Global Coal Mining
While coal mining has been around for more than 5,000 years, large-scale coal mining only developed in the 18th century. Coal is mined in two ways: surface (ie open pit) mining and underground (ie deep well) mining. There are two methods of underground mining; room-and-pillar mining and longwall mining.
The room-and-pillar mining method is a coal mining method in which a network of coal mining rooms is established in the coal seam, and coal pillars are reserved between the coal rooms to support the roof. The mining rate of coal is 50% to 60%. The longwall mining method is to use the shearer to crush and collect the coal (100~250m wide) on the working face. Self-propelled hydraulic power temporarily props up the roof while coal is being mined, while the roof collapses behind the face. Its recovery rate is about 75%. Open pit mining is only economically viable when the coal seam is close to the surface. The coal mining rate of open pit mining is higher than that of underground mining, but it will destroy the land and reduce the availability of the land.
Global coal production in 2011 was 7678Mt. Of this, about 6637Mt is hard coal and 1041Mt is lignite (WCA2012). Among these hard coals, 5670Mt is thermal coal and 967Mt is coking coal (WCA2012). In addition, if you are interested, you can read the article Global coal reserves introduced earlier.
Coal production in the Asia-Pacific region was huge, with an increase of about 120%, followed by Latin America with a 78.8% increase. Compared with 2010, coal production in Asia Pacific and Latin America increased by a record 7.8% and 13.3% respectively in 2011, while the global average growth rate was only 6.1%. Annual coal production in the United States, Germany and Poland is on a downward trend, while Asian countries, especially China, Indonesia and India, have a clear upward trend.
Coal production forecast to 2035
ElA’s Energy Outlook report predicts that from 2008 to 2035, the average annual growth rate of coal production in non-OECD countries will be 1.8%, while that in OECD countries will be 0.5%.
It is estimated that from 2008 to 2035, China’s coal production will grow the fastest, accounting for 67% of the world’s total coal production growth (the world’s total coal production growth is 68 trillion Btu, of which China’s is 45.5 trillion Btu). The outlook report further pointed out that China’s coal production in China will mainly supply its own development needs. Other countries with larger increases in coal production include Australia (6.5 trillion Btu), New Zealand (9% of total world coal production growth), India (4.5 trillion Btu), non-OECD countries (excluding China and India at 4.5 trillion Btu), Africa (3.6 trillion Btu), the United States (2.7 trillion Btu) and Latin America (2.5 trillion Btu).
Much of the growth in coal production in Australia, New Zealand, and Latin America is due to their increasing coal exports. The increase in coal production in Africa and non-OECD countries (excluding China and India) is to meet the increase in their own coal consumption and export volume. The increase in U.S. coal production was mainly due to an increase in coal consumption in China.
