Metallurgical coal
Metallurgical coal is a black sedimentary rock found within the earth's crust. It is higher in carbon, typically low in moisture and is an essential part of the steel-making process.
What is metallurgical coal?
Metallurgical (met) coal (or coking coal) is a naturally occurring sedimentary rock found within the earth’s crust. Categories of met coal include hard coking coal, semi-hard coking-coal, semi-soft coking coal and pulverised coal for injection (PCI). These apply to the different quality grades of met coal, all of which are used to make steel. Met coal typically contains more carbon, less ash and less moisture than thermal coal, which is used for electricity generation.
Prehistoric
Coal is formed from prehistoric vegetation that has been heated and compressed over millions of years.
Energy
The energy we get from coal today comes from the sunlight that was absorbed by plants millions of years ago.
Heavy machinery
The equipment used to mine coal is huge! Excavators can weigh up to 800 tonnes and haul trucks can carry up to 300 tonnes per load.
Steel
It takes around 770kgs of met coal to make the steel used in a typical mid-sized car.
How is metallurgical coal used?
Metallurgical coal is an essential ingredient in the production of steel, one of the most widely used building materials on earth. It takes around 770 kilograms of coal to make one ton of steel with approximately 70 per cent of global steel produced in basic oxygen blast furnaces. The challenge for steelmaking is to produce this vital commodity to enable sustainable growth, while reducing the greenhouse gas emissions footprint of the production process itself.
Construction
Buildings, bridges and other infrastructure around the world are built with steel made from iron ore that’s been blasted in a furnace powered by met coal.
Transport
Every mode of transportation relies on the steel that’s produced from iron ore and met coal. That includes planes, trains, ships, trucks and cars.
Household appliances
You’ll find steel in everyday household appliances like ovens, fridges and cutlery.
How is steel made?
Creating coke
Met coal is heated above 1,000ºC in a coking oven to create coke – a hard, porous lump.
Blast furnace
The coke is then added to a blast furnace with iron ore. Hot air and PCI are introduced, creating a flame temperature over 2,000ºC.
Converting to a liquid
The burning coal and coke produces carbon monoxide, which, along with the high temperature, converts the iron ore into a liquid.
Molten steel
This molten ‘pig iron’ is transported to a steel shop, where impurities are removed and alloys are added to make steel.
Where is metallurgical coal found?
Metallurgical coal comes mainly from the United States, Canada and Australia. We have seven operating coal mines in the Bowen Basin area of Central Queensland in Australia.
Queensland
Queensland Coal comprises the seven BHP Mitsubishi Alliance (BMA) assets in Australia's Bowen Basin region of central Queensland.
Think steel
0:30
Think steel
When the world's cities grow, Australia grows too.
As one of the world’s largest producers of iron ore, we’re helping you get to where you need to be.
How is metallurgical coal mined?
Mining methods differ depending on how far the coal is located below the Earth’s surface.
Underground
At our Broadmeadow mine in Central Queensland, coal is mined by a longwall shearer deep underground. The coal is then transported to the surface on a conveyor belt and stockpiled. Impurities are removed through washing and treatment at a coal handling and preparation plant. It’s then transported by train to port, loaded onto ships and exported to our customers.
Open cut
At our open cut mines, we extract coal from seams relatively close to the surface. We blast and remove the surface layers of soil and rock to expose the coal, which we then mine using excavators, draglines, shovels and trucks. The coal is then transported to stock piles. Impurities are removed through washing and treatment at a coal handling and preparation plant. It’s then transported by train to port, loaded onto ships and exported to our customers.
Underground
At our Broadmeadow mine in Central Queensland, coal is mined by a longwall shearer deep underground. The coal is then transported to the surface on a conveyor belt and stockpiled. Impurities are removed through washing and treatment at a coal handling and preparation plant. It’s then transported by train to port, loaded onto ships and exported to our customers.
Open cut
At our open cut mines, we extract coal from seams relatively close to the surface. We blast and remove the surface layers of soil and rock to expose the coal, which we then mine using excavators, draglines, shovels and trucks. The coal is then transported to stock piles. Impurities are removed through washing and treatment at a coal handling and preparation plant. It’s then transported by train to port, loaded onto ships and exported to our customers.
Where is our metallurgical coal exported to?
BHP's met coal is shipped to steel mills and coking plants in China, India, Japan, South-East Asia, South Korea, Europe and Latin America.
