GB790790A - Improvements in or relating to the refining of impure iron - Google Patents

Abstract

790,790. Refining impure iron. BRITISH OXYGEN CO., Ltd. May 16, 1956 [June 2, 1955], No. 15898/55. Class 72 A process for partly refining impure iron comprises passing the molten metal downwardly through a tower containing incombustible packing material, preheated to such a temperature that the metal remains molten, in counter current to a stream of oxidizing gas consisting of air, air enriched with oxygen, oxygen mixed with carbon dioxide or steam, or pure oxygen, in such manner that an oxidizing zone is produced at the bottom of the tower and a reducing zone at the top. As shown, a tower 1 may be filled to about one third with coke which is burned by an oxidizing gas from tuyeres 3 additions of lime or limestone being made until the tower is full, combustion being continued until all the coke is burned. Molten metal is then poured over the hot lime'bed and the partly purified metal collected on a renewable hearth 4. Lime or limestone and fluxes, e.g. iron oxide or fluorspar, may be added with the blast and carburizing agents or' other finishing agents may be added in a stream of inert gas, e.g. nitrogen or argon. The tower may be filled with refractory packing and may be heated electrically or by burning fuel gas or oil. It is stated that steel may be produced by passing molten metal repeatedly through the tower or the metal after one or more passes may be converted to steel by any of the well known processes.