Assessing the Global Availability of Platinum Group Metal Resources

Platinum group metals (PGMs) are critical mineral resources for many countries, playing a critical role in energy transitions and the development of emerging strategic industries. Over 95% of global PGMs occur in co-associated forms. This study compiled data from 197 active PGM mines worldwide, representing 88.77% of global reserves. Using knowledge graph techniques, the study constructed a network of PGM co-associations, integrating these relationships into availability cost calculations to reduce prediction uncertainties. Data were processed using multiple imputation based on random forests and small-sample machine learning models optimized via grid search, and the availability was further evaluated using ensemble algorithms. The results reveal that PGM co-associations are mainly categorized into PGEs-Nickel-Copper±Cobalt±Silver and PGEs-Gold±Chromium, with XGBoost identified as the most effective algorithm for calculating availability costs, driven by factors such as total reserves, deposit type, milling capacity, and mining method. PGEs-Nickel-Copper±Cobalt±Silver associations exhibit higher availability costs and reserves compared to PGEs-Gold±Chromium. The supply trajectory of PGMs includes three phases and two critical risk points, with potential risks involving the depletion of 75% of cumulative reserves and exhaustion of low-cost mines in South Africa. Technological innovations and diversification in new energy vehicles can mitigate global PGM supply risks, but China’s demand-supply gap will persist, and only a high-recycling scenario can significantly enhance domestic supply security.