RU2002130713A - METHOD AND DEVICE FOR DIRECT Smelting - Google Patents

Claims (19)

1. Direct smelting method for the production of metals (this term also includes metal alloys) from iron-containing material, which includes the following steps (a) forming a bath of molten metal and molten slag in a metallurgical converter, (b) injecting the charge materials in the form solid material and carrier gas into the molten bath at a speed of at least 40 m / s through a downward lance for injecting solid materials, which includes a transport pipe with an inner diameter of 40-200 mm, to which is located so that the central axis of the outlet end of the lance is inclined at an angle from 20 to 90 ° to the horizontal axis, and generating in the molten bath a surface gas stream of at least 0.04 Nm ³ / s / m ² (where m ² refers to the horizontal cross-sectional area of the molten bath), at least in part due to reactions of the injected material in the bath, which causes the molten material to surge upward in the form of bursts, droplets and streams and the formation of an expanded zone of the molten bath, The new stream and the molten material thrown upward cause a substantial movement of the material within the molten bath and strong mixing of the molten bath, the charge materials being selected so that, in a general sense, the reaction of the charge materials in the molten bath is endothermic, and (c) injection of oxygen-containing gas into the upper the area of the converter through at least one lance for injecting gaseous oxygen and afterburning combustible gases released from the molten bath, thanks why the rising and then lowering molten material in the expanded zone of the molten bath contributes to the transfer of heat to the molten bath. 2. The method according to claim 1, characterized in that step (b) includes injecting the charge materials into the molten bath so that the charge materials penetrate into the lower region of the molten bath. 3. The method according to claim 1 or 2, characterized in that step (b) includes injecting the charge materials into the molten bath through a lance at a speed of 80-100 m / s. 4. The method according to claim 3, characterized in that step (b) includes injecting the charge materials into the molten bath through a lance at a mass flow rate reaching 2.0 t / m ² / s, where m ² refers to the cross-sectional area lance transport pipe. 5. The method according to any one of the preceding paragraphs, characterized in that step (b) comprises injecting the charge materials into the molten bath through a tuyere at a ratio of solid materials to gas of 10-25 kg of solid materials / nm ³ gas. 6. The method according to claim 5, characterized in that the ratio of solid materials to gas is 10-18 kg of solid materials / nm ³ gas. 7. A method according to any one of the preceding paragraphs, characterized in that step (b) comprises injecting the charge materials through a plurality of tuyeres for injecting solid materials and generating at least 0.04 Nm ³ / s / m ² in the molten bath. 8. The method according to any one of the preceding paragraphs, characterized in that the gas stream in the molten bath generated in step (b) is at least 0.04 Nm ³ / s / m ² on the nominal calm surface of the molten bath. 9. The method according to claim 8, characterized in that the gas flow rate in the molten bath is at least 0.2 Nm ³ / s / m ² . 10. The method according to claim 8, characterized in that the gas flow rate is at least 0.3 Nm ³ / s / m ² . 11. The method according to any one of the preceding paragraphs, characterized in that the gas stream in the molten bath generated in step (b) is less than 2 Nm ³ / s / m ² . 12. The method according to any one of the preceding paragraphs, characterized in that the oxygen-containing gas injected into the molten bath in step (c) is air or oxygen-enriched air. 13. The method according to p. 12, characterized in that step (c) includes injecting into the converter air or oxygen-enriched air at a temperature of 800-1400 ° C and at a speed of 200-600 m / s through at least one a lance for injecting gaseous oxygen and pushing the expanded zone of the molten bath in the region of the lower end of the lance from the lance and the formation of “free” space around the lower end of the lance, in which the concentration of molten material is lower than the concentration of molten material in the expanded zone is molten of the bath, while the lance is positioned so that (i) the central axis of the lance is inclined at an angle from 20 to 90 ° to the horizontal axis, (ii) the lance extends into the converter at a distance at least equal to the outer diameter of the lower end of the lance, and (iii) the lower end of the lance is located above the calm surface of the molten bath at a distance of at least 3 times the outer diameter of the lower end of the lance. 14. The method according to any one of the preceding paragraphs, characterized in that it includes the injection of air or oxygen-enriched air into the converter in a vortex stream. 15. The method according to any one of the preceding paragraphs, characterized in that it includes monitoring that the content of dissolved carbon in the molten iron is at least 3 wt.%, As well as maintaining the slag under highly reducing conditions, leading to the content of FeO in the slag less than 6 wt.%, more preferably less than 5 wt.%. 16. The method according to any one of the preceding paragraphs, characterized in that it includes facilitating the discharge of molten metal into the upper space above the expanded zone of the molten bath. 17. The method according to any one of the preceding paragraphs, characterized in that step (c) includes the afterburning of combustible gases, wherein the afterburning level is at least 40%, where the afterburning is defined as

where [СО ₂ ] - volumetric content in% СО ₂ in the exhaust gases; [Н ₂ О] - volumetric content in% Н ₂ О in the exhaust gases; [СО] - volumetric content in% of СО in the exhaust gases; [H ₂ ] - volumetric content in% of H ₂ in the exhaust gases. 18. A device for producing metal from iron-containing material using a direct smelting method, said device including a fixed, non-tilting converter, which comprises a molten bath of metal and slag and includes a lower region and an expanded zone located above the lower region a molten bath, wherein the expanded zone of the molten bath is formed by a gas stream from the lower region carrying the molten material upward from the lower region, said converter including includes (a) a hearth made of refractory material and having a base and sides in contact with the lower region of the molten bath, (b) side walls directed upward from the sides of the hearth and in contact with the upper region of the molten bath and continuous gas space, with the side walls in contact with the continuous gas space including water-cooled panels and a slag layer on the panels, (c) at least one lance directed down into the converter and injecting oxygen carrying gas to a converter above the molten bath, (d) at least one lance injecting charge materials, which are iron-containing material and / or carbon-containing material and carrier gas, into the molten bath at a speed of at least 40 m / s, with the lance so that the central axis of the outlet end of the tuyere is inclined downward at an angle of 20 to 90 ° to the horizontal axis, and the tuyere includes a transport pipe for injection of charge materials, the inner diameter of which is 40-200 mm, and (e) a discharge means molten metal and slag from the converter. 19. The device according to p. 18, characterized in that the lance for the injection of charge materials is located so that the outlet of the lance is 150-1500 mm above the nominal calm surface of the metal layer in the molten bath.