In five short years, Lundin Gold successfully developed the Fruta del Norte (FDN) gold deposit into a world-class mining operation, the first of its kind in Ecuador. Overcoming several challenges along the way, the first gold production was reached in December 2019 (Lundin Gold Inc 2019), and commercial production was achieved in February 2020 (Lundin Gold Inc 2020). The project has delivered many firsts to Ecuador. The new paste backfill system (Figure 1) is just one example where best-practice principles and state-of-the-art technology were used to meet technical challenges head-on and provide the best long-term solution for the mine.
Paterson & Cooke (P&C) was involved from the beginning and performed the trade-off studies, test work, and engineering design to shepherd the backfill project through to a successful start-up in October 2020. Starting with the paste plant location, it was essential to get the operation as close to the top of the orebody as possible. This meant constructing the plant remotely from the mill but directly over the orebody in order to achieve the best possible backfill recipes at the lowest possible operating cost.
The challenges that were overcome included developing the project in an environmentally sensitive remote rainforest setting; the Rio Manchinaza, which runs through the project site, is a source tributary for the Amazon basin. Likewise, commissioning ran in two phases due to an interruption from the COVID-19 pandemic, but the paste plant was started up successfully in October 2020.
This paper documents the design, construction, and commissioning challenges and achievements associated with implementing Lundin Gold’s FDN paste plant system.