System and method for regeneration and recirculation of a reducing agent using highly exothermic reactions induced by mixed industrial slags

Patent metadata

Field	Value
Publication number	US-9840756-B1
Application number	US-201514790082-A
Country	US
Kind code	B1
Filing date	Jul 2, 2015
Priority date	Oct 17, 2014
Publication date	Dec 12, 2017
Grant date	Dec 12, 2017

Abstract

Embodiments relate to systems and methods for regenerating and recirculating a CO, H 2 or combinations thereof utilized for metal oxide reduction in a reduction furnace. The reduction furnace receives the reducing agent, reduces the metal oxide, and generates an exhaust of the oxidized product. The oxidized product is transferred to a mixing vessel, where the oxidized product, a calcium oxide, and a vanadium oxide interact to regenerate the reducing agent from the oxidized product. The regenerated reducing agent is transferred back to the reduction furnace for continued metal oxide reductions.

First claim

What is claimed is:

1. A method for the regeneration and recirculation of a reducing agent comprising:
inserting a charge into a reduction furnace, where the charge comprises a metal oxide ore, where the metal oxide ore comprises a metal oxide;
contacting the metal oxide ore and a reducing agent, where the reducing agent is CO, H 2 , or combination thereof, and generating an oxidized product, where the oxidized product is CO 2 , H 2 O, or combinations thereof;
transferring a portion of the oxidized product to a mixing vessel;
supplying a vanadium oxide feedstock to the mixing vessel and supplying a generated slag to the mixing vessel, where the vanadium oxide feedstock comprises a vanadium oxide where the vanadium oxide is VO, V 2 O 3 , V 3 O 5 , VO 2 , or combinations thereof, and where the generated slag comprises CaO, and mixing the vanadium oxide feedstock, the generated slag, and the portion of the oxidized product in the mixing vessel, and generating a calcium vanadate and a regenerated agent, where the regenerated agent is CO, H 2 , or combination thereof;
displacing a portion of the regenerated agent to the reduction furnace; and
repeating the inserting step, the contacting step, the transferring step, the supplying step, and the displacing step using the portion of the regenerated agent as some portion of the reducing agent, thereby regenerating and recirculating the reducing agent.

2. The method of claim 1 where mixing the vanadium oxide feedstock, the generated slag, and the portion of the oxidized agent forms a mixture, and further comprising establishing the mixture at a temperature of at least 669° C.

3. The method of claim 2 where the generated slag has a temperature of at least 669° C.

4. The method of claim 3 where transferring the portion of the oxidized product to the mixing vessel occurs at an oxidized product mass transfer rate, supplying the vanadium oxide feedstock to the mixing vessel occurs at a vanadium oxide mass transfer rate, and supplying the generated slag to the mixing vessel occurs at a generated slag mass transfer rate, and further comprising adjusting the oxidized product mass transfer rate, the vanadium oxide mass transfer rate, and the generated slag mass transfer rate to establish a specific composition of the mixture, where the specific composition comprises greater than 0.1 ton and less than 3.0 ton of the oxidized product per 1.0 ton of vanadium oxide and greater than 0.2 and less than 3.5 ton of CaO per 1.0 ton vanadium oxide.

5. The method of claim 4 where the generated slag is comprised of at least 5 wt. % CaO.

6. The method of claim 5 where the vanadium oxide feedstock is comprised of at least 2 wt. % of the vanadium oxide.

7. The method of claim 4 where the generated slag is comprised of at least 5 wt. % CaO and less than 75 wt. % of the vanadium oxide, and where the vanadium oxide feedstock is comprised of at least 2 wt. % of the vanadium oxide and less than 60 wt. % CaO.

8. The method of claim 1 where the reducing agent is CO, the oxidized product is CO 2 , and the generated agent is CO.

9. The method of claim 8 where the charge further comprises a carbonaceous fuel and further comprising:
combusting the carbonaceous fuel and generating a quantity of CO; and
utilizing some portion of the quantity of CO as some portion of the reducing agent.

10. The method of claim 9 where combusting the carbonaceous fuel generates a combustion CO 2 a portion of which reacts with the carbon comprising the carbonaceous fuel and generating the quantity of CO.

11. The method of claim 10 where the carbonaceous fuel comprises coal, petcoke, char, ash, slag, or mixtures thereof.

12. The method of claim 11 where the metal oxide is an iron oxide.

13. The method of claim 10 where the charge further comprises a fluxing agent and further comprising:
generating a furnace slag comprising a slag CaO, where the slag CaO is comprised of some portion of the fluxing agent; and
transferring a portion of the furnace slag to the mixing vessel, thereby supplying the generated slag to the mixing vessel.

14. The method of claim 1 where the reducing agent is H 2 , the oxidized product is H 2 O, and the generated agent is H 2 .

15. The method of claim 14 where the generated slag is comprised of at least 5 wt. % CaO and less than 75 wt. % of the vanadium oxide, and where the vanadium oxide feedstock is comprised of at least 2 wt. % of the vanadium oxide and less than 60 wt. % CaO.

16. The method of claim 15 where the reducing agent is CO, the oxidized product is CO 2 , and the generated agent is CO, and where the charge further comprises a carbonaceous fuel and further comprising:
combusting the carbonaceous fuel and generating a quantity of CO; and
utilizing some portion of the quantity of CO as some portion of the reducing agent.

17. The method of claim 16 where the metal oxide is an iron oxide.

18. The method of claim 17 where the reduction furnace further comprises a slag tap in fluid communication with the generated slag inlet of the mixing vessel, and where the charge further comprises a fluxing agent, and further comprising:
generating a furnace slag comprising a slag CaO, where the slag CaO is comprised of some portion of the fluxing agent; and
transferring a portion of the furnace slag through the slag tap and through the generated slag inlet to the mixing vessel, thereby supplying the generated slag to the mixing vessel.

19. The method of claim 18 where the carbonaceous fuel comprises coal, petcoke, char, ash, slag or mixtures thereof.

20. A method for the regeneration and recirculation of a reducing agent comprising:
obtaining a system comprising,
a reduction furnace comprising a reduction furnace exhaust and a furnace inlet;
a mixing vessel comprising a mixing zone, a vanadium oxide inlet, a generated slag inlet, and a regenerated agent outlet, where the mixing zone is in fluid communication with the furnace exhaust, and where the vanadium oxide inlet is in fluid communication with the mixing zone, and where the generated slag inlet is in fluid communication with the mixing zone, and where the regenerated agent outlet is in fluid communication with the mixing zone and in fluid communication with the furnace inlet;

inserting a charge into the reduction furnace, where the charge comprises a metal oxide ore, where the metal oxide ore comprises a metal oxide;
contacting the metal oxide ore and a reducing agent in the reduction furnace, where the reducing agent is CO, H 2 , or combination thereof, and generating an oxidized product, where the oxidized product is CO 2 , H 2 O, or combinations thereof;
exhausting a portion of the oxidized product from the furnace exhaust and transferring a quantity of the portion of the oxidized product to the mixing zone of the mixing vessel;
supplying a vanadium oxide feedstock through the vanadium oxide inlet and into the mixing zone of the mixing vessel and supplying a generated slag through the generated slag inlet to the mixing zone of the mixing vessel, where the vanadium oxide feedstock comprises a vanadium oxide where the vanadium oxide is VO, V 2 O 3 , V 3 O 5 , VO 2 , or combinations thereof, and where the generated slag has a temperature of at least 669° C. and the generated slag comprises CaO, and mixing the vanadium oxide feedstock, the generated slag, and the portion of the oxidized product in the mixing zone of the mixing vessel to generate a mixture, where the mixture has a temperature of at least 669° C., and generating

Assignees

• Nakano Jinichiro
• Bennett James P
• Nakano Anna
• Us Dept Energy

Inventors

• Nakano Jinichiro
• Bennett James P
• Nakano Anna

Classifications

• C01G31/02

  Oxides · CPC title

• C22B34/22 Primary

  Obtaining vanadium · CPC title

• C22B5/12

  by gases · CPC title

• C01F11/00

  Compounds of calcium, strontium, or barium (C01F7/00 takes precedence) · CPC title

• C01G31/00

  Compounds of vanadium · CPC title