Coal mining

Over 7212 million tonnes (Mt) of hard coal is currently produced worldwide and 810.5 Mt of brown coal/lignite. Coal is mined by two methods: surface or 'opencast' mining, and underground mining.

Surface coal mining

Coal producers

The largest coal producing countries are not confined to one region - the top five hard coal producers are China, the USA, India, Australia and Indonesia. Much of global coal production is used in the country in which it was produced; only around 15% of hard coal production is destined for the international coal market.

Top ten coal producers (2014e)

PR China 3748 Mt Russia 334 Mt
USA 916 Mt South Africa 253 Mt
India 668 Mt Germany 187 Mt
Australia 491 Mt Poland 137 Mt
Indonesia 471 Mt Kazakhstan 116 Mt
Source: IEA Coal Information 2015


Mining methods

Coal is mined by two methods: surface or ‘opencast’ mining or underground or ‘deep’ mining.

The choice of mining method largely depends on the geology of the coal deposit. Underground mining currently accounts for a bigger share of world coal production than opencast; although in several important coal producing countries surface mining is more common.

  • Coal mining
  • Surface mining
  • Underground mining
  • Resources

Photo: Peabody Energy

Only around 15% of hard coal production is destined for the international coal market.

Surface mining

Surface mining is only economic when the coal seam is near the surface. This method recovers a higher proportion of the coal deposit than underground mining as all coal seams are exploited - 90% or more of the coal can be recovered. Large opencast mines can cover an area of many square kilometres and use very large pieces of equipment, such as draglines, power shovels, large trucks, bucket wheel excavators and conveyors.

The overburden of soil and rock is first broken up by explosives; it is then removed by draglines or by shovel and truck. Once the coal seam is exposed, it is drilled, fractured and systematically mined in strips. The coal is then loaded on to large trucks or conveyors for transport to either the coal preparation plant or direct to where it will be used.

Mine rehabilitation

Coal mining is only a temporary use of land, so it is vital that rehabilitation of land takes place once mining operations have stopped. In best practice a detailed rehabilitation or reclamation plan is designed and approved for each coal mine, covering the period from the start of operations until well after mining has finished.

Surface Mining

Underground mining

There are two main methods of underground mining: room-and-pillar and longwall mining.

Room-and-pillar mining

In room-and-pillar mining, coal deposits are mined by cutting a network of 'rooms' into the coal seam and leaving behind 'pillars' of coal to support the roof of the mine. These pillars can be up to 40% of the total coal in the seam - although this coal can sometimes be recovered at a later stage.

Longwall mining

Longwall mining involves the full extraction of coal from a section of the seam, or 'face' using mechanical shearers. The coal 'face' can vary in length from 100-350m. Self-advancing, hydraulically-powered supports temporarily hold up the roof while coal is extracted. When coal has been extracted from the area, the roof is allowed to collapse. Over 75% of the coal in the deposit can be extracted from panels of coal that can extend 3km through the coal seam.

Technological advancements have made coal mining today more productive than it has ever been. To keep up with technology and to extract coal as efficiently as possible, modern mining personnel must be highly skilled and well-trained in the use of complex, state-of-the-art equipment.

The quality of a coal deposit is determined by:

  • Types of vegetation from which the coal originated
  • Depths of burial
  • Temperatures and pressures at those depths
  • Length of time the coal has been forming in the deposit


Peabody Energy Ereen Mine Restoration

Shenhua Group Safety Management Programme

Alpha Natural Resources Running Right Leadership Academy

BHP Billiton Middleburg Colliery - South Africa