Abstract: Ferro-manganese is decarburized from a carbon content of as high as 7.5% down to 2% or less by blowing an oxidizing gas into the melt in two stages through one or more immersed tuyeres protected with a peripheral fluid introduced into said tuyeres, utilizing temperatures between 1650.degree. and 1750.degree. C.

Abstract: A converter for the refinement of liquid metal comprising a generally cylindrical body having closed ends and an opening in the circumference thereof, the body being arranged with its axis horizontal and being rotatable thereabout, a refractory arch with a heating unit movable into one part of the opening in the "normal" position of the body in which the opening is in an upper part thereof, a gas collection system aligned with the other part of the opening in the "normal" position of the body, and blast pipes extending into the body through a lower part of the body in the "normal" position thereof.

Abstract: In a process of manufacturing an alloy steel, particularly stainless steel, in an electric arc furnace, in a first stage the furnace charge is brought to a molten state, in a second stage ferro-alloy in divided form is continuously supplied to the molten charge and simultaneously a refining fluid is blown into the charge, and in a third stage the molten charge is decarburized, if necessary, to give the required carbon content, and chromium oxide in the slag is reduced.

Abstract: In a method of making chrome steel in an electric arc furnace, a charge of chrome-bearing molten metal in the furnace is decarburized by blowing into the charge a jet of pure oxygen and water vapor through a double lance consisting of two concentric tubes and extending into the furnace through a wall or the roof of the furnace, the end of the lance being submerged in the charge and surrounded by a medium which protects it against high temperature wear.

Abstract: Nickel-containing mattes are desulphurized down to low sulphur levels (less than 1%) in a multi-stage process effected in a single converter vessel. In the first stage, an oxidizing gas is blown into the molten matte to reduce the sulphur level to about 4 to 7% and in one or more subsequent stages, oxygen and a diluent are blown into the matte, with a peripheral flow of protective fluid to protect the tuyeres against wear. The diluent, which may be argon or steam for example, dilutes the sulphur dioxide in the matte.

Abstract: Chromium-containing steels are decarburised without substantial losses of chromium by blowing simultaneously into the molten steels, below the surface thereof, water vapor and a non-oxidising gas such as hydrogen, nitrogen, argon or helium. A triple feed tuyere is used, with the water vapor in the central or intermediate tube, and the non-oxidizing gas in the other inner tube, and with a protective fluid in the outer tube. The proportions of water vapor and non-oxidizing gas are selected so that the temperature of the steel bath is thereby controlled and also the desired decarburisation occurs without substantial chromium loss.