Exploration and mining of tantalum-niobium (coltan) and tin with handheld XRF analyzers

Importance of the Topic

The critical demand for high-performance metals such as tantalum, niobium, and tin in electronics, aerospace, and nuclear industries drives the need for rapid, accurate mineral analysis. Handheld XRF analyzers enable on-site evaluation of ore quality, supporting exploration, grade control, and environmental assessments with minimal sample preparation.

Objectives and Study Overview

This application note evaluates the performance of Thermo Scientific™ Niton™ handheld XRF analyzers for determining Ta, Nb, and Sn concentrations in coltan and cassiterite samples. The goal is to compare field results against laboratory ICP and AAS data and demonstrate suitability for mining workflows.

Methodology

High-grade pulped samples of coltan and cassiterite were analyzed in Mining mode using a Niton XL3t GOLDD+ analyzer. The built-in fundamental parameters algorithm quantified over 30 elements without user calibration. A post-measurement calibration using reference samples was applied to refine accuracy.

Instrumentation Used

• Niton XL2 Plus handheld XRF analyzer
• Niton XL3t GOLDD+ handheld XRF analyzer
• Niton XL5 Plus handheld XRF analyzer

The instruments feature high-power X-ray tubes with dynamic current adjustment and state-of-the-art silicon drift detectors.

Main Results and Discussion

Correlation between handheld XRF and laboratory methods was excellent, with R² values exceeding 0.99 for Ta2O5, Nb2O5, and SnO2. The slope of the regression lines approached unity, indicating minimal bias. Rapid, in-field quantification distinguishes high- and low-grade concentrates reliably, even in dark-grain mineral matrices.

Benefits and Practical Applications

• Real-time elemental analysis accelerates exploration and grade control.
• Minimal sample preparation reduces operational costs and time.
• Portable design supports on-site decision making in remote locations.
• High accuracy enhances trading value assessments for critical metals.

Future Trends and Opportunities

Advances in detector sensitivity, machine learning-driven calibration, and integration with GPS and data platforms will expand handheld XRF capabilities. Emerging alloys and complex mineral assemblages will benefit from tailored algorithms, while automation and cloud connectivity will streamline mining analytics.

Conclusion

Thermo Scientific Niton handheld XRF analyzers deliver rapid, accurate analysis of tantalum, niobium, and tin in mineral samples. Their strong correlation with laboratory techniques and ease of use across exploration, extraction, and processing make them invaluable tools for modern mining operations.

Reference

Thermo Fisher Scientific. Application Note MCS-AN1064-EN, 2024.