Jens Mose and John Terembula, Product Line Management, FLSmidth A/S, explore how cement manufacturers can utilise VRMs to reduce the clinker factor and meet their environmental targets, in the final part of this three-part series. You can find parts one and two in the August and September issues of Indian Cement Review.
OPTIMISING PARTICLE SIZE DISTRIBUTION Experience has shown that practically every type of cement around the world can be – and is already being – produced in an OK MillTM. While the particle size distribution (PSD) of the product is normally steeper in a VRM cement mill compared to a traditional ball mill, this can, to some extent, be modified by working with various parameters such as grinding pressure and dam ring height. The air flow and the separator speed are also used to customise the PSD curve to customer specific requirements. However, as interest in greater utilisation of SCMs increases, cement manufacturers are keen to grind to an even steeper PSD curve to allow for the possibility of mixing more SCMs into the finished product.
THE ADVANTAGES OF VRMS FOR SCMS When the VRM is designed specifically for grinding cement and cementitious materials, cement manufacturers experience better:
Efficiency: Lowest power consumption compared to other vertical roller mills on the market.
Reliability: The run factor is very high, > 95 per cent
Versatility: Rapid change between different feed compositions and the ability to grind a wide range of materials to very high Blaine or the lowest residues
The OK MillTM was designed with these priorities in mind, and has retained its original shape with a dual lobed roller surface and central grooved and bowl-shaped table design. As the only VRM in the market specifically designed for cement grinding, all rollers are active with each performing material bed compaction and de-aeration, and high-pressure grinding. Sustainability is also a priority, which is why the mill is designed to require minimal water injection on the mill table, using an average 50 per cent less water than competing mill designs.
Maintenance is also a sustainability issue. Better to repair a part than replace it; better to be proactive than reactive. Predictive maintenance services aim to enable a higher level of proactivity, preventing unexpected downtime and reducing the cost of maintenance. Over the last 20 years, in-situ rewelding or hard facing has become the standard maintenance practice for VRM, particularly for OK MillsTM with segmented wear liners that can tolerate repeated welding. Roller liner segments can be rewelded as many as 10 times or more and table segments 15 times or more. In order to improve its service capability for VRMs, FLSmidth works with welding services providers across the globe. We have also developed ceramic wear segments in an OK MillTM, which not only perform better but can also be recycled.
DIGITAL TOOLS FOR GREATER FLEXIBILITY Digitalisation makes it easier to use SCMs and will enable further reductions in the clinker factor. The following are just a snapshot of the tools currently available; more are in development all the time:
Process control solutions give operators greater control over their mill operating parameters to optimise performance and ensure maximum efficiency.
Sensors continually monitor mill operation, enabling you to see any drop in stability as it happens and react swiftly.
Automated laboratories enable optimum quality control throughout the process.
Condition monitoring services and remote service support give you 24/7 access to expert assistance.
CONCLUSION As the cement industry works to reduce its carbon footprint, investments have to be made in future-proof technologies capable of adapting to changing cement mixes and regulatory requirements. In the grinding process, cement manufacturers need a flexible, efficient system that is operated and maintained in an optimal manner. With the latest VRM technologies, advanced digital offerings and condition monitoring services, FLSmidth believes the industry is ready to achieve more widespread use of SCMs and achieve its carbon reduction goals.
Star Cement has launched ‘Star Smart Building Solutions,’ a new initiative aimed at promoting sustainable construction practices, as per a recent news report. This venture introduces a range of eco-friendly products, including tile adhesives, tile cleaners and grouts, designed to enhance durability and reduce environmental impact. The company plans to expand this portfolio with additional value-added products in the near future. By focusing on sustainable materials and innovative building solutions, Star Cement aims to contribute to environmentally responsible construction and meet the evolving needs of modern infrastructure development.
Nuvoco Vistas reported its highest-ever quarterly consolidated EBITDA of Rs.556 crore in Q4 FY25, with annual EBITDA at Rs.1,391 crore. Cement sales reached 19.4 MMT in FY25, with Q4 contributing 5.7 MMT. Revenue rose 4 per cent YoY to Rs.3,042 crore in Q4. Net debt reduced by Rs.390 crore to Rs.3,640 crore. The company received NCLT approval for acquiring Vadraj Cement, targeting 31 MMTPA capacity by FY27. Key marketing initiatives, expanding RMX and MBM businesses, and a focus on sustainability (457 kg CO2/tonne) drove performance. Nuvoco remains focused on premiumisation, operational efficiency, and market expansion.
UltraTech Cement has expanded its production capacity by 1.4 million tonnes per annum (Mt/yr) through a combination of debottlenecking efforts and operational efficiency upgrades across several of its plants. The enhancements include an addition of 0.6Mt/yr in grinding capacity at the Nagpur facility in Maharashtra and a combined 0.8Mt/yr at the Panipat and Jhajjar units in Haryana. With these upgrades, the company’s total domestic grey cement capacity has risen to 184.8Mt/yr, while its global capacity now stands at 190.2Mt/yr.