Paragraph: Copper is the most noble of the first row transition...

Paragraph: Copper is the most noble of the first row transition metals and occurs in small deposits in several countries. Ores of copper include chalcanthite $\left(\mathrm{CuSO}_4 \cdot 5 \mathrm{H}_2 \mathrm{O}\right)$, atacamite $\left(\mathrm{Cu}_2 \mathrm{Cl}(\mathrm{OH})_3\right)$, cuprite \left(\mathrm{Cu}_2 \mathrm{O}\right)$, copper glance \left(\mathrm{Cu}_2 \mathrm{~S}\right)$ and malachite \left(\mathrm{Cu}_2(\mathrm{OH})_2 \mathrm{CO}_3\right)$. However, 80\% of the world copper production comes from the ore chalcopyrite \left(\mathrm{CuFeS}_2\right)$. The extraction of copper from chalcopyrite involves partial roasting, removal of iron and self-reduction.Question: Iron is removed from chalcopyrite as