Applications in cement industry

Significance of the Topic

The use of combined wavelength dispersive X-ray fluorescence and integrated X-ray diffraction represents a powerful tool in cement production quality assurance. It addresses the need for rapid, comprehensive elemental and phase analysis in raw materials, clinker and finished cement. This approach reduces reliance on multiple separate analyses and supports process optimization and regulatory compliance.

Objectives and Study Overview

This application note describes the implementation of the Thermo Scientific ARL X900 spectrometer in cement industry laboratories. Its primary aims include:

• Quantification of up to 12 major and minor oxides in raw meal, clinker and cement
• Phase identification and quantification of clinker minerals and raw feed phases
• Enhanced workflow through automated sample handling and software integration

Methodology and Instrumentation

The ARL X900 spectrometer features:

• WDXRF goniometer covering elements from F to Am with rhodium anode X-ray tube
• Optional fixed channels for simultaneous measurement and reduced counting times
• Three power configurations (1500 W, 2500 W, 4200 W) with minimal cooling requirements
• Integrated XRD module within the same vacuum chamber to analyse crystalline phases
• OXSAS software for LIMS connectivity, automation and data processing

Sample preparation modes include pressed pellets for routine oxide analysis and lithium borate fusion beads for multi-mineral calibrations. Calibration ranges for typical Portland cement oxides span from ppm to 100 % concentrations.

Main Results and Discussion

The performance evaluation highlighted:

• Fast oxide determinations in under two minutes with precisions suitable for QA/QC
• Determination of F from CaF2 additions, noting matrix absorption effects in raw meal versus clinker
• Sulfur versus sulfate analysis via the S K beta satellite peak to monitor slag incorporation
• General oxide calibration applied to diverse matrices such as limestone, marl, slags and ash
• Phase analysis by integrated XRD allowing quantification of quartz, free lime, alite, belite, aluminate and ferrite phases for process control

Benefits and Practical Applications

The combined XRF/XRD approach offers:

• Rapid turnaround and minimal sample prep
• Wide dynamic range from trace to major components
• Improved phase quantification over traditional Bogue calculations
• Reduced laboratory footprint and maintenance costs
• Energy savings optimization through free lime and phase monitoring

Future Trends and Potential Applications

Emerging developments may include:

• Advanced calibration strategies leveraging machine learning for complex matrices
• Enhanced automation and remote monitoring for continuous process feedback
• Expanded fixed channel arrays for further reduction of analysis times
• Integration with real-time kiln control systems to adjust firing parameters dynamically

Conclusion

The ARL X900 spectrometer, with its modular WDXRF and integrated XRD capabilities, provides a robust, efficient solution for comprehensive cement industry analysis. Its adaptability to various sample types and rapid, precise measurements support improved process control, quality assurance and sustainable manufacturing practices.