Raw mix flux for continuous casting of steel

Claim 2

A flux composition, said composition being a mix of ceramic raw materials and having the following theoretical analysis based on the composition formed on melting the raw materials: K 2 O: 0 to 5 percent by weight Na 2 O: 20 to 35 percent by weight CaO: 5 to 25 percent by weight MgO: 0 to 1 percent by weight Al 2 O 3 : 3 to 10 percent by weight B 2 O 3 : 15 to 30 percent by weight SiO 2 : 5 to 20 percent by weight F: 10 to 25 percent by weight Fe 2 O 3 : 0 to 1 percent by weight and wherein the percentages of said ingredients total 100 percent by weight.

Claim 3

The flux of claim 1 further comprising a vitreous flux blended therewith.

Claim 4

The flux of claim 1 wherein said analysis comprises: ______________________________________ Broad Preferred Composition Composition Ingredient wt. % wt. % ______________________________________ K.sub.2 O 0-5 0.25-3 Na.sub.2 O 20-35 22-32 CaO 5-25 6-22 MgO 0-1 0.05-0.25 Al.sub.2 O.sub.3 3-10 5-9 B.sub.2 O.sub.3 15-30 16-27 SiO.sub.2 5-20 6-16 F 10-25 14-21 Fe.sub.2 O.sub.3 0-1 0-0.03 ______________________________________ wherein the percentages are selected to total 100%.

Claim 5

In a process for the continuous casting of steel wherein a pool of molten steel is maintained in the upper end of an open-ended continuous casting mold, the improvement which comprises adding intermittently to the top of said pool the flux composition of claim 1, whenever the viscosity of the working flux is too high.