Cement analysis according to ASTM C114 with the ARL QUANT’X EDXRF Spectrometer

Importance of the topic

Cement composition directly influences material properties such as strength, durability and performance in construction. Rapid and accurate elemental analysis supports quality control, regulatory compliance and cost-effective production in cement plants. Energy-dispersive X-ray fluorescence (EDXRF) offers a compact and efficient solution for on-site monitoring compared with larger wavelength-dispersive systems.

Objectives and overview of the study

This study evaluates the Thermo Scientific ARL QUANT’X EDXRF spectrometer for cement analysis under the strict ASTM C114 protocol. Key goals include:

• Assessing precision and accuracy using seven NIST certified reference cements (SRMs 1880a–1889a).
• Comparing duplicate measurements over two days.
• Verifying detection limits for major oxides.

Used Instrumentation

• ARL QUANT’X EDXRF spectrometer with Rh anode X-ray tube (0.05 mm Be window, 50 W).
• Silicon drift detector (30 mm2), electrically cooled.
• Nine primary beam filters for optimized excitation.
• 10-position automatic sample changer.

Methodology

Cement CRMs were ground and pressed into 32 mm pellets with boric acid backing. Two excitation conditions were applied under vacuum: 4 kV (200 s) for light elements (Na2O–SO3) and 16 kV with Pd filter (100 s) for heavier oxides. Each sample underwent duplicate analysis on two separate days, following ASTM C114 requirements to calculate differences between duplicates and average deviations from certified values.

Main results and discussion

Most analytes met the ASTM C114 limits for duplicate differences (e.g., MgO Δ ≤0.16 %) and average deviations (e.g., CaO Δ ≤0.30 %). A single SiO2 average deviation slightly exceeded 0.20 % but remained within twice the permissible value. Detection limits ranged from 0.001 % (SO3, Fe2O3, ZnO) to 0.018 % (Na2O). Overall, the ARL QUANT’X delivered performance comparable to WDXRF with shorter analysis times.

Benefits and practical applications

• Compact footprint ideal for small and large cement plants.
• Fast cycle times (≤300 s) without compromising accuracy.
• Unattended operation via sample changer.
• Cost-effective alternative or backup to WDXRF instruments.

Future trends and possibilities

• Integration of real-time process monitoring and automation.
• Advanced detector technology to lower detection limits further.
• Machine learning for spectral deconvolution and drift correction.
• Expansion to blended cements and other construction materials.

Conclusion

The ARL QUANT’X EDXRF spectrometer fulfills ASTM C114 requirements for cement oxide analysis with high precision, accuracy and rapid throughput. Its compact design and automated features make it a reliable choice for production and quality control in the cement industry.