Find the number of ores from the following which can be concentrated by magnetic separation method,

$\begin{array}{r}{\mathrm{Fe}}_2{\mathrm{O}}_3,{\mathrm{Fe}}_3{\mathrm{O}}_4,{\mathrm{FeCO}}_3,{\mathrm{FeS}}_2,{\mathrm{CuFeS}}_2,{\mathrm{Cu}}_2\mathrm{O},\mathrm{ZnS},{\mathrm{ZnCO}}_3,\mathrm{ZnO}\end{array}$

The ores which can be concentrated by the magnetic separation method are,

${\mathrm{Fe}}_2{\mathrm{O}}_3,{\mathrm{Fe}}_3{\mathrm{O}}_4,{\mathrm{FeCO}}_3,{\mathrm{FeS}}_2$

There are 4 ores that can be separated by this process.

Chalcopyrite is a sulfide mineral with a formula ${\mathrm{CuFeS}}_2$. It can not be separated by the magnetic separation.