Coal recovery
Coal is recovered from the site using traditional opencast methods but utilising modern technology. To prevent dust being raised by the vehicles used on site, dust suppression units will spray water on all running surfaces. The excavated material will be stored in dumps known as overburden dumps which are located mainly to the east and south of the excavation.
During the excavation, coal seams are exposed and recovered cleanly, using hydraulic shovels and mechanical coal cleaners. The coal is then loaded into coal lorries and transported over site roads to the Coal Disposal Point (DP) at Cwmbargoed. The coal lorries will need to cross the 'Bogey Road' at an approved crossing point before entering the DP. Lorries leaving site to cross the 'Bogey Road' will pass through a wheel wash. Once the coal is at the DP, it will then be blended and dispatched into railway wagons for onward distribution, by rail, to the market.
As can be seen from the schematic diagram above, the first major excavation is the development of a box cut, this provides for sufficient work room for men and equipment to operate safely and efficiently. The material excavated from the box cut is taken to a temporary dump above ground. This overburden dump is also grassed and maintained until such time as the material is replaced in the final void, thereby completing the restoration works.
After completion of the box cut, all subsequent excavation is carried out in successive strips and the excavated material from these strips is progressively placed behind the current workings, into the previously worked out voids. This system of working provides for a 'wave like' activity to flow through the Scheme, thus enabling restoration of the land behind to be carried out progressively as the works continue. The final void is then filled using the overburden temporary stored in the dump above ground.