A gasifier for the gasification of a fuel material includes a chamber in which the material is converted into a gas and a molten slag. A quenching apparatus is provided for cooling and solidifying the molten slag. A nozzle extends between the chamber and the quenching apparatus. The nozzle includes an orifice having an inlet end for receiving the molten slag from the chamber and an outlet end for discharging the molten slag into the quenching apparatus. A recessed zone is provided between the outlet end of the orifice and the quenching apparatus. The recessed zone may be formed within the nozzle. An electric induction heating coil provides heat in the recessed zone to prevent the solidification of the slag at the outlet end of the orifice.