The industrial development program of any country, by and large, is based on its natural resources. Currently the majority of the world’s steel is produced through either one of the two main routes: i) the integrated Blast Furnace – Basic Oxygen Furnace (BF – BOF) route or ii) the Direct Reduced Iron - Electric Arc Furnace (DRI - EAF) route. Depleting resources of coking coal, the world over, is posing a threat to the conventional (Blast Furnace [Bf]–Basic Oxygen Furnace [BOF]) route of iron and steelmaking. During the last four decades, a new route of ironmaking has rapidly developed for Direct Reduction (DR) of iron ore to metallic iron by using noncoking coal/natural gas. This product is known as Direct Reduced Iron (DRI) or Sponge Iron. Processes that produce iron by reduction of iron ore (in solid state) below the melting point are generally classified as DR processes. Based on the types of reductant used, DR processes can be broadly classified into two groups: (1) coal-based DR process and (2) gas-based DR process. Details of DR processes, reoxidation, storage, transportation, and application of DRI are discussed in this presentation. This presentation reviews the different DR processes used to produce Direct Reduced Iron (DRI), providing an analysis on the quality requirements of iron-bearing ores for use in these processes. The presentation also discusses the environmental sustainability of such processes. DR processes reduce iron ore in its solid state by the use of either natural gas or coal as reducing agents, and they have a comparative advantage of low capital costs, low emissions and production flexibility over the BF process.

1. Dr. Hassan Z. Harraz
hharraz2006@yahoo.com
Autum 2023
“Iron Ore is more Integral to the Global
Economy than any Other Commodity,
Except Perhaps Oil”.
Christopher LaFemina, mining analyst at Barclays Capital
(In 2011 the Financial Times quoted)
DIRECT REDUCED IRON ORE:
Production
@Hassan Harraz 2023
DIRECT REDUCED IRON ORE: Production
DOI: 10.13140/RG.2.2.27808.15366

2. Contents
1. INTRODUCTION
1.1. Definition of Direct Reduced Iron
1.2. Direct Reduction Processes
1.2.1. Coal-based processes
1.2.2. Gas-based processes
2. RAW MATERIALS
2.1. Iron Ore
2.2. Coal
2.3. Natural Gas
2.4. Dolomite/Limestone
2.5. Sizes of Raw Materials
2.6. Composite Pellets
2.7. Quality Requirements For Raw
Materials
3. REACTIONS OF DIRECT REDUCTION
PROCESSES
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4. DIRECT REDUCTION PROCESSES
4.1. Coal-Based Processes
4.1.1. Rotary kiln process
4.1.2. Rotary hearth process
4.1.2.1. FASTMET process.
4.1.2.2. ITmk3 process.
4.2. Gas-Based Processes
4.2.1. Midrex process
4.2.2. HyL process
4.2.2.1. HyL III process.
4.2.2.2. HyL IV M process.
4.4.3. Purofer process
4.4.4. Finmet process
4.4.5. HIB process
5. CHARACTERISTICS AND USES OF DRI
5.1. Characteristics of DRI
5.2. Quality of DRI
5.3. Reoxidation, Storage, and Transportation of DRI
5.3.2.1. The hazards of DRI.
5.3.2.2. Classification of DRI according to the IMSBC
Code.
5.4. Usages of DRI

3. Abstract

4. 1. INTRODUCTION

5. 1. INTRODUCTION ……. (Cont.)

6. 1.1. Definition of Direct Reduced Iron

7. 1.2. Direct Reduction Processes
❑ Based on the types of reductant used, the DR processes can be broadly classified into
two groups:
1) Using solid reductant, that is, coal-based DR process.
2) Using gaseous reductant, that is, gas-based DR process
❑ DR processes are summarized in Table 1.
Table 1: Direct reduction processes.

8. Direct Reduction Reactor/Furnace Types

9. 1.2.1. Coal-based processes

10. 1.2.1. Coal-based processes

11. 1.2.2. Gas-based processes

12. Overview of Gas-based Direct Reduction
Process Types

13. 2. RAW MATERIALS

14. 2.1. Iron Ore

15. 2.1. Iron Ore (Cont.)

16. 2.2. Coal

17. 2.3. Natural Gas

18. 2.4. Limestone or Dolomite Materials

19. 2.5. Sizes of Raw Materials

20. 2.6. Composite Pellets

21. 2.7. Quality Requirements For Raw Materials

22. 3. REACTIONS OF DIRECT REDUCTION PROCESSES

23. 3.3. Reduction Reaction for Gaseous Reductant:

24. Direct Reduction Processes For Iron

25. 4. DIRECT REDUCTION PROCESSES

26. 4.1.1. Rotary kiln process

27. SL/RN process
Fig.3: SL/RN direct reduction process flowsheet

28. iii) SL / RN process

29. 4.1.1. Rotary kiln process

30. 4.1.1. Rotary kiln process

31. 4.1.1. Rotary kiln process

32. 4.1.2. Rotary hearth process

33. 4.1.2.1. FASTMET process

34. 4.1.2.1. FASTMET process
Fig. 4: Flow sheet of the FASTMET process.

35. 4.1.2.2. ITmk3 process

36. 4.1.2.2. ITmk3 process
Fig. 5: Flow sheet of the ITmk3 process.

37. 4.2. Gas-Based Processes

38. @Hassan Harraz 2023
DIRECT REDUCED IRON ORE: Production
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40. Midrex® process
Midrex® direct reduction process flowsheet
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DIRECT REDUCED IRON ORE: Production
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41. 4.2.1. Midrex process

42. 4.2.2. HyL process
Fig. 7: Flow sheet of the HyL I/II process

43. 4.2.2. HyL process

44. 4.2.2.1. HyL III process

45. Fig.8: Flow sheet of the HyL III process

46. 4.2.2.2. HyL IV M process.

47. Fig.9: Flow sheet of the HyL-IV M process

48. 4.4.3. Purofer process

49. 4.4.4. Finmet process

50. Finmet / Finored Megatrain process

51. 4.4.5. HIB process

52. 5. CHARACTERISTICS AND USES OF DRI
5.1. Characteristics of DRI

53. 5.1. Characteristics of DRI

54. Fig. 10 Different forms of DRI: (A) Lump, (B)
Pellets, and (C) Hot-Briquetted Iron (HBI).
Table 6: Typical chemical composition of Direct Reduction
Iron.
Table 7: Physical properties of Direct Reduction Iron.
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55. 5.2. Quality of DRI

56. Table 8: Heat effects during reoxidation of DRI.
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57. 5.3. Reoxidation, Storage, and Transportation of DRI

58. 5.3. Reoxidation, Storage, and Transportation of DRI

59. 5.3. Reoxidation, Storage, and Transportation of DRI

60. Table 9: High-density type, DRI (A).
Table 10: Low-density type, DRI (B).

61. 5.3.2.2. Classification of DRI according to the IMSBC Code

63. 5.4. Usages of DRI

64. 5.4. Advantages Usages of DRI

65. 6. ENVIRONMENTAL SUSTAINABILITY
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