GB514352A - Process and apparatus for the preliminary and final refining of pig iron by air - Google Patents

Abstract

514,352. Pig iron and steel; converters. ROCHLING'SCHE EISEN-UND STAHLWERKE GES. Jan. 24, 1938, Nos. 2237, 2238 and 2239. Void. Convention dates, Jan. 23, 1937, Jan. 28, 1937 and Nov. 10, 1937. [Class 72] In the refining of pig iron or production of steel in a converter, the molten pig iron is caused to flow uniformly through a converter and is converted into steel by the use of air, oxygen or enriched air, and the iron refined in one converter may be finished in one or more similar converters connected in series with the first converter. The supply of pig iron to the converter may be maintained constant by hand based on the indications of measuring apparatus, or automatically by regulators so that the composition of the metal in the separate stages is regulated accurately. The steel produced may be deoxidised either in a separate vessel or in an extension of the converter which is filled with protective gas. The finished steel may be cast under exclusion of air into small ingots which can be immediately rolled in a billet mill train. The pig iron before treatment in the converter may be desulphurised with alkalies and solid or liquid refining or deoxidising agents may be added to the iron as it flows through the converter. The converter comprises a horizontal drum A, provided with a reduced end section Q having a feeding trough H and an outlet M<2> for waste gases, and with a middle elongated portion D having air nozzles E communicating with a chest F to which is connected an air conduit G rotatably mounted in a stuffing box X. The chamber D is provided with a transverse dam O<1> a slag outlet L, and an inlet N for refining additions to the metal flowing through the converter, which is also provided with a reduced end portion R in which the metal is deoxidised and which is provided with a transverse dam 0 <2>, apertures M<1> and V, a second dam T, and a syphon outlet K for the finished steel. Waste gases, which may be used for pre-heating the refining or deoxidising additions, escape through the aperture M<1> and the deoxidising additions are fed in through the aperture V. If desired the chest F may be divided so that the iron may be treated with different gaseous agents, e.g., first with oxygen, and then with air.