Limestone is mixed with iron ore for extraction of iron in blast furnace. (Text Book)

Ans.

1. In the blast furnace, limestone decomposes to calcium oxide.
2. Calcium oxide combines with silica present in Iron ore to form a slag of calcium silicate.
3. This slag can be easily removed from the bottom of the blast furnace.
4. Hence, limestone is mixed with iron ore for extraction of iron in blast furnace.