Patent ID: 6478848
Filing Date: 2002-11-12
Classification: C21B,C21C,C22B,F27B,F27D,Y02P

Abstract:
A direct smelting process for producing metal from a metalliferous feed material which includes the steps of:(a) forming a molten bath having a metal layer and a slag layer on the metal layer in a metallurgical vessel; (b) injecting an oxygen deficient carrier gas, a metalliferous feed material, and a solid carbonaceous material into the molten bath via a plurality of downwardly extending solid material injection lances/tuyeres positioned so that outlet ends of the lances/tuyeres are below the surface of the molten bath and above the metal layer and causing molten material to be projected from the molten bath as splashes, droplets and streams into a space above a nominal quiescent surface of the molten bath to form a transition zone; (c) smelting metalliferous feed material to metal in the molten bath; (d) injecting an oxygen-containing gas into the vessel via one or more than one lance/tuyere and post-combusting reaction gases released from the molten bath, whereby the ascending and thereafter descending splashes, droplets and streams of molten material in the transition zone facilitate heat transfer to the molten bath, and whereby the transition zone minimizes heat loss from the vessel via the side walls in contact with the transition zone; and the process further includes extending the effective length of the solid material injection lances/tuyeres by forming pipes of solid material on the outlet ends of the lances/tuyeres while injecting the metalliferous feed material and the carbonaceous material and the oxygen-deficient gas through the lances/tuyeres.