SOIL FORMATION IN ALKALINE MINE TAILINGS AND PROCESSING RESIDUES

Mine tailings and mineral processing residues are a novel soil parent material with properties vastly different to those of bedrock parent materials. However, they experience the same drivers of natural soil formation (climate, organisms, relief, time) after deposition in tailings storage facilities. Understanding how these drivers interact during tailings weathering is of importance in accelerating natural processes of soil formation and attainment of a desired ecosystem endpoint. Alkaline tailings are relatively understudied in comparison to acidic, sulfide-bearing tailings, and require further investigation in order to improve current management strategies. This review presents a conceptual model of soil formation (pedogenesis) in alkaline tailings and processing residues and identifies key knowledge gaps for future research, using bauxite residue as a case study.