Specifications Specifications Environmental Environmental Impact

Coal Recovery

Having identified an area of coal reserves, an efficient blasting process is carefully planned out in order to dislodge the rock without wasting too much explosive material.

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

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



Run of Mine coal enters the washing plant to be ‘cleaned’ of rock and other non-coal 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 coal to 4” top size before feeding to the coal preparation plant.

The coal 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.


Mine Reclamation

Concurrent mine reclamation is practised at Stockton – as the overburden is removed, it is taken to a disposal area in a previously mined section of the pit. This continual backfilling process ensures all reclamation remains current and maintains the open pit within permitted limits, without having to establish an overburden dump elsewhere.

Excavated overburden “bulks up” to a greater volume than it was in the ground (the “swell” or “bulkage” factor) so the backfilled areas are restored to slightly above original contours even after taking into account removal of the coal. The reclamation is completed by seeding with grass and planting trees.