Research progress on mineralogical characteristics, rare earth elements occurrence phases and enrichment mechanisms of marine ferromanganese nodules/crusts

Key Points

• This research aims to explore the mineralogical characteristics and enrichment mechanisms of rare earth elements in marine ferromanganese nodules and crusts.
• Reviewed studies on the distribution and enrichment of rare earth elements in marine ferromanganese nodules and crusts.
• Analyzed the different formation processes affecting rare earth element content.
• Considered mining technology implications for deep-sea ferromanganese nodules.
• Hydrogenetic ferromanganese nodules have the highest rare earth element content.
• Diagenetic nodules have lower rare earth element concentrations than hydrogenetic ones.
• Mining of hydrogenetic nodules is preferred due to their higher content and ease of extraction.