Geologically, Stockton is located in the eastern portion of the Hazleton Coal basin, part of the Eastern Middle Anthracite coalfield. The Hazleton Coal basin is a relatively long, narrow synclinal fold striking east northeast – west southwest.

Stockton is primarily located in the Mammoth seam, which reaches thickness of over 20ft in the bottom of the basin, although there are significant reserves to be found in the overlying Primrose, Diamond and Orchard seams too.

Having identified an area of anthracite reserves, an efficient blasting process is carefully planned out in order to fracture the rock so that it can be excavated.

Overburden (rock lying above the anthracite) is removed at a ratio of 18:1 (cubic yards of overburden: tons of clean coal) using large hydraulic excavators, and taken away by 100 tons capacity dump trucks.

Smaller excavators then remove the anthracite carefully to reduce the amount of rock carried to the washing plant.

Run of Mine anthracite enters the washing plant to be ‘cleaned’ of rock and other non-anthracite material and is then sorted into a range of sized anthracite products suitable for market. ROM anthracite is fed into a hopper from the ROM storage bay using a Front End Loader. Large rock is removed from the plant feed before being conveyed to a fixed grizzly screen and jaw crusher station that sizes the anthracite to 4” top size before feeding to the preparation plant.

The anthracite product is sorted into 8 standard sizes. Coarse refuse is collected on a belt conveyor and discharged to ground storage pile while fine refuse from the clarifier is collected in a sump and pumped to a disposal pond.