Abstract: A mold flux for the continuous casting of steel (including ultra low carbon steel) comprises refractory metal oxide, at least one fluxing agent, a binder, and expandable graphite in the amount of 0.3-1.0% by weight, the expandable graphite having a size less than about 80 mesh, and the flux in the form of spherical granules 200-500 microns in diameter. The binder typically comprises between about 8-14% weight soda ash, or between about 4-7% by weight lithium carbonate, or a combination of soda ash and lithium carbonate wherein double the percentage of lithium carbonate plus the percentage of soda ash is between about 8-14%. The flux may additionally include--especially where ultra low carbon steel is being continuously cast--starch and MnO.sub.2 to reduce slag rim, improve thermal insulation, and reduce carbon pickup.

Abstract: A granular mould flux for use in the continuous casting of steel comprises refractory metal oxide, one or more fluxing agents, a binder and 0.1% to 3% by weight based on the weight of the flux of an expanding agent such as expandable perlite, expandable vermiculite or expandable graphite.

Abstract: A metallurgical flux composition comprising calcium oxide, alumina, magnesium oxide and silica contains 22-35% by weight magnesium oxide and has a weight ratio of calcium oxide to magnesium oxide of from 0.6:1 to 2.5:1. The preferred composition contains 28-42% by weight calcium oxide, 13-21% by weight alumina, 22-35% by weight magnesium oxide and 3-8% by weight silica, preferably has a calcium oxide to magnesium oxide weight ratio of from 0.8:1 to 1.9:1 and preferably has a calcium oxide to silica weight ratio of from 6.0:1 to 7.5:1. The flux composition is particularly useful as a tundish cover in the continuous casting of steel.

Abstract: A tundish for continuous casting of molten metal having an outer metal casing and, adjacent the casing, a permanent refractory lining is provided with an inner, expendable lining comprising refractory, heat-insulating slabs having an erosion resistant backing layer and an inward facing layer of lower density than that of the backing layer.The density of the facing layer is at least 0.2 g/cm.sup.3 but not more than 85% of the density of the backing layer. The presence of the inward facing layer exerts less chilling effect on the molten metal poured into the tundish than if the slab consisted of the backing layer alone.

Abstract: Fluxes for use in the casting of metals e.g. steel comprise granules containing carbonaceous powder in which the proportion of carbonaceous powder in the surface of the granules is greater than the overall proportion of carbonaceous powder in the granules. The fluxes are particularly suitable for use in the continuous casting of steel.