Metal-making process and apparatus involving the smelting reduction of metallic oxides.

摘要

A metal-making apparatus using raw ore which contains a metallic oxide and which is in the state of particles in a wide range of size, comprising a solid-state prereduction furnace (F2) for preliminarily reducing raw ore in a solid state, and a smelting reduction furnace (F1) for smelting and finally reducing the prereduced ore in a molten state. In order to make possible the use of raw ore particles in a wide range of size without any such pretreatment as sizing, comminution or pelletizing, raw ore particles of larger size (7a, 7b) are prereduced in the prereduction furnace (F2) by forming a fluidized bed on its distributor (6), whereas smaller size particles (7c) are prereduced while being recirculated through the prereduction furnace. On discharge from the prereduction furnace, the prereduced ore particles of larger size are recharged by gravity into the smelting reduction furnace (F1). The prereduced ore particles of smaller size are recovered from the waste gas of the prereduction furnace, as by a cyclone separator (8), and pneumatically injected into the smelting reduction furnace (F1) as by a submerged injection nozzle (35a) or by an injection lance (51) located above the level of the bath (S, M) within the furnace (F1).