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US 5,654,976 AGranted
Method for melting ferrous scrap metal and chromite in a submerged arc furnace to produce a chromium containing iron
AssigneeElkem Technology a/s
InventorsPeter Cowx, Hjalte Rognsaa
Life of this patent
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Abstract
The process feeds a mixture of scrap metal, chromite, flux materials, carbonaceous material and wood chips to a submerged arc furnace to make a base iron suitable for iron and steel purposes. The mixture contains about 1-60% chromite, about 1 to 20% flux materials, about 5 to 35% carbonaceous material, about 0-10% wood chips, all based on the weight of scrap in the mixture. By maintaining the charge in the furnace, good energy efficiencies are obtained.
Claims19
A method for continuously converting ferrous scrap metal and chromite into a chromium containing iron product the method comprising the steps of:
- (a) feeding to a submerged arc furnace having an electrode positioned therein, a charge comprising;
- (i) about 1-60% by weight of scrap of chromite,
- (ii) about 1-20% by weight of scrap of flux materials;
- (iii) about 5-35% by weight of scrap of carbonaceous material,
- (iv) about 0-20% by weight of scrap of wood chips, and
- (v) a remainder of ferrous scrap metal wherein said scrap metal comprises about 70-99% by weight iron;
- (b) melting said charge in said furnace such that said furnace contains a molten layer and a layer of solid charge above said molten layer, said molten layer comprising a slag layer floating on top of a molten metal layer;
- (c) maintaining a layer of solid charge above said molten layer in said furnace such that said electrode is surrounded by said solid charge and such that said solid charge at least partly covers the molten layer in said furnace;
- and
- (d) removing from said furnace said molten metal layer to obtain a molten chromium containing iron product having a chromium content of about 1-25% by weight, a silicon content of about 0.5-4% by weight, and a carbon content of about 1.5-7% by weight.
7 more elements
Dependencies are inferred from the claim text.