Question 1
What are the three raw materials fed into the blast furnace?
The right answer is the one marked above.
Haematite (Fe2O3), limestone (CaCO3) and coke (C). They are mixed in the required proportions, finely ground and fed in at the top.
Silica and alumina are the impurities in the ore — they are not added as raw materials. Slag is a product formed inside the furnace.