『Abstract
　Platinum group elements (PGEs) are increasingly used in a variety of environmentally-related technologies, such as chemical process catalysts, catalytic converters for vehicle exhaust control, hydrogen fuel cells, electronic components, and a variety of specialty medical uses, amongst others - almost all of which have strong expected growth to meet environmental and technological challenges this century. Economic geologists have been arguing on the case of abundant geologic resources of PGEs for some time while others still raise concerns about long-term supply - yet there remains no detailed analysis of formally reported mineral resources and key trends in the PGEs sector. This paper presents such a detailed review of the PGEs sector, including detailed mine production statistics and mineral resources by principal ore types, providing an authoritative case study on the resource sustainability for a group of elements which are uniquely concentrated in a select few regions of the earth. The methodology, compiled data sets and trends provide strong assurance on the contribution that PGEs can make to the key sustainability and technology challenges of the 21st century such as energy and pollution control.

keywords: Platinum group elements (PGEs); Economic mineral resources; Mineral resource sustainability; Bushveld Complex; Great Dyke; Noril'sk-Talnakh』

1. Introduction
2. Brief review of the economic geology of platinum group elements
　2.1. Principal ore types
　2.2. The Bushveld Complex, South Africa
3. Economic PGE mineral resources
　3.1. Reported mineral resources
　3.2. Comparison of PGE resource estimates
4. Mining and processing of PGE ores
　4.1. Overview
　4.2. Production trends
5. Discussion
6. Conclusion
Acknowledgements
References

Fig. 4. Recent global platinum demand by use (JM, 2011). Fig. 3. Historical global production of PGEs by country, including nominal and real price data - inset. Data combined from CMSA (2008), Kelly et al. (2010), Loferski (2010), NRC, var.; SADME (2007), and Vermaak (1995). Fig. 7. Linear trend line for PGE production (1960 to 2009) (left); two ‘peak PGE’ models (right). Mudd(2012)による『Key trends in the resource sustainability of platinum group elements』から