Perlatti, F, Kutchenski, FE, Pasti, HA, Silva, CA & Lamarque, OJS 2023, 'Legacy coal mines in Southern Brazil: Actions from National Mining Agency to promote fair mine closure and their transitions to another land-use', in B Abbasi, J Parshley, A Fourie & M Tibbett (eds), Mine Closure 2023: Proceedings of the 16th International Conference on Mine Closure, Australian Centre for Geomechanics, Perth, https://doi.org/10.36487/ACG_repo/2315_095
(https://papers.acg.uwa.edu.au/p/2315_095_Perlatti/)
Abstract: Issues related to legacy mines and their environmental and social impacts that occur in the coal basin in southern Brazil, in the state of Santa Catarina, Brazil, are described in this paper, as well as actions promoted by the Brazilian government to identify and measure the extent and severity of the impacts. In this region the extraction and processing of coal began in the early 20th century, when the legislation for the activity were not well-established, leading to the abandonment of dozens of mines, exceeding thousands of hectares. These legacy coal mines, with high levels of sulphur and heavy metals, have been causing several environmental impacts over time due to exposure and abandonment of waste rock and tailings from open pits and underground mines. Problems such as generation of acidic drainage as well as water and soil contamination jeopardize the adjacent ecosystems and the public health of local communities. The Brazilian Federal Government, represented by the National Mining Agency (ANM), which is responsible for issuing mine permits, was forced to find solutions for these legacy sites, as well as some companies that still operate. For more than ten years, works have been carried out, with the aim of reclaiming these areas using techniques to minimize the geochemical impacts of coal tailings, as well as to recover affected ecosystems. In this paper, the main technical and regulatory challenges in the Brazilian legacy coal mining industry are presented, as well as the search for solutions to overcome these obstacles. Some examples of reclaimed areas including monitoring data from three river basins are presented, which show the success and failure cases of the techniques used. We address also the main challenges that still need to be overcome so that these areas, public and private, can be returned to the environment and society in a way that provide quality ecosystem services, as well as sustainable future uses, providing a fair transition for stakeholders.

Keywords: acid drainage, metals, contamination, social impacts, environmental rehabilitation