Question

Extraction of copper by smelting uses silica as an additive to remove :

• A. ${Cu_2 S}$
• B. ${FeO}$
• C. ${FeS}$
• D. ${Cu_2O}$

Answer 1

Answer: (B)

${FeO}$

Answer 2

$FeO$ is gangue and $SiO_2$ is flux to form slag $FeSiO_3$.
$[FeO + SiO_3 \to FeSiO_3 ]$