CRMs in Base Metal Systems

Base metal deposits are a major source of copper, zinc, lead, and nickel – and a hidden reservoir of critical raw materials (CRMs). CAMM-CRM’s research turns these overlooked elements into new opportunities for sustainable recovery, resource efficiency, and supply chain resilience.

Summary

Led by Lina Hällström, Associate Senior Lecturer in Applied Geochemistry, the CRMs in Base Metal Systems Research Pillar (RP3) addresses knowledge gaps along the entire value chain – from exploration to processing, recycling, and environmental assessment. Elements such as As, Bi, Co, Ga, Ge, Sb, V, W, and the platinum-group metals (PGMs) occur as trace components or lattice-bound elements within common ore minerals and are often lost to waste. This pillar aims to maximize their recovery from primary ores and as co- or by-products, transforming elements previously regarded as problematic into valuable resources while mitigating environmental risks and improving resource efficiency.

Goals

• Increase supply-chain resilience and resource efficiency by valorising existing base-metal operations.
• Maximize value of CRMs in base metal deposits.
• Advance geological and geometallurgical understanding.
• Develop innovative processing and recovery solutions.
• Mitigate environmental risks and improve monitoring.

Research Focus and Key Areas of Work

• CRM Occurrence and Mineral Systems
  Research integrates geological, geochemical, mineralogical, geophysical, geometallurgical, mineral processing, and metallurgical methods to identify and quantify CRM deportment in ore systems and to establish predictive models for their occurrence. Elements such as Sb, Bi, and As often accumulate in Cu deposits, while Ga, Ge, and In are enriched in some Zn deposits. Understanding these variations – through structural, isotopic, paragenetic, and fluid-inclusion studies combined with micro- to nano-scale mineralogical analyses – clarifies the controls on CRM distribution and supports the identification of CRM-endowed deposit types. The combined use of magnetotelluric (MT) and seismic methods further enables a holistic “source-to-sink” understanding of these mineral systems.
• Processing and Recovery
  From a processing perspective, CRMs are frequently lost to waste streams or treated as deleterious impurities affecting concentrate quality. This research pillar aims to develop integrated mineral-processing, hydro-, and pyrometallurgical flowsheets, and advanced separation technologies to valorise these elements. Research also assesses recovery potential from mine tailings, slags, dusts, sludges, process water, and recycled feedstocks, linking CRM mineralogy with processing behaviour through geometallurgical approaches to define realistic industrial recovery pathways. Particular challenges remain for elements that volatilize or condense during thermal processing, forming amorphous phases that complicate extraction.
• Environmental Behaviour and Monitoring
  The environmental mobility of elements such as As, Sb, V, and W from mining waste to groundwater remains poorly understood. This research pillar investigates these processes to inform future waste management and remediation strategies that minimize environmental impact and foster social acceptance. Because CRMs are rarely monitored in groundwater, the research pillar also supports systematic mapping of CRM geochemistry in mine tailings and groundwater, providing essential baseline data. The environmental implications of “new waste” from tailings reprocessing are also evaluated to ensure sustainable extraction practices.
• Strategic Significance
  The strategic value of this research lies in transforming elements traditionally viewed as detrimental into valuable products, thereby improving raw material efficiency, reducing environmental burdens, and enhancing the resilience of European supply chains. By combining mineral system analysis, advanced characterization, and innovative processing, this research pillar contributes to the sustainable exploitation of Sweden’s and Europe’s mineral resources and reinforces the role of base-metal producers as suppliers of both bulk and critical elements for the green and digital transitions.

Current Projects

• Geological controls on critical raw materials in base metal sulfide deposits
• Geometallurgy of Co, Ni, As, Bi and Sb in complex Zn-Pb-Ag and Cu-Zn deposits
• Valorisation of the CRMs existing within the base metal extraction
• Method for extraction of bismuth and antimony, and removal of arsenic from industrial residue
• Baseline of CRM in the Skellefteå Area – Environmental monitoring and geochemical exploration