An apparatus for injecting particulate and/or gaseous material into a metallurgical vessel for performing a metallurgical process is disclosed. The apparatus comprises a duct and an annular duct tip at a forward end of the duct. The apparatus also comprises inner and outer cooling water flow passages configured such that out flowing water passing from the duct tip to a rear end of the duct must travel through a longer flow path than inflowing water passing from the rear end of the duct to the duct tip.