2 World Coal Institute

The build-up of silt and other sediments,together with movements in the earth’s crust(known as tectonic movements) buried theseswamps and peat bogs, often to great depths.With burial, the plant material was subjectedto high temperatures and pressures. Thiscaused physical and chemical changes in thevegetation, transforming it into peat and theninto coal.

Coal formation began during theCarboniferous Period – known as the first coal age – which spanned 360 million to 290million years ago.

The quality of each coal deposit is determinedby temperature and pressure and by the lengthof time in formation, which is referred to as its‘organic maturity’. Initially the peat is convertedinto lignite or ‘brown coal’ – these are coal-types with low organic maturity. In comparisonto other coals, lignite is quite soft and itscolour can range from dark black to variousshades of brown.

Over many more millions of years, thecontinuing effects of temperature andpressure produces further change in thelignite, progressively increasing its organic

maturity and transforming it into the rangeknown as ‘sub-bituminous’ coals.

Further chemical and physical changes occuruntil these coals became harder and blacker,forming the ‘bituminous’ or ‘hard coals’. Underthe right conditions, the progressive increasein the organic maturity can continue, finallyforming anthracite.

Types of CoalThe degree of change undergone by a coal as itmatures from peat to anthracite – known ascoalification – has an important bearing on itsphysical and chemical properties and isreferred to as the ‘rank’ of the coal.

Low rank coals, such as lignite and sub-bituminous coals are typically softer, friablematerials with a dull, earthy appearance. Theyare characterised by high moisture levels andlow carbon content, and therefore a low energycontent.

Higher rank coals are generally harder andstronger and often have a black, vitreouslustre. They contain more carbon, have lowermoisture content, and produce more energy.Anthracite is at the top of the rank scale and

Definition

Coal is a fossil fuel. It is acombustible, sedimentary,organic rock, which iscomposed mainly of carbon,hydrogen and oxygen. It isformed from vegetation,which has been consolidatedbetween other rock strataand altered by the combinedeffects of pressure and heatover millions of years toform coal seams.

Photographs courtesy of theAustralian Coal Association

SECTION ONE

WHAT IS COAL?

>> Coal is the altered remains of prehistoric vegetationthat originally accumulated in swamps and peat bogs. >>

Peat

Brown Coal

Sub-bituminous

Bituminous

The Coal Resource: A Comprehensive Overview of Coal 3

has a correspondingly higher carbon andenergy content and a lower level of moisture(see diagram on page 4).

Where is Coal Found?It has been estimated that there are over 984billion tonnes of proven coal reservesworldwide (see definitions). This means thatthere is enough coal to last us over 190 years(see graph). Coal is located worldwide – it canbe found on every continent in over 70countries, with the biggest reserves in theUSA, Russia, China and India.

ResourceThe amount of coal that may be present in adeposit or coalfield. This does not take intoaccount the feasibility of mining the coaleconomically. Not all resources arerecoverable using current technology.

ReservesReserves can be defined in terms of proved (ormeasured) reserves and probable (orindicated) reserves. Probable reserves havebeen estimated with a lower degree ofconfidence than proved reserves.

Proved ReservesReserves that are not only considered to berecoverable but can also be recoveredeconomically. This means they take intoaccount what current mining technology canachieve and the economics of recovery. Provedreserves will therefore change according tothe price of coal; if the price of coal is low,proved reserves will decrease.

Source: IEA Coal Information 2004

0

50

100

150

200

250

USA

RussiaChina

India

Australia

Germany

South Afri

ca

Ukraine

0

50

100

150

200

Countries with the Largest Reserves of Coal, 2003 (billion tonnes)

Source: BP 2004

Reserves-to-production Ratios, 2003 (Years)

Source: BP 2004

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Low Rank Coals47%

Sub-Bituminous30%

Bituminous52%

ThermalSteam Coal

MetallurgicalCoking Coal

Anthracite~1%

Lignite17%

Hard Coal53%

Largely power generation

Power generation Cement manufacture

Industrial uses

Power generation Cement manufacture

Industrial uses

Manufacture of iron and steel

Domestic/industrial including

smokeless fuel

USE

S%

OF

WO

RLD

RES

ERV

ES

HIGH

HIGH

MOISTURE CONTENT OF COAL

CARBON/ENERGY CONTENT OF COAL

Types of Coal

While it is estimated that there is enough coal to last us 190 years, this could extend still further through a number ofdevelopments, including:

>> the discovery of new reserves throughongoing and improved explorationactivities;

>> advances in mining techniques, which willallow previously inaccessible reserves to bereached.

All fossil fuels will eventually run out and it isessential that we use them as efficiently aspossible. Significant improvements continue tobe made in how efficiently coal is used so thatmore energy can be generated from eachtonne of coal produced.

Finding CoalCoal reserves are discovered throughexploration activities. The process usuallyinvolves creating a geological map of the area,then carrying out geochemical and geophysicalsurveys, followed by exploration drilling. Thisallows an accurate picture of the area to bedeveloped.

The area will only ever become a mine if it islarge enough and of sufficient quality that thecoal can be economically recovered. Once thishas been confirmed, mining operations begin.

SECTION ONE END

The Coal Resource: A Comprehensive Overview of Coal 5

Coal Reserves Showing Regional Shares (at end of 2003)

■ Europe and Eurasia 36%

■ Asia Pacific 30%

■ North America 26%

■ Africa 6%

■ South and Central America 2%

Middle East coal reserves less than 1% of total reserves

Source: BP 2004

Gas Reserves Showing Regional Shares (at end of 2003)

■ Middle East 41%

■ Europe and Eurasia 35%

■ Asia Pacific 8%

■ Africa 8%

■ North America 4%

■ South and Central America 4%

Source: BP 2004

Oil Reserves Showing Regional Shares (at end of 2003)

■ Middle East 63%

■ Africa 9%

■ South and Central America 9%

■ Europe and Eurasia 9%

■ North America 6%

■ Asia Pacific 4%

Source: BP 2004