Phytomining as an Emerging Metal Recovery Route: A Critical Review of Plant Uptake Mechanisms, Processing Strategies, And Industrial Constraints (2020–2025)

Abstract : Phytomining has re-emerged as a promising strategy for the sustainable recovery of valuable and critical metals from soils, mine tailings, and industrial residues, while simultaneously contributing to environmental remediation. This critical review synthesizes advances published between 2020 and 2025, focusing on the biological, agronomic, and metallurgical foundations that govern phytomining performance and scalability. Recent progress in hyperaccumulator selection, soil amendments, plant–microbe interactions, and biomass processing has expanded the range of target metals beyond nickel to include gold, platinum-group metals, rare-earth elements, and scandium. However, field-scale deployment remains constrained by trade-offs between biomass productivity and metal concentration, as well as by the efficiency and cost of downstream ash processing and metal recovery. By integrating reported case studies, techno-economic assessments, and environmental indicators, this review positions phytomining within circular economy and nature-based remediation frameworks. Key knowledge gaps have been identified in process integration, quantitative performance metrics, and long-term sustainability, providing a roadmap for transitioning phytomining from experimental trials to industrially relevant applications.