Patent · US Expired

Steel conversion method

US4302244A · kind A · utility

8Cited by
6References
13Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 18, 1980
Grant dateNov 24, 1981
Priority date
Expiry dateJul 18, 2000

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC21C5/35
  • WIPO fieldMaterials, metallurgy
  • WIPO sectorChemistry

Abstract

A steel conversion method includes the steps of delivering a first quantity of oxygen and a surrounding sheath of hydrocarbon shielding fluid beneath the level of a quantity of molten ferrous metal or bath contained in a vessel by means of bottom tuyeres and simultaneously delivering a second quantity of oxygen to the bath from above through a top lance. The oxygen delivered through the bottom tuyeres is sufficient to promote mixing and is about 10% to 40% of the oxygen required for oxidation of impurities with the balance delivered through the top lance. An additional quantity of oxygen is delivered through the top lance to the space above the bath for post-combustion of off-gases to increase the thermal energy in the bath. Fluxes such as lime are added from above in lump form in the conventional manner or are entrained in the upper oxygen stream as required. As the level of carbon in the bath falls toward desired levels, an inert gas is introduced through the bottom tuyeres at an increased rate while the proportion of oxygen is decreased.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.