Abstract: A gas scavenging apparatus for a metallurgical vessel containing molten metal includes a frusto-conical refractory inner scavenging block inserted in the refractory lining of the vessel and having a smaller end surface facing the molten metal and a larger base end directed away from the molten metal. A frusto-conical refractory outer scavenging block is embedded within a mounting brick positioned outwardly of the inner scavenging block. The outer scavenging block has a smaller end surface smaller than and facing the larger base end of the inner scavenging block and a larger base end directed away from the inner scavenging block. The larger base end of the inner scavenging block has an annular end surface extending generally radially outwardly away from the smaller end surface of the outer scavenging block and resting on the mounting brick. Scavenging gas is passed through the outer scavenging block and then through the inner scavenging block to the molten metal.