy support, and industry collaboration. By adopting alternative fuels, implementing carbon capture technology, integrating SCMs, and improving energy efficiency, the industry can take significant strides in minimising its carbon footprint. Achieving sustainability in cement production is essential not only for the industry’s future but also for the planet’s well-being. Together, industry players, policymakers, and consumers can support the transition to a net-zero future, ensuring that cement remains a vital yet sustainable component of global infrastructure.

– Kanika Mathur

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Concrete

Maximising AFR in Cement Manufacturing

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Shreesh A Khadilkar, Consultant and Advisor, and Former Director Quality and Product Development, ACC Ltd Thane, discusses the importance of optimising the use of alternative fuel and raw materials (TSR percentage) in cement production without affecting clinker quality, in part one of this two-part series.

Over the past decade or so, the Indian cement industry has made significant progress in terms of improvement in energy efficiency and productivity. However, the use of alternative fuel and raw material (AFR) to replace coal for thermal energy needs, remains an area where the Indian cement industry is yet to catch up with global benchmarks. Though a few cement plants co-process large quantities and varieties of AFR in their kilns, and are reported to reach a level of around 40 per cent Thermal Substitution Rate (TSR), many plants are still at much lower levels of TSR percentage.
Most of the cement plants have now installed co-processing facilities or are on the verge of having one. Some of the plants also have pre-processing facilities, which could include shredding, segregation, impregnation, foreign body removal etc., while some others source a pre-processed solid AFR (RDF, MSW, Industrial waste sludges, agro wastes etc.).
This article shares important aspects such as assessment of clinker quality in plant clinker quality optimisation, influence of alkalis, chlorides and SO3, effects of some important minor constituents and subsequently discusses the concept for maximising AFR (TSR percentage) without affecting clinker quality through with or without use of XRD technique for in process control. The author further recommends bi-hourly quality and in process dashboard for consistent kiln performance and consistent clinker quality.

Assessment of Clinker Quality
The clinker quality assessment can best be done by Lab Ball Mill grinding of day average clinker with mineral gypsum (with SO3 of the lab ground cement targeted at 2.2 to 2.4 with fixed grinding time to achieve Blaine’s of around 300-320 M2/kg with the residue on 45 microns of the cement in range of 18 per cent to 20 per cent, at this fineness, the clinker is observed to clearly depict changes in clinker reactivity in terms of changes in 1 Day strengths of cements (± 3 to 5 MPa). At lower grinding Blaine’s (of around 250 M2/kg), which is presently being practiced by many cement plants, one does not observe the changes in clinker reactivity, as the difference of 1 Day compressive strengths is only ± 1 MPa, which does not show the changes in clinker reactivity.
Typically, clinkers with good reactivity are observed to show 1 Day strengths in lab ground cements of 30 to 35 MPa. Higher values being observed when clinker alkali sulphates are high (especially with Petcoke as fuel), the achieved Blaine’s and quantity of nibs removed from the lab ground cement, in the fixed grinding time is also indicative of clinker grindability. Judicious raw mix optimisation with existing or alternative corrective materials (with the fuel mix used by the plant) can be attempted so as to have a clinker with improved reactivity/hydraulic potential. In a running plant the approach has to be by attempting small gradual changes to clinker composition and assessing the impact of the changes, on kiln performance and clinker quantity.
The changes to be attempted could be indicated through data analysis.
In each plant, the QC and process has detailed analysis data of the day average clinkers along with its lab ground cement test results. It is also suggested to test at least one spot clinker per day for chemical parameters and physical tests of lab ground cement. From the analysis data it could be observed that on some days the lab ground cements show much higher strengths. Why on some days or in some spot clinkers, the clinker reactivity is suddenly very good? Such clinkers should be preserved and evaluated by XRD, so as to identify the optimum clinker composition which shows higher reactivity. Such an evaluation could also indicate at times the impact of changes in fuel / sources of coal / proportions of coal and Petcoke (even source of Petcoke) / solid AFR usage levels.
Typically, the target clinker composition to give a good hydraulic potential would be with LSF of 93 to 95 with a bogues potential C3S of >55 per cent clinker (especially with Petcoke as main fuel in fuel mix), with C3A (6.5 per cent to 8.5 per cent) if the clinker is used for PPC/PSC and also for OPC (especially if OPC is supplied to RMX customers) and SM 2.2 to 2.4 A/F 1.2 to 1.4. In plants where clinker MgO is higher (> 4.5 per cent), besides having the LSF target of around 93 to 95, the minimum clinker lime targeted should be such to have C/S ratio of 2.95 to 3.1 for having good clinker reactivity in spite of high clinker MgO.

Co-Processing of AFR (Liquid AFR /Solid AFR)
The properties of AF(R) co-processed in the calciner have an impact on environment, health and safety, plant operations and product quality as shown in Table 1:

  • Alkalis without sulphidisation: Formation of orthorhombic C3A, fast setting
  • Alkali sulphates (Na2SO4, K2SO4, 2CaSO4.K2SO4 or even Ca-langebnite): Increased early strength, usually shows decrease of later age strengths. Changes must be accounted for in gypsum optimisation
  • Excess of sulphur over alkalis
  • Integration of SO3 in C2S and/or formation of CaSO4
  • Possible reduction of final strength could be observed
  • Reduces the CaO availability for C3S formation
  • The clinker could be harder to grand
  • Changes the Clinker Liquid Characteristics which affects the phase formations
  • Chlorides tend to be higher in AFR liquid/solid, the control on chlorides is necessary to prevent inlet/cyclone jamming and to have < 0.06 per cent in clinker, so that the OPC has <0.04 per cent chlorides and is suitable for
  • RMC/structural concrete. To avoid problems of kiln inlet and cyclone jamming caused by SO3 and Cl. Preferably maintain the Hot Meal (2 Cl + SO3) < 3.5. The threshold value for a given plant needs to
    be assessed.

If the value goes above the plant threshold value, immediate actions of adding caustic soda for 2 to 3 shifts (in small polyethene bags) should be done to remove the depositions and avoid kiln stoppage.

Effects of some minor constituents on the clinker quality

Effects of ZnO

  • Zinc in clinker nearly distributes evenly between the silicates ad matrix phases (with preference to ferrite), trigonal C3S and ß C2S is stabilised by zinc.
  • Presence of zinc reduces the amount of aluminates in favour of alumino ferrite.
  • Each 1 per cent zinc reduces aluminates by
    1 per cent and increases alumino-ferrites by
    2 per cent.
  • Zinc is very effective flux and mineraliser, it lowers clinkerisation temperatures and accelerates lime combination. Knofel reports increased comp. strengths by up to 20 per cent and above at early ages.

Effects of TiO2

  • The clinker TiO2 should be <0.7 per cent, it should be noted that TiO2 is a viscous flux like Al2O3 and so for understanding the clinker liquid property for good C3S formation and based on the kiln conditions adjust the clinker Fe2O3 contents accordingly.
  • At higher TiO2, contents for improved kiln conditions the clinker Fe2O3 content needs to be much higher which is aggravated if clinker SO3 is higher (which also affects the viscosity of clinker liquid)
  • At high total liquid the clinker becomes silica deficient and so free lime tends to be higher (with clinker balls with calcined un sintered material inside)
  • In plants that use red mud especially with petcoke due to its higher alkalis, many sources of red muds also have TiO2, the plant should target Al2O3 + TiO2 as the viscous flux and then adjust the clinker Fe2O3 to get good kiln conditions as indicated above. Targeting higher liquid only increases the limestone LSF from mines and also affects clinker grindability.

Effects P2O5 sources

  • Many types of agriculture waste, biowastes, phosphate sludge, paint sludges, medical waste, RDF/municipal solid waste, expired detergent, cow dung cakes, etc.
  • Under Indian conditions of clinker phase composition, any increase of P2O5 contents can substantially affect clinker quality.
  • When higher P2O5 are present, the dicalcium silicate (C2S) is stabilised and inhibits formation of alite (C3S) i.e can decrease the percentage of C3S although bogue may show high percentage C3S.
  • When P2O5 present exceeds 0.4 per cent in the clinker it reduces the percentage of C3S by 10 per cent and 1 Day Comp. Strengths by around 5-6 MPa with negative effects on clinker reactivity and setting of cement.
  • Use of wastes containing phosphates in controlled manner so that P2O5 in the clinker (maximum limit in clinker is 0.25 per cent) can enhance the use of agricultural waste or use of other wastes with P2O5. It may be noted that in some regions limestone and laterite also have shown P2O5 contents.
  • In some plants up to 5 to 7 per cent TSR there is no impact observed on quality or productivity, however as the TSR/AFR percentage is increased say above >8 per cent to 10 per cent, the kiln conditions get frequently disturbed with a very high dust generation and there is a drop in clinker reactivity/quality.

In the plants a judicious study of process conditions and understanding the burnability of kiln feed could help achieve productivity without affecting the clinker quality with increased AFR/TSR.

In one of my consultancy visits to an integrated plant, similar observations as above were reported. In a brainstorming discussions with the plant process, production and QC teams, it was noted that:

  • There was substantial variation in calciner outlet/kiln inlet material/C6 material temperature it fluctuated from around 920oC to as low as 860oC, these changes in temperatures nearly corresponded with the fluctuation in percentage of moisture and feed rate of solid AFR (SAFR), RDF and other solid wastes.
  • The kiln torque decreased below the desired levels, when the calciner outlet and kiln inlet material temperatures (in this case C6 material temperatures) were less than 890oC and the kiln performance showed high dust recirculation/generation.
  • The bi-hourly XRF analysis of clinker showed lower LSF/high free lime. The decrease in clinker LSF was understandable as the SAFR ash showed a higher percentage of ash.

It was decided to collect hot meal samples 900oC to 910oC and 920oC to 930oC and also corresponding clinker samples collected after 40 minutes of the sample collection time of hot meal samples. The hot meal samples were analysed for XRD and clinker samples for XRF (Chemical analysis with free lime) and XRD (for clinker phase formation).
The XRD analysis of hot meal samples is shown in Table 2.
The XRD analysis indicates that:

  • The calcination percentage is much higher than the convention DOC of hot meal samples.
  • The un-combined CaO decreases with increase in temperature of collected sample.
  • The total belite increases with increase in temperature.

It was observed in the plant that when attempts were made to maintain the kiln inlet material temperature at 910oC to 920oC, the kiln torque showed an improvement and the kiln performance improved. The clinker quality showed improvements with lower free lime. However due to the fluctuations in ash percentage content of SAFR the clinker LSF showed lower values during the day. As a corrective action, lime sludge (available at the plant) was added on the SAFR conveyor. These corrective actions helped achieve a consistent improved clinker quality.

About the author:
With an MSc in Organic Chemistry from Jodhpur University (now JNV University), Shreesh Khadilkar joined ACC’s Organic Chemical Product Development Division in 1981 and later transitioned to the Cement R&D Division as a technical assistant. He took over as VP of R&D (Quality and Product Development Division) and retired as Director of the department in 2018, with over 37 years of experience in cement manufacturing and cements/cementitious products.

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