Analysis of ilmenite ore samples from Australia and China with ARL EQUINOX 100 XRD & ARL QUANT'X XRF instruments

Importance of the topic

Ilmenite (FeTiO3) represents the world’s most abundant titanium ore, supplying nearly half of global TiO2 pigment production. Accurate determination of its chemical and mineralogical composition underpins quality assessment in mining, processing and end-use industries. Combining X-ray diffraction (XRD) and X-ray fluorescence (XRF) techniques ensures comprehensive characterization of ore grade, impurity levels and phase assemblages critical for pigment, metallurgical and ceramic applications.

Aims and overview of the study

This work compares ilmenite samples from Australia and China to evaluate differences in composition and phase distribution. Using the Thermo Scientific ARL EQUINOX 100 diffractometer and ARL QUANT’X energy-dispersive XRF spectrometer, the study demonstrates methods to reduce interference from Fe fluorescence in XRD and to obtain rapid, standard-less semi-quantitative chemical analysis by XRF. Results highlight geographic variability in ore quality and illustrate optimized measurement protocols.

Methodology

• Sample preparation included grinding to a fine powder and ensuring representative reflection geometry mounts for XRD, plus pressing of powder pellets for XRF after screening to 200 mesh.
• XRD measurements were carried out under Cu-Kα radiation with a PVC filter to attenuate Fe fluorescence, and under Co-Kα radiation to further improve peak resolution.
• Phase identification and quantification used Rietveld analysis via MDI JADE 2010 with the ICDD PDF4+ database.
• Semi-quantitative elemental analysis by XRF employed the UniQuant fundamental-parameters software without external calibration.

Použitá instrumentace

• ARL EQUINOX 100 X-ray diffractometer with micro-focus Cu (50 W) or Co (15 W) tubes, curved position sensitive detector for real-time simultaneous peak collection.
• ARL QUANT’X energy-dispersive XRF spectrometer with Rh or Ag tube (50 W, up to 50 kV) and silicon drift detector, enabling measurement of elements from Na to U.

Main results and discussion

Chemical analysis revealed that Australian ore contains higher TiO2 (42–47 %) and Fe2O3 (43–54 %) with minor MgO, Al2O3 and trace constituents, while Chinese ore showed elevated impurity oxides (Al2O3 up to 8.5 %, SiO2 up to 8.5 %, CaO up to 2.7 %).

Phase quantification indicated Australian ilmenite comprises ~86 % ilmenite, 7 % rutile, 5–9 % hematite and <2 % anatase. Chinese samples included 72–83 % ilmenite plus diopside (5–10 %), pseudobrookite (5–11 %), browneite and lizardite phases, reflecting a more complex mineralogy. Co-Kα measurement provided sharper diffraction peaks and more accurate phase fractions, especially for overlapped reflections.

Benefits and practical applications

Combining filtered Cu-Kα and Co-Kα XRD strategies effectively suppresses fluorescence noise and improves resolution for robust phase analysis. The portable, low-maintenance EQUINOX 100 system supports field-to-lab transferability. The QUANT’X analyzer’s UniQuant routine allows fast, standard-free elemental screening, facilitating rapid ore grade evaluation without extensive calibration.

Future trends and applications

Advances in detector technology and machine-learning driven data processing will further speed up multi-phase quantification and enhance detection of minor phases. Integration of in-situ XRF/XRD combined probes may enable real-time monitoring of ore processing streams. Expansion of databases and fundamental-parameter algorithms will improve accuracy for mixed and amorphous materials.

Conclusion

The presented approach using ARL EQUINOX 100 and QUANT’X instruments provides a comprehensive workflow for ilmenite ore characterization. Dual-radiation XRD reduces fluorescence interference and yields precise phase data, while energy-dispersive XRF offers rapid, calibration-free chemistry. Together these methods support reliable ore grading and process optimization.

Reference

• Thermo Fisher Scientific Inc. Application Note AN41113, 2018.