Abstract: A substantially planar slab has two opposite edges castellated in such fashion that two such slabs may be interengaged with the slabs in the same plane with the castellations of one edge of one slab interfitting the castellations on the other edge of the other slab. The sides of the castellations are inclined in a direction not normal to the plane of a major face of the slab. Such slabs are useful for lining containers for molten metal, and when forming such a lining all joint faces of the interengaging castellations not lying in vertical planes can be arranged to slope downwardly away from the interior of the molten metal container. The thickness of the slabs, the angle of the castellations, the period of the castellations and the inclination of the slabs can be so chosen relative to the angle of repose of a loose fill of refractory material under the slabs that the loose fill particulate refractory material does not penetrate the joints between adjacent slabs.

Abstract: A molten metal container, e.g. a tundish, consists of an outer metal casing, usually a relatively permanent refractory lining and an inner expendable lining of refractory heat-insulating slabs, behind which slabs is a loose fill of particulate refractory material. In order that the loose fill material does not pass through the joints between the slabs, leaf-seals are provided at the joints between the slabs.