Why copper matte is put in silica lined converter?

Explanation

Copper matte consist of `Cu_(2) S` along with some unchenged FeS when a blast of hot air is passed through milten matte placed in silica inled converter ,FeS present in matte is oxidised to Fe O which combines with silica `(Sio_(2))` to form `FeSiO_(3)` slag .
`2FeS to 2FeO +2SO_(2)`
`FeO+underset("silica")SiO_(2)to underset(Slag") FeSio_(3)`
when whole of iron been removed as slag some of the `Cu_(2)S` undergoes oxidation to form `Cu_(2) O` which then reacts with more `Cu_(2)S` to form copper metal .
`2Cu_(2)S+3O_(2) to 2CU_(2)O+SO_(2)`
`2Cu_(2) O+Cu_(2)S to 6Cu+SO_(2)`
thus copper mette is heated in silica lined coverter to remove FeS present in matte as `FeSiO_(3)` slag.