title: Hydrochemical characterization of a mine water geothermal energy resource in NW Spain.
abstract: Abandoned and flooded mine networks provide underground reservoirs of mine water that can be used as a renewable geothermal energy source. A complete hydrochemical characterization of mine water is required to optimally design the geothermal installation, understand the hydraulic behavior of the water in the reservoir and prevent undesired effects such as pipe clogging via mineral precipitation. Water pumped from the Barredo-Figaredo mining reservoir (Asturias, NW Spain), which is currently exploited for geothermal use, has been studied and compared to water from a separate, nearby mountain mine and a river that receives mine water discharge and partially infiltrates into the mine workings. Although the hydrochemistry was altered during the flooding process, the deep mine waters are currently near neutral, net alkaline, high metal waters of Na-HCO3type. Isotopic values suggest that mine waters are closely related to modern meteoric water, and likely correspond to rapid infiltration. Suspended and dissolved solids, and particularly iron content, of mine water results in some scaling and partial clogging of heat exchangers, but water temperature is stable (22°C) and increases with depth, so, considering the available flow (>100Ls-1), the Barredo-Figaredo mining reservoir represents a sustainable, long-term resource for geothermal use.
authors: Dep. Explotación y Prospección de Minas, University of Oviedo, Independencia, 13, 33004 Oviedo, Asturias, Spain. Electronic address: loredocovadonga@uniovi.es.
authors: C
authors: C
authors: Loredo
authors: Dep. Explotación y Prospección de Minas, University of Oviedo, Independencia, 13, 33004 Oviedo, Asturias, Spain.
authors: A
authors: A
authors: Ordóñez
authors: Dep. Explotación y Prospección de Minas, University of Oviedo, Independencia, 13, 33004 Oviedo, Asturias, Spain.
authors: E
authors: E
authors: Garcia-Ordiales
authors: Dep. Explotación y Prospección de Minas, University of Oviedo, Independencia, 13, 33004 Oviedo, Asturias, Spain.
authors: R
authors: R
authors: Álvarez
authors: Dep. Explotación y Prospección de Minas, University of Oviedo, Independencia, 13, 33004 Oviedo, Asturias, Spain.
authors: N
authors: N
authors: Roqueñi
authors: Dep. Explotación y Prospección de Minas, University of Oviedo, Independencia, 13, 33004 Oviedo, Asturias, Spain.
authors: P
authors: P
authors: Cienfuegos
authors: Hulleras del Norte, S. A. (HUNOSA), Avenida de Galicia 44, ES-33005 Oviedo, Spain.
authors: A
authors: A
authors: Peña
authors: School of Engineering, University of Glasgow, G12 8QQ, UK.
authors: N M
authors: NM
authors: Burnside
keywords: Clogging; Geothermal energy; Hydrochemistry; Isotopic study; Mine water