Both a method and apparatus for producing molten steel are provided wherein ferrous materials rich in carbonaceous materials are fused in a first vessel of a single electric furnace having separate first and second vessels. The carbonized molten metal thus obtained is then pretreated in a separate pretreatment facility to remove contaminants and the pretreated molten metal is then decarburized in the second vessel of the electric furnace. The decarburization of the pretreated metal in the second vessel of the furnace avoids reintroducing contaminants into the steel by avoiding contact between the pretreated metal and the slag produced when the initial carbonaceous materials are fused. Preferably, the first and second vessels are two vessels of a single electric furnace having a single electric power source.
The invention concerns a method which consists in injecting into a molten metal bath to be treated, jointly but separately into the same bath zone, oxygen and carbon in a form capable of being blown (powder carbon preferably) so as to generate locally in the bath CO bubbles from those two elements, which will then be loaded in denitriding nitrogen. A stoichiometric adjustment of the carbon and oxygen inputs enable a constant carbon denitriding in the bath. The method is preferably applicable to the production of low-carbon steel grades, in particular in an electric oven.
An improved charging stock for steel production which facilitates earlier and more uniform carbon oxidation, and increases the rate of oxygen transport in the melt, comprises and iron-carbon alloy having silicon therein and an oxide-containing material. The iron-carbon alloy preferably has a ratio of carbon to silicon in the range of approximately 4-40:1. The ratio of oxide-containing material surface area to the weight of the iron-carbon alloy is preferably maintained in the range of 5-100 m.sup.2 /ton.
A composite charge for metallurgical processing which reduces the content of non-metallic inclusions in the end product(s) comprises 40-83 wt. % of a metallic agent, 17-50 wt. % of an oxide agent and 0.1-10.0 wt. % of a carbonaceous agent. The carbonaceous agent includes a mixture of metal carbides and free carbon, preferably graphite, having a ratio in the range of 0.1-10.0:1.
