Which of the following metals is extracted by the amalgamation process?

The thermite process is used to extract metals:

What is the purpose of adding $Na_3AlF_6$ to $Al_2O_3$ during electrolysis?

The following reactions take place in the blast furnace during the preparation of impure iron. Identify the reaction pertaining to the formation of the slag.

The reactions which occur in a blast furnace at $500-800 \ K$ during the extraction of iron from haematite are:
$(i)$ $3 Fe_2O_3 + CO \rightarrow 2 Fe_3O_4 + CO_2$
$(ii)$ $Fe_2O_3 + 3 C \rightarrow 2 Fe + 3 CO$
$(iii)$ $Fe_3O_4 + 4 CO \rightarrow 3 Fe + 4 CO_2$
$(iv)$ $Fe_2O_3 + CO \rightarrow 2 FeO + CO_2$

The Hall-Heroult process is represented by which of the following reactions?