What other non metal can be used to displace less active metals from their metal oxides

Carbon as it is more reactive than many metals such as iron therefore iron can be extracted from its ore using carbon however for metal oxides such as calcium, carbon is unable to displace the metal thus it will not separate metal oxides higher than itself in the reactivity series. So in summary carbon will displace metals which are lower than itself in the reactivity series.

Halogens is the least active non metal.