Mastering the Commodities Markets

MINING AND PRODUCTION

The mining or extraction of coal is carried out using one or both of two key methods; the method chosen depends on a number of factors including geology, thickness of coal seam, overburden and environment (see Figure 5.2). In essence if the coal seams are shallow and found close together, surface mining is generally chosen; whereas if the coal seams are thick (greater than 5 feet) and more than 200 feet deep, then nine times out of ten the underground mining method is more economically viable and preferable.

The two key methods – with descriptions from the World Coal Association (www.worldcoal.org) – are shown below:

• Surface or opencast mining, which accounts for approximately 40 per cent globally – but in the US it is ...