Wyodak is a surface coal mine set up as a mine-mouth operation. That means that the coal produced at the mine is shipped directly to the adjacent power plant customers.
A surface coal mine removes the relatively shallow soils above the mineral resource. First, we remove and stockpile topsoil ahead of the mine advance. Topsoil removal and stockpiling is essential because reclamation efforts use this material to re-establish native environments after mining.
After the topsoil’s removed, overburden (the soil and rock above the coal seam) is blasted and removed. At Wyodak, there is approximately 200 feet of overburden on top of the coal. Four overburden benches, each about 50 feet tall, are advanced to uncover the coal resource. Electric shovels remove the overburden from these benches, and large end-dump haul trucks carry the overburden to the spoils where it’s used to build post-mining topography.
After we remove the overburden, we blast the coal seam to fragment the coal for safe and efficient digging. We use front-end loaders to mine the coal. The loaders place the coal into an in-pit crusher. It’s then transported by conveyor to the adjacent power plant complex.
Wyodak’s coal seam is approximately 80 feet thick, and average daily production is between 11,000 and 12,000 tons.