Method and apparatus for the continuous production of sponge iron from iron ore

Abstract

An arrangement for continuously producing sponge iron from iron ore, comprising: a direct reduction shaft (1), arrangements (24, 25, 26) for introducing pressurized and heated hydrogen-rich reducing gas into the direct reduction shaft (1) for reducing the iron ore to produce sponge iron, and a charging vessel (2) having an inert gas inlet (8) for charging the iron ore into the direct reduction shaft (1). A control unit (14) is configured to supply pressurized inert gas into the charging vessel (2) such that a pressure in the inert gas charging vessel (2) is equal to or less than a pressure in the direct reduction shaft (1) before discharging the iron ore from the charging vessel (2) to the direct reduction shaft (1), and to control the inert gas inlet valve (9) based on inputs from the reduction shaft (1) pressure sensor (12) and the charging vessel pressure sensor (13) to close the gas inlet valve (9) during discharge of the iron ore from the charging vessel (2) to the direct reduction shaft (1).

Description

[Technical field]

[0001] Technical Field The present invention relates to a method for continuously producing sponge iron from iron ore, comprising the steps of: charging iron ore into a direct reduction shaft via a charge vessel; introducing heated hydrogen-rich reducing gas into the direct reduction shaft for reducing the iron ore to produce sponge iron, wherein a process pressure above atmospheric pressure is generated in the direct reduction shaft; and removing the produced sponge iron from the direct reduction shaft via a discharge vessel.

[0002] The present invention also relates to an arrangement for continuously producing sponge iron from iron ore, comprising a direct reduction shaft, an arrangement for introducing pressurized and heated hydrogen-rich reducing gas into the direct reduction shaft for reducing iron ore to produce sponge iron, a charging vessel for charging the iron ore into the direct reduction shaft, and a discharging vessel for discharging the sponge iron from the direct reduction shaft. [Background technology]

[0003] background In an arrangement for the direct reduction (DR) of iron ore to sponge iron, a charging vessel may be used to charge the iron ore into a reduction shaft and a discharge vessel may be used to discharge the sponge iron from the same shaft. The iron ore is charged into the charging vessel which is first flushed with an inert seal gas to remove air from the vessel. The inert gas is pressurized using the seal gas to a pressure slightly higher than the operating pressure of the DR shaft. Once pressurized, a valve separating the charging vessel from the DR shaft is opened, allowing the iron ore to be introduced into the shaft together with the pressurized seal gas. To prevent the reduction gas from entering the charging vessel, the vessel is constantly flushed with a flow of seal gas during the charging operation. Once the ore has been charged, the valve can be closed and the charging vessel can be opened to receive further quantities of ore for charging. When discharging the sponge iron from the DR shaft, a corresponding sequence of steps is also carried out with respect to the discharge vessel.

[0004] Due to overpressurization of the seal gas and continuous flashing during charging, a large amount of seal gas enters the DR shaft and dilutes the reducing gas. Since the seal gas is inert and accumulates in the reduction circuit, this creates the need to flare the reducing gas, which is costly (especially when the reducing gas is electrolytic hydrogen, which is expensive). Summary of the Invention [Problem to be solved by the invention]

[0005] Objective of the invention The object of the present invention is to provide a method and arrangement for the direct reduction of iron ore to sponge iron, which reduces the dilution of the reducing gas by the inert seal gas, as compared to the prior art disclosed above. The method and arrangement should be designed such that the losses of the seal gas and the reducing gas are minimized, thereby contributing to the efficient operation of the arrangement. [Means for solving the problem]

[0006] overview The object of the present invention is to - charging the iron ore into a direct reduction shaft via a charging vessel; - introducing heated hydrogen-rich reducing gas into a direct reduction shaft for reducing iron ore to produce sponge iron, wherein a process pressure above atmospheric pressure is generated in the direct reduction shaft; - removing the produced sponge iron from the direct reduction shaft via a discharge vessel, The charging step includes the following steps: - sealing the iron ore outlet of the charging vessel in an airtight manner relative to the reduction shaft; - charging the charging vessel with iron ore via an iron ore inlet to the charging vessel; - closing the ore inlet of the charging vessel in an airtight manner against the atmosphere; - filling the charging vessel with inert gas via an inert gas inlet to the charging vessel; - opening the iron ore outlet and discharging the iron ore from the charging vessel directly into the reduction shaft; Including, The step of filling the charging vessel with the inert gas includes the steps of measuring a process pressure in the direct reduction shaft and filling the charging vessel with the inert gas to a pressure equal to or lower than the process pressure in the direct reduction shaft, and the inert gas inlet is closed during the opening of the iron ore outlet and during the discharge of the iron ore from the charging vessel to the direct reduction shaft. This is achieved by a process for the continuous production of sponge iron from iron ore.

[0007] According to one embodiment, the step of charging the charging vessel with inert gas includes charging the charging vessel with inert gas to a pressure less than 2 bar lower than the pressure in the direct reduction shaft. In other words, when the discharge of the iron ore into the direct reduction shaft is started, the difference between the pressure of the inert gas in the charging vessel and the pressure in the direct reduction shaft is less than or equal to 2 bar.

[0008] According to one embodiment, the step of charging the charging vessel with inert gas includes charging the charging vessel with inert gas to a pressure less than 1 bar lower than the pressure in the direct reduction shaft. In other words, when the discharge of the iron ore into the direct reduction shaft is started, the difference between the pressure of the inert gas in the charging vessel and the pressure in the direct reduction shaft is less than or equal to 1 bar.

[0009] According to one embodiment, after the iron ore outlet is opened and the iron ore is discharged from the charging vessel directly into the reduction shaft, the iron ore outlet is closed, and then the gas outlet of the charging vessel is opened and inert gas is flowed into the charging vessel through the inert gas inlet and gas outlet of the charging vessel.

[0010] According to one embodiment, the pressure in the charging vessel is reduced to approximately atmospheric pressure prior to charging the iron ore into the charging vessel through the iron ore inlet.

[0011] According to one embodiment, the inert gas mainly comprises nitrogen gas, which also prevents or reduces the production of ammonia in the direct reduction chamber, since nitrogen is prevented to a large extent from leaking into the direct reduction chamber.

[0012] According to one embodiment, the hydrogen-rich reducing gas introduced into the direct reduction shaft comprises at least 80 vol.%, preferably at least 90 vol.% hydrogen gas (vol.% determined at normal conditions of 1 atm. and 0° C.).

[0013] The object of the present invention is also to - charging the iron ore into a direct reduction shaft via a charging vessel; - introducing heated hydrogen-rich reducing gas into a direct reduction shaft for reducing iron ore to produce sponge iron, wherein a process pressure above atmospheric pressure is generated in the direct reduction shaft; - removing the produced sponge iron from the direct reduction shaft via a discharge vessel, The process of extracting sponge iron includes the following steps: - closing the sponge iron outlet of the discharge vessel air-tightly against the atmosphere; - hermetically closing the sponge iron inlet from the direct reduction shaft to a discharge vessel; - filling the discharge vessel with inert gas via an inert gas inlet to the discharge vessel; - opening the sponge iron inlet and charging sponge iron from the direct reduction shaft through the sponge iron inlet into the discharge vessel; - sealing the sponge iron inlet of the discharge vessel in an airtight manner against the direct reduction shaft; - opening the sponge iron outlet and discharging the iron from the discharge container; The step of filling the discharge vessel with the inert gas includes the steps of measuring a process pressure in the direct reduction shaft and filling the discharge vessel with the inert gas to a pressure equal to or lower than the process pressure in the direct reduction shaft, and the inert gas inlet is closed while the sponge iron inlet is open and while the sponge iron is being charged from the direct reduction shaft to the discharge vessel. This is achieved by a process for the continuous production of sponge iron from iron ore.

[0014] According to one embodiment, the step of filling the discharge vessel with inert gas comprises filling the discharge vessel with inert gas to a pressure less than 2 bar lower than the pressure in the direct reduction shaft, in other words, when discharge of sponge iron from the direct reduction shaft is started, the difference between the pressure of the inert gas in the discharge vessel and the pressure in the direct reduction shaft is less than or equal to 2 bar.

[0015] According to one embodiment, the step of filling the discharge vessel with inert gas comprises filling the discharge vessel with inert gas to a pressure less than 1 bar lower than the pressure in the direct reduction shaft, in other words, when discharge of sponge iron from the direct reduction shaft is started, the difference between the pressure of the inert gas in the discharge vessel and the pressure in the direct reduction shaft is less than or equal to 1 bar.

[0016] According to one embodiment, before opening the sponge iron outlet and discharging the sponge iron from the discharging vessel, an inert gas is flowed into the discharging vessel via the inert gas inlet and gas outlet of the discharging vessel.

[0017] According to one embodiment, the pressure in the discharge vessel is allowed to decrease to approximately atmospheric pressure before opening the sponge iron outlet and discharging the iron from the discharge vessel.

[0018] According to one embodiment, the inert gas mainly comprises nitrogen gas, which also prevents or reduces the production of ammonia in the direct reduction chamber, since nitrogen is prevented to a large extent from leaking into the direct reduction chamber.

[0019] The object of the present invention is also to - a direct reduction shaft; - an arrangement for introducing pressurized and heated hydrogen-rich reducing gas directly into the reduction shaft for reducing iron ore to produce sponge iron; - a charging vessel for charging the iron ore directly into the reduction shaft; - a discharge vessel for discharging the sponge iron from the direct reduction shaft; - an iron ore inlet for charging the charging vessel with iron ore; - an inlet valve arranged at the iron ore inlet and configured to hermetically close the iron ore inlet; - an iron ore outlet for discharging the iron ore from the charging bin directly into the reduction shaft; - an outlet valve arranged at the iron ore outlet and configured to hermetically close the iron ore outlet; - an inert gas source configured to supply pressurized inert gas to the charging vessel; - an inert gas inlet for introducing inert gas into the charging vessel, the inert gas inlet having a gas inlet valve for controlling the flow of inert gas into the charging vessel; - a gas outlet for discharging gas from the charging vessel, the gas outlet having a gas outlet valve device for controlling the flow of gas out of the charging vessel; - a reduction shaft pressure sensor for measuring the gas pressure in the direct reduction shaft; - a charge vessel pressure sensor for measuring the inert gas pressure in the charge vessel; Including, a control unit configured to supply pressurized inert gas into the charging vessel such that a pressure of the inert gas in the charging vessel is equal to or lower than a pressure in the direct reduction shaft before discharging the iron ore from the charging vessel to the direct reduction shaft, and to control the gas inlet valve based on inputs from the reduction shaft pressure sensor and the charging vessel pressure sensor to close the gas inlet valve during discharging the iron ore from the charging vessel to the direct reduction shaft. This is achieved by arrangements for the continuous production of sponge iron from iron ore.

[0020] According to one embodiment, the control unit is configured to control the gas inlet valve based on inputs from the reduction shaft pressure sensor and the charging vessel pressure sensor to supply pressurized inert gas into the charging vessel such that the pressure of the inert gas in the charging vessel is less than 2 bar lower than the pressure in the direct reduction shaft before discharging the iron ore from the charging vessel to the direct reduction shaft.

[0021] According to one embodiment, the control unit is configured to control the gas inlet valve based on inputs from the reduction shaft pressure sensor and the charging vessel pressure sensor to supply pressurized inert gas into the charging vessel such that the pressure of the inert gas in the charging vessel is less than 1 bar lower than the pressure in the direct reduction shaft before discharging the iron ore from the charging vessel to the direct reduction shaft.

[0022] The object of the present invention is also to - a direct reduction shaft; - an arrangement for introducing pressurized and heated hydrogen-rich reducing gas directly into the reduction shaft for reducing iron ore to produce sponge iron; - a charging vessel for charging the iron ore directly into the reduction shaft; - a discharge vessel for discharging the sponge iron from the direct reduction shaft; - a sponge iron inlet for charging the sponge iron into the discharge vessel; - an inlet valve arranged at the sponge iron inlet and configured to hermetically close the sponge iron inlet; - a sponge iron outlet for discharging the sponge iron from the discharge container; - an outlet valve arranged at the sponge iron outlet and configured to hermetically close the sponge iron outlet; - an inert gas source configured to supply pressurized inert gas to a discharge vessel; - an inert gas inlet for introducing inert gas into the discharge vessel, the inert gas inlet having a gas inlet valve for controlling the flow of inert gas into the discharge vessel; - a gas outlet for discharging gas from the discharge receptacle, the gas outlet having a gas outlet valve for controlling the flow of gas out of the discharge receptacle; - a reduction shaft pressure sensor for measuring the gas pressure in the direct reduction shaft; - a discharge vessel pressure sensor for measuring the inert gas pressure in the discharge vessel; Including, a control unit configured to supply pressurized inert gas into the discharge vessel such that a pressure of the inert gas in the discharge vessel is equal to or lower than a pressure in the direct reduction shaft before the sponge iron is charged into the discharge vessel, and to control a gas inlet valve of the discharge vessel based on inputs from the reduction shaft pressure sensor and the discharge vessel pressure sensor to close the gas inlet valve during charging of the sponge iron from the direct reduction shaft into the discharge vessel. This is achieved by arrangements for the continuous production of sponge iron from iron ore.

[0023] According to one embodiment, the control unit is configured to control the gas inlet valve based on inputs from the reduction shaft pressure sensor and the discharge bin pressure sensor to supply pressurized inert gas into the discharge bin such that the pressure of the inert gas in the discharge bin is less than 2 bar lower than the pressure in the direct reduction shaft before charging the sponge iron from the direct reduction shaft to the discharge bin.

[0024] According to one embodiment, the control unit is configured to control the gas inlet valve based on inputs from the reduction shaft pressure sensor and the discharge bin pressure sensor to supply pressurized inert gas into the discharge bin such that the pressure of the inert gas in the discharge bin is less than 1 bar lower than the pressure in the direct reduction shaft before charging the sponge iron from the direct reduction shaft to the discharge bin.

[0025] BRIEF DESCRIPTION OF THE DRAWINGS An embodiment of the present invention is disclosed with reference to FIG. 1, which shows a schematic diagram of an arrangement according to the present invention. [Brief description of the drawings]

[0026] [Figure 1] 1 shows a schematic diagram of an arrangement according to the invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Detailed Description 1 shows one embodiment of an arrangement for the continuous production of sponge iron from iron ore. The arrangement includes a direct reduction shaft 1, arrangements 24, 25, 26 for introducing pressurized and heated hydrogen-rich reducing gas into the direct reduction shaft 1 for reducing the iron ore to produce sponge iron, a charging vessel 2 for charging the iron ore into the direct reduction shaft 1, a feeding device 28 for feeding the iron ore to the charging vessel 2, and a discharging vessel 3 for discharging the sponge iron from the direct reduction shaft 1. Further provided is an iron ore inlet 4 for charging iron ore into the charging vessel 2, an inlet valve 5 arranged at the iron ore inlet 4 and configured to close the iron ore inlet 4 gas-tightly, an iron ore outlet 6 for discharging iron ore from the charging vessel 2 to the direct reduction shaft 1, an outlet valve 27 arranged at the iron ore outlet 6 and configured to close the iron ore outlet 6 gas-tightly, an inert gas source 7 arranged to supply pressurized inert gas to the charging vessel 2, an inert gas inlet 8 for introducing inert gas into the charging vessel 2 having a gas inlet valve 9 for controlling the flow of inert gas into the charging vessel 2, a gas outlet 10 for discharging gas from the charging vessel 2 having a gas outlet valve 11 device for controlling the flow of gas out of the charging vessel 2, a reduction shaft pressure sensor 12 for measuring the gas pressure in the direct reduction shaft 1, and a charging vessel 2 pressure sensor 13 for measuring the inert gas pressure in the charging vessel 2.

[0028] 24, 25, 26 for introducing pressurized and heated hydrogen-rich reducing gas into the direct reduction shaft 1 includes a hydrolyzer 24 for producing hydrogen gas, a heater 25 for heating the hydrogen gas before it enters the direct reduction shaft 1, and a process gas recycle circuit having treatment devices for cleaning etc. of off-gas from the direct reduction shaft 1 which is mixed with hydrogen from the hydrolyzer 24 to produce hydrogen-rich reducing gas used for the direct reduction of iron ore to sponge iron. The hydrogen-rich reducing gas contains at least 90 vol.% hydrogen gas (vol.% determined at normal conditions of 1 atm. and 0°C).

[0029] The arrangement for continuously producing sponge iron from iron ore further includes a control unit 14 configured to supply pressurized inert gas into the charging vessel 2 such that a pressure of the inert gas in the charging vessel 2 is approximately equal to a pressure in the direct reduction shaft 1 before discharging the iron ore from the charging vessel 2 to the direct reduction shaft 1, and to control the gas inlet valve 9 based on inputs from the reduction shaft 1 pressure sensor 12 and the charging vessel pressure sensor 13 to close the gas inlet valve 9 during discharging the iron ore from the charging vessel 2 to the direct reduction shaft 1.

[0030] The arrangement for continuously producing sponge iron from iron ore further comprises a sponge iron inlet 15 for charging sponge iron into the discharge vessel 3, an inlet valve 16 arranged at the sponge iron inlet 15 and configured to close the sponge iron inlet 15 gas-tightly, a sponge iron outlet 17 for discharging sponge iron from the discharge vessel 3, and an outlet valve 18 arranged at the sponge iron outlet 17 and configured to close the sponge iron outlet 17 gas-tightly. The inert gas source 7 is configured to supply pressurized inert gas to the discharge vessel 3. Further provided is an inert gas inlet 19 for introducing inert gas into the discharge vessel 3, having a gas inlet valve 20 for controlling the flow of inert gas into the discharge vessel 3, and a gas outlet 21 for discharging gas from the discharge vessel 3, having a gas outlet valve 22 for controlling the flow of gas out of the discharge vessel 3. A discharge vessel pressure sensor 23 for measuring the inert gas pressure in the discharge vessel 3 is also provided.

[0031] The control unit 14 is configured to supply pressurized inert gas into the discharge vessel 3 so that the pressure of the inert gas in the discharge vessel 3 is approximately equal to the pressure in the direct reduction shaft 1 before charging the sponge iron into the discharge vessel 3, and to control the gas inlet valve 20 of the discharge vessel 3 based on inputs from the reduction shaft pressure sensor 23 and the discharge vessel pressure sensor 23 to close the gas inlet valve 20 during charging of the sponge iron from the direct reduction shaft 1 into the discharge vessel 3.

[0032] The iron ore inlet valve 5 , the iron ore outlet valve 27 , the sponge iron inlet valve 16 and the sponge iron outlet valve 18 are control valves configured to be controlled by the control unit 14 .

[0033] The gas inlet valves 9 and 20, and the gas outlet valves 11 and 22 are control valves configured to be controlled by the control unit 14. The inert gas source 7 is configured to supply an inert gas having a high pressure. Preferably, the inert gas mainly comprises nitrogen gas.

[0034] The arrangement for the continuous production of sponge iron from iron ore is adapted to carry out the method according to the invention, which method comprises a continuous process, namely: - charging the iron ore into the direct reduction shaft 1 via a charging vessel 2; - introducing heated hydrogen-rich reducing gas into a direct reduction shaft 1 for reducing iron ore to produce sponge iron, whereby a process pressure above atmospheric pressure is generated in the direct reduction shaft 1; - removing the produced sponge iron from the direct reduction shaft 1 via a discharge vessel 3, The charging step comprises the following steps: - closing the iron ore outlet 6 of the charging vessel 2 in an airtight manner relative to the reduction shaft 1; - charging the charging vessel 2 with iron ore via the iron ore inlet 4 to the charging vessel 2; - closing the iron ore inlet 4 of the charging vessel 2 in an airtight manner against the atmosphere; - filling the charging vessel 2 with inert gas via the inert gas inlet 8 to the charging vessel 2; opening the iron ore outlet 6 and discharging the iron ore from the charging vessel 2 directly into the reduction shaft 1.

[0035] The step of filling the charging vessel 2 with inert gas includes a step of measuring the process pressure in the direct reduction shaft 1 and a step of filling the charging vessel 2 with inert gas to a pressure approximately equal to the process pressure in the direct reduction shaft 1, and the inert gas inlet 8 is closed during the opening of the iron ore outlet 6 and during the discharge of the iron ore from the charging vessel 2 to the direct reduction shaft 1.

[0036] After opening the iron ore outlet 6 and discharging the iron ore from the charging vessel 2 directly into the reduction shaft 1, the iron ore outlet 6 is closed and then the gas outlet 10 of the charging vessel 2 is opened and inert gas is allowed to flow into the charging vessel 2 via the inert gas inlet 8 and the gas outlet 10 of the charging vessel. The pressure in the charging vessel 2 is thereby reduced to approximately atmospheric pressure before the next subsequent charging of iron ore into the charging vessel 2 via the iron ore inlet 4.

[0037] An arrangement for the continuous production of sponge iron from iron ore is also adapted to carry out the method according to the invention, which method comprises a continuous process, namely: - charging the iron ore into the direct reduction shaft 1 via a charging vessel 2; - introducing heated hydrogen-rich reducing gas into a direct reduction shaft 1 for reducing iron ore to produce sponge iron, whereby a process pressure above atmospheric pressure is generated in the direct reduction shaft 1; - removing the produced sponge iron from the direct reduction shaft 1 via a discharge vessel 3, the step of removing the sponge iron comprising the steps of: - closing the sponge iron outlet 17 of the discharge container 3 in an airtight manner against the atmosphere; - hermetically closing the sponge iron inlet 15 from the direct reduction shaft 1 to the discharge vessel 3; - filling the discharge vessel 3 with inert gas via the inert gas inlet 19 to the discharge vessel 3; - opening the sponge iron inlet 15 and charging sponge iron from the direct reduction shaft 1 through the sponge iron inlet 15 into the discharge vessel 3; - hermetically closing the sponge iron inlet 15 of the discharge vessel 3 to the direct reduction shaft 1; - opening the sponge iron outlet 17 and discharging the sponge iron from the discharge container 3; Includes.

[0038] The step of filling the discharge vessel 3 with inert gas includes the steps of measuring the process pressure in the direct reduction shaft 1 and filling the discharge vessel 3 with inert gas to a pressure approximately equal to the process pressure in the direct reduction shaft 1, the inert gas inlet 19 being closed while the sponge iron inlet 15 is open and while sponge iron is being charged from the direct reduction shaft 1 to the discharge vessel 3.

[0039] Before opening the sponge iron outlet 17 and discharging the sponge iron from the discharging vessel 3, an inert gas is flowed into the discharging vessel 3 through the inert gas inlet 1 and the gas outlet 21 of the discharging vessel 3. Thereby, the pressure in the discharging vessel 3 is reduced to approximately atmospheric pressure before opening the sponge iron outlet 17 and discharging the iron from the discharging vessel 3.

Claims

1. 1. A process for the continuous production of sponge iron from iron ore, comprising: - charging the iron ore into the direct reduction shaft (1) via a charging vessel (2); - introducing heated hydrogen-rich reducing gas into the direct reduction shaft (1) for reducing the iron ore to produce sponge iron, generating a process pressure in excess of atmospheric pressure in the direct reduction shaft (1); - removing the produced sponge iron from the direct reduction shaft (1) via a discharge vessel (3); Including, said charging step comprises the following steps: - closing the iron ore outlet (6) of said charging vessel (2) gas-tightly with respect to said reduction shaft (1); - charging the charging vessel (2) with the iron ore via an iron ore inlet (4) to the charging vessel (2); - closing the iron ore inlet (4) of the charging vessel (2) in an airtight manner against the atmosphere; - filling said charging vessel (2) with inert gas via an inert gas inlet into said charging vessel (2); - opening the iron ore outlet (6) and discharging the iron ore from the charging vessel (2) into the direct reduction shaft (1), The method, characterized in that the step of filling the charging vessel (2) with inert gas comprises the steps of measuring the process pressure in the direct reduction shaft (1) and filling the charging vessel (2) with inert gas to a pressure equal to or less than the process pressure in the direct reduction shaft (1), wherein the inert gas inlet is closed during the opening of the iron ore outlet (6) and during the discharge of iron ore from the charging vessel (2) to the direct reduction shaft (1).

2. 2. The method according to claim 1, wherein the step of filling the charging vessel (2) with inert gas comprises filling the charging vessel (2) with inert gas to a pressure less than 2 bar lower than the pressure in the direct reduction shaft (1).

3. 2. The method according to claim 1, wherein the step of filling the charging vessel (2) with inert gas comprises filling the charging vessel (2) with inert gas to a pressure less than 1 bar lower than the pressure in the direct reduction shaft (1).

4. 4. The method according to claim 1, wherein after opening the iron ore outlet (6) and discharging the iron ore from the charging vessel (2) to the direct reduction shaft (1), the iron ore outlet (6) is closed, then a gas outlet of the charging vessel (2) is opened and inert gas is flowed into the charging vessel (2) via the inert gas inlet and the gas outlet (10) of the charging vessel.

5. 5. The method according to any one of claims 1 to 4, wherein the pressure in the charging vessel (2) is reduced to approximately atmospheric pressure before charging the iron ore into the charging vessel (2) through the iron ore inlet (4).

6. 1. A process for the continuous production of sponge iron from iron ore, comprising: - charging the iron ore into the direct reduction shaft (1) via a charging vessel (2); - introducing heated hydrogen-rich reducing gas into the direct reduction shaft (1) for reducing the iron ore to produce sponge iron, generating a process pressure in excess of atmospheric pressure in the direct reduction shaft (1); - removing the produced sponge iron from the direct reduction shaft (1) via a discharge vessel (3); Including, said step of extracting said sponge iron comprises the following steps: - closing the sponge iron outlet (17) of said discharge vessel (3) airtight against the atmosphere; - hermetically closing the sponge iron inlet (15) from said direct reduction shaft (1) to said discharge vessel (3); - filling said discharge vessel (3) with inert gas via an inert gas inlet (19) to said discharge vessel (3); - opening the sponge iron inlet (15) and charging sponge iron from the direct reduction shaft (1) through the sponge iron inlet (15) into the discharge vessel (3); - hermetically closing the sponge iron inlet (15) of the discharge vessel (3) to the direct reduction shaft (1); - opening the sponge iron outlet (17) and discharging the iron from the discharge container (3); Including, The method, characterized in that the step of filling the discharge vessel (3) with inert gas comprises the steps of measuring the process pressure in the direct reduction shaft (1) and filling the discharge vessel (3) with inert gas to a pressure equal to or less than the process pressure in the direct reduction shaft (1), wherein the inert gas inlet (19) is closed during the opening of the sponge iron inlet (15) and during the charging of sponge iron from the direct reduction shaft (1) into the discharge vessel (3).

7. 7. The method according to claim 6, wherein the step of filling the discharge vessel (3) with inert gas comprises filling the discharge vessel (3) with inert gas to a pressure less than 2 bar lower than the pressure in the direct reduction shaft (1).

8. 7. The method according to claim 6, wherein the step of filling the discharge vessel (3) with inert gas comprises filling the discharge vessel (3) with inert gas to a pressure less than 1 bar lower than the pressure in the direct reduction shaft (1).

9. The method according to any one of claims 6 to 8, wherein before opening the sponge iron outlet (17) and discharging the sponge iron from the discharging vessel (3), an inert gas is flowed into the discharging vessel (3) via the inert gas inlet (19) and the gas outlet (21) of the discharging vessel (3).

10. 10. The method according to any one of claims 6 to 9, wherein the pressure in the discharge vessel (3) is reduced to approximately atmospheric pressure before opening the sponge iron outlet (17) and discharging the iron from the discharge vessel (3).

11. 1. An arrangement for continuously producing sponge iron from iron ore, comprising: - a direct reduction shaft (1), - arrangements (24, 25, 26) for introducing pressurized and heated hydrogen-rich reducing gas into said direct reduction shaft (1) for reducing said iron ore to produce sponge iron; a charging vessel (2) for charging iron ore into said direct reduction shaft (1); - a discharge vessel (3) for discharging the sponge iron from said direct reduction shaft (1); - an iron ore inlet (4) for charging the iron ore into said charging vessel (2); an inlet valve (5) arranged at said iron ore inlet (4) and adapted to close said iron ore inlet (4) gas-tight; an iron ore outlet (6) for discharging the iron ore from said charging vessel (2) to said direct reduction shaft (1); an outlet valve (27) arranged at said iron ore outlet (6) and adapted to tightly close said iron ore outlet (6); an inert gas source (7) configured to supply pressurized inert gas to said charging vessel (2); an inert gas inlet (8) for introducing inert gas into the charging vessel (2), the inert gas inlet valve (9) for controlling the flow of inert gas into the charging vessel (2); a gas outlet (10) for discharging gas from said charging vessel (2), said gas outlet valve (11) device for controlling the flow of gas out of said charging vessel (2); a reduction shaft pressure sensor (12) for measuring the gas pressure in said direct reduction shaft (1); a charge vessel (2) pressure sensor (13) for measuring the inert gas pressure in said charge vessel (2); Including, the arrangement further comprising: a control unit (14) configured to supply pressurized inert gas into the charging vessel (2) such that a pressure of the inert gas in the charging vessel (2) is equal to or lower than a pressure in the direct reduction shaft (1) before discharging the iron ore from the charging vessel (2) to the direct reduction shaft (1), and to control the gas inlet valve (9) based on inputs from the reduction shaft (1) pressure sensor (12) and the charging vessel pressure sensor (13) to close the gas inlet valve (9) during discharge of the iron ore from the charging vessel (2) to the direct reduction shaft (1).

12. 12. The arrangement of claim 11, wherein the control unit (14) is configured to control the gas inlet valve (9) based on inputs from the reduction shaft pressure sensor (13) and the charging vessel pressure sensor (13) to supply pressurized inert gas into the charging vessel (2) such that a pressure of the inert gas in the charging vessel (2) is less than 2 bar lower than a pressure in the direct reduction shaft (1) before discharging iron ore from the charging vessel (2) to the direct reduction shaft (1).

13. 12. The arrangement of claim 11, wherein the control unit (14) is configured to control the gas inlet valve (9) based on inputs from the reduction shaft pressure sensor (12) and the charging vessel pressure sensor (13) to supply pressurized inert gas into the charging vessel (2) such that a pressure of the inert gas in the charging vessel (2) is less than 1 bar lower than a pressure in the direct reduction shaft (1) before discharging iron ore from the charging vessel (2) to the direct reduction shaft (1).

14. 1. An arrangement for continuously producing sponge iron from iron ore, comprising: - a direct reduction shaft (1), - arrangements (24, 25, 26) for introducing pressurized and heated hydrogen-rich reducing gas into said direct reduction shaft (1) for reducing said iron ore to produce sponge iron; a charging vessel (2) for charging iron ore into said direct reduction shaft (1); - a discharge vessel (3) for discharging the sponge iron from said direct reduction shaft (1); a sponge iron inlet (15) for charging the sponge iron into said discharge vessel (3); an inlet valve (16) arranged at said sponge iron inlet (15) and adapted to close said sponge iron inlet (15) gas-tight; a sponge iron outlet (17) for discharging the sponge iron from said discharge container (3); an outlet valve (18) arranged at said sponge iron outlet (17) and adapted to close said sponge iron outlet (17) gas-tightly; an inert gas source (7) configured to supply pressurized inert gas to said discharge vessel (3); an inert gas inlet (19) for introducing inert gas into said discharge vessel (3), said inlet valve (20) for controlling the flow of inert gas into said discharge vessel (3); a gas outlet (21) for discharging gas from said discharge vessel (3), said gas outlet valve (22) for controlling the flow of gas out of said discharge vessel (3); a reduction shaft pressure sensor (12) for measuring the gas pressure in said direct reduction shaft (1); - an evacuation vessel pressure sensor (23) for measuring the inert gas pressure in said evacuation vessel (3); Including, the arrangement further comprises a control unit (14) configured to supply pressurized inert gas into the discharge vessel (3) such that a pressure of the inert gas in the discharge vessel (3) is equal to or lower than a pressure in the direct reduction shaft (1) before charging the discharge vessel (3) with sponge iron, and to control the gas inlet valve (20) of the discharge vessel (3) based on inputs from the reduction shaft pressure sensor (23) and the discharge vessel pressure sensor (23) to close the gas inlet valve (20) during charging of the sponge iron from the direct reduction shaft (1) to the discharge vessel (3).

15. 15. The arrangement of claim 14, wherein the control unit (14) is configured to control the gas inlet valve (20) based on inputs from the reduction shaft pressure sensor (12) and the discharge bin pressure sensor (23) to supply pressurized inert gas into the discharge bin (3) such that a pressure of the inert gas in the discharge bin (3) is less than 2 bar lower than a pressure in the direct reduction shaft (1) before charging sponge iron from the direct reduction shaft (1) to the discharge bin (3).

16. 15. The arrangement of claim 14, wherein the control unit (14) is configured to control the gas inlet valve (20) based on inputs from the reduction shaft pressure sensor (12) and the discharge bin pressure sensor (23) to supply pressurized inert gas into the discharge bin (3) such that a pressure of the inert gas in the discharge bin (3) is less than 1 bar lower than a pressure in the direct reduction shaft (1) before charging sponge iron from the direct reduction shaft (1) to the discharge bin (3).

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