4.2.2. Burnt clay bricks
These are very commonly used for building construction.
It is estimated that about 70 billion bricks are produced
in India annually. The common brick size is 230mm
110mm 60–75 mm. They require considerable amount
of thermal energy during the burning process. Coal, coal
cinder and firewood are the most commonly used fuels for
brick burning in India. In general, each brick needs either
0.20 kg of coal or 0.25–0.30 kg of firewood for the burning
process. This translates into a thermal energy of 3.75–
4.75 MJ per brick. An average value of 4.25 MJ per brick
(size: 230mm 110mm 70 mm) has been considered