Upstream stacking of thickened tailings at Neves Corvo

摘要

Neves Corvo is a world-class underground copper-zinc mine located in the south of Portugal. The mine has been operating since 1988 by Somincor (Sociedade Mineira de Neves-Corvo SA), a wholly-owned subsidiary of Lundin Mining Corporation from Canada.The pyritic tailings produced has a very high acid generation potential and until 2010 had been placed subaqueously in the Barragem Cerro do Lobo (BCL), a large tailings pond (190 ha) created by a rockfill dam, 42 m high, across a natural water course. In late 2010 Somincor switched to using subaerial paste/thickened tailings deposition over the existing subaqueous slurry deposit. This approach accommodates the required 17.4 Mt storage capacity from 1 January 2010, as per Somincor's 2005 life-of-mine (LOM) plan, and allows maintaining the existing perimeter embankment at its current elevation and facilitates site closure (Lopes et al. 2013).The results of the first two years of operation of the paste production plant and depositional performance of the first 2 to 4 m of paste/thickened tailings over the very loose subaqueous deposit, were presented at Paste 2013 in Brazil (Lopes et al. 2013).