Heavy metal pollution in complex polymetallic ore processing: migration mechanism, treatment technologies, and future...

Complex polymetallic ores (CPOs) are crucial mineral resources supporting industrial development. However, the processing of CPOs is often accompanied by the release and migration of heavy metals (HMs), posing long-term risks to ecosystems and human health. Current research still lacks a comprehensive understanding of migration behavior of HMs and corresponding targeted control strategies throughout the mineral processing chain. This review has for the first time established a comprehensive framework for the heavy metal control throughout the entire processing of CPOs. The occurrence forms (independent mineral phase, isomorphous state, adsorbed state, and inclusion phase) of heavy metals (HMs) in CPOs and distribution characteristics have been comprehensively clarified. The migration and transformation mechanisms of HMs during the key processing stages have also been elucidated. In addition, advanced heavy metal treatment technologies are analyzed and summarized across the entire pollution control chain, including source prevention, process interception, and end-of-pipe remediation. Emphasis is placed on the collaborative strategy of pollution control and resource recovery. Finally, the key challenges and future research directions related to technological industrialization, collaborative multi-metal management, and standardization are clearly identified. This work advances heavy metal pollution control toward a full-process collaborative management framework, thereby providing both a theoretical foundation and technical support for the green, efficient, and sustainable utilization of CPOs.