Composite iron pellets and methods of making same

Patent metadata

Field	Value
Publication number	US-11530464-B2
Application number	US-201615565444-A
Country	US
Kind code	B2
Filing date	Apr 18, 2016
Priority date	Apr 24, 2015
Publication date	Dec 20, 2022
Grant date	Dec 20, 2022

Abstract

Disclosed herein are methods and compositions for producing composite pellets comprising a core comprising: iron ore and a carbonaceous reducing agent; and a shell comprising: iron ore; and having a core and shell transition in a manner such that no visible boundary exists between the core and the shell in a cross-section of the pellet. The methods can be used to produce composite pellets with improved productivity and quality, and the resulting composite pellets can be used to produce direct reduced iron (DRI).

First claim

The invention claimed is:

1. A pellet comprising:
25 wt. % to 75 wt. % of a core wherein the core comprises: from 93 wt. % to 97 wt. % of an iron ore in the core and from 3 wt. % to 7 wt. % of a carbonaceous reducing agent, based on the total weight of the core;
25 wt. % to 75 wt. % of a shell comprising an iron ore in the shell wherein the shell contains from 0 wt. % to less than 3 wt. % the carbonaceous reducing agent based on the total weight of the shell;
and an intermediate region between the core and the shell;
wherein the core and the shell transition in a manner such that no clearly distinct boundary exists between the core and the shell in a cross-section of the pellet;
wherein the iron ore in both the core and the shell comprises at least one member selected from the group consisting of hematite, magnetite, limonite, siderite, iron pyrite and goethite; and
wherein the pellet comprises from greater than 0 wt. % to 3 wt. % silicon oxide.

2. The pellet of claim 1 , wherein the iron ore in both the core and the shell comprises at least one member selected from the group consisting of magnetite, limonite, siderite, iron pyrite and goethite.

3. The pellet of claim 1 , wherein the iron ore in the core comprises hematite.

4. The pellet of claim 1 , where the iron ore in both the core and the shell comprises at least one member selected from the group consisting of limonite, siderite, iron pyrite and goethite.

5. The pellet of claim 1 , wherein the carbonaceous reducing agent comprises charcoal.

6. The pellet of claim 1 , wherein the shell contains at least some to less than 2 wt % carbonaceous reducing agent.

7. The pellet of claim 1 , wherein the core comprises 3.1 wt. % of the carbonaceous reducing agent.

8. The pellet of claim 1 , wherein the shell further comprises a binder comprising at least one member selected from the group consisting of bentonite, molasses, and dextrin.

9. The pellet of claim 1 , wherein the core comprises from 95 wt. % to 97 wt. % of the iron ore.

10. The pellet of claim 8 , wherein the pellet comprises from about 1.0 wt % to about 8.0 wt % of the binder.

11. A method to prepare the pellet of claim 1 , comprising the steps of:
(a) forming a core from a mixture comprising an iron ore and at least one carbonaceous reducing agent;
(b) forming a shell around the core to produce a composite pellet, wherein the shell comprises iron ore and wherein the core is not dried prior to forming the shell; and
(c) drying the composite pellet.

12. A method for producing iron comprising
(a) providing the pellet of claim 1 ;
(b) charging the pellet to a furnace; and
(c) reducing the pellet in the presence of reformed natural gas to thereby provide iron.

13. A pellet comprising:
25 wt. % to 75 wt. % of a core wherein the core comprises: from 93 wt. % to 97 wt. % of an iron ore and from 3 wt. % to 7 wt. % of a carbonaceous reducing agent, based on the total weight of the core;
25 wt. % to 75 wt. % of a shell comprising the iron ore, wherein the shell contains from 0 wt. % to less than 3 wt. % of the carbonaceous reducing agent based on the total weight of the shell;
an intermediate region between the core and the shell;
wherein the core and the shell transition in a manner such that no clearly distinct boundary exists between the core and the shell in a cross-section of the pellet;
wherein the iron ore in both the core and the shell comprises at least one member selected from the group consisting of hematite, magnetite, limonite, siderite, iron pyrite and goethite; and
wherein the shell further comprises a binder comprising at least one member selected from the group consisting of dextrin, bentonite and molasses.

14. The pellet of claim 13 , wherein the binder comprises bentonite.

15. A pellet comprising:
25 wt. % to 75 wt. % of a core wherein the core comprises iron oxide and from about 3 wt. % to about 9 wt. % of a carbonaceous reducing agent, based on the total weight of the core;
25 wt. % to 75 wt. % of a shell comprising iron ore and from at least some to less than 3 wt. % of the carbonaceous reducing agent based on the total weight of the shell; and
wherein the pellet comprises Fe 2 O 3 in an amount ranging from greater than 88 wt. % to 99 wt. %, based on the total weight of the pellet,
wherein the pellet further comprises a binder selected from the group consisting of bentonite, molasses and dextrin.

16. The pellet of claim 15 , wherein the pellet comprises an intermediate region between the core and the shell; wherein the core and the shell transition in a manner such that no clearly distinct boundary exists between the core and the shell in a cross-section of the pellet.

17. The pellet of claim 15 , wherein the pellet comprises 93 wt. % to 99 wt. % Fe 2 O 3 , based on the total weight of the pellet.

Assignees

• Sabic Global Technologies Bv

Inventors

• Saddik Mohamed Bahgat
• Hanafy Hesham Ahmed

Classifications

• Y02P10/134

  by avoiding CO2, e.g. using hydrogen · CPC title

• C22B1/2406

  pelletizing · CPC title

• C22B1/245 Primary

  with carbonaceous material for the production of coked agglomerates · CPC title

• C21B13/0046

  making metallised agglomerates or iron oxide · CPC title

• C22B1/2413

  enduration of pellets · CPC title