Coal and Cement Making
What is Cement?
Cement is the main binding ingredient in concrete,
the most common building and construction material
in the world. Major uses include buildings, both
commercial and homes, manufacturing, mining and
tourism facilities, and infrastructure development
such as roads, airports, bridges, harbours, reservoirs
and dams.
The world uses more than 1,350 million tonnes
of cement every year.
Source: Queensland Cement Limited (QCL) http://www.qcl.com.au
Coal and Cement Making
Cement is made from a mixture of calcium carbonate
(generally in the form of limestone), silica,
iron oxide and alumina.
A high-temperature kiln fuelled by coal, natural
gas or alternative fuels (waste tyres, oils and
solvents) heats the raw materials to a partial
melt at 1450°C, transforming them chemically
and physically into clinker. This grey pebble-like
material comprises the special compounds that
give cement its binding properties. Clinker is
mixed with gypsum and ground to a fine powder
to make cement.
The cement industry requires energy to produce
cement and coal will remain an important input
for the global cement industry. A number of coal
producers and cement plant operators have identified
and developed strong long-term relationships for
the supply of coal to meet all or part of the
energy needs of the plant.
Coal combustion products (CCPs), such as Fly
Ash also play an important role in cement manufacture
and in the construction industry generally. When
Fly Ash is added to concrete, for example, the
spherical particles act like ball bearings in
the mix, improving the workability and fluidity
of concrete as well as the grading curve of the
concrete mixture.
The Australian Cement Industry
In Australia about 7 million tonnes of cement
is used annually - the actual amount depending
largely on construction activity in the main population
centers in coastal Australia, which in turn is
sensitive to the level of economic activity.
 The
Australian cement industry has plants in all states,
a capital investment of $2.5 billion and an annual
turnover of more than $1 billion. The industry
is also a significant regional employer.
Australian cement plants are located in regional
centres or in small rural communities where the
industry is a significant direct employer, with
over 2000 employees in total. In addition, the
industry is a major user of local services for
maintenance, supplies and construction activities.
Indirect employment generated by the industry
is about 4 times the direct employment and brings
very substantial economic benefits to the local
region as well as the broader economy. As a consequence
the cement industry is a major contributor to
government revenue at the national, State and
local levels.
Sources: World Coal Institute;
Cement Industry Federation (Australia)
Further References/Links:
More detailed and technical information on
cement manufacture and the Australian Cement Industry
is available from the Cement Industry Federation
of Australia website at: http://www.cement.org.au
For further information on Coal combustion
products and their use, visit the ECOBA (European
Association for Use of the By-Products of Coal-Fired
Power Stations eV) website at: http://www.ecoba.com
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