Type of Mine: Surface Bituminous
Coal Formation: Olmos Formation
Average Seam Thickness: 5.5 feet
Average Depth: 50 feet

Average Coal Quality (As received):
Heat Content - 6,700 BTUs/lb
Sulfur - 1.00%
Ash - 40%
Moisture - 11%

Predominantly all machinery and equipment belongs by the owner of the mine.

The Eagle Pass Mine began selectively mining the thin coal seams with a Wirtgen type 4200 SM surface miner in October 2015.

The Wirtgen surface miner is used to selectively extract coal from the rock. This enables to achieve a high material quality. The four seams lie beneath an 18.3 m layer of top soil and overburden, in a series of layers around 6,0 m thick. Barely 1.65 to 2.0 m of this is coal.

The 4200 SM transfers a 250 t payload onto dumpers. They transport the coal to a transshipment center equipped with five grizzlies and conveyors. Each grizzly supplies one loading conveyor which transports the coal to the train-loading station.

The surface miner crushes the coal to a maximum size of 10 cm while minimizing fines. As coal fines tend to block the loading conveyors at the transfer points when there is a high moisture content, a low proportion of fines is a great advantage. Almost 95% of the coal is crushed and loaded by the 4200 SM. The remaining 5% – i. e., material located in inaccessible corners or right at the end of a drift – is broken up by bulldozers and loaded by front loaders.