US 2003/0164066 A1 · Direct smelting process and apparatus

Abstract

A molten bath-based direct smelting process for producing ferrous metal from a ferrous feed material is disclosed. The process is characterised by injecting pre-heated air downwardly into metallurgical vessel at an angle of 20 to 90° C. relative to a horizontal axis and at a temperature of 800-1400° C. and at a velocity of 200-600 m/s via at least one lance (27). This step forces molten material in the region of a lower end of the lance away from the lance and forming a “free” space around the lower end of the lance that has a concentration of molten material that is lower than the molten material concentration in the raised bath. The process is further characterised in that the lance is located so that: (i) the lance extends into the vessel a distance that is at least the outer diameter of the lower end of the lance; and (ii) the lower end of the lance is at least 3 times the outer diameter of the lower end of the lance above a quiescent surface of the molten bath.

Claims17

Dependent claims

A direct smelting process for producing ferrous metal from a ferrous feed material which includes the steps of:

(a) forming a bath of molten metal and molten slag in a metallurgical vessel;
(b) injecting ferrous feed material into the molten bath and smelting the ferrous feed material to metal in the molten bath;
(c) injecting solid carbonaceous material into the molten bath;
(d) generating a gas flow in the molten bath at least in part by reactions of injected material in the bath which carries molten material upwardly above a quiescent surface of the molten bath (as defined herein) to form a raised bath;
(e) injecting pre-heated air into the vessel such that it impinges on or penetrates the raised bath and post-combusts reaction gases released from or contained within the raised bath, and thereby facilitating heat transfer to the molten bath;
which process is characterised by injecting pre-heated air downwardly into the vessel at an angle of 20 to 90° C. relative to a horizontal axis and at a temperature of 800-1400° C. and at a velocity of 200-600 m/s via at least one lance and forcing molten material in the raised bath in the region of a lower end of the lance away from the lance and forming a “free” space around the lower end of the lance that has a concentration of molten material that is lower than the molten material concentration in the raised bath, the lance being located so that:
(i) the lance extends into the vessel a distance that is at least the outer diameter of the lower end of the lance;
and (ii) the lower end of the lance is at least 3 times the outer diameter of the lower end of the lance above the quiescent surface of the molten bath.

5 more elements

An apparatus for producing ferrous metal from a ferrous feed material by a direct smelting process, which apparatus includes a vessel that contains a molten bath of molten metal and molten slag and a gas continuous space above the molten bath, which vessel includes:

(a) a hearth formed of refractory material having a base and sides in contact with a lower region of the molten bath;
(b) side walls extending upwardly from the sides of the hearth and being in contact with an upper region of the molten bath and the gas continuous space, wherein the side walls that contact the gas continuous space include water cooled panels and a layer of slag on the panels;
(c) a means supplying ferrous feed material and carbonaceous material into the vessel;
(d) a means generating a gas flow in the molten bath which carries molten material upwardly above a nominal quiescent surface of the molten bath (as defined herein) and forms a raised bath;
(e) at least one lance extending downwardly into the vessel and injecting pre-heated air into the vessel at an angle of 20 to 90° relative to a horizontal axis at a velocity of 200-600 m/s and at a temperature of 800-1400° C., the lance being located so that:
(i) the lance extends into the vessel a distance that is at least the outer diameter of a lower end of the lance;
and
(ii) the lower end of the lance is at least 3 times the outer diameter of the lower end of the lance above a quiescent surface of the molten bath;
the air impinging on or penetrating the raised bath and post-combusting reaction gases released from or contained within the raised bath, and the injection of air forcing molten material in the raised bath in the region of the lower end of the lance away from the lower end so that there is a “free” space around the lower end of the lance that has a concentration of molten material lower than that in the raised bath;
and
(f) a means for tapping molten metal and slag from the vessel.

8 more elements

Dependencies are inferred from the claim text.

Direct smelting process and apparatus

Life of this patent

Direct smelting process and apparatus

Life of this patent

Abstract

Claims17