title: Spectral induced polarization (SIP) response of mine tailings.
abstract: Mine tailings impoundments are a source of leachates known as acid mine drainage (AMD) which can pose a contamination risk for surrounding surface and groundwater. Methodologies which can help management of this environmental issue are needed. We carried out a laboratory study of the spectral induced polarization (SIP) response of tailings from the Haveri Au-Cu mine, SW Finland. The primary objectives were, (1) to determine possible correlations between SIP parameters and textural properties associated with oxidative-weathering mechanisms, mineralogical composition and metallic content, and (2) to evaluate the effects of the pore water chemistry on SIP parameters associated with redox-inactive and redox-active electrolytes varying in molar concentration, conductivity and pH. The Haveri tailings exhibit well defined relaxation spectra between 100 and 10,000Hz. The relaxation magnitudes are governed by the in-situ oxidative-weathering conditions on sulphide mineral surfaces contained in the tailings, and decrease with the oxidation degree. The oxidation-driven textural variation in the tailings results in changes to the frequency peak of the phase angle, the imaginary conductivity and chargeability, when plotted versus the pore water conductivity. In contrast, the real and the formation electrical conductivity components show a single linear dependence on the pore water conductivity. The increase of the pore water conductivity (dominated by the increase of ions concentration in solution) along with a transition to acidic conditions shifts the polarization peak towards higher frequencies. These findings show the unique sensitivity of the SIP method to potentially discriminate AMD discharges from reactive oxidation zones in tailings, suggesting a significant advantage for monitoring threatened aquifers.
authors.affiliation: Aalto University, School of Engineering, Department of Civil and Environmental Engineering, P.O. Box 16200, FI-00076 Aalto, Finland. Electronic address: edmundo.placencia@aalto.fi.
authors.forename: Edmundo
authors.initials: E
authors.lastname: Placencia-Gómez
authors.affiliation: Universidad de Granada, Facultad de Ciencias, Dpto. de Mineralogía y Petrología, Avda. Fuente Nueva s/n, C.P. 18002 Granada, Spain. Electronic address: aparviainen@ugr.es.
authors.forename: Annika
authors.initials: A
authors.lastname: Parviainen
authors.affiliation: Rutgers University, Department of Earth & Environmental Sciences, Newark, NJ, United States. Electronic address: lslater@andromeda.rutgers.edu.
authors.forename: Lee
authors.initials: L
authors.lastname: Slater
authors.affiliation: Aalto University, School of Engineering, Department of Civil and Environmental Engineering, P.O. Box 16200, FI-00076 Aalto, Finland. Electronic address: jussi.leveinen@aalto.fi.
authors.forename: Jussi
authors.initials: J
authors.lastname: Leveinen
mesh_terms: D004553:Electric Conductivity; D004784:Environmental Monitoring / Q000379:methods*; D005387:Finland; D060587:Groundwater / Q000737:chemistry*; D007220:Industrial Waste / Q000032:analysis*; D008903:Minerals / Q000737:chemistry; D008906:Mining; D010084:Oxidation-Reduction; D013440:Sulfides / Q000737:chemistry
chemical_list: D007220:Industrial Waste; D008903:Minerals; D013440:Sulfides
keywords: AMD; Mine tailings; Oxidative-weathering; Spectral induced polarization; Sulphides