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Coal. Second only to petroleum, it is the most-consumed fossil fuel in the world today.

What is Coal?

Coal is an energy-rich, combustible solid material comprised of carbon, hydrogen, nitrogen, oxygen, phosphorus, ash, and sulphur, as well as other constituents. The energy potential of coal is related most to its relative carbon content.

The world’s coal reserves are distributed all over the planet, found in sedimentary strata (or layers of soil). Coal is a non-renewable resource. It was formed from decayed and rotting plant matter that decomposed in bogs and swamps millions of years ago when the Earth was covered in thick, marshy forests. Natural geological processes, including heat and pressure, compressed these biological remains and altered them over millions of years, transforming them chemically and physically (forcing out the oxygen and leaving carbon) into what we recognise as coal.

Here are some fascinating coal facts.

Did You Know?

Geologically:

  • The world currently has six times more coal reserves than it does for petroleum and oil.
  • The majority of the world’s coal was formed 360-300 million years ago, during the Carboniferous Age. This also represents the best quality coal, as it has the highest carbon content. The volume of nitrogen, oxygen and moisture in coal deposits diminish over time, while the proportion of carbon within coal increases. This is influenced by the depth and pressure at which it was formed – with deeper coal reserves having a higher carbon content.

There are five main type of coal:

  1. Anthracite – the hardest type of coal, has the highest carbon content and the highest energy potential. It ignites and burns slowly with few pollutants. Some geologists consider coal to be a form of metamorphic rock.
  2. Bituminous – close in energy content to anthracite, it is widely used and is usually black. There are no remaining traces of vegetative material.
  3. Sub-bituminous – compressed lignite, has 75% of the energy of bituminous coal.
  4. Lignite – compressed peat, it is soft brown coal with low carbon content and the highest sulphur content. It can spontaneously combust.
  5. Peat – decayed vegetative material dug from peat bogs, it has many impurities and low carbon content. It burns in the same way as wood, giving low levels of heat and emitting a lot of smoke. It leaves a lot of ashy residues. 

During the process of coalification, peat is transformed into lignite; lignite to sub-bituminous coal; sub-bituminous coal to bituminous coal; and bituminous coal to anthracite. These processes take many millions of years.

Historically:

The earliest use of coal dates back thousands of years. Indigenous Australians burned coal for energy to heat and cook, and the Awabakal People from the Newcastle, NSW area have a Dreamtime legend about the formation of coal.

There is evidence dating back six thousand years that the people inhabiting northeastern China used coal to carve ornaments. By 1000 BC it was used to smelt copper in China.

Bronze Age people in Great Britain used coal for funeral pyres, and the ancient Greeks recorded the use of coal in metalworking. Coal was an essential power source and aspect of trade during the Roman Empire. The Romans exploited all of the main coalfields in England and Wales and there is archaeological evidence of the Roman coal trade all over Britain.

Over time, coal became used for heating and cooking when firewood was scarce, and it was the favoured home fuel in Europe by the 1600s. This led to the wider adoption of coal for industrial purposes. Thanks to the Industrial Revolution, more comprehensive use of coal arose and the steam engine overtook the waterwheel. In 1700, the vast majority of the world’s active coal mines were in Great Britain and coal mining remained a huge industry in the UK.

Due to both the natural erosion of exposed coal seams and spills from coal cargo ships dating back centuries, coal is still washed up on beaches worldwide.

Economically:

  • Coal may be mined underground or from the surface. 
  • 5.3 billion tonnes of coal are consumed worldwide each year.
  • Coal currently accounts for more than 37% of the global electricity supply. It is more accessible and cheaper to source and use than other fossil fuels. 
  • Coal is versatile and requires no processing after mining before it can be used, unlike other fossil fuels which must be refined.
  • Coal-based electricity is less expensive to produce than that from many other sources. Coal is also a safe, easy material to handle, transport, and store.
  • Coal is intrinsic to:

    Electricity Generation – this is the primary use for coal worldwide. Coal is burnt in furnaces to create steam; this steam drives turbines and generators to produce electricity.

    Cement Production – coal combustion by-products (e.g. fly ash) are used to manufacture cement, and coal-powered energy is used in the production processes.

    Metal Production
    – coking or metallurgical coal is used in steelmaking for 70% of the planet’s steel. Coal is also used to manufacture copper, aluminium, and other metals.

    Chemical Production
    – gasified coal by-products are processed to produce chemicals including ammonia, methanol, and urea.

    Liquefaction/Gasification
    – gasification is the process of heating and pressurising coal with steam to produce gas for domestic cooking, heating, and lighting purposes. Liquefaction refers to turning solid coal into liquid form to create synthetic fuels that resemble diesel or petroleum.Other Industries – coal is used in the manufacture of glass, textile, paper, silicon metals, carbon fibre, and others.

Coal in Australia:

  • Australia has the fourth-largest known coal reserves worldwide, after the USA, Russia, and China. Black coal reserves are located primarily in NSW and QLD, though there are also resources in WA, Tasmania, And SA. Bron coal resources are located in SA, WA, Tasmania, Victoria, and QLD.
  • Brown coal is used in Australia to supply local power stations near the reserves and to produce fertilisers and soil conditioners.
  • The coal within Australia ranges from the Permian to the Jurassic eras – or 28 million to 150 million years old – the majority are Permian.
  • In Australia, 80% of coal mining is open cut, compared with just 40% elsewhere worldwide.
  • Coal currently fuels approximately 77% of Australia’s electricity needs.
  • Australia’s first known export was coal. European settlers discovered it for themselves in the Newcastle area in the late 1700s, and it was first exported from Newcastle, NSW in 1799, being shipped to Bengal, India. The Port of Newcastle ships coal to this day.
  • The Australian coal industry directly employs more than 40,000 individuals. Another 100,000 people are employed indirectly by the local coal industry. In 2019 alone, it generated $69.5 billion in export revenue. 
  • Modern coal mining practices are undertaken with environmental, economic, and social responsibility to be as sustainable as possible. This includes land rehabilitation planning, monitoring groundwater, and using advanced technology.

Work with PIMS Group

PIMS Group is an Australian coal mining industry leader, delivering superior mining services and solutions for the underground coal mining sector:

• Human workforce
• Equipment
• Workplace health and safety
• Training

To understand how we can deliver the underground coal mining solutions you seek, please visit our services page or our training page.

You may contact our Head Office on (07) 4969 3900 or our Wollongong Office on (02) 4258 3420. Email us at admin@pimsgroup.com.au.