Abstract: The continuous refining of molten metal is carried out in a refining apparatus having communicating first and second refining stage spaces. Refining gas, such as oxygen, is blown into the molten metal in the presence of a slag layer on the molten metal. The molten metal and the slag are conveyed as two separate non-intermingled streams through the refining stage spaces, as distinguished from a slag-metal emulsion. The slag in the second refining stage space is caused continuously to flow back into the first refining stage space to form a slag layer on the molten metal in the first refining stage space. Refining gas is blown into the molten metal in the first refining stage space below the slag layer, and the molten metal is conveyed from the first refining stage space to the second refining stage space while preventing the flow of slag from the first refining stage space to the second refining stage space.

Abstract: A process for continuous refining in which liquid pig iron is supplied to a pig iron melt which is at least partially refined while said melt is being intensively agitated, the refining means (preferably oxygen) is introduced into the pig iron melt by means of tuyeres mounted in the refining vessel, and discharging the refining means beneath the surface of thepig iron melt, the tuyeres being positioned and the refining means being furnished so that the kinetic energy of the refining means contributes to the bath agitation. The tuyeres are preferably composite tuyeres like those described in U.S. Pat. Nos. 3,706,549 issued Dec. 19, 1972 and 3,771,998 issued Nov. 13, 1973, for discharging oxygen surrounded by a gaseous and/or liquid hydrocarbon, and possibly lime or other solid powder into the bath.

Abstract: Oxygen or oxygen-containing gas is blown onto a molten crude iron bath inside a converter. A layer of slag or metal-slag emulsion forms atop the molten crude iron bath and grows in height during the course of the refining reaction. The height of such layer is indirectly determined by detecting an electrical characteristic of the layer. The layer of slag or metal-slag emulsion is made to serve as the dielectric of a capacitive reactive and/or as the flux-permeable part of an inductive reactance, and such reactance, or a plurality of such reactances, form part of a resonant circuit.