2. Dry purification. Wet purification

The blast furnace is a thermochemical heat exchanger, and the gas, which is produced at high temperature ("2,100°C) at the tuyere, cools down by transferring heat to the solids. Under normal operating conditions, the gas temperature at the throat varies between 80 and 200°C. Any deviation from this can lead to very rapid and significant temperature rises, which are unacceptable for the circuit. For this reason, the gas temperature is systematically checked by washing it with water before it is fed into the network.

Depending on the type of scrubber used, the scrubbing effect is more or less significant. The disadvantage of this system is that it produces sludge, which is much more difficult to treat than dry dust, so it is preferable to separate as much dry dust as possible.

In addition, the charge contains zinc, which is removed in the...