HEAT-RESISTANT PLATE FOR SLIDE VALVE CLOSURES AT FOUNDRY LADLES

A refractory plate for use in slide closures for metallurgical vessels includes a basic plate element adapted to face a liquid metal melt. The basic plate element is formed of a moldable refractory concrete material including 70 to 95% by weight of alumina and 5 to 30% by weight of a cement containing approximately 80% by weight alumina. Alternatively, the 70 to 95% by weight of alumina may be replaced by an alumina-containing raw material containing more than 70% by weight of alumina, for example at least one raw material selected from the group consisting of sintered bauxite, synthetic mullite, corundum, and grinding disk fragments. The basic plate element has embedded therein a ceramic oxide insert having a cold bending strength higher than 300 kp/cm2, a hot bending strength at 1500 DEG C. higher than 40 kp/cm2, a cold compressive strength higher than 2000 kp/cm2, and a permeability to gas lower than 1.0 nanoperm. The basic plate element and the insert have extending therethrough a throughflow opening. The width of the insert, in a direction transverse to the direction of movement of the refractory plate, is from 1.3 to 3.5 times the diameter of the throughflow opening.