Improving the sustainable management of mining tailings through microbially induced calcite precipitation: A review

Mining activities offers evident potential economic benefits for mineral rich countries. However, mining operations can produce a series of environmental impacts. Many of them are associated with the generation and management of tailings. Biogeochemical processes have potential to modify the properties of particulate solids, such as tailings. Microbial induced calcite precipitation (MICP) is probably the most studied biogeochemical process. It promotes calcite precipitation, as a result of biological activity of different microorganisms. Available research indicates that MICP is a tool that has the potential to contribute to a more sustainable management of tailing deposits. Indeed, MICP have been reported as a technology suitable for removal and/or immobilization of heavy metals, creation of impermeable barriers, prevention of soil liquefaction and control of windblown dust emissions. However, several challenges still need to be addressed to enable relible full-scale implementation, requiring research in the near future. These are consideration of the particular chemical composition of tailings, reduction of urea requirements, determination of optimal reagents dosage, evaluation of the long term stability of the treatment and calculation of costs associated to ecah particular application.

Automated summary

Mining activities have economic benefits, but also environmental impacts on tailings generation and management. Biogeochemical processes, particularly microbial induced calcite precipitation (MICP), can modify the properties of tailings. MICP has potential for sustainable management of tailing deposits, with applications including removal or immobilization of heavy metals, creation of impermeable barriers, prevention of soil liquefaction, and control of windblown dust emissions. However, challenges remain in considering tailings' chemical composition, reducing urea requirements, determining optimal reagents dosage, evaluating long-term stability, and calculating associated costs.