Non-fired pellets for reduction and method for producing same

Patent metadata

Field	Value
Publication number	US-2026043102-A1
Application number	US-202219100439-A
Country	US
Kind code	A1
Filing date	Aug 1, 2022
Priority date	Aug 1, 2022
Publication date	Feb 12, 2026
Grant date	—

Abstract

Non-fired pellets are used in a solid reduction furnace and are effective in preventing clustering by reducing the possibility of contact between low-melting-temperature slags and thus preventing the fusion therebetween. A method produces such non-fired pellets. Non-fired pellets for reduction, in which the proportion of high-viscosity slag components (Al 2 O 3 +MgO+SiO 2 ) to the total Fe (T.Fe) satisfies an expression: (Al 2 O 3 +MgO+SiO 2 )/T.Fe≥0.12, and a method for producing the same. In the expression, Al 2 O 3 represents the concentration (mass %) of Al 2 O 3 in the non-fired pellets, MgO represents the concentration (mass %) of MgO in the non-fired pellets, SiO 2 represents the concentration (mass %) of SiO 2 in the non-fired pellets, and T.Fe represents the concentration (mass %) of T.Fe in the non-fired pellets.

First claim

1 . Non-fired pellets for reduction,
wherein a proportion of high-viscosity slag components (Al 2 O 3 +MgO+SiO 2 ) to total Fe (T.Fe) satisfies the following Expression (1):

(

Al
2

⁢

O
3

+
MgO
+

SiO
2

)

/

T
·
Fe

≥

0
.12

,

(
1
)

where Al 2 O 3 represents a concentration (mass %) of Al 2 O 3 in the non-fired pellets,
MgO represents a concentration (mass %) of MgO in the non-fired pellets,
SiO 2 represents a concentration (mass %) of SiO 2 in the non-fired pellets, and
T.Fe represents a concentration (mass %) of T.Fe in the non-fired pellets.

2 . Non-fired pellets for reduction,
wherein a proportion of high-viscosity slag components (Al 2 O 3 +MgO+SiO 2 ) to total Fe (T.Fe) satisfies the following Expression (2):

(

Al
2

⁢

O
3

+
MgO
+

SiO
2

)

/

T
·
Fe

≥

0
.15

,

(
2
)

where Al 2 O 3 represents a concentration (mass %) of Al 2 O 3 in the non-fired pellets,
MgO represents a concentration (mass %) of MgO in the non-fired pellets,
SiO 2 represents a concentration (mass %) of SiO 2 in the non-fired pellets, and
T.Fe represents a concentration (mass %) of T.Fe in the non-fired pellets.

3 . A method for producing the non-fired pellets for reduction according to claim 1 , further comprising
using an iron-containing raw material formulated to achieve an average LOI (Loss on Ignition) of 5% or more.

4 . The method for producing the non-fired pellets for reduction according to claim 3 , wherein
the iron-containing raw material has been pretreated for removal of crystal water in advance so as to achieve an average LOI (Loss on Ignition) of 2% or less.

5 . The method for producing the non-fired pellets for reduction according to claim 3 , wherein
a mixed raw material containing 4 mass % to 24 mass % M.Fe is prepared by mixing a raw material containing M.Fe and is granulated.

6 . The method for producing the non-fired pellets for reduction according to claim 5 , wherein
the raw material is reduced iron with a particle size of 3 mm or less that has been reduced in a solid reduction furnace.

7 . The method for producing the non-fired pellets for reduction according to claim 6 , wherein
the reduced iron contains 79 mass % or more M.Fe.

8 . A method for producing the non-fired pellets for reduction according to claim 2 , further comprising
using an iron-containing raw material formulated to achieve an average LOI (Loss on Ignition) of 5% or more.

9 . The method for producing the non-fired pellets for reduction according to claim 8 , wherein
the iron-containing raw material has been pretreated for removal of crystal water in advance so as to achieve an average LOI (Loss on Ignition) of 2% or less.

10 . The method for producing the non-fired pellets for reduction according to claim 4 , wherein
a mixed raw material containing 4 mass % to 24 mass % M.Fe is prepared by mixing a raw material containing M.Fe and is granulated.

11 . The method for producing the non-fired pellets for reduction according to claim 8 , wherein
a mixed raw material containing 4 mass % to 24 mass % M.Fe is prepared by mixing a raw material containing M.Fe and is granulated.

12 . The method for producing the non-fired pellets for reduction according to claim 9 , wherein
a mixed raw material containing 4 mass % to 24 mass % M.Fe is prepared by mixing a raw material containing M.Fe and is granulated.

13 . The method for producing the non-fired pellets for reduction according to claim 10 , wherein
the raw material is reduced iron with a particle size of 3 mm or less that has been reduced in a solid reduction furnace.

14 . The method for producing the non-fired pellets for reduction according to claim 11 , wherein
the raw material is reduced iron with a particle size of 3 mm or less that has been reduced in a solid reduction furnace.

15 . The method for producing the non-fired pellets for reduction according to claim 12 , wherein
the raw material is reduced iron with a particle size of 3 mm or less that has been reduced in a solid reduction furnace.

16 . The method for producing the non-fired pellets for reduction according to claim 13 , wherein
the reduced iron contains 79 mass % or more M.Fe.

17 . The method for producing the non-fired pellets for reduction according to claim 14 , wherein
the reduced iron contains 79 mass % or more M.Fe.

18 . The method for producing the non-fired pellets for reduction according to claim 15 , wherein
the reduced iron contains 79 mass % or more M.Fe.

Assignees

• Jfe Steel Corp

Inventors

• Takehara Kenta
• Yamamoto Tetsuya
• Higuchi Takahide
• Iwami Yuji
• Fujiwara Shohei
• Morita Yuya
• HORITA Kenya
• Hirosawa Toshiyuki
• Igawa Daisuke

Classifications

• C21B13/105

  Rotary hearth-type furnaces · CPC title

• C21B13/008 Primary

  Use of special additives or fluxing agents · CPC title

• C21B13/0046

  making metallised agglomerates or iron oxide · CPC title

• C22B1/2406

  pelletizing · CPC title

• Y02P10/20

  Recycling · CPC title