# US 7,608,128 B2 · Direct reduction process and apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,608,128 B2 - Document ID: US7608128B2 - Status: Granted - Kind: B2 - Application number: 11/569,739 - Filed: 2005-05-20 - Published: 2007-11-08 - Granted: 2009-10-27 - Earliest claimed: 2004-05-31 - Assignees: Outotec Oyj - Applicants: Jeantine Van Gemund, legal representative - Inventors: Andreas Orth; Heinz Eichberger; Donald Keith Philp; Rod Dry - Web page: https://patentgrep.com/patent/US7608128B2 ## CPC - C21B 13/0033: {In fluidised bed furnaces or apparatus containing a dispersion of the material} - C21B 13/14: Multi-stage processes {processes carried out in different vessels or furnaces} - C22B 5/14: fluidised material - Y02P 10/122: by capturing or storing CO2 - Y02P 10/134: by avoiding CO2, e.g. using hydrogen - C21B: MANUFACTURE OF IRON OR STEEL (preliminary treatment of ferrous ores or scrap C22B1/00) - C22B: PRODUCTION AND REFINING OF METALS (electrolytic C25); PRETREATMENT OF RAW MATERIALS - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract A direct reduction process for a metalliferous material includes supplying a solid carbonaceous material and an oxygen-containing gas into a fluidized bed in a first vessel and generating heat by reactions between the oxygen-containing gas and the solid carbonaceous material and any other oxidizable solids and gases in the fluidized bed and discharging a hot off-gas stream containing entrained solids. The process also includes supplying the metalliferous material to a fluidized bed in a second vessel and supplying the hot off-gas stream containing entrained solids from the first vessel to the fluidized bed in the second vessel and partially reducing the metalliferous feed material in the solid state in the fluidized bed and discharging a product stream of partially reduced metalliferous material and an off-gas stream containing entrained solids. ## Claims ### Claim 1 A direct reduction process for a metalliferous material comprising: supplying a solid carbonaceous material, an oxygen-containing gas and a fluidizing gas to a first vessel for maintaining a fluidized bed in the first vessel and generating heat by reactions between the oxygen-containing gas and the solid carbonaceous material and any other oxidizable solids and gases in the fluidized bed and discharging a hot off-gas stream containing entrained solids, and supplying the metalliferous material and a fluidizing gas to a second vessel for maintaining a fluidized bed in the second vessel and supplying the hot off-gas stream containing entrained solids from the first vessel to the fluidized bed in the second vessel and at least partially reducing the metalliferous feed material in the solid state in the fluidized bed and discharging a product stream of at least partially reduced metalliferous material and an off-gas stream containing entrained solids, and wherein the oxygen-containing gas is supplied into the first vessel so that there is a downward flow of the gas in the first vessel. ### Claim 2 (depends on 1) Process according to claim 1, comprising operating the first vessel at higher temperatures than the second vessel. ### Claim 3 (depends on 1) Process according to claim 1, comprising operating the first vessel at temperatures above 1000° C. ### Claim 4 (depends on 1) Process according to claim 1, comprising operating the second vessel at temperatures below 1000° C. ### Claim 5 (depends on 1) Process according to claim 1, comprising injecting the oxygen-containing gas into the first vessel via at least one lance having a lance tip with an outlet positioned in the first vessel inwardly of the side wall of the vessel in a central region of the vessel. ### Claim 6 (depends on 5) Process according to claim 5, wherein the lance tip is directed vertically downwardly. ### Claim 7 (depends on 5) Process according to claim 5, comprising water-cooling the lance tip. ### Claim 8 (depends on 5) Process according to claim 5, wherein comprising water-cooling an outer surface of the lance tip. ### Claim 9 (depends on 5) Process according to claim 5, comprising injecting the oxygen-containing gas through a central pipe of the lance. ### Claim 10 (depends on 9) Process according to claim 9, comprising injecting nitrogen and/or steam and/or other suitable shrouding gas and shrouding a lower end of the central pipe. ### Claim 11 (depends on 5) Process according to claim 5, comprising injecting the oxygen-containing gas with sufficient velocity to form a substantially solids-free zone in the region of the lance tip to decrease the possibility of accretions forming on the lance tip that could block the injection of the oxygen-containing gas. ### Claim 12 (depends on 1) Process according to claim 1, comprising controlling the temperature difference between the bulk temperature in the fluidized bed in the second vessel and the average temperature of the inwardly facing surface of a side wall of the second vessel to be no more than 100° C. ### Claim 13 (depends on 1) Process according to claim 1, wherein the metalliferous material is in the form of iron ore fines, and the bulk temperature in the fluidized bed in the second vessel is in the range 850° C. to 1000° C. ### Claim 14 (depends on 1) Process according to claim 1, comprising controlling variation in temperature within the fluidized bed in the second vessel to be less than 50° C. ### Claim 15 (depends on 1) Process according to claim 1, comprising controlling the pressure in at least the second vessel to be in the range of 1-10 bar absolute. ### Claim 16 (depends on 1) Process according to claim 1, wherein the metalliferous material is in the form of iron ore fines. ### Claim 17 (depends on 1) Process according to claim 1, wherein the solid carbonaceous material is coal. ### Claim 18 (depends on 1) Process according to claim 1, comprising supplying a non-oxidizing gas as a fluidizing gas. ### Claim 19 (depends on 1) Process according to claim 1, comprising supplying a reducing gas to the second vessel as a fluidizing gas. ### Claim 20 (depends on 19) Process according to claim 19, comprising supplying a mixture of CO and H2 to the second vessel as the fluidizing gas, and wherein the amount of H2 in the fluidizing gas in the second vessel is at least 10% by volume of the total volume of CO and H2 in the gas. ### Claim 21 (depends on 1) Process according to claim 1, comprising separating at least partially reduced metalliferous feed material and at least a portion of other solids from the product stream from the second vessel. ### Claim 22 (depends on 21) Process according to claim 21, comprising returning at least a part of the other solids separated from the product stream to the first vessel and/or the second vessel. ### Claim 23 (depends on 1) Process according to claim 1, comprising separating at least a portion of the entrained solids from the off-gas stream from the second vessel. ### Claim 24 (depends on 23) Process according to claim 23, comprising supplying the solids separated from the output off-gas stream to the first vessel. ### Claim 25 (depends on 1) Process according to claim 1, comprising preheating metalliferous feed material with the off-gas from the second vessel. ### Claim 26 (depends on 25) Process according to claim 25, comprising treating the off-gas after the preheating step and returning at least a part of the treated off-gas to the first vessel and/or the second vessel as fluidizing gas. ### Claim 27 (depends on 26) Process according to claim 26, wherein the off-gas treatment comprises one or more of (a) solids removal, (b) cooling, (c) H2O removal, (d) CO2 removal, (e) compression, and (f) reheating. ### Claim 28 (depends on 26) Process according to claim 26, wherein the off-gas treatment comprises returning at least a portion of the separated solids to the first vessel and/or the second vessel. ### Claim 29 (depends on 1) Process according to claim 1, wherein the oxygen-containing gas comprises at least 90% by volume oxygen. ### Claim 30 (depends on 1) Process according to claim 1, comprising an additional smelting process for melting and further reducing the partially reduced metalliferous material to molten metal. ### Claim 31 A direct reduction process for a metalliferous material comprising: supplying a solid carbonaceous material, an oxygen-containing gas and a fluidizing gas to a first vessel for maintaining a fluidized bed in the first vessel and generating heat by reactions between the oxygen-containing gas and the solid carbonaceous material and any other oxidizable solids and gases in the fluidized bed and discharging a hot off-gas stream containing entrained solids, supplying the metalliferous material and a fluidizing gas to a second vessel for maintaining a fluidized bed in the second vessel and supplying the hot off-gas stream containing entrained solids from the first vessel to the fluidized bed in the second vessel and at least partially reducing the metalliferous feed material in the solid state in the fluidized bed and discharging a product stream of at least partially reduced metalliferous material and an off-gas stream containing entrained solids, and supplying an oxygen-containing gas into the second vessel. ### Claim 32 (depends on 31) Process according to claim 31, comprising operating the first vessel at higher temperatures than the second vessel. ### Claim 33 (depends on 31) Process according to claim 31, comprising operating the first vessel at temperatures above 1000° C. ### Claim 34 (depends on 31) Process according to claim 31, comprising operating the second vessel at temperatures below 1000° C. ### Claim 35 (depends on 31) Process according to claim 31, comprising supplying the oxygen-containing gas into the second vessel so that there is a downward flow of gas in the second vessel. ### Claim 36 (depends on 31) Process according to claim 31, comprising injecting the oxygen-containing gas into the second vessel via at least one lance having a lance tip with an outlet positioned in the first vessel inwardly of the side wall of the vessel in a central region of the vessel. ### Claim 37 (depends on 34) Process according to claim 34, wherein the lance tip is directed downwardly. ### Claim 38 (depends on 34) Process according to claim 34, comprising water-cooling the lance tip. ### Claim 39 (depends on 34) Process according to claim 34, wherein comprising water-cooling an outer surface of the lance tip. ### Claim 40 (depends on 34) Process according to claim 34, comprising injecting the oxygen-containing gas through a central pipe of the lance. ### Claim 41 (depends on 40) Process according to claim 40, comprising injecting nitrogen and/or steam and/or other suitable shrouding gas and shrouding a lower end of the central pipe. ### Claim 42 (depends on 36) Process according to claim 36, comprising injecting the oxygen-containing gas with sufficient velocity to form a substantially solids-free zone in the region of the lance tip to decrease the possibility of accretions forming on the lance tip that could block the injection of the oxygen-containing gas. ### Claim 43 (depends on 31) Process according to claim 31, comprising controlling the temperature difference between the bulk temperature in the fluidized bed in the second vessel and the average temperature of the inwardly facing surface of a side wall of the second vessel to be no more than 100° C. ### Claim 44 (depends on 31) Process according to claim 31, wherein the metalliferous material is in the form of iron ore fines, and the bulk temperature in the fluidized bed in the second vessel is in the range 850° C. to 1000° C. ### Claim 45 (depends on 31) Process according to claim 31, comprising controlling variation in temperature within the fluidized bed in the second vessel to be less than 50° C. ### Claim 46 (depends on 31) Process according to claim 31, comprising controlling the pressure in at least the second vessel to be in the range of 1-10 bar absolute. ### Claim 47 (depends on 31) Process according to claim 31, wherein the metalliferous material is in the form of iron ore fines. ### Claim 48 (depends on 31) Process according to claim 31, wherein the solid carbonaceous material is coal. ### Claim 49 (depends on 31) Process according to claim 31, comprising supplying a non-oxidizing gas as a fluidizing gas. ### Claim 50 (depends on 31) Process according to claim 31, comprising supplying a reducing gas to the second vessel as a fluidizing gas. ### Claim 51 (depends on 50) Process according to claim 50, comprising supplying a mixture of CO and H2 to the second vessel as the fluidizing gas, and wherein the amount of H2 in the fluidizing gas in the second vessel is at least 10% by volume of the total volume of CO and H2 in the gas. ### Claim 52 (depends on 31) Process according to claim 31, comprising separating at least partially reduced metalliferous feed material and at least a portion of other solids from the product stream from the second vessel. ### Claim 53 (depends on 52) Process according to claim 52, comprising returning at least a part of the other solids separated from the product stream to the first vessel and/or the second vessel. ### Claim 54 (depends on 31) Process according to claim 31, comprising separating at least a portion of the entrained solids from the off-gas stream from the second vessel. ### Claim 55 (depends on 54) Process according to claim 54, comprising supplying the solids separated from the output off-gas stream to the first vessel. ### Claim 56 (depends on 31) Process according to claim 31, comprising preheating metalliferous feed material with the off-gas from the second vessel. ### Claim 57 (depends on 56) Process according to claim 56, comprising treating the off-gas after the preheating step and returning at least a part of the treated off-gas to the first vessel and/or the second vessel as fluidizing gas. ### Claim 58 (depends on 57) Process according to claim 57, wherein the off-gas treatment comprises one or more of (a) solids removal, (b) cooling, (c) H2O removal, (d) CO2 removal, (e) compression, and (f) reheating. ### Claim 59 (depends on 57) Process according to claim 57, wherein the off-gas treatment comprises returning at least a portion of the separated solids to the first vessel and/or the second vessel. ### Claim 60 (depends on 31) Process according to claim 31, wherein the oxygen-containing gas comprises at least 90% by volume oxygen. ### Claim 61 (depends on 31) Process according to claim 31, comprising an additional smelting process for melting and further reducing the partially reduced metalliferous material to molten metal. ### Claim 62 A direct reduction apparatus for a metalliferous material comprising: (a) a first vessel for generating a hot off-gas stream containing entrained solids, the first vessel comprising an inlet means for supplying a solid carbonaceous material, a fluidizing gas, and an oxygen-containing gas into the first vessel and maintaining a fluidized bed in the vessel and producing the hot off-gas stream containing entrained solids, and an outlet means for discharging the hot off-gas stream containing entrained solids from the vessel; and (b) a second vessel for at least partially reducing metalliferous material in a solid state in a fluidized bed in the second vessel, the second vessel comprising an inlet means for supplying the metalliferous material, the hot off-gas stream containing entrained solids from the first vessel, and a fluidizing gas into the second vessel and maintaining the fluidized bed in the vessel, an outlet means for discharging a predominantly solids stream of at least partially reduced metalliferous feed material from the second vessel, and an outlet means for discharging a stream of an off-gas and entrained solids from the second vessel. ### Claim 63 (depends on 62) Apparatus according to claim 62, wherein the first vessel comprises separate inlet means for supplying each of the solid carbonaceous material, the fluidizing gas, and the oxygen-containing gas into the first vessel. ### Claim 64 (depends on 63) Apparatus according to claim 63, wherein the inlet means for supplying oxygen-containing gas into the first vessel comprises a lance having a lance tip with an outlet positioned in the vessel inwardly of the side wall of the vessel in a central region of the vessel. ### Claim 65 (depends on 64) Apparatus according to claim 64, wherein the lance tip is directed downwardly in a central region of the vessel for injecting the oxygen-containing gas in a downward flow. ### Claim 66 (depends on 62) Apparatus according to claim 62, wherein the second vessel comprises separate inlet means for supplying each of the metalliferous feed material, the hot off-gas stream containing entrained solids from the first vessel, and the fluidizing gas into the second vessel. ### Claim 67 (depends on 62) Apparatus according to claim 62, wherein the second vessel comprises an inlet means for supplying oxygen-containing gas into the second vessel. ### Claim 68 (depends on 67) Apparatus according to claim 67, wherein the inlet means for supplying oxygen-containing gas into the second vessel comprises a lance having a lance tip with an outlet positioned in the vessel inwardly of the side wall of the vessel in a central region of the vessel. ### Claim 69 (depends on 68) Apparatus according to claim 68, wherein the lance tip is directed downwardly in a central region of the second vessel for injecting the oxygen-containing gas in a downward flow. ### Claim 70 (depends on 62) Apparatus according to claim 62, comprising a means for separating entrained solids from the off-gas stream from the second vessel. ### Claim 71 (depends on 70) Apparatus according to claim 70, wherein the first vessel further comprises an inlet means for supplying separated solids from the off-gas separation means into the first vessel. ### Claim 72 (depends on 70) Apparatus according to claim 70, comprising a means for processing the off-gas stream from the second vessel and producing at least part of the fluidizing gas for the first vessel and/or the second vessel.