Reduction of acid mine drainage by passivation of pyrite surfaces: A review

Acid mine drainage (AMD), a source of considerable environmental pollution worldwide, has prompted the development of many strategies to alleviate its effects. Unfortunately, the methods available for remedial treatment of AMD and the damage it cause are generally costly, labor-intensive, and time-consuming. Furthermore, such treatments may result in secondary pollution. Alternatively, treating the AMD problem at its source through pyrite surface passivation has become an important topic for research because it has the potential to reduce or prevent the generation of AMD and associated pollution. This review summarizes various pyrite anti-corrosion technologies, including the formation of various passivating coatings (inorganic, organic and organosilane) and carrier-microencapsulation. Several effective long-term passivators are identified, although many of them currently have important deficiencies that limit their practical application. Combining the mechanisms of existing passivation agents or new artificial materials, while considering environmental conditions, costs, and long-term passivation performance, is a feasible direction for future research.