DUPLEX PROCEDURE FOR THE PRODUCTION OF METALS AND METAL ALLOYS FROM OXIDIC METAL ORES

Abstract: The production of highly metallised feed, an intermediate product produced solely by gaseous reductants in two stage reduction processes of that kind, encounters sticking problems, which interfere with continuous processing and productivity. This problem has been overcome by exploiting a high volatile carbonaceous material, such as coal, as the reducing agent for the (partially reduced) oxide ore starting material in the solid state prereduction stage of a duplex process, in which the final stage consists of smelting, to produce the final metal (alloy). Intermediate products of the first stage are char from the coal, which avoids the sticking problem, partially reduced ore and CO and H2, which participate in the prereduction. The process has particular application to iron ores, such as haematite and magnetite and similar derivatives, namely, chromite and oxidic nickel ores. The process may be extended to a triplex, which includes drying, preheating and partial reduction in the first stage, followed by further partial reduction and finally the smelting step. Plant for the process may consist of a shaft furnace or fluidised bed for the prereduction sequence, preferably the latter. For the triplex process, two associated fluidised beds (3, 5) are preferred. Any suitable furnace (7) may be used for smelting, as long as it is equipped for the injection of partially reduced ore, char and fluxes, hot air lancing, off gas and the tapping of molten metal and slag. The final stage of solid state reduction takes place at a temperature of at least 550 DEG C, preferably 750-900 DEG C. At least 50 % of metallisation is essential for satisfactory processing, preferably at least 80 %.

Description: DUPLEX PROCEDURE FOR THE PRODUCTION OF METALS AND METAL ALLOYS FROM OXIDIC METAL ORES The present invention relates to a method and an apparatus for producing metals and metal alloys, in particular, although by no means exclusively iron and iron alloys, from metal oxides, such as ores and partly reduced ores. There are a number of known methods of smelting iron ore to produce molten iron which are based on the use of a metallurgical vessel (hereinafter referred to as a "smelt reduction vessel") containing a molten bath of iron and slag. In general terms, these known methods comprise injecting iron ore or partially reduced iron ore and a source of a carbonaceous material into a molten bath of iron and slag. In the molten bath the iron ore or partially reduced iron ore is reduced to metallic iron and melted. The carbonaceous material (in solid or gaseous form) is required as a source of reductant and thermal energy and to carburise the molten bath to produce pig iron (typically 1 to 4 wt.% carbon in metal). In a number of known processes, reaction gases that are discharged from the smelt reduction vessel are used to preheat and to partially reduce iron ore in a pre- reduction vessel, such as a shaft furnace, prior to transferring the partially reduced iron ore into the smelt reduction vessel. These known processes are commonly described as being two-stage linked processes. An object of the present invention is to provide a method and an apparatus for producing molten iron which is an improvement over the known two-stage linked processes . According to the present invention there is provided a method of producing metals and metal alloys from metal oxides which comprises the steps of: (i) partially reducing metal oxides and/or partially reduced metal oxides and at least partially devolatilising a solid carbonaceous material, by injecting metal oxides and/or partially reduced metal oxides and the solid carbonaceous material into a pre-reduction vessel and maintaining a temperature of at least 550°C in the pre¬ reduction vessel; and (ii) reducing further the partially reduced metal oxides to produce molten metal by injecting the partially reduced metal oxides and the at least partially devolatilised solid carbonaceous material from step (i) into a smelt reduction vessel containing a molten bath of metal and slag. The at least partially devolatilised solid carbonaceous material produced in pre-reduction step (i) is a source of carbon for use in the subsequent smelt reduction step (ii) . Aβ is discussed above, the carbon is needed in the smelt reduction step (ii) : (a) to reduce the pre-reduced metal oxides to metal; (b) to provide a source of thermal energy to melt the metal oxides; and (c) to carburise the bath to provide levels of dissolved carbon in metal that may be required to produce metal alloys in the molten bath. The invention does not preclude injection into the smelt reduction vessel of carbonaceous materials in addition to the at least partially devolatilised solid carbonaceous material that is produced in the pre-reduction vessel. For example, the invention extends to the injection of coal or other suitable solid carbonaceous materials or any suitable gaseous carbonaceous materials into the smelt reduction vessel in addition to the injection of the at least partially devolatilised solid carbonaceous material produced in the pre-reduction vessel. It is preferred that the at least partially devolatilised solid carbonaceous material be char. The term "char" is understood herein to mean the product of heating coal without burning the coal. It is preferred that the pre-reduction step (i) partially reduces the metal oxides and/or partially reduced metal oxides to a pre-reduction degree of at least 50%. The term "pre-reduction degree" is understood herein to mean the percentage of oxygen removal starting from Fe 2 0 3 . It is preferred particularly that the pre¬ reduction step (i) partially reduces the metal oxides and/or partially reduced metal oxides to a pre-reduction degree of at least 60%. It is preferred more particularly that the pre- reduction step (i) partially reduces the metal oxides and/or partially reduced metal oxides to a pre-reduction degree of at least 70%. Typically, the pre-reduction step (i) partially reduces the metal oxides and/or partially reduced metal oxides to a pre-reduction degree of 80%. The purpose of the solid carbonaceous material injected into the pre-reduction vessel in the pre-reduction step (i) is to provide: (a) a source of the char or other at least partially devolatilised solid carbonaceous material for use subsequently in the smelt reduction step (ii); and (b) a source of reductant to pre-reduce the metal oxides in the pre-reduction vessel. It is preferred that the solid carbonaceous material injected into the pre-reduction vessel be coal. In that event, it is preferred that the temperature in the pre-reduction vessel be maintained at a temperature, typically less than 1000°C, at which the fixed carbon component of the coal does not act readily as a reductant. In such a situation, the volatiles, such aβ hydrocarbons, in the coal are the main βource of reductant. Specifically, the hydrocarbons crack to form the reductantβ CO and H 2 0 (and other products) . It is noted that the invention does not preclude the use of fixed carbon in the coal as a reductant in the pre-reduction vessel. It is preferred that the pre-reduction step (i) comprises forming a fluidised bed of the metal oxides and/or partially reduced metal oxides and the solid carbonaceous material in the pre-reduction vessel. It is preferred particularly that the fluidised bed be formed by injecting air into the pre-reduction vessel either directly or indirectly. It is preferred that the temperature be maintained at the temperature of at least 550°C in the pre¬ reduction vesβel by: (i) con-busting coal and/or other carbonaceous materials (including gaβeous carbonaceous materials) in the pre-reduction vessel; and/or (ii) providing heat energy by indirect heat exchange. It is preferred that the temperature in the pre¬ reduction vesβel be maintained at a temperature of at least 600°C. It is preferred particularly that the temperature in the pre-reduction vessel be maintained at a temperature of at least 750°C. It is preferred more particularly that the temperature in the pre-reduction vesβel be maintained at a temperature of at least 800°C. It is preferred that the temperature in the pre¬ reduction vesβel be maintained at a temperature of less than 1000°C. It is preferred particularly that the temperature in the pre-reduction vessel be maintained at a temperature of less than 1000°C. The preferred temperature range for the pre¬ reduction vessel is 750 to 950°C. The reduction and melting reactions in the smelt reduction step (ii) described above are endothermic and, therefore, it is preferred that the method includes a step of maintaining the temperature of the molten bath in the smelt reduction vesβel above a minimum temperature. It is preferred that the minimum temperature of the molten bath be in the range of 1350°C - 1500°C. It is preferred that the step of maintaining the temperature of the molten bath in the smelt reduction vesβel above the minimum temperature comprises post- combusting reaction gaseβ, such aβ CO and H 2 , released from the molten bath by injecting oxygen-containing gas into a gas space in the smelt reduction vessel above the molten bath and transferring energy generated by the post- co buβtion to the molten bath. It is preferred that the oxygen-containing gas be air. It is preferred particularly that the air be preheated to a temperature of at least 1000°C. It is preferred that the pre-reduction step (i) comprises pre-reducing the metal oxides and/or partially reduced metal oxides in two or more pre-reduction stages. It is preferred particularly that the pre¬ reduction step (i) comprises: (i) a first pre-reduction stage of injecting metal oxides and reaction gases from the smelt reduction vessel and/or a second pre¬ reduction vesβel into one pre-reduction veββel to dry, pre-heat, and partially reduce the metal oxides and, thereafter; (ii) partially reducing further the metal oxides and producing the at least partially devolatilised solid carbonaceous material in the second pre-reduction stage by injecting the partially reduced metal oxides and solid carbonaceous material into another pre-reduction veββel and maintaining a temperature of at least 550°C in the pre-reduction veββel. It is preferred that the metal oxides be iron ore or ferrous containing wastes. According to the present invention there is also provided an apparatus for producing metals and metal alloys from metal oxides which comprises: (i) a pre-reduction vesβel for at leaβt partially reducing metal oxides and/or partially reduced metal oxides and for producing at least partially devolatilised solid carbonaceous material, the pre¬ reduction veββel comprising an inlet for injecting metal oxides and/or partially reduced metal oxides, an inlet for injecting solid carbonaceous material, and an outlet for discharging at leaβt partially reduced metal oxides and at leaβt partially devolatilised solid carbonaceous material; and (ii) a smelt reduction vesβel for reducing further partially reduced metal oxides to produce metal and melting the metal, the βmelt reduction veββel being adapted to contain a molten bath of metal and slag, the smelt reduction vesβel comprising an inlet for the at least partially reduced metal oxides and the at least partially devolatilised solid carbonaceous material from the pre-reduction vesβel and a meanβ for injecting an oxygen-containing gas into the βmelt reduction veββel to poet combust reaction gases released from the molten bath. It is preferred that the smelt reduction vesβel comprises an outlet for reaction gases. It is preferred that the smelt reduction veββel comprises a means for tapping slag from the smelt reduction vesβel. It is preferred that the βmelt reduction veββel comprises a means for tapping metal from the smelt reduction vesβel. According to the preβent invention there is also provided an apparatus for producing metals and metal alloys from metal oxides which compriseβ: (i) a first pre-reduction vesβel for partially reducing metal oxides; (ii) a second pre-reduction vesβel for at leaβt partially reducing partially reduced metal oxides from the first pre¬ reduction veββel and for producing at leaβt partially devolatiliβed βolid carbonaceous material, the pre-reduction vessel comprising an inlet for injecting partially reduced metal oxides, an inlet for injecting βolid carbonaceous material, and an outlet for discharging at leaβt partially reduced metal oxides and at leaβt partially devolatiliβed βolid carbonaceous material; and (iii) a βmelt reduction veββel for reducing further the partially reduced metal oxides to produce metal and melting the metal, the smelt reduction vesβel being adapted to contain a molten bath of metal and βlag, the βmelt reduction veββel comprising an inlet for the at leaβt partially reduced metal oxides and the at leaβt partially devolatilised solid carbonaceous material from the pre- reduction vessel and a means for injecting an oxygen-containing gas into the βmelt reduction veββel to poet combust reaction gases released from the molten bath. It is preferred that the first pre-reduction veββel compriβeβ an inlet for reaction gaβeβ from the βmelt reduction veββel. It iβ preferred that the βmelt reduction veββel compriβeβ an outlet for reaction gaβeβ. It iβ preferred that the βmelt reduction veββel compriβeβ a meanβ for tapping βlag from the βmelt reduction veββel . It iβ preferred that the βmelt reduction vessel compriseβ a meanβ for tapping metal from the βmelt reduction veββel. The preβent invention iβ described further by way of example with reference to the accompanying drawing which is a flowβheet, in largely βchematic form, of one preferred embodiment of the method and the apparatuβ of the preβent invention. The description of the preferred embodiment shown in the figures is in the context of producing iron from iron ore. However, it is noted that the preferred embodiment is equally applicable to producing metals and metal alloys from other metal oxides. With reference to the figure, in accordance with the preferred embodiment shown in that figure: (i) iron ore is partially reduced in two successive stages in first and second pre-reduction vessels 3, 5 and, thereafter; (ii) the partially reduced iron ore is reduced further to produce iron and the iron iβ melted in a βmelt reduction veββel 7. The iron ore may be in any suitable form, such as lump or fines. The pre-reduction vessels 3, 5 may be of any suitable type, such aβ shaft furnaces or fluidised beds. As will be discusβed in more detail hereinafter, it iβ preferred that the pre-reduction veββel 5 be a fluidised bed. The source of reductant for the first pre¬ reduction veββel 3 compriβeβ reaction gaβeβ from the βmelt reduction veββel 7. The operating parameters of the first pre- reduction vesβel 3 are βelected to dry, pre-heat, and partially reduce iron ore to an initial, relatively low pre-reduction degree, typically of the order of 11% (ie magnetite) . The pre-reduction vessels 3, 5 are linked together by a standpipe (not shown) or any other suitable means to enable the tranβfer of partially reduced- iron ore from the firβt pre-reduction veββel 3 into the βecond pre¬ reduction veββel 5. The source of reductant for the second pre- reduction vesβel 5 compriβeβ coal. The source of reductant may also comprise any other suitable carbon containing species. The operating parameters of the second pre¬ reduction vesβel 5 are βelected so that: (a) the volatiles, typically hydrocarbons, of the coal are cracked to produce carbon monoxide and hydrogen and the carbon monoxide and hydrogen complete reduction of the partially reduced iron oxides from the firβt pre-reduction veββel 3 to a required pre-reduction degree; and (b) the greater proportion of fixed carbon in the coal produces char. The reactions to crack hydrocarbons, to reduce the partially reduced iron oxides, and to produce char are endothermic. Therefore, it iβ necessary to maintain the temperature of the second pre-reduction veββel 5 above a minimum temperature of 550°C to provide βufficient thermal energy for the reactionβ. One option for maintaining the temperature iβ by direct-in-bed combustion of coal with air. Another option for maintaining the temperature is by indirect heat exchange, either via tubes or hot solidβ circulation or the like. Aβ noted above, it iβ preferred that the second pre-reduction vesβel 5 operates as a fluidised bed. Typically, the fluidised bed is maintained by injecting preheated air into the pre-reduction vessel 5, either directly or indirectly. The fluidised bed may also be maintained by injecting oxygen and air/oxygen mixtures into the pre-reduction veββel 5. The βmelt reduction veββel 7 may be any suitable form of vesβel. The preferred βmelt reduction veββel 7 iβ constructed to hold a molten bath of iron and slag and compriβeβ: (i) tuyeres (not shown) for injecting the at leaβt partially reduced iron ore and char from the second pre-reduction veββel 5 into the molten bath; (ii) tuyeres (not shown) for injecting a blast of hot air, typically at a temperature greater than 1000°C, into the space above the surface of the molten bath to post- combuβt reaction gaβeβ such as carbon monoxide and hydrogen released from the molten bath. (iii) meanβ for periodically tapping molten iron and βlag; and (iv) an outlet for reaction gaβeβ. The configuration of the βmelt reduction veββel 7, including the poβitioning of the tuyeres, and the operating parameters of the method are βelected to form a transition zone in the space above the molten bath βurface in which there are ascending and therefore descending droplets or splashes of molten metal and slag which mix with reaction gaβeβ from the molten bath, top blown hot air, and the reaction gaβeβ from post combustion.- The purpose of the transition zone is to facilitate the efficient transfer to the molten bath of heat that is released by post combustion reaction gases from the molten bath. The transition zone may be formed by any suitable means. For example, the transition zone may be formed by injecting a suitable gas, such as an inert gaβ through the bottom of the βmelt reduction veββel 7 to cauβe eruption of droplets or splashes of molten metal and slag from the molten bath into the space above the molten bath surface. Alternatively, the transition zone may be formed by controlled injection of the at leaβt partially reduced iron ore and char from the second pre-reduction vesβel 5 into the molten bath through the side tuyeres in the βmelt reduction veββel 7. In accordance with the preferred embodiment, iron ore iβ injected into the first pre-reduction vesβel 3 and iβ partially reduced, preferably to magnetite, and preheated by reaction gaβeβ discharged from the smelt reduction vesβel 7. The partially reduced iron ore iβ discharged from the firβt pre-reduction veββel 3 and iβ injected with coal into the βecond pre-reduction veββel 5. Preferably, preheated air iβ also injected into the second pre-reduction veββel 5 (after being pre-contacted with fresh coal) and forms a bubbling fluidised bed of the partially reduced iron ore and char. As iβ discussed above, the operating parameters of the second pre-reduction vesβel 5 are βelected so that the bulk of the carbon component of the coal forms char and the volatilise of the coal are cracked to the reductants carbon monoxide and hydrogen which reduce the partially reduced iron ore to a required pre-reduction degree. Finally, the pre-reduced iron ore and char are discharged from the βecond pre¬ reduction veββel 5 and, together with fluxes, are injected into a molten bath of iron and slag in the smelt reduction vesβel 7. Preheated air iβ also injected into the gas space of the smelt reduction vesβel 7 and poet combusts reaction gases, such aβ carbon monoxide and hydrogen, released from the molten bath. The heat generated by the poet combustion is transferred to the molten bath to maintain the molten bath above a minimum temperature for enabling reduction of the partially reduced iron ore to metallic iron and melting the metallic iron. The above described preferred embodiments of the present invention have a number of important advantages over conventional smelt reduction processes such aβ linked two-stage processes. 1. A significant increase in productivity in the βmelt reduction veββel, leading to a reduction in refractory consumption and heat lose (per tonne of metal) . 2. A widening of the span of coals which will perform well in a molten bath-based βmelt reduction veββel. Since coal iβ pyrolyβed and volatiles are used in the second pre-reduction veββel 5, only the char component iβ injected into the smelt reduction vesβel. unlike the known iron bath-baβed methods, high volatile coals can readily be accepted without penalties in coal consumption and productivity. 3. Decreased capital investment per annual tonne of capacity, along with decreased operating costs through reduced- coal consumption. 4. The production of char in the pre- reduction stage of the method avoids sticking problems commonly encountered when producing highly metallised feed. Many modifications may be made to the preferred embodiments of the method and the apparatuβ deβcribed above without departing from the βpirit and βcope of the invention.

Claims: CLAIMS : 1. A method of producing metals and metal alloys from metal oxides which compriβeβ the steps of: (i) partially reducing metal oxides and/or partially reduced metal oxides and at least partially devolatilising a solid carbonaceouβ material, by injecting metal oxides and/or partially reduced metal oxides and the solid carbonaceous material into a pre-reduction vesβel and maintaining a temperature of at- leaβt 550°C in the pre-reduction veββel; and (ii) reducing further the partially reduced metal oxides to produce molten metal, by injecting the partially reduced metal oxides and the at least partially devolatilised solid carbonaceous material from step (i) into a βmelt reduction vessel containing a molten bath of metal and slag. 2. The method defined in claim 1 further compriβeβ injecting βolid carbonaceouβ materials or gaseous carbonaceous materials into the smelt reduction veββel in βmelt reduction βtep (ii) in addition to injecting the at leaβt partially devolatiliβed βolid carbonaceouβ material produced in the pre-reduction veββel. 3. The method defined in claim 1 or claim 2 wherein at leaβt partially devolatiliβed βolid carbonaceous material is char. 4. The method defined in any one of the preceding claims compriseβ partially reducing the metal oxideβ and/or partially reduced metal oxideβ in the pre¬ reduction βtep (i) to a pre-reduction degree of at leaβt 50%. 5. The method defined in claim 4 compriβeβ partially reducing the metal oxideβ and/or partially reduced metal oxideβ in a pre-reduction βtep (i) to a pre¬ reduction degree of at leaβt 60%. 6. The method defined in claim 5 comprises partially reducing the metal oxides and/or partially reduced metal oxides in pre-reduction βtep (i) to a pre¬ reduction degree of at leaβt 70%. 7. The method defined in any one of the preceding claims wherein the solid carbonaceouβ material injected into the pre-reduction veββel in pre-reduction βtep (i) iβ coal. 8. The method defined in claim 7 compriβeβ maintaining the temperature in the pre-reduction veββel at a temperature, typically less than 1000°C, at which the bulk of the fixed carbon component of the coal does not act readily as a reductant. 9. The method defined in any one of the preceding claims wherein the pre-reduction step (i) compriβeβ forming a fluidised bed, either bubbling or circulating, of the metal oxides and/or partially reduced metal oxideβ and the βolid carbonaceouβ material in the pre-reduction veββel. 10. The method defined in claim 9 comprises forming the fluidised bed by injecting air into the pre¬ reduction veββel, either directly or indirectly. 11. The method defined in any one of the preceding claims compriβeβ maintaining the temperature of at leaβt 550°C in the pre-reduction veββel by: (i) combusting coal and/or other carbonaceous materials (including gaseous carbonaceous materialβ) in the pre-reduction veββel; and/or (ii) providing heat energy by some form of indirect heat exchange, such as in-bed tubes or solids circulation. 12. The method defined in any one o-f the preceding claims comprises maintaining a temperature of at least 600°C in the pre-reduction vesβel. 13. The method defined in claim 12 compriβeβ maintaining a temperature of at least 750°C in the pre- reduction vesβel. 14. The method defined in any one of the preceding claims compriβeβ maintaining the temperature of the molten bath in the smelt reduction veββel above a minimum temperature. 15. The method defined in claim 14 compriβeβ maintaining the temperature of the molten bath in the range of 1350°C - 1500°C. 16. The method defined in any one of the preceding claimβ compriβeβ maintaining the temperature of the molten bath in the βmelt reduction veββel above the minimum temperature by post-combusting reaction gases, such as CO and H 2 , released from the molten bath by injecting oxygen-containing gaβ into a gaβ space in the smelt reduction vesβel above the molten bath and transferring energy generated by the post-combustion to the molten bath. 17. The method defined in claim 16 wherein the oxygen-containing gaβ iβ air. 18. The method defined in any one of the preceding claims wherein the pre-reduction step (i) compriβeβ pre-reducing the metal oxideβ and/or partially reduced metal oxideβ in two or more pre-reduction βtageβ. 19. The method defined in claim 18 wherein the pre-reduction βtep (i) compriβeβ the steps of: (i) injecting reaction gases discharged from the smelt reduction vesβel and/or a βecond pre-reduction veββel and metal oxideβ and/or partially reduced metal oxideβ into one pre-reduction veββel to dry, pre-heat, and partially reduce the metal oxideβ and, thereafter; (ii) injecting the dried, pre-heated, partially reduced metal oxideβ and the βolid carbonaceouβ material into another pre-reduction veββel and maintaining a temperature of at leaβt 550°C in the pre¬ reduction veββel to reduce further the metal oxideβ and produce the at least partially devolatilised βolid carbonaceouβ material. 20. The method defined in claim 19 wherein the metal oxideβ are iron ore or ferrous containing wasteβ 21. An apparatuβ for producing metals and metal alloys from metal oxideβ which compriβeβ: (i) a pre-reduction veββel for at leaβt partially reducing metal oxideβ and/or partially reduced metal oxideβ and for producing at leaβt partially devolatiliβed βolid carbonaceouβ material, the pre-reduction veββel compriβing an inlet for injecting metal oxideβ and/or partially reduced metal oxideβ, an inlet for injecting βolid carbonaceouβ material, and an outlet for discharging at least partially reduced metal oxides and at least partially devolatilised βolid carbonaceous material; and (ii) a smelt reduction veββel for reducing further partially reduced metal oxides to produce molten metal, the βmelt reduction veββel being adapted to contain a molten bath of metal and βlag, the βmelt reduction veββel comprising an inlet for the at least partially reduced metal oxideβ and the at leaβt partially devolatiliβed βolid carbonaceouβ material from the pre-reduction veββel and a meanβ for injecting an oxygen-containing gaβ into the βmelt reduction vessel to post combuβt reaction gaβeβ released from the molten bath. 22. The apparatus defined in claim 21 wherein the smelt reduction veββel compriβeβ an outlet for reaction gaβeβ. 23. The apparatuβ defined in claim 21 or claim 22 wherein the smelt reduction vessel compriseβ a meanβ for tapping βlag from the βmelt reduction veββel. 24. The apparatuβ defined in any one of claimβ 21 to 23 wherein the βmelt reduction veββel compriβeβ a meanβ for tapping metal from the βmelt reduction veββel. 25. An apparatuβ for producing metals and metal alloys from metal oxides which compriseβ: (i) a firβt pre-reduction veββel for partially reducing metal oxideβ; (ii) a βecond pre-reduction veββel for at leaβt partially reducing partially reduced metal oxideβ from the firβt pre¬ reduction veββel and for producing at leaβt partially devolatiliβed βolid carbonaceouβ material, the pre-reduction veββel comprising an inlet for injecting partially reduced metal oxides, an inlet for injecting solid carbonaceous material, and an outlet for discharging at leaβt partially reduced metal oxideβ and at leaβt partially devolatiliβed βolid carbonaceouβ material; and (iii) a βmelt reduction veββel for reducing further the partially reduced metal oxideβ to produce molten metal, the βmelt reduction veββel being adapted to contain a molten bath of metal and βlag, the βmelt reduction veββel comprising an inlet for the at least partially reduced metal oxides and the at leaβt partially devolatiliβed βolid carbonaceouβ material from the pre-reduction veββel and a meanβ for injecting an oxygen-containing gaβ into the βmelt reduction veββel to poet combust reaction gaβeβ released from the molten bath. 26. The apparatus defined in claim 25 wherein the first pre-reduction vesβel compriβeβ an inlet for reaction gaβeβ. 27. The apparatuβ defined in claim 25 or claim 26 wherein the βmelt reduction veββel compriβeβ an outlet for reaction gaβeβ. 28. The apparatuβ defined in any one of claims 25 to 27 wherein the smelt reduction vesβel compriβeβ a meanβ for tapping βlag from the βmelt- reduction veββel. 29. The apparatuβ defined in any one of claims 25 to 28 wherein the smelt reduction vesβel compriβeβ a meanβ for tapping metal from the βmelt reduction veββel.

Inventors: DRY RODNEY JAMES, INNES JOHN ALEXANDER, DRY, RODNEY, JAMES, INNES, JOHN, ALEXANDER
Applicants: DRY RODNEY JAMES, INNES JOHN ALEXANDER, TECH RESOURCES PTY LTD, DRY, RODNEY, JAMES, INNES, JOHN, ALEXANDER, TECHNOLOGICAL RESOURCES PTY. LTD.
Application year: 1996
Main classification: C21B5
IPC codes: C21B11, C21B13, C22B1, C22B5, F27B19