Find the number of ores which can be concentrated by magnetic separation method.
`Fe_(2)O_(3), Fe_(3)O_(4), FeCO_(3), FeS_(2), CuFeS_(2), Cu_(2)O, ZnS, ZnCO_(3), ZnO`

Fe_2O_3, Fe_3O_4, FeS_2, Cu_2 O

Which of the following ores can be concentrated by froth floatation method and why? Fe_2O_3, ZnS, Al_2O_3

Which of the following ores cannot be concentrated by electromagnetic separation? Chromite (FeCr_(2)O_(4)), magnetite (Fe_(3)O_(4)) , zinc blende (ZnS) , pyrolusite (MnO_(2)) .

Haematite is Fe_2O_3 / Fe_3O_4 .