Page 27 - Curriculum Visions Dynamic Book

Carbon monoxide: the reducing agent
Carbon monoxide gas is produced at the bottom of the furnace. As air is blown in, the coke, which is almost entirely carbon, is oxidised to produce carbon dioxide gas.
Solid carbon plus oxygen gas from the air react to give carbon dioxide gas, also giving out heat.
As the carbon dioxide bubbles up the furnace, it reacts with more of the coke in the mixture, changing to carbon monoxide gas. This gas then reacts with the iron oxide in the middle of the furnace to give liquid iron.
ore: a rock containing enough of a useful substance to make mining it worthwhile.
reducing agent: a substance that gives electrons to another substance. Carbon monoxide is a reducing agent in a blast furnace.
slag: a mixture of substances that are waste products of
a furnace. Most slags are composed mainly of silicates.
Gases pass up through the mixture in the furnace.
Liquids descend through the mixture in the furnace.
EQUATION: Oxidation of coke
carbon + oxygen ➪ carbon dioxide C(s) + O2(g) ➪ CO2(g)
EQUATION: Carbon dioxide reduced
carbon dioxide + carbon ➪ carbon monoxide CO2(g) + C(s) ➪ 2CO(s)
Iron ore to iron metal
Iron oxide sinks down the furnace where it reacts with carbon monoxide gas coming up from the bottom of the furnace. The two then react to produce carbon dioxide gas and liquid iron.
Carbon monoxide reacts with iron ore to produce molten iron and carbon dioxide gas. The molten iron sinks to the bottom of the furnace.
The oxygen reacts with the coke to produce carbon dioxide gas, which in turn reacts with more of the coke to produce carbon monoxide.
Oxygen gas is pumped in.
EQUATION: Iron oxide is reduced
Iron oxide + carbon monoxide ➪ iron metal + carbon dioxide
Fe2O3(s)
+ 3CO(g) ➪ 2Fe(l) + 3CO2(g)
 When the iron is tapped from the bottom of the furnace, it is often transferred into “submarines”. These insulated containers take the molten iron to the nearby
steel furnace for conversion to steel. This process is explained on pages 30 and 31.
The molten iron, which is densest, is tapped off as pig iron.
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