Application of the Thermo Scientific Portable XRF Analyzer in PGE Exploration

Importance of the Topic

Exploration for platinum group elements (PGEs) is increasingly challenging due to rising metal values and lower cut-off grades. Rapid, field-based analytical techniques are essential to identify prospective mineralized zones, reduce sample throughput to laboratories, and support on-the-spot decision making.

Study Objectives and Overview

This study evaluates the application of a portable X-ray fluorescence (XRF) analyzer for PGE exploration on the Merensky Contact Reef in South Africa’s Bushveld Complex. By focusing on easily measured pathfinder elements, the project aims to demonstrate how real-time data can guide targeted sampling of gold, platinum, and palladium mineralization.

Methodology and Instrumentation

63 rock and drill-core samples were collected along a defined stratigraphic section encompassing pyroxenite, anorthosite, harzburgite, and chromite-rich lithologies. Laboratory assays were performed by ICP at a commercial laboratory to establish correlations between target PGEs (Pt, Pd, Au) and potential pathfinders (Ni, Cu). In parallel, Thermo Scientific Niton XL3t GOLDD+ portable XRF measurements were conducted in both direct-shot and pulverized-pulp modes.

Instrumentation Details

• Thermo Scientific Niton XL3t GOLDD+ handheld XRF analyzer
• Geometrically Optimized Large Area Drift Detector (GOLDD) technology for elements from Mg to U
• TestAll Geo automatic mode for major, minor, and trace element selection

Main Results and Discussion

Lab assays revealed strong positive correlations between Pt, Pd, Au and the pathfinder elements Ni and Cu. Portable XRF data reproduced these trends, confirming that Ni and Cu halos extend beyond the PGE mineralized zones, as illustrated in figure summaries. Stratigraphic profiles showed coincident peaks of target and pathfinder concentrations, validating direct-shot XRF as an effective tool for preliminary PGE vectoring.

Benefits and Practical Applications

• Immediate, on-site geochemical analysis of ore, rock, core, and chips
• Validation and refinement of deposit models in real time
• Significant reduction in samples sent for expensive laboratory assays
• Enhanced field decision support and project management efficiency

Future Trends and Possibilities

Advances may include integration of portable XRF datasets with GIS and machine learning for predictive mapping, expanded calibration libraries for low-Z elements, and improved detector sensitivity down to sub-ppm levels. Autonomous field platforms and wireless data transmission will further accelerate exploration workflows.

Conclusion

This case study demonstrates that portable XRF analysis of Ni and Cu pathfinder elements offers a rapid, cost-effective method to locate high-grade PGE zones. By guiding targeted sampling, this approach enhances the efficiency and success rate of precious metal exploration.

Reference

No external references were provided in the original material.