Analysis of various oxide materials

Significance of the Topic

Modern industries depend on high-grade raw materials; efficient elemental analysis of oxide materials is vital for quality control and productivity in mining and manufacturing.

Aims and Overview of the Study

This application note evaluates the Thermo Scientific ARL OPTIM’X WDXRF spectrometer, using a General Oxide calibration, to analyze a broad range of oxide materials with high accuracy and throughput.

Methodology and Instrumentation

• Sample preparation: flux fusion (lithium tetraborate/metaborate) at 1050°C to form glass beads, removing grain size and mineralogical effects. Two workflows: non-ignited (rapid, LOI corrected by software) and ignited samples (950°C, 1 h, LOI measured).
• Instrument: ARL OPTIM’X WDXRF (200 W Rhodium anode X-ray tube) with SmartGonio covering elements O–Am; no external water cooling; superior spectral resolution vs. EDXRF; optional fixed channels for enhanced detection of specific elements; controlled by OXSAS software.

Main Results and Discussion

• Calibration ranges for major oxides (e.g., CaO 0.03–94.4%, SiO2 0.35–99.7%) with standard errors of estimation below 0.3%.
• Limits of detection: ppm-level LODs in 20 s per element (e.g., CaO 45 ppm, SiO2 160 ppm), further reduced by extended counting times.
• Precision tests (11 repeats) show relative standard deviations typically below 1% for major oxides across limestone, iron ore, rock, and slag samples, demonstrating excellent repeatability and stability.

Benefits and Practical Applications

• Rapid, robust multi-element oxide analysis from ppm to high percentages with minimal preparation variations.
• Single calibration streamlines analysis of diverse materials: minerals, ores, ceramics, cement, and slags.
• High throughput enabled by short counting times (down to 10 s) without sacrificing precision.

Future Trends and Opportunities

• Further LOD improvements via longer counting times or lower flux-to-sample dilution ratios (e.g., 1:5).
• Integration of fixed monochromator channels for targeted trace element enhancements.
• Automation of sample preparation and real-time LOI correction through advanced software algorithms.

Conclusion

The ARL OPTIM’X WDXRF with General Oxide calibration reliably quantifies a wide variety of oxide materials using fused bead preparation, offering high accuracy, precision, and operational efficiency ideal for mining, QA/QC, and industrial analytics.

References

• Bonvin D. Application note AN41731, Thermo Fisher Scientific, 2023.