Q.The flux added during extraction of Iron from hematite are its?
a. Silica
b. Calcium carbonate
c. Sodium carbonate
d. Alumina

Step 1. Recall what a flux does in iron extraction. A flux is added to react with and remove the gangue (unwanted impurities like silica, alumina, phosphates) from the ore, forming a molten slag that can be separated from the metal.

Step 2. Identify the flux used for haematite. Section 8.9.2 states 'Limestone acts as flux, it combines with the gangue material to form molten slag', and the blast-furnace reactions confirm this: limestone (CaCO3) decomposes to CaO (CaCO3 -> CaO + CO2), and this CaO then reacts directly with the silica/alumina gangue (CaO + SiO2 -> CaSiO3; 12CaO + 2Al2O3 -> 4Ca3AlO3 + 3O2) to form the slag. …

Direct recall of Section 8.9.2's blast-furnace flux (limestone/CaCO3) …

• Confusing the gangue (silica, alumina -- the impurities being removed) with the flux (limestone -- the substance added to remove them). …