There are two types of mines in operation at Newmont: surface and underground. Which one do you want to learn more about?
Constructing a Surface Mine
As we dig farther down, it may be necessary to dewater the mine to ensure that the water level remains below the pit floor. We may need to pump significant volumes of water from the pit each day. Much of it is reused on site (for dust control, processing, etc.). Whenever possible, excess water is treated, tested and safely discharged back into nearby underground aquafers, rivers or lakes.
A significant amount of monitoring takes place in and around the open pit, to keep a watchful eye on:
- Slope stability and dewatering-induced settlement
- Noise, dust and vibration
- Water levels and water quality, including pit wall run-off
- Social impacts
Constructing an Underground Mine
Underground mines are used to recover minerals or metals from deep in the Earth. When building an underground mine, first we dig a tunnel to get to the minerals contained in the ore body. This can be a straight vertical tunnel, called a shaft, or a tunnel called a decline, which will use a spiral pattern at any point underground to navigate into the Earth. To access the ore from the shaft or decline, we dig other tunnels (in mining, called drifts). We also develop other shafts for drifts specifically to provide proper ventilation and emergency exits.
We excavate the tunnels and the ore body by drilling and blasting. The ore is mined from designed “rooms,” called stopes, which are of varying sizes and shapes to ensure we maximize the extraction of ore. The broken-up ore is then transported to the surface for processing. Barren rock known as waste may also be transported to the surface or left in the mine and used to fill mined-out stopes.