The San Rafael Mine, which is owned by Minsur S.A. (Minsur), is an underground mine located 120 km from Puno City in southeastern Peru, in the cordillera of the Andes at 4,500 masl. B3 is an active tailings storage facility (TSF) with 15 Mt of capacity. The main structure of the facility is the 90 m high rockfill dam, which is being raised following the central axis method, and the other component is the 25 m high auxiliary dam.
Knight Piésold has been supporting Minsur as the civil-geotechnical designer for the project since 2010. Services provided for the B3 TSF include geotechnical characterization, liquefaction analysis, and seismic behavior assessment. Other services provided include hydraulic design, water balance, dam breach analysis and consequence assessment, and quality assurance during construction.
Minsur has been improving its governance model since 2015 with the intention of reducing the risk of the B3 TSF. Knight Piésold has been contributing towards the implementation of industry best practices and global initiatives, such as the International Council on Mining and Metals (ICMM) and the Mining Association of Canada, to drive sustainable and long-term project success of the San Rafael Mine.
Knight Piésold was designated as the Engineer of Record (EOR) for the facility in 2018 and has been helping Minsur since then to meet their performance indicators and policies in each phase of the life of the tailings deposit. Knight Piésold has reached a deep understanding of Minsur’s objectives that allowed for a differentiated support regarding informed decision-making and risk management. Knight Piésold has achieved one of the main challenges as an EOR by guiding Minsur on technical and strategic aspects to properly integrate tailings management aspects with mining operational activities.
Currently, the final raise of the tailings dam (4,490 masl) is in progress, and Knight Piésold, as the EOR, is providing transition support to the new B4 TSF and working in accordance with the ICMM adherence plan.