Abstract: An injector for introducing particulate material into the bath of a pyrometallurgical vessel via existing tuyeres. An existing mechanical puncher may be removed and replaced with an injector adapted to be attached to the existing tuyere body so as not to disturb the existing blast air connections. The injector, including a housing spatially circumscribing an injector pipe and forming an annular space part way therewith, is inserted into the tuyere. A source of pressurized fluid is injected into the annular space keeping the tuyere open so the particulate material can be introduced through the pipe.