# US 9,752,209 B2 · Method for producing hematite for ironmaking

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- Number: US 9,752,209 B2
- Document ID: US9752209B2
- Status: Granted
- Kind: B2
- Application number: 14/784,336
- Filed: 2014-04-14
- Published: 2016-04-28
- Granted: 2017-09-05
- Earliest claimed: 2013-04-24
- Assignees: Sumitomo Metal Mining Co., Ltd.
- Applicants: Sumitomo Metal Mining Co., Ltd.
- Inventors: Go Ohara; Hideki Sasaki; Yasumasa Kan; Masaki Imamura
- Web page: https://patentgrep.com/patent/US9752209B2

## CPC

- C22B 3/22: by physical processes, e.g. by filtration, by magnetic means {, or by thermal decomposition} (treatment or purification of solutions by liquid-liquid extraction C22B3/26)
- B03B 5/34: Applications of hydrocyclones
- B03B 7/00: Combinations of wet processes or apparatus with other processes or apparatus, e.g. for dressing ores or garbage
- B03C 1/025: High gradient magnetic separators
- B03C 1/30: Combinations with other devices, not otherwise provided for
- C01G 49/06: Ferric oxide [Fe2O3]
- C22B 7/005: {Separation by a physical processing technique only, e.g. by mechanical breaking}
- B03C 2201/20: Magnetic separation of bulk or dry particles in mixtures
- Y02P 10/20: Recycling
- C22B: PRODUCTION AND REFINING OF METALS (electrolytic C25); PRETREATMENT OF RAW MATERIALS
- B03B: SEPARATING SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS
- B03C: MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS (separating isotopes B01D59/00; combinations of magnetic or electrostatic separation with separation of solids by other means B03B, B07B)
- C01G: COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F (metal hydrides {monoborane, diborane or addition complexes thereof} C01B6/00; salts of oxyacids of halogens C01B11/00; peroxides, salts or peroxyacids C01B15/00; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium, or tellurium C01B19/00; binary compounds of nitrogen with metals C01B21/06; azides C01B21/08; {compounds containing nitrogen, other non-metals and metal C01B21/082}; metal amides C01B21/092; nitrites C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; carbides C01B32/90; compounds containing silicon C01B33/00; compounds containing boron C01B35/00; compounds having molecular sieve properties but not having base-exchange properties C01B37/00; compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites, C01B39/00; cyanides C01C3/08; salts of cyanamide C01C3/16; thiocyanates C01C3/20)
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

A method is provided for separating a leach residue from which a hematite-containing material capable of being used as a raw material for ironmaking can be obtained. A method also is provided for producing hematite for ironmaking from the leach residue. The method utilizes a leach residue as a raw material, the leach residue being obtained from a hydrometallurgical refining plant where a nickel oxide ore treated by a high pressure acid leach process. The method includes, in sequence: a separation step of separating the leach residue into an overflow and an underflow with a wet cyclone; and another separation step of separating the separated overflow into a strong magnetic substance and a weak magnetic substance using magnetic force, wherein a strong-magnetic-field magnetic separator is used in the another separation step using the magnetic force.

## Claims

### Claim 1

A method for producing hematite for ironmaking, utilizing a leach residue as a raw material, the leach residue being obtained from a hydrometallurgical refining plant where a nickel oxide ore treated by a high pressure acid leach process, the method comprising, in sequence:
a first separation step of separating the leach residue into an overflow containing hematite and chromite and an underflow containing gypsum by using a wet cyclone under a condition that the wet cyclone is adjusted to have a setting between 1 μm or less and 2 μm or less as a classification particle size for the overflow; and then
a second separation step of separating the hematite and the chromite contained in the overflow using magnetic force having a magnetic field intensity of 5 to 20 [kGauss] by a strong-magnetic-field magnetic separator having a mesh that applies magnetic force to powders when the powders pass through the mesh, thereby producing a hematite cake.

### Claim 2 (depends on 1)

The method for producing hematite for ironmaking according to claim 1, further comprising a dehydration process of adjusting a moisture content of the hematite cake to be 10 wt % to 17 wt %.

### Claim 3

A method for producing hematite for ironmaking, utilizing a leach residue, the leach residue having an iron grade of 30% to 35% and a sulfur grade of 3% to 10% as a raw material, the method comprising, in sequence:
a first separation step of separating the leach residue into an overflow containing hematite and chromite and an underflow containing gypsum by using a wet cyclone under a condition that the wet cyclone is adjusted to have a setting between 1 μm or less and 2 μm or less as a classification particle size for the overflow; and then
a second separation step of separating the hematite and the chromite contained in the separated overflow using magnetic force having a magnetic field intensity of 5 to 20 [kGauss] by a strong-magnetic-field magnetic separator having a mesh that applies magnetic force to powders when the powders pass through the mesh thereby producing a hematite cake.

### Claim 4 (depends on 3)

The method for producing hematite for ironmaking according to claim 3, further comprising a dehydration process of adjusting a moisture content of the hematite cake to be 10 wt % to 17 wt %.

### Claim 5 (depends on 3)

The method for producing hematite for ironmaking according to claim 3, further comprising granulating the hematite cake to form a granulated material.

### Claim 6 (depends on 3)

The method for producing hematite for ironmaking according to claim 3, further comprising heating the hematite cake at a temperature of 600° C. or higher.