Constancia Mine

Project Overview

The Constancia Project, which is owned by HudBay Perú S.A.C. (HudBay), is a copper and molybdenum deposit that includes the development of two open pits: Constancia and Pampacancha. Constancia started operations in 2014 with an expected Life of Mine of 17 years.

Project Role

Since 2007, Knight Piésold has been involved in project development from pre-feasibility to detailed design for the following facilities: tailings storage facility (TSF), waste rock deposits (NAG and PAG), hydraulic structures, haul roads, and water reservoir. The scope of work also included a water management plan, process plant foundation assessment, and environmental impact assessment.

The most complex structure in the project is the Constancia TSF, a zoned rockfill dam that will reach a final height of approximately 200 m high (4,190 masl), a length of 4.7 km, and a capacity of 448.8 Mt. The eastern basin will be fully lined with geomembrane. The design considered two stages for the construction of the embankment: the first by downstream method and the second by switching to a centerline method at an elevation of 4,090 masl. The upstream rockfill platform relies on consolidated tailings.

Knight Piésold has been providing ongoing technical support for following: tailings deposition planning, real-time geotechnical monitoring, water balance, and seismic deformation analysis by FLAC.

Knight Piésold has also been providing field engineering, quality assurance, and Engineer of Record services for the TSF, waste rock facility, and main sediment pond.

The TSF has reached an elevation of 4,121 masl, corresponding to Stage 7 of the project. According to HudBay’s construction plan, an expansion of the TSF will be developed every year throughout its mine life.