Non-carbonate geochemical options for long-term sustainable acid and metalliferous drainage control at-source

Acid mine drainage (AMD) from mine wastes is a critical environmental issue worldwide. It is caused principally by the oxidation of pyrite (FeS ₂ ) through a combination of complex reactions (physical, chemical, and biological), often associated with toxic metals/metalloids with varying toxicity, such as As, Cd, Pb and Zn. This paper is specifically focused on the role of reactive silicate minerals (including aluminosilicates) in contributing to pyrite surface passivation (at-source control for reduced AMD generation) and neutralisation processes for long-term AMD mitigation. The neutralisation potential of (alumino)silicate minerals (those readily accessible on-site) to buffer acid generation at reduced pH levels in the long-term is also discussed in the review. Overall, the review aims to present cost-effective solutions, using readily available (alumino)silicate minerals, to provide long-term neutralisation and precursors required for pyrite surface passivation (source control) for sustainable at-source geochemical AMD control.