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Facts about metallurgical coal

Download our fact sheet to learn more about metallurgical coal, including its properties, how we mine it, and its role in the steel making process.

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What is metallurgical coal?

Metallurgical (met) coal (sometimes referred to as 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 pulverized coal for injection (PCI). These apply to the different quality grades of met coal, all of which are used to make steel.

These categories refer to the quality of the grades of coal and how well they perform in the coke and iron making process. 

Better quality met coal tends to have more of the reactive fusible components, resulting in stronger coke, while PCI coal tends to have low levels of fusible material.

Met coal typically contains more carbon, less ash and less moisture than thermal coal, which is used for electricity generation.

 

Facts about metallurgical coal

 
Fact about met coal

Coal is formed from prehistoric vegetation that has been heated and compressed over millions of years.

Fact about met coal

The energy we get from coal today comes from the sunlight that was absorbed by plants that were alive millions of years ago

Fact about met coal

The equipment used to mine coal is huge! Excavators can weigh up to 800 tonnes and haul trucks can carry up to 300 tonnes of material per load. 

 Fact about met coal  Met coal was first used to make steel in China in the 11th Century.
 Fact about met coal  It takes around 770 kilograms of met coal to make the steel for a typical mid-sized car.

 

How is metallurgical coal used?

Met coal is a primary ingredient in the steel making process. It takes around 770 kilograms of coal to make one ton of steel.

Approximately 70% of global steel is produced in basic oxygen blast furnaces. 

The majority of steel is used in:

Facts about met coal

Construction: like buildings, bridges and infrastructure

Facts about met coal

Transport: like ships, planes and trains

Facts about met coal

Household appliances: like ovens, fridges and cutlery



How is steel made?

Met coal is heated above 1,000ºC in a coking oven to create coke – a hard, porous lump.
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. 
The burning coal and coke produces carbon monoxide, which, along with the high temperature, converts the iron ore into a liquid. 
This molten ‘pig iron’ is transported to a steel shop, where impurities are removed and alloys are added to make steel. 
 Fact about met coal

Why does BHP mine metallurgical coal?

Met coal is an essential ingredient in the production of steel.

Steel is one of the most widely used building materials on earth, and we expect it to remain so in the coming decades.

In 2019, BHP produced 70 million tonnes of met coal. That’s enough to produce enough steel to build the Burj Khalifa (the world’s tallest building) over 1,600 times!

Where does BHP mine metallurgical coal?

BHP has nine operating met coal mines in the Bowen Basin area of Central Queensland in Australia.

Facts about met coal


How is metallurgical coal mined?

Mining methods differ depending on how far the coal is located below the Earth’s surface.

Underground Open cut 

At our Broadmeadow mine in Central Queensland, coal is mined by a longwall shearer deep underground.

Fact about met coal

Facts about met coal

The coal is then transported to the surface on a conveyor belt. 

Fact about met coal

Facts about met coal

At our open cut mines, we extract coal from seams relatively close to the surface.

Fact about met coal

Facts about met coal

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. 

Fact about met coal

Facts about met coal

The coal is then transported to stock piles .

 Fact about met coal

Facts about met coal

Impurities are removed through washing and treatment at a coal handling and preparation plant.

Fact about met coal

Facts about met coal

It is then transported by train to port, loaded onto ships and exported to our customers. 

 Fact about met coal

Fact about met coal

Where is metallurgical coal exported?

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.

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