In a blast furnace, maximum temperature is in.
A) Zone of fusion.
B) Zone of combustion.
C) Zone of slag combustion.
D) Zone of reaction.

Hint: We know that a furnace may be a sort of metallurgical furnace used for smelting to supply industrial metals, generally iron, but also others like lead or copper. Blast refers to the combustion air being forced or supplied above air pressure.

Complete step by step answer:
As we know, in a furnace, fuel ores, and limestone are continuously supplied through the very best of the furnace, while a hot blast of air is blown into the lower section of the furnace through a series of pipes. So as that the chemical reactions happen throughout the furnace because the fabric falls downward. The highest products are usually molten metal and slag phases tapped from the lowest and waste gases exiting from the very best of the furnace. In contrast, air furnaces are naturally aspirated, usually by the convection of hot gases during a chimney flue. The bloomeries for iron, blowing houses for tin and smelt mills for lead are classified as blast furnaces. However, the term has usually been limited to those used for smelting ore to provide iron, an intermediate material utilized within the assembly of economic iron and steel, and thus the shaft furnaces utilized together with sinter plants in base metals smelting.
We can write the reaction takes place in the blast furnace as,
\[2C + O2 \to 2CO + {\text{ }}heat\]
\[C + O2 \to CO2 + heat\]
Both the combustion reactions are exothermic so temperature in the zone of combustion is maximum.

So, the correct answer is Option B .

Note:
We must remember that a mixture of an ore, coke and limestone is fed into the blast furnace because the limestone decomposes to calcium oxide and carbon dioxide. The calcium oxide which has Lewis base helps to remove the acidic and amphoteric oxide impurities from the ore. The mixture of products is known as slag.