Production of Pig Iron in a Blast Furnace

Edward Alfred Cowper (1819-1893), a British engineer, invented the regenerative preheating system of blast furnace air. He also invented the tangential spokes for bicycles. 

The following main reactions take place in the blast furnace  

The CO formed in the tuyeres now reduces wuestite [Eq. (6.5.18)], which is formed in the upper part of the furnace by reduction of hematite and magnetite. As long as the temperature is high enough ( 1000 °C as shown below), the CO2 that is formed by the reduction is regenerated to CO. Thus by combining Eqs. (6.5.15) and (6.5.18) we obtain  

For lower temperatures ( 1000 °C), CO2 is no longer converted into CO, and thus reduction only occurs by CO [Eqs. (6.5.16)-(6.5.18)], which is called indirect 

To prove that direct reduction, that is, the Boudouard reaction [Eq. (6.5.15)], comes to a standstill for T 1000 °C, we have to inspect the kinetics of coke gasification in more detail. 

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