The addition of silica during the extraction of copper from its sulphide ore:

The thermite process is used to extract metals:

Which of the following compounds acts as a flux in the extraction of copper from copper pyrites?

Explain the extraction of elements by oxidation.

When alumina is heated with carbon in a nitrogen atmosphere,the products are

Choose the correct option with reference to the following statements:
$(1)$ Pig iron is produced at a temperature of $1270 \ K$.
$(2)$ Pig iron contains $4 \%$ carbon.
$(3)$ Pig iron cannot be cast into a variety of shapes.
$(4)$ Pig iron contains small amounts of impurities like $P, S, Si, Mn$.