Magnetic separator, magnetic separation method, and iron source manufacturing method

Patent metadata

Field	Value
Publication number	US-10857548-B2
Application number	US-201615778225-A
Country	US
Kind code	B2
Filing date	Nov 30, 2016
Priority date	Nov 30, 2015
Publication date	Dec 8, 2020
Grant date	Dec 8, 2020

Abstract

A magnetic separator comprises: at least one pair of guide rolls; and a conveyor belt that extends between the pair of guide rolls, and conveys a powdery and/or granular material containing ferromagnetic particles, wherein one guide roll of the pair of guide rolls is a hollow roll, and includes, in a hollow part thereof, a magnet roll including a plurality of magnets that are arranged along an inner peripheral surface of the guide roll in lines at intervals so that different magnetic poles alternate in a circumferential direction, and the magnetic separator further comprises a shield wall that covers a circular arc region of an outer peripheral surface of the guide roll except a circular arc region around which the conveyor belt is wound, to block magnetic lines of force from the plurality of magnets.

First claim

The invention claimed is:

1. A magnetic separator comprising:
a first pair of guide rolls; and
a first conveyor belt that extends between the first pair of guide rolls, and conveys a powdery and/or granular material containing ferromagnetic particles,
wherein one guide roll of the first pair of guide rolls is a hollow roll, and includes, in a hollow part thereof, a magnet roll including a plurality of magnets that are arranged along an inner peripheral surface of the guide roll in lines at intervals so that different magnetic poles alternate in a circumferential direction, and
the magnetic separator further comprises
a shield wall that covers a circular arc region of an outer peripheral surface of the guide roll except a circular arc region around which the first conveyor belt is wound, to block magnetic lines of force from the plurality of magnets, and wherein
a thickness of the shield wall is 30 mm or more and the shield wall is made of a non-metallic material.

2. The magnetic separator according to claim 1 , further comprising:
a second pair of guide rolls; and
a second conveyor belt that is located below the first conveyor belt, and conveys the powdery and/or granular material containing the ferromagnetic particles, the second conveyor belt extending between the second pair of guide rolls,
wherein a part of the first conveyor belt corresponding to the magnet roll is located near a powdery and/or granular material conveyance downstream side of the second conveyor belt.

3. The magnetic separator according to claim 1 , further comprising
at least one conduit that passes through the shield wall from a back surface thereof to a side facing the guide roll, and supplies air to a clearance between the shield wall and the guide roll.

4. The magnetic separator according to claim 1 ,
wherein the magnet roll is rotatable independently of the guide roll.

5. The magnetic separator according to claim 1 ,
wherein the magnetic roll includes P pairs of a north pole and a south pole arranged side by side in the circumferential direction on a surface of the magnet roll facing the powdery and/or granular material, and
the magnet roll rotates at x rpm so that a magnetic field change frequency F (Hz) defined by the following expression (1) is 30 Hz or more and 160 Hz or less:
F =( x·P )/60  (1).

6. The magnetic separator according to claim 1 ,
wherein magnetic poles of magnets adjacent in an axial direction of the magnet roll from among the plurality of magnets are the same.

7. The magnetic separator according to claim 1 ,
wherein magnetic poles of magnets adjacent in an axial direction of the magnet roll from among the plurality of magnets are different.

8. The magnetic separator according to claim 1 ,
wherein a rotational direction of the one guide roll and a rotational direction of the magnet roll are the same.

9. The magnetic separator according to claim 1 ,
wherein a rotational direction of the one guide roll and a rotational direction of the magnet roll are opposite.

10. The magnetic separator according to claim 2 ,
wherein a rotational direction of the first conveyor belt and a rotational direction of the second conveyor belt are the same.

11. The magnetic separator according to claim 2 ,
wherein a rotational direction of the first conveyor belt and a rotational direction of the second conveyor belt are opposite.

12. The magnetic separator according to claim 1 ,
wherein the first conveyor belt and the one guide roll are made of a non-metallic material.

13. The magnetic separator according to claim 1 ,
wherein any of the first pair of guide rolls is a non-drive roll.

14. A magnetic separation method of separating, from a powdery and/or granular material containing ferromagnetic particles, the ferromagnetic particles using the magnetic separator according to claim 1 , the magnetic separation method comprising
supplying the powdery and/or granular material onto the first conveyor belt, with a thickness that is greater than a diameter of a smallest particle contained in the powdery and/or granular material.

15. An iron source manufacturing method of manufacturing an iron source from a by-product of a steelmaking process, using the magnetic separator according to claim 1 .

16. An iron source manufacturing method of manufacturing an iron source from a by-product of a steelmaking process, using the magnetic separation method according to claim 14 .

17. The magnetic separator according to claim 1 ,
wherein the thickness of the shield wall is 50 mm or more.

18. The magnetic separator according to claim 1 ,
wherein the shield wall extends across a full width of the guide roll in an axial direction of the guide roll.

Assignees

• Jfe Steel Corp

Inventors

• Ishida Kyohei
• TAKAKI Yuki

Classifications

• B03C2201/22

  characterised by the magnetic field, e.g. its shape or generation · CPC title

• B03C2201/20

  Magnetic separation of bulk or dry particles in mixtures · CPC title

• B03C1/18 Primary

  with magnets moving during operation · CPC title

• B03C1/00

  Magnetic separation · CPC title

• Y02P10/20

  Recycling · CPC title