This invention relates to a tundish flux for use with aluminium-killed steel consisting essentially of 31 to 75% by weight calcium carbonate, 4 to 14% alkali metal carbonate, up to 18% fluorspar, and 14 to 38% sodium fluoride. Preferably, the ingredients are finely-divided materials which are blended and agglomerated into pellets about one-quarter to one-half inch in diameter.

A process of refining steel in a ladle using solid granules or briquettes made from recycled LMF slag and raw materials to make a desulfurizing addition, a slag conditioner or synthetic refining slag is described. The preferred recycled LMF slag material generally comprises of 35% to about 65% CaO; 10% to about 35% Al.sub.2 O.sub.3 ; 1% to about 10% SiO.sub.2 ; 3% to about 15% MgO; 0.3% to about 10% FeO; 0.1% to about 5% MnO; 0% to about 0.5% P.sub.2 O.sub.5 ; and 0.1% to about 0.5% S. The ladle refining additive comprises from about 10% to about 90% of a recycled ladle metallurgy furnace slag and the balance of raw materials selected from the group consisting of: a calcium oxide source; soda ash; fluorspar; borax; calcium carbonate; aluminum source; calcium aluminate; alumina source; metallic calcium, magnesium, sodium and their oxides, fluorides and carbides; and mixtures of all of the foregoing.

The tundish flux composition of the invention employs solid recycled ladle metallurgy furnace (LMF) slag as a fluidizing and refining base ingredient in a mixture of raw materials. The preferred recycled LMF slag material comprises about 35% to about 65% CaO, about 10% to about 35% Al.sub.2 O.sub.3, about 1% to about 10% SiO.sub.2, about 3% to about 15% MgO, about 0.3% to about 10% FeO, about 0.1% to about 5% MnO, about 0.1% to about 0.15% P.sub.2 O.sub.5, and about 0.1% to about 0.5% S. The tundish flux composition comprises from about 10% to about 80% of recycled LMF slag with the balance being raw materials selected from a calcium oxide source, a fluorine source, a magnesium oxide source, a carbon source, a silica source, a sodium source, a potassium source, and mixtures of these raw materials.

The tundish flux composition of the invention employs solid recycled ladle metallurgy furnace (LMF) slag as a fluidizing and refining base ingredient in a mixture of raw materials. The preferred recycled LMF slag material comprises about 35% to about 65% CaO, about 10% to about 35% Al.sub.2 O.sub.3, about 1% to about 10% SiO.sub.2, about 3% to about 15% MgO, about 0.3% to about 10% FeO, about 0.1% to about 5% MnO, about 0.1% to about 0.15% P.sub.2 O.sub.5, and about 0.1% to about 0.5% S. The tundish flux composition comprises from about 10% to about 80% of recycled LMF slag with the balance being raw materials selected from a calcium oxide source, a fluorine source, a magnesium oxide source, a carbon source, a silica source, a sodium source, a potassium source, and mixtures of these raw materials.