Why copper matte its put in silica lined converter ?

Explanation

Copper matte.chiefly consists of `Cu_(2)S` along with some unchanged Fes. When a blast of hot air is påssed through molten matte taken in a silica fined converter, Fės present in matte is cridised to Feo which combines with silica `(SiO_(2))` to form `FeSiO_(3)` slag.
`2FeS+3O_(2) to 2FeO+2SO_(2)`
`underset("Silica")(FeO+SiO_(2)) to underset("slag")(FeSiO_(3))`
When whole of iron has 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) to2Cu_(2)O+2SO_(2)`
`2Cu_(2)O+Cu_(2)S to 6Cu+SO_(2)`
Thus, copper matre is heated in silica lined converter the remove Fes present in matte as Fesioz slag.