SRK Consulting (UK) Limited were commissioned by Sociedade Mineira de Neves-Corvo, SA (Somincor) to undertake a conceptual study on dewatering options for the Lombador extension at the Neves Corvo polymetallic mine in Portugal. The study aimed to review and optimize water management practices related to underground dewatering, focusing on sustainable resource usage and minimizing environmental impacts.
The Neves Corvo mine, located in the Alentejo region of southern Portugal, initially operated as a copper-tin mine before evolving into a zinc-copper operation. The mine features complex geological and hydrogeological conditions, including underground facilities, processing plants, waste rock dumps, tailings storage facilities, and various water management ponds. The high pyrite content of the orebody is reflected in the geochemistry of the tailings stored in the Cerro do Lobo Tailings Management Facility, which has historically received aqueous tailings but has been the recipient of paste tailings since 2007.
SRK's work involved a conceptual level review of dewatering options, including the assessment of existing dewatering infrastructure, historical inflow data, water balance, and mine water quality. The study aimed to develop an innovative underground water management option or optimize an existing solution to be taken forward to feasibility study (FS) and detailed design (DD) stages. Key tasks included evaluating groundwater inflows, service water demand, backfill water, and potential parameters of concern such as total suspended solids (TSS), nitrates, sulphates, and carbonates.
The project concluded with the successful development of a conceptual dewatering strategy that addresses both surface water and groundwater challenges. The preferred option involved direct pumping from the 220 Level to the 700 Level, utilizing GEHO piston-diaphragm pumps and lamella clarifiers for TSS removal. The study emphasized the importance of ongoing monitoring and adaptive management to protect local water resources and maintain the stability of the mine's infrastructure. The outcomes provided valuable insights for future water management practices and highlighted the need for further evaluation during the FS and DD stages.
