Method and apparatus for refining steel
US4919714A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 14, 1988 |
| Grant date | Apr 24, 1990 |
| Priority date | — |
| Expiry date | Nov 14, 2008 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21C5/35
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Disclosed are an improved method of refining steel and an apparatus for practicing the method. The refining method comprises, basically, carrying out the refining, particularly, decarburization, while stirring molten steel in the refining furnace by injecting gas thereinto, while supplying heat with a burner installed at the top of the furnace to the molten steel. According to this method, it is possible to start at an initial carbon content of the moltend steel lower than that of known AOD process, and complete the refining in a curtailed period of time and with a decreased oxidation loss of Cr. Thus, damage of refractory materials of the furnace is reduced, and the amount of Si necessary for reducing Cr-oxides in the latter stage of the refining is also reduced. Oxygen for the decarburization is supplied usually in the form of gas, but can be supplied from a solid oxygen source. In an alternative of the present method, powdery metal oxide, which is reducable equally to or more easily than Cr-oxides, is shot into the furnace through the burner or injected into the molten steel through a tuyere or an immersed lance. Preferably, the burner is of a type of variable flame length. Use …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.