In the extraction of copper from copper pyrites, iron is removed as : — Metallurgy and Isolation of Elements Chemistry Question

💡 Solution & Explanation

Step 1: Copper pyrites (CuFeS2) contain a significant amount of iron sulfide (FeS). During the smelting process, FeS is oxidized to basic iron(II) oxide (FeO). Step 2: Silica (SiO2), which is added as an acidic flux, reacts with the basic FeO at high temperatures. Step 3: This reaction produces molten iron(II) silicate (FeSiO3), which forms a distinct slag layer floating on top of the copper matte and is easily removed: FeO + SiO2 -> FeSiO3. Hence, iron is removed as FeSiO3, matching option (b).