Continuous Bath Smelting and Refining of Oxide Ores to Steel

摘要

1,193,457. Extracting and refining iron. CONZINC RIOTINTO OF AUSTRALIA Ltd. Nov. 23, 1967 [Nov. 28, 1966], No. 53453/67. Heading C7D. [Also in Division F4] In a continuous process for the direct production of steel, oxidic iron ore which may be pre-heated and pre-reduced is fed into a bath of metal contained in the smelting zone of a furnace having also a refining zone and a slag separation zone, while carbon-containing reductant, at a least part of which is in the form of molten pig-iron, semisteel or other carbon-containing ferrous alloy is also fed continuously into the smelting zone either directly or via the slag separation zone. Preferably the temperature of the metal in the smelting zone is maintained at 1400‹ -1550‹ C. while in the refining zone metal is lanced with oxygen containing gas and slag flows counter current to the metal for at least part of the length of the zone. As shown in Fig. 1 molten pig-iron is fed into the primary smelting zone 11 at 16, while hot reduced ore with any necessary fuel or additional carbonaceous reducing agent is charged through lances 161 The bath circulates to secondary smelting zone 12 where some of the evolved carbon monoxide is burnt with hot air or oxygen introduced at 18. Onward passage of slag is prevented by bridge 19, which causes slag to be diverted to zone 15 from where it is removed after metal has separated out. Part of the metal flows into refining zone 14 where it is lanced with oxygen and fluxes added. Other forms of apparatus are described, in some of which the metal is subjected to two-stage refining