Use and recovery of mining waste and tailings for sustainable management of works related to extractive activities

Extractive waste (EW), including tailings, are produced in large quantities during mining activities.

In recent years, the linear economic model (based on “take-use-and-throw” approach) has been replaced by a circular approach, in which even waste and extractive residues acquire importance through sustainable use and recovery.

The use and recovery of EW shows also positive technological (in term of technological innovations), economic and social (in terms of new expertise and skills linked to sustainability), and environmental impacts (to be evaluated and faced to reduce the ecological footprint).

The use and recovery of EW takes place through the application and development of innovative protocols linked to waste exploitation (sustainable and environmentally friendly), i.e. BAT, which aim at the technological and process improvement of the activities and at the production of renewed, highly performing green materials. Mining waste and tailings, if suitably characterized, can be used to improve and make sustainable the works connected to the management of mining activities.

The qualitative-quantitative characterization of EW is essential not only for any subsequent reuse but also for assessing the extent of environmental impacts (AMD, dust, high concentrations of heavy metals, etc.) in the various matrices and risk to human health and the environment.

The application areas of use vary according to the type of waste and mining tailings, the morphological characteristics of the deposits, and the geological, geomorphological and logistic context of the area.

In this study, some examples of sustainable use of tailings and mining waste are presented (i.e. use of calcareous tailings to reduce acid drainage and the production of artificial substrates for environmental rehabilitation, waste for mining backfills, waste/landfill waste recovered for extraction RM/CRM, etc.). Further to this, positive impacts on the economic, environmental and technological/social level are also analysed. The latter actions, together with energy saving and the adoption of appropriate financial instruments, contribute to the transition of mining activities into "sustainable mining".