Question

) Explain combustion zone of iron.​

Answer 1

Answer:

Combustion zone of iron

Explanation:

In blast furnace, iron oxides are reduced at different temperature ranges.

In the lower part of the blast furnace, the temperature is as high as 2200 K.

It is called combustion zone.

At the top, the temperature is as low as 500−800 K.

It is called reduction zone.

In the lower temperature range, carbon is the reducing agent and in the higher temperature range, CO is the reducing agent. In the reduction zone (500−800 K), following reactions occur.

3Fe2O  3 +CO→2Fe3 O4 +CO2

Fe  3 O4 +4CO→3Fe+4CO2

Fe2 O3 +CO→2FeO+CO2

​In the temperature range 900-1500 K, following reactions occur.

C+CO2 →2CO

FeO+CO→Fe+CO2

Around 1270 K (middle portion), decomposition of limestone gives lime (CaO) and CO 2

Lime is a flux and combines with silicate impurity to form slag of calcium silicate.

CaCO3 →CaO+CO  

2 CaO+SiO  2  →CaSIO  3