Platinum Group Elements (PGEs) are valuable metals with significant economic and geological relevance. Their ore grade enrichment in the geologic record is generally associated with magmatic processes, similar as the production of geothermal heat. Circulation of such fluids within the host rock can remobilize elements, probing the sub-surface. Despite the economic value of PGEs, there are limited reports of PGEs in geothermal occurrences.
Their presence in geothermal waters offers the potential for co-extraction with geothermal energy, enhancing the economic viability of geothermal projects. However, the analysis of PGEs in geothermal waters presents analytical challenges due to their low concentrations and complex matrix.
This study aims to develop a simplified analytical routine for PGEs in geothermal waters, focusing on reducing the need for complex column chemistry. A key strategy involves the combination of isotope dilution (ID) and high-resolution ICP MS. By using an isotope spike for ID, accuracy and precision can be improved, enabling further sample treatment. While column chemistry remains a common approach for matrix elimination and pre-concentration, this research seeks to explore alternative methods to streamline the analytical process.
Preliminary results from an exploratory field study of geothermal waters from a well in Cornwall indicate elevated palladium (Pd) concentrations. The geothermal well is targeted for co-extraction of Li and geothermal heat and part of the EU-funded CRM-geothermal project. These findings demonstrate the potential for PGE occurrence in geothermal environments. By establishing a more efficient analytical method, this research contributes to advancing our understanding of PGE distribution and behavior in geothermal environments. This knowledge is essential for optimizing geothermal resource development and exploring potential by-product recovery of valuable metals.