Application of electrical resistivity tomography to the environmental characterization of abandoned massive sulphide mine ponds (Iberian Pyrite Belt, SW Spain)

Abstract

Mining activity in the Iberian Pyrite Belt, on the south‐west of the Iberian Peninsula, has generated a great amount of mine tailing ponds, which once the extractive activity is finished, are abandoned and become a serious environmental problem. Here we present the results of applying the electrical resistivity tomography (ERT) technique to characterize the abandoned mine ponds in two sites: Monte Romero and Mina Concepción. ERT has allowed us to determine both the general geometry of the pond’s base and the maximum thickness of the mine tailings. In all cases, the resistivity contrast between the infilling and the bedrock is high enough to clearly define the bottom pond boundary. The low‐resistivity values (lower than 5 Ωm) obtained for the infilling are explained by the high concentration of pyrite in the tailings and the occurrence of acid waters. Whereas the Monte Romero mine pond is almost completely saturated with water, in Mina Concepción it has been possible to identify the presence of inner acid water flows, the outlet of which through the damaged dyke originates a spilling of acid waters to the Odiel River. No low‐resistivity water flows through the base of the ponds into the bedrock have been observed, indicating a good isolation of the base of the studied mine ponds.

Geoenvironmental Characterization of Sulfide Mine Tailings

“…From the different electrode arrays available, a Wenner-Schlumberger array has been selected because it provides a good penetration depth, the signal to noise ratio is good, and both vertical and horizontal resolutions are also reasonable. Moreover, different authors have previously used this array successfully in several similar studies [3][4][5][6][7]18] because it shows a high contrast between the resistivity values of the vase of the mine ponds and the resistivity values of the infilling. From the field data, the information obtained about the resistance measurements between the different electrodes and distances between them is used to calculate the apparent resistivity values.…”

Integrated geophysical and geochemical methods applied for recognition of acid waste drainage (AWD) from Zn-Pb post-flotation tailing pile (Olkusz, southern Poland)

“…Transfer of the sulphide oxidation products: Zn 2+ , Cd 2+ , Pb 2+ , Mg 2+ , Ca 2+ and SO 4 2− change the electrical conductivity of the rock mass (Schön 2015). Therefore electrical resistivity and electromagnetic methods are successfully used to identify zones of acid drainage related to exploitation and processing of metal ores (Vanhala et al 2004;Chouteau et al 2006;Cabala et al 2008;Iacob and Orza 2008;Gómez-Ortiz et al, 2010;Nearing et al 2013;Acosta et al 2014;Olenchenko et al 2016;Epov et al 2017) and of hard coal (Ladwig 1983;Pierwola and Kowalska 2012;Pierwoła 2013;Power et al 2018).…”

Electrical Resistivity Tomography as a Support Tool to Estimate Physicochemical Properties of Mining Tailings Pond

“…Indeed, metal-based ore processing generates large amount of mine tailings, which are watery sludge composed of medium-to finegrained material [2]. Due to natural leaching from these reactive materials, contamination of the environment close to the deposits often occurs [3]. In the Cartagena-La Union mining district (SE Spain) the legacy of more than 2500 years of intensive mining activity has left a large number of tailings ponds with considerable environmental impacts by generating leachates with high contents of sulphides and certain metallic elements [1,[4][5][6][7] due to their wastes are characterized by significant content in metals such as Pb, Zn, Cu, and Cd, high salinity, acidic pH levels and low soil organic matter content [8].…”