From December 2017 to April 2019, employees at Pinos Altos safely and successfully extracted the Santo Niño Crown Pillar.
Our Pinos Altos mine in northern Mexico reached a milestone event earlier this year – transitioning from a combination surface and underground mine to a fully underground operation.
The decision came after geological and economic studies revealed it would be a safer, more efficient and profitable way to mine the remaining orebody.
But one key technical challenge remained. How to recover the Santo Niño crown pillar – the valuable ore reserves that lie between the bottom of the open pit and the upper level of the underground mine – without exposing employees to any additional risks or ground instability and with an eye to safeguarding the future of the underground mine?
“Extracting this valuable ore without compromising employee safety was our top priority. Given the strengthening market demand and gold price, we were determined to optimize this asset and move it totally underground,” says Marc Legault, Senior Vice-President, Operations for U.S.A. and Latin America.
A comprehensive technical feasibility study was conducted, the first of its kind in Mexico and one which eventually gained international recognition from the American Rock Mechanics Association due to the level of complexity and safety measures which would have to be put in place. The study outlined a work plan that required extensive coordination between the open pit and underground operating teams, the technical services team and the equipment and service providers to Pinos Altos.
Marco Antonio Perea Gallegos, the mine’s general manager, comments, “I want to thank everyone at Pinos Altos for helping us solve this complex mining challenge while keeping our people safe and meeting our production targets. We have already produced 36,000 ounces of gold and by year-end, we expect to safely extract close to 100% of the minerals from the Santo Niño crown pillar.”
Marco adds that with this success behind them, the Pinos Altos team plans to take a similar approach to recovering the crown pillar reserves at its Oberon de Weber open pit and underground facilities.
Congratulations to everyone at Pinos Altos! Their high skill in collaborating and executing on this ‘first’ for our Mexico mines and for the achievement in keeping everyone safe on this very complex project has allowed us to learn and take note of best practices for our future projects.