Challenges and Innovations of Opencast and Underground Mining

The Kiena mine, located west of Val-d'Or, entered a new phase of commercial production in 2022 with the development of the Kiena Deep deposit located more than 1.0 km below surface. Having been shut down since 2013, and with infrastructure dating back to the 70s and 80s, restarting operations under such conditions brings its own set of challenges for an operation targeting a production rate of 100,000 oz/year. In addition to the investments in surface and underground infrastructure that were made for the restart, ground conditions and increased haulage distance at depth add to the series of challenges that require a long-term strategy for the operation's viability. This presentation covers the solutions found and the challenges ahead.

In recent years, the mining industry has undergone a phase of accelerated transformation in line with the technological developments that are changing our daily lives. For almost 30 years, the CMAC-Thyssen Mining Group has been pursuing this ideology of continuous improvement, pushing its vision and culture of innovative entrepreneurship ever further. The presentation will focus on a series of innovations achieved in recent years by the CMAC-Thyssen Mining Group.

Ore grinding is one of the most energy-intensive and inefficient industrial processes ever invented by man. Every year around the world, this process reduces billions of tonnes of ore to dust, consuming over 22,000 TWh of energy – around 3% of the world's electricity production.

Although ore fragmentation can be induced by a number of different processes, the ball mill remains the machine most often used in the mining industry. The fineness required to liberate the minerals is achieved by tumbling the ore in a rotating horizontal cylinder with grinding media, usually spherical steel balls.

The scientific literature tells us that the shape of the grinding media has a major influence on the energy efficiency of ball mills. Among other things, it mentions the Reuleaux tetrahedron as one of the grinding media shapes with the greatest potential for increasing mill efficiency. However, Relo grinding media (RGM) do not appear to be of interest to grinding media manufacturers or the mining industry on this side of the Atlantic.

Many tasks need to be completed to ensure the successful deployment of a mine. An inaccuracy, a delay or an accident could have a significant impact. In an industry as dynamic as mining, time is of the essence, and safety is key. The introduction of drones into our operations at Canadian Royalties has enabled us to meet these challenges and gain in efficiency while increasing safety. Indeed, drones have become an integral part of our operations. They play an essential role in our many underground and open-pit mines. Moreover, they are used from the project development phase right through to our day-to-day production operations. We need them to accurately capture the data required for planning and design, as well as to track and reconcile information. Drones are an essential tool for our success, and a win on many fronts.

Located approximately 3 km east of the entrance to the town of Malartic, the Odyssey Mine, owned by Agnico Eagle Mines Limited, will become one of the largest underground gold mines in Canada. With an estimated lifespan extending to 2042, the Odyssey Mine is a large-scale, state-of-the-art project that allows for innovation on many levels.

The presentation will cover the various milestones reached since the announcement of the mine's construction in February 2021, the most recent developments and the major milestones to come.

The Westwood Mine is a complex geological environment. It comprises three mining zones. On October 30, 2020, a large-scale atypical seismic event with a magnitude of 3.7 (Nuttli scale) occurred, causing significant damage and trapping a miner. The miner was safely rescued, but the event led to the decision to close the mine for re-evaluation. A strategy was developed to thoroughly investigate the seismic and geotechnical behavior of the mine and develop mitigation measures to safely reopen the mine. Internal resources and external consultants were entrusted with this task. A process was developed to build a robust geological, geotechnical and mining model to anticipate the behavior of the terrain. Mitigation measures can then be planned strategically, to reduce seismic risk through proactive design and sequencing, and, if necessary, tactically through field support and operational controls. Risk assessments can then be carried out to evaluate uncertainties and mitigation measures, and determine the acceptability of residual risks.