Technology
Optimising Plant Performance
Published
9 years agoon
By
admin
The Rietveld method of quantitative analysis of amorphous materials has gained importance in the light of the BIS issuing specifications for composite cement.
Nowadays, many industries are looking for possibilities to reduce CO2 emissions, energy consumption and increase the reuse of waste materials, These demands are enforced by various regulations and international agreements, and in the long term, they will cause cost reductions. In the cement industry, this can be achieved by using modern techniques in production and by an optimisation of the burning process, by fuel substitutions, alternative clinker compositions or by the production of blended cements with different additives. A variety of completely or partly amorphous materials are used as additives, like slag, fly ash, silica, pozzolana and others. Controlling these additives quantitatively is essential in order to guarantee the cement norms.
Since the mineralogy strongly influences the reactivity of the cement as well as the physical properties of the hydrated product, the need for a direct mineralogical assessment by X-ray diffraction is more important than ever before. X-ray diffraction (phase analysis) opens enormous possibilities for process and quality control. Moreover, the recent development of ultra-high-speed X-ray detectors and of the software for quantitative X-ray diffraction analysis allows truly interactive process control. The quantitative Rietveld analysis is an important tool to control raw materials as well as industrial products, hence offering significant benefits in terms of cement production. Cluster analysis in combination with Automatic Program Selection increases the reliability of quantification results.
The examples presented in this paper will show how X-ray diffraction is being used to quantify blended cements with a complex mineralogy containing crystalline and amorphous phases.
Production and quality control using XRD
Nowadays X-ray fluorescence (XRD) and X-ray diffraction (XRF) analyses are standard tools for process and quality control in cement plants. XRD analysis in combination with Rietveld refinement is a reliable, precise and very reproducible way to quantify the relative phase abundances in building materials. The whole process from sample preparation, through measurement to Rietveld evaluation can be implemented in existing laboratory automation systems and takes approximately 10 minutes. Due to the completely automated operating principle, no additional staff are required and the results are user-independent. The Rietveld method is now being applied in industrial laboratories and also in various cement plants as the standard method for quantitative analyses of raw materials, Portland cement clinkers, Portland cements (OPC) and all types of blended cements.
For clinker, the Rietveld method is the only option to determine the phase content in an accurate and fast way, because the Bogue calculation is usually not correct due to the incorporation of higher amounts of minor and trace elements in the clinker phases, especially when alternative fuels are used. The quantitative mineralogical composition of the cement is directly linked to the hardening behavior and the compressive strength after 28 days. Blended cements are classified under different norms. In order to fulfill these norms and to guarantee the quality of the product, it is necessary to determine the exact amount of added blending materials which is only possible by Rietveld quantification.
Figure 1: Contribution of crystalline and amorphous phases to
an XRD pattern
Figure 2: Rietveld quantification of a pure fly ash, containing
mullite, quartz and around 45 per cent amorphous material..
Figure 3: Rietveld quantification of a fly ash
cement with separate
Figure 4: Cluster analysis of different slag cements with low
(blue), medium (grey) and high (green) amounts of slag
quantification of the fly ash components, including amorphous content
Application of Rietveld analysis for blended cements
The Rietveld analysis uses the whole XRD pattern for quantification and not only single peaks like the classical free lime determination. All peaks from the pattern are used for the refinement and the crystalline compounds are normalised to 100 wt.-%. The Rietveld analysis requires information on the structure data of all crystalline phases in the material and other crystallographic parameters. The quantification of amorphous material requires special procedures. Amorphous material doesn?t give clear diffraction peaks; the pattern may just show a higher background or a hump in a certain region. This hump is not always discernible, especially for low concentrations of the amorphous phases. The background noise strongly influences the quantification results for the amorphous material. Figure 1 illustrates the contribution of crystalline and amorphous phases to a XRD pattern.
Different approaches to determine the amorphous content are described in the literature. The addition of an internal standard is a common method for the determination of the amorphous content.
A defined amount of a standard (like corundum or rutile) is added to the material, and the amorphous content can be calculated from the obtained standard amount from the Rietveld quantification. Influences on the quantification resulting from mixing of the sample with the standard, from possible amorphous content in the standard (Whitfield & Mitchell, 2003) or from crystallographic parameters (De La Torre et al., 2001) were studied. Westphal et al. (2009) showed that the calculation of the amorphous content via Rietveld analysis using an internal standard follows a nonlinear function. For an industrial application, especially for automated systems, the internal standard method is not suitable.
Figure 5: Cluster analysis of different limestones rich in quartz, dolomite
or mica. Outlier in red was a damaged sample.
Figure 6: Working scheme of the Automatic Program Selection
based on Cluster Analysis.
For industrial applications, other methods for quantification of the amorphous material were developed. One possibility is the external standard method. In this case a crystalline standard material is prepared only once and measured separately on a weekly basis. Via mathematical procedures the data obtained from this scan are used for the determination of the amorphous content in the cement. The advantage of this method is that no mixing of standard material and cement sample is necessary. Another possibility is to calculate the area or the intensity of the amorphous contribution to the powder diffraction pattern. This approach is known as the ?HKL? method. The amorphous part is considered as an additional phase and included in the Rietveld calculation. The final result including all crystalline and amorphous phases is again normalised to 100 wt.-%.
Table 1 shows typical ranges of reproducibility and repeatability for different slag cements containing slag from 8 wt.% to 65 wt.%. Table 2 shows typical ranges of reproducibility and repeatability for different fly ash cements with fly ash contents from 10 wt.% to 30 wt.%. For the reproducibility sets of 10 separately prepared samples of the same material were measured. The variation of the results is mainly caused by sample inhomogenities and preparation effects. For the repeatability values one prepared sample was measured 10 times.
Some blended cements have a very complex composition containing more than 20 crystalline phases and one or more amorphous components, introduced by the addition of materials like fly ash or other compounds. Fly ashes used in the cement industry contain usually 30 – 70 per cent amorphous material and as main crystalline phases quartz and mullite. Different feldspars, magnetite, hematite, anhydrite or other phases may also occur.
A Rietveld refinement of an example of a fly ash containing quartz, mullite and amorphous material is shown in Figure 2.
The described quantification methods including amorphous contents can easily be integrated into automation systems. The output file can be defined according to the needs, either all crystalline phases are shown separately (as depicted in Figure 3), or a total value for the amount of slag, fly ash, pozzolana or other added material is given.
A Rietveld refinement of a cement sample containing 20 per cent fly ash is shown in Figure 3.
Cluster Analysis
Statistical analysis techniques are necessary for the data interpretation.
Cluster analysis is a useful tool, as it greatly simplifies the analysis of large amounts of data. This application can be used for simple pass/fail analyses of raw materials, characterisation of blended cements, and automatic selection of control files for Rietveld analysis (APS).
Powder diffraction scans or other data sets are sorted automatically into separate clusters, with closely related scans in a cluster. The most representative as well as the most different scans or data sets can be identified. Outliers are clearly visible as they do not fit into any of the defined classes. Outliers represent deviations or problems in the production process, like changes in the composition, instabilities in a kiln or others. They can be also a result of problems with the sample itself, resulting from sample preparation or transport, like uneven surface or a broken sample. An example of cluster analysis of different slag cements is shown in Figure 4. In Figure 5 an example for an outlier produced by a damaged sample is given.
Automatic Process Control (APS)
The quality of the control files for the Rietveld quantification is decisive for the accuracy of the results and therefore also for the whole process control. A control file can work over a large range of compositions, e.g. from very low to very high amounts of slag in a cement, with good results. For smaller ranges, the control files can be designed with an optimised accuracy. Separate control files are also recommended if different fly ash types are used. Special designed refinement strategies, different background treatment and an optimised fitting for other parameters can be implemented to achieve higher accuracy for the quantification. The selection of a control file can be done automated by cluster analysis. After a measurement, the scan is compared with a pool of scans, the master scans. These scans define separate clusters, representing clinkers or cements with different compositions, like slag cements with low, mid, and high amounts of slag. The variability of each cluster, represented by the diameter of the spheres in the PCA (Principal Component Analysis) plot, is defined by the allowed range of composition for each material. Every measured scan is classified into an existing cluster, if it is within the allowed range, or rated as an outlier.
To each cluster, an optimised control file for the automated quantification is assigned. Each scan can then be processed by a special control file designed for this material. The results of the quantification can be handled by a LIMS (Laboratory Information Management Solution) system. Outliers have to be treated in a special way. The scan can be processed with the control file of the nearest cluster, accompanied by a warning message, that the quantification is of limited reliability. In any way, human interaction is necessary or recommended. The process scheme of the Automatic Program Selection is shown in Figure 6.
Conclusion
Phase analysis by X-ray diffraction opens enormous possibilities for process and quality control in the cement industry especially for blended cements. Moreover, the development of fast X-ray detectors allows fast quantitative X-ray diffraction analysis and truly interactive process control. The Rietveld method allows precise and reproducible quantitative analysis of all types of blended cements. It can be performed in an automated, stable and accurate way. Using an external standard or HKL fit, the determination of the amorphous content can be done directly on the cement sample. The result output includes the quantitative analysis of the crystalline and amorphous phases as well as the total amount of added cementitious material. Nowadays the Rietveld method is being applied in many cement plants worldwide as the standard method for quantitative phase analyses of all types of blended cements. The integration of the cluster analysis into the Rietveld quantification allows fully automated selection of an optimised control file for each material. This increases the accuracy of the quantification and allows an easy identification of outliers.
References
1.Rietveld, H. M. (1969): A profile refinement method for nuclear and magnetic structures, J. Appl. Cryst. 2, 65-71
2. Young, R. A. (1993): The Rietveld Method, Oxford University Press
3.De La Torre, A. G., Bruque, S., and Aranda, M. A. G. (2001): Rietveld quantitative amorphous content analysis, J. Appl. Crystallogr. 34, 196-202.
4.Westphal, T., F?llmann, T., and P?llmann, H. (2003): Rietveld quantification of amorphous portions with an internal standard-mathematical consequences of the experimental approach, Powder Diffr. 24, 239-243
5.Walenta, G., Gimenez, M., and F?llmann, T. (2008): Quantitative analyses of blended cements in industrial applications.- International Cement Review, July 2008, 67-71
6.Whitfield, P. S. and Mitchell, L. D. (2003): Quantitative Rietveld analysis of The amorphous content in cements and clinkers, J. Mater. Sci. 38, 4415-4421.
7.Westphal, T., F?llmann, T.: Quantifying Amorphous Portions in Blended Cements – A Comparative Study.
8.F?llmann, T., Meier, R., and Witzke, T.(2012): Use of X-ray techniques to optimize the efficiency of cement and concrete characterization.
Fuellmann, T., Witzke, T., van Weeren, H. PANalytical B.V., Lelyweg 1, 7602 EA Almelo, The Netherlands
Concrete
We consistently push the boundaries of technology
Published
1 month agoon
April 18, 2025By
admin
Swapnil Jadhav, Director, SIDSA Environmental, discusses transforming waste into valuable resources through cutting-edge technology and innovative process solutions.
SIDSA Environmental brings decades of experience and expertise to the important niche of waste treatment and process technologies. As a global leader that is at the forefront of sustainable waste management, the company excels in recycling, waste-to-energy solutions and alternative fuel production. In this conversation, Swapnil Jadhav, Director, SIDSA Environmental, shares insights into their advanced shredding technology, its role in RDF production for the cement industry and emerging trends in waste-to-energy solutions.
Can you give us an overview of SIDSA Environmental’s role in waste treatment and process technologies?
SIDSA is a leading innovator in the field of waste treatment and process technologies, dedicated to delivering sustainable solutions that address the growing challenges of waste management.
SIDSA is a more than 52-year-old organisation with worldwide presence and has successfully realised over 1100 projects.
Our expertise is in the engineering and development of cutting-edge systems that enable the conversion of waste materials into valuable resources. This includes recycling technologies, waste-to-energy (W2E) systems, and advanced methods for producing alternative fuels such as refuse derived fuel (RDF). The organisation prioritises environmental stewardship by integrating energy-efficient processes and technologies, supporting industrial sectors—including the cement industry—in reducing their carbon footprint. Through our comprehensive approach, we aim to promote a circular economy where waste is no longer a burden but a resource to be harnessed.
How does SIDSA Environmental’s shredding technology contribute to the cement industry, especially in the production of RDF?
SIDSA’s shredding technology is pivotal in transforming diverse waste streams into high-quality RDF. Cement kilns require fuel with specific calorific values and uniform composition to ensure efficient combustion and operational stability, and this is where our shredding systems excel. In India, we are segment leaders with more than 30 projects including over 50 equipment of varied capacity successfully realised. Some of the solutions were supplied as complete turnkey plants for high capacity AFR processing. Our esteemed client list comprises reputed cement manufacturers and chemical industries. Our technology processes various types of waste—such as plastics, textiles and industrial residues—breaking them down into consistent particles suitable for energy recovery.
Key features include:
- High efficiency: Ensures optimal throughput for large volumes of waste.
- Adaptability: Handles mixed and heterogeneous waste streams, including contaminated or complex materials.
- Reliability: Reduces the likelihood of operational disruptions in RDF production. By standardising RDF properties, our shredding technology enables cement plants to achieve greater energy efficiency while adhering to environmental regulations.
What are the key benefits of using alternative fuels like RDF in cement kilns?
The adoption of RDF and other alternative fuels offers significant advantages across environmental, economic and social dimensions:
- Environmental benefits: Cement kilns using RDF emit fewer greenhouse gases compared to those reliant on fossil fuels like coal or petroleum coke. RDF also helps mitigate the issue of overflowing landfills by diverting waste toward energy recovery.
- Economic savings: Alternative fuels are often more cost-effective than traditional energy sources, allowing cement plants to reduce operational expenses.
- Sustainability and resource efficiency: RDF facilitates the circular economy by repurposing waste materials into energy, conserving finite natural resources.
- Operational flexibility: Cement kilns designed to use RDF can seamlessly switch between different fuel types, enhancing adaptability to market conditions.
What innovations have been introduced in waste-to-energy (W2E) and recycling solutions?
SIDSA’s machinery is meticulously engineered to handle the complex requirements of processing hazardous and bulky waste.
This includes:
- Robust construction: Our equipment is designed to manage heavy loads and challenging waste streams, such as industrial debris, tires and large furniture.
- Advanced safety features: Intelligent sensors and automated controls ensure safe operation when dealing with potentially harmful materials, such as chemical waste.
- Compliance with standards: Machinery is built to adhere to international environmental and safety regulations, guaranteeing reliability under stringent conditions.
- Modular design: Allows for customisation and scalability to meet the unique needs of various waste management facilities.
How does your organisation customised solutions help cement plants improve sustainability and efficiency?
We consistently push the boundaries of technology to enhance waste management outcomes.
General innovations and new product development focus on:
- Energy-efficient shredders: These machines consume less power while maintaining high throughput, contributing to lower operational costs.
- AI-powered sorting systems: Utilise advanced algorithms to automate waste classification, increasing material recovery rates and minimising errors.
- Advanced gasification technologies: Convert waste into syngas (a clean energy source) while minimising emissions and residue.
- Closed-loop recycling solutions: Enable the extraction and repurposing of materials from waste streams, maximising resource use while reducing environmental impact.
What future trends do you foresee in waste management and alternative fuel usage in the cement sector?
Looking ahead, several trends are likely to shape the future of waste management and alternative fuels in the cement industry:
- AI integration: AI-driven technologies will enhance waste sorting and optimise RDF production, enabling greater efficiency.
- Bio-based fuels: Increased use of biofuels derived from organic waste as a renewable and low-carbon energy source.
- Collaborative approaches: Strengthened partnerships between governments, private industries and technology providers will facilitate large-scale implementation of sustainable practices.
- Circular economy expansion: The cement sector will increasingly adopt closed-loop systems, reducing waste and maximising resource reuse.
- Regulatory evolution: More stringent environmental laws and incentives for using alternative fuels will accelerate the transition toward sustainable energy solutions.
(Communication by the management of the company)
Concrete
FORNNAX Technology lays foundation for a 23-acre facility in Gujarat
Published
3 months agoon
March 17, 2025By
admin
FORNNAX Technology, a leading manufacturer of recycling equipment in India, has marked a major milestone with the Groundbreaking (Bhoomi Pujan) ceremony for its expansive 23-acre manufacturing facility in Gujarat. Specialising in high-capacity shredders and granulators, FORNNAX is strategically positioning itself as a global leader in the recycling industry. The new plant aims to produce 250 machinery units annually by 2030, making it one of the largest manufacturing facilities in the world.
The foundation stone for this ambitious project was laid by Jignesh Kundaria, CEO and Director, alongside Kaushik Kundaria, Director. The ceremony was attended by key leadership members and company staff, signifying a new chapter for FORNNAX as it meets the growing demand for reliable recycling solutions. Speaking on the occasion, Jignesh Kundaria stated, “This marks a historic moment for the recycling sector. Our high-quality equipment will address various waste categories, including tyre, municipal solid waste (msw), cables, e-waste, aluminium, and ferrous metals. this facility will strengthen our global presence while contributing to India’s Net Zero emissions goal by 2070.”
FORNNAX is actively expanding its footprint in critical markets such as Australia, Europe and the GCC, forging stronger sales and service partnerships. The facility will house an advanced Production Department to ensure seamless manufacturing.
Concrete
Decarbonisation is a focus for our R&D effort
Published
4 months agoon
February 12, 2025By
admin
Dyanesh Wanjale, Managing Director, Gebr. Pfeiffer discusses the need to innovate grinding technologies to make the manufacturing process more efficient and less fuel consuming.
Gebr. Pfeiffer stands at the forefront of grinding technology, delivering energy-efficient and customised solutions for cement manufacturers worldwide. From pioneering vertical roller mills to integrating AI-driven optimisation, the company is committed to enhancing efficiency and sustainability. In this interview, we explore how their cutting-edge technology is shaping the future of cement production.
Can you tell us about the grinding technology your company offers and its role in the cement industry?
We are pioneers in grinding technology, with our company being based in Germany and having a rich history of over 160 years, a milestone we will celebrate in 2024. We are widely recognised as one of the most efficient grinding technology suppliers globally. Our MBR mills are designed with energy efficiency at their core, and for the past five years, we have been focused on continuous improvements in power consumption and reducing the CO2 footprint. Innovation is an ongoing process for us, as we strive to enhance efficiency while supporting the cement industry’s sustainability goals. Our technology plays a critical role in helping manufacturers reduce their environmental impact while improving productivity.
The use of alternative fuels and raw materials (AFR) is an ever-evolving area in cement production. How does your technology adapt to these changes?
Our vertical roller mills are specifically designed to adapt to the use of alternative fuels and raw materials. These mills are energy-efficient, which is a key advantage when working with AFR since alternative fuels often generate less energy. By consuming less power, our technology helps bridge this gap effectively. Our solutions ensure that the use of AFR does not compromise the operational efficiency or productivity of cement plants. This adaptability positions our technology as a vital asset in the industry’s journey toward sustainability.
What are some of the challenges your company faces, both in the Indian and global cement industries?
One of the major challenges we face is the demand for expedited deliveries. While customers often take time to decide on placing orders, once the decision is made, they expect quick deliveries. However, our industry deals with heavy and highly customised machinery that cannot be produced off the shelf. Each piece of equipment is made-to-order based on the client’s unique requirements, which inherently requires time for manufacturing.
Another significant challenge comes from competition with Chinese suppliers. While the Indian cement industry traditionally favoured our technology over Chinese alternatives, a few customers have started exploring Chinese vertical roller mills. This is concerning because our German technology offers unmatched quality and longevity. For example, our mills are designed to last over 30 years, providing a long-term solution for customers. In contrast, Chinese equipment often does not offer the same durability or reliability. Despite the cost pressures, we firmly believe that our technology provides superior value in the long run.
You mentioned that your machinery is made-to-order. Can you elaborate on how you customise equipment to meet the specific requirements of different cement plants?
Absolutely. Every piece of machinery we produce is tailored to the specific needs of the customer. While we have standard mill sizes to cater to different capacity requirements, the components and configurations are customised based on the client’s operational parameters and budget. This process ensures that our solutions deliver optimal performance and cost efficiency. Since these are heavy and expensive items, maintaining an inventory of pre-made equipment is neither practical nor economical. By adopting a made-to-order approach, we ensure that our customers receive machinery that precisely meets their needs.
The cement industry is focusing not only on increasing production but also on decarbonising operations. How does your company contribute to this dual objective, and how do you see this evolving in the future?
Decarbonisation is a key focus for our research and development efforts. We are continuously working on innovative solutions to reduce CO2 emissions and improve overall sustainability. For example, we have significantly reduced water consumption in our processes, which was previously used extensively for stabilisation. Additionally, we are leveraging artificial intelligence to optimise mill operations. AI enables us to monitor the process in real-time, analyse feedback, and make adjustments to achieve optimal results within the given parameters.
Our commitment to innovation ensures that we are not only helping the industry decarbonise but also making operations more efficient. As the cement industry moves toward stricter sustainability goals, we are confident that our technology will play a pivotal role in achieving them.
Can you provide more details about the use of digitalisation and artificial intelligence in your processes? How does this improve your operations and benefit your customers?
Digitalisation and AI are integral to our operations, enabling us to offer advanced monitoring and optimisation solutions. We have developed three distinct models that allow customers to monitor mill performance through their computer systems. Additionally, our technology enables real-time feedback from our German headquarters to the customer. This feedback highlights any inefficiencies, such as when a parameter is outside the optimal range,
and provides actionable recommendations to address them.
By continuously monitoring every parameter in real time, our AI-driven systems ensure that mills operate at peak efficiency. This not only enhances production but also minimises downtime. I am proud to say that our mills have the lowest shutdown rates compared to other manufacturers. This reliability, combined with the insights provided by our digital solutions, ensures that customers achieve consistent and efficient operations. It’s a game-changer for reducing costs and enhancing overall productivity.

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