US20150050200A1 - Production method for hematite for iron production - Google Patents
Production method for hematite for iron production Download PDFInfo
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- US20150050200A1 US20150050200A1 US14/386,222 US201314386222A US2015050200A1 US 20150050200 A1 US20150050200 A1 US 20150050200A1 US 201314386222 A US201314386222 A US 201314386222A US 2015050200 A1 US2015050200 A1 US 2015050200A1
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- United States
- Prior art keywords
- nickel
- sulfur
- leach
- hematite
- iron
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- Abandoned
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- 229910052595 hematite Inorganic materials 0.000 title claims abstract description 23
- 239000011019 hematite Substances 0.000 title claims abstract description 23
- LIKBJVNGSGBSGK-UHFFFAOYSA-N iron(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Fe+3].[Fe+3] LIKBJVNGSGBSGK-UHFFFAOYSA-N 0.000 title claims abstract description 23
- 238000004519 manufacturing process Methods 0.000 title abstract description 11
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 title description 28
- 229910052742 iron Inorganic materials 0.000 title description 14
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims abstract description 40
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims abstract description 40
- 238000000034 method Methods 0.000 claims abstract description 35
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 20
- 229910000480 nickel oxide Inorganic materials 0.000 claims abstract description 15
- GNRSAWUEBMWBQH-UHFFFAOYSA-N oxonickel Chemical compound [Ni]=O GNRSAWUEBMWBQH-UHFFFAOYSA-N 0.000 claims abstract description 15
- 238000002386 leaching Methods 0.000 claims abstract description 10
- 230000001590 oxidative effect Effects 0.000 claims abstract description 8
- 239000007800 oxidant agent Substances 0.000 claims abstract description 7
- 238000010438 heat treatment Methods 0.000 claims description 18
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 abstract description 39
- 239000011593 sulfur Substances 0.000 abstract description 39
- 229910052717 sulfur Inorganic materials 0.000 abstract description 39
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 abstract description 22
- 239000002994 raw material Substances 0.000 abstract description 22
- 238000007670 refining Methods 0.000 abstract description 12
- 239000002253 acid Substances 0.000 abstract description 7
- 229910052751 metal Inorganic materials 0.000 description 10
- 239000002184 metal Substances 0.000 description 10
- 150000002739 metals Chemical class 0.000 description 9
- 239000002002 slurry Substances 0.000 description 7
- 238000006386 neutralization reaction Methods 0.000 description 6
- 238000011084 recovery Methods 0.000 description 6
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 5
- 239000000920 calcium hydroxide Substances 0.000 description 5
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 5
- 235000011116 calcium hydroxide Nutrition 0.000 description 5
- 239000007788 liquid Substances 0.000 description 5
- 238000000926 separation method Methods 0.000 description 5
- 229910000831 Steel Inorganic materials 0.000 description 4
- OSGAYBCDTDRGGQ-UHFFFAOYSA-L calcium sulfate Chemical compound [Ca+2].[O-]S([O-])(=O)=O OSGAYBCDTDRGGQ-UHFFFAOYSA-L 0.000 description 4
- 239000010959 steel Substances 0.000 description 4
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- 238000003723 Smelting Methods 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 3
- 229910052500 inorganic mineral Inorganic materials 0.000 description 3
- 239000011707 mineral Substances 0.000 description 3
- 235000010755 mineral Nutrition 0.000 description 3
- 239000013049 sediment Substances 0.000 description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- 229910001341 Crude steel Inorganic materials 0.000 description 2
- 235000019738 Limestone Nutrition 0.000 description 2
- RAHZWNYVWXNFOC-UHFFFAOYSA-N Sulphur dioxide Chemical compound O=S=O RAHZWNYVWXNFOC-UHFFFAOYSA-N 0.000 description 2
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 2
- 239000005083 Zinc sulfide Substances 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 229910052935 jarosite Inorganic materials 0.000 description 2
- 239000006028 limestone Substances 0.000 description 2
- 239000011505 plaster Substances 0.000 description 2
- 229910052725 zinc Inorganic materials 0.000 description 2
- 239000011701 zinc Substances 0.000 description 2
- 229910052984 zinc sulfide Inorganic materials 0.000 description 2
- DRDVZXDWVBGGMH-UHFFFAOYSA-N zinc;sulfide Chemical compound [S-2].[Zn+2] DRDVZXDWVBGGMH-UHFFFAOYSA-N 0.000 description 2
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- QPLDLSVMHZLSFG-UHFFFAOYSA-N Copper oxide Chemical compound [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 description 1
- 239000005751 Copper oxide Substances 0.000 description 1
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 239000000571 coke Substances 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 229910000431 copper oxide Inorganic materials 0.000 description 1
- OMZSGWSJDCOLKM-UHFFFAOYSA-N copper(II) sulfide Chemical compound [S-2].[Cu+2] OMZSGWSJDCOLKM-UHFFFAOYSA-N 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005868 electrolysis reaction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 1
- VTHJTEIRLNZDEV-UHFFFAOYSA-L magnesium dihydroxide Chemical compound [OH-].[OH-].[Mg+2] VTHJTEIRLNZDEV-UHFFFAOYSA-L 0.000 description 1
- 239000000347 magnesium hydroxide Substances 0.000 description 1
- 229910001862 magnesium hydroxide Inorganic materials 0.000 description 1
- 239000000395 magnesium oxide Substances 0.000 description 1
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 1
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 230000003472 neutralizing effect Effects 0.000 description 1
- -1 nickel salt compound Chemical class 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- WWNBZGLDODTKEM-UHFFFAOYSA-N sulfanylidenenickel Chemical compound [Ni]=S WWNBZGLDODTKEM-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G49/00—Compounds of iron
- C01G49/02—Oxides; Hydroxides
- C01G49/06—Ferric oxide [Fe2O3]
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B3/00—Extraction of metal compounds from ores or concentrates by wet processes
- C22B3/20—Treatment or purification of solutions, e.g. obtained by leaching
- C22B3/22—Treatment or purification of solutions, e.g. obtained by leaching by physical processes, e.g. by filtration, by magnetic means, or by thermal decomposition
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B17/00—Sulfur; Compounds thereof
- C01B17/48—Sulfur dioxide; Sulfurous acid
- C01B17/50—Preparation of sulfur dioxide
- C01B17/501—Preparation of sulfur dioxide by reduction of sulfur compounds
- C01B17/507—Preparation of sulfur dioxide by reduction of sulfur compounds of iron sulfates
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B23/00—Obtaining nickel or cobalt
- C22B23/04—Obtaining nickel or cobalt by wet processes
- C22B23/0453—Treatment or purification of solutions, e.g. obtained by leaching
- C22B23/0461—Treatment or purification of solutions, e.g. obtained by leaching by chemical methods
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B3/00—Extraction of metal compounds from ores or concentrates by wet processes
- C22B3/20—Treatment or purification of solutions, e.g. obtained by leaching
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/80—Compositional purity
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Definitions
- the present invention relates to a production method for refining a leach residue obtained by hydrometallurgical refining of nickel oxide ore into hematite that can be used as an iron-making raw material and has low-grade sulfur.
- the iron oxide that is a raw material of the steel is a limited resource, and furthermore it is gradually hard to obtain high-quality iron ore required to maintain a quality of steel.
- nickel oxide ore such as limonite or saprolite is put into a pressure device such as an autoclave along with a sulfuric acid, and nickel is leached under high pressure and high temperature of about 240 to 260° C.
- the nickel leached into a solution of the sulfuric acid is used as nickel metal or a nickel salt compound by adding a neutralizer to neutralize a surplus acid, separating a leach residue by solid-liquid separation, separating impurities to recover the leach residue as an intermediate raw material in the form of hydroxide or sulfide, and further refining the intermediate raw material.
- HPAL high pressure acid leach
- nickel can be almost completely leached even from low-grade ore in which valuable metals intended for recovery are contained by not more than 1% to 2% by weight (hereinafter indicated by “%” with regard to a grade).
- the HPAL process has a feature of concentrating the valuable metals up to the same grade as a conventional raw material by producing an intermediate raw material from a leachate, and refining the nickel in a process similar to a conventional process.
- HPAL process may be applied to various types of ores such as nickel sulfide ore, copper sulfide ore, and copper oxide ore, in addition to the nickel oxide ore.
- a main component of the leach residue obtained by the HPAL process is iron oxide having the form of hematite. This is secondarily obtained because each of oxide ore and sulfide ore of nickel or copper used as a raw material contains iron of an amount far more than a content of nickel or copper.
- leach residues are created at a high temperature, and thus have the form of oxide that is chemically or environmentally stable.
- the leach residues have no special utility value, and have been scrapped to a residue disposal yard. For this reason, it has been a grave challenge how to secure the disposal yards for an enormous amount of leach residues generated along with the smelting.
- the leach residue of the HPAL process cannot be directly used for the aforementioned iron-making raw material.
- the reason is that the leach residue of the HPAL process contains gangue and impurities, particularly sulfur, in addition to the iron oxide and requires exhaust gas treatment, and thus is not suitable for the raw material used in the conventional iron-making process in common.
- a grade of sulfur in iron oxide usable for the iron-making raw material differs depending on facility capacity and an amount of production of individual ironworks, and generally needs to be suppressed to less than 1%.
- the sulfur is hardly contained in the original nickel oxide ore. Nevertheless, the sulfur contained in the leach residue by about 1 to 3% results from calcium sulfate (plaster) generated by reaction of sulfuric acid and limestone or slaked lime added as the neutralizer in order to neutralize free sulfuric acid remaining at the leach slurry.
- calcium sulfate plaster
- the neutralizer suitable for such application includes sodium hydroxide, potassium hydroxide, magnesium hydroxide, and magnesium oxide.
- JP H03-176081 A discloses a method that includes stirring a jarosite-containing residual and a zinc sulfide inclusion in an autoclave at least under oxygen partial pressure of 1000 kPa at a temperature of 130 to 170° C. along with a free sulfuric acid of 40 to 100 g/l, substantially dissolving iron and zinc fractions of a concentrate containing the residual and zinc sulfide, introducing the solution into a leach circulation passage for zinc electrolysis to settle iron in the form of hematite, and separating sulfur from the above solid, and supplying the residual for separate application.
- the invention is intended to provide a production method for refining hematite, which has such a low sulfur component as to be used as an iron-making raw material, from a leach residue containing iron oxide produced by a high pressure acid leach (HPAL) process.
- HPAL high pressure acid leach
- a first aspect of the present invention provides a method for producing (high purity) hematite for ironmaking by a process of adding an oxidant and sulfuric acid to nickel oxide ore and then leaching nickel.
- the method further includes heating a leach residue, which is obtained after the nickel is leached, to 600° C. or more.
- a second aspect of the present invention provides a method for producing (high purity) hematite for ironmaking by a process of adding an oxidant and sulfuric acid to nickel oxide ore and then leaching nickel.
- the method further includes heating a leach residue, which is obtained after the nickel is leached, to 800° C. or more and 1400° C. or less.
- the present invention can bring about several industrially significant effects.
- wastes such as a leach residue, discharged in a refining process can be applied to the iron-making raw materials, and it is thus possible to remarkably reduce an amount of the scrapped leach residue and further reduce production costs by lowering an environmental risk, reducing scrapping costs, and reducing construction costs of a leach residue disposal yard;
- FIG. 1 is a flow chart showing a recovery process of performing high-pressure sulfuric acid leach on a mineral containing valuable metals and iron to recover the valuable metals, and further showing a refining process of hematite having low-grade sulfur which is associated with the recovery process;
- FIG. 2 is a diagram illustrating a relation between a heating temperature and a grade of sulfur in a leach residue.
- the present invention is to heat a leach residue obtained when a mineral, such as nickel oxide ore, containing valuable metals and iron is subjected to high-pressure sulfuric acid leach, to separate sulfur, and to produce high-purity hematite that can be used as an iron-making raw material having a low sulfur content.
- FIG. 1 illustrates a flow for a recovery process of performing high-pressure sulfuric acid leach on a mineral, such as nickel oxide ore, containing valuable metals and iron to recover the valuable metals and a further flow for a refining process of a production method according to the present invention of producing hematite having low-grade sulfur from a leach residue obtained in association with the recovery process.
- a mineral such as nickel oxide ore
- the flow for the recovery process of the valuable metals is indicated by an outline arrow, and the flow for the refining process of the hematite according to the invention is indicated by a black arrow.
- a leach residue to be a starting raw material of the present process is obtained as sediment when a leach slurry, which is generated by neutralizing a leachate obtained in the event of high-pressure sulfuric acid leach as illustrated in FIG. 1 , is subjected to solid-liquid separation.
- the leach residue is formed in a state in which a reaction product of a neutralizer input in the neutralization process and a surplus acid is contained. Accordingly, limestone or slaked lime added as the neutralizer and sulfuric acid are reacted to neutralize a free sulfuric acid remaining in the leach slurry.
- the leach residue contains sulfur resulting from created calcium sulfate (plaster) by several percentage (%).
- the leach residue is heated on given conditions. That is, as illustrated in FIG. 1 , the iron oxide (hematite) for ironmaking which has low-grade sulfur is refined by roasting the leach residue and evaporating the sulfur component.
- FIG. 2 illustrates a relation between a heating temperature and the sulfur grade in the leach residue.
- a temperature at which the leach residue is heated is 600° C. or more, preferably 800° C. or more, which is an effective temperature in order to make the sulfur grade in the leach residue less than 1%. Further, when the heating temperature exceeds 800° C., the sulfur grade is sharply reduced, which is more preferable. When the heating temperature becomes 1300° C., the sulfur grade can be reduced up to 0.1% or less, which is more preferable, but when the heating temperature more preferably exceeds 1400° C., this gives no great difference, and is not very preferable in the aspect of facility investment such as an increase in heating energy or a need for heat resistance of a furnace wall material. Accordingly, the heating temperature is 600° C. or more and 1400° C. or less, and preferably 800° C. or more and 1300° C. or less.
- a heating time is affected by a furnace size and an amount of the residue, and thus may be adequately adjusted. Further, the heating is performed in an oxidizing atmosphere such as atmospheric air. Thereby, along with the heating, the sulfur is removed from the leach residue as sulfur dioxide, and the high-purity iron oxide (hematite) is formed.
- an oxidizing atmosphere such as atmospheric air.
- Nickel oxide ore having 1% nickel grade and 46 to 48% iron grade was adjusted to be a slurry of 30 to 40% by weight, and then was mixed with sulfuric acid of 64% by weight. Subsequently, the slurry was charged into a pressure device, heated to 240 to 250° C., and maintained for one hour, and a leachate was obtained by leaching nickel in the ore (HPAL).
- the leachate was cooled to about 70° C., and then slaked lime was added to neutralize a surplus acid (neutralization).
- the slurry containing a leach residue after the surplus acid was neutralized (hereinafter the leach residue after the neutralization is referred to as “neutralized residue’) was subjected to solid-liquid separation using Nutsche and a filtering bottle, and was separated into the leachate and the neutralized residue (solid-liquid separation).
- the neutralized residue was equally divided into six parts, which were respectively raised to 30° C., 200° C., 800° C., 1000° C., 1200° C., and 1400° C., heated for one hour, and cooled.
- the sulfur grade is reduced up to about 1% at about 600° C., and that, when the temperature exceeds 800° C., the sulfur grade is sharply reduced, and the sulfur can be effectively separated.
- Table 1 results of measuring the iron and sulfur grades in the neutralized residue after the heating are illustrated.
- the iron and sulfur grades were measured by fluorescent X-ray analysis.
- FIG. 1 A first figure.
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- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Inorganic Chemistry (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Geochemistry & Mineralogy (AREA)
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- Compounds Of Iron (AREA)
Abstract
Provided is a production method for refining iron oxide (hematite), which has such a low sulfur content as to be used as a raw material for ironmaking from a leach residue containing iron oxide, the leach residue being produced by a high pressure acid leach (HPAL) process and being a raw material that can be cheaply and stably procured. In the method of producing (high purity) hematite for ironmaking by a process of adding an oxidant and sulfuric acid to nickel oxide ore and then leaching nickel, a leach residue obtained after the leaching of nickel is heated to 600° C. or more, and preferably 800° C. or more and 1400° C. or less.
Description
- 1. Field of the Invention
- The present invention relates to a production method for refining a leach residue obtained by hydrometallurgical refining of nickel oxide ore into hematite that can be used as an iron-making raw material and has low-grade sulfur.
- 2. Description of the Related Art
- In steel smelting, a method of charging iron ore containing iron oxide into a blast furnace along with a reductant such as coke, heating and melting the iron ore under a reducing atmosphere to obtain crude steel, and refining the crude steel in a converter to obtain desired steel has been used.
- The iron oxide that is a raw material of the steel is a limited resource, and furthermore it is gradually hard to obtain high-quality iron ore required to maintain a quality of steel.
- Meanwhile, with respect to nickel becoming a raw material of stainless steel, technology for smelting low-grade oxide ore as a raw material due to a tendency toward resource exhaustion of sulfide ore that has been used in the past has been developed and put to practical use.
- To be specific, nickel oxide ore such as limonite or saprolite is put into a pressure device such as an autoclave along with a sulfuric acid, and nickel is leached under high pressure and high temperature of about 240 to 260° C.
- The nickel leached into a solution of the sulfuric acid is used as nickel metal or a nickel salt compound by adding a neutralizer to neutralize a surplus acid, separating a leach residue by solid-liquid separation, separating impurities to recover the leach residue as an intermediate raw material in the form of hydroxide or sulfide, and further refining the intermediate raw material.
- In such a process called high pressure acid leach (HPAL), nickel can be almost completely leached even from low-grade ore in which valuable metals intended for recovery are contained by not more than 1% to 2% by weight (hereinafter indicated by “%” with regard to a grade). Further, the HPAL process has a feature of concentrating the valuable metals up to the same grade as a conventional raw material by producing an intermediate raw material from a leachate, and refining the nickel in a process similar to a conventional process.
- Further, the HPAL process may be applied to various types of ores such as nickel sulfide ore, copper sulfide ore, and copper oxide ore, in addition to the nickel oxide ore.
- Further, a main component of the leach residue obtained by the HPAL process is iron oxide having the form of hematite. This is secondarily obtained because each of oxide ore and sulfide ore of nickel or copper used as a raw material contains iron of an amount far more than a content of nickel or copper.
- These leach residues are created at a high temperature, and thus have the form of oxide that is chemically or environmentally stable. However, the leach residues have no special utility value, and have been scrapped to a residue disposal yard. For this reason, it has been a grave challenge how to secure the disposal yards for an enormous amount of leach residues generated along with the smelting.
- Furthermore, the leach residue of the HPAL process cannot be directly used for the aforementioned iron-making raw material. The reason is that the leach residue of the HPAL process contains gangue and impurities, particularly sulfur, in addition to the iron oxide and requires exhaust gas treatment, and thus is not suitable for the raw material used in the conventional iron-making process in common.
- Particularly, a grade of sulfur in iron oxide usable for the iron-making raw material differs depending on facility capacity and an amount of production of individual ironworks, and generally needs to be suppressed to less than 1%.
- The sulfur is hardly contained in the original nickel oxide ore. Nevertheless, the sulfur contained in the leach residue by about 1 to 3% results from calcium sulfate (plaster) generated by reaction of sulfuric acid and limestone or slaked lime added as the neutralizer in order to neutralize free sulfuric acid remaining at the leach slurry.
- Therefore, it is considered that what creates a soluble salt may be used as the added neutralizer, not the slaked lime or what forms insoluble sediment, such as the slaked lime, after the neutralization.
- For example, the neutralizer suitable for such application includes sodium hydroxide, potassium hydroxide, magnesium hydroxide, and magnesium oxide.
- However, these neutralizers are expensive, and have a limited amount of production. Thus, when a large quantity of neutralizer is required as in the HPAL process, it is industrially difficult to cover the whole quantity.
- For this reason, there has been no choice but to use a calcium-based neutralizer in whole or in part which forms the insoluble sediment after the neutralization as described above, and thereby mixing of the sulfur has been inevitable. As such, it has been impossible to process the leach residue created in the HPAL process into the hematite and to use it as the iron-making raw material.
- On the other hand, a method of separating sulfur in jarosite using a pressure device such as an autoclave is also known.
- For example, JP H03-176081 A discloses a method that includes stirring a jarosite-containing residual and a zinc sulfide inclusion in an autoclave at least under oxygen partial pressure of 1000 kPa at a temperature of 130 to 170° C. along with a free sulfuric acid of 40 to 100 g/l, substantially dissolving iron and zinc fractions of a concentrate containing the residual and zinc sulfide, introducing the solution into a leach circulation passage for zinc electrolysis to settle iron in the form of hematite, and separating sulfur from the above solid, and supplying the residual for separate application.
- However, this method requires an expensive device such as an autoclave, increases a facility cost, and further has a problem even in the aspect of productivity.
- The invention is intended to provide a production method for refining hematite, which has such a low sulfur component as to be used as an iron-making raw material, from a leach residue containing iron oxide produced by a high pressure acid leach (HPAL) process.
- To solve the above problems, a first aspect of the present invention provides a method for producing (high purity) hematite for ironmaking by a process of adding an oxidant and sulfuric acid to nickel oxide ore and then leaching nickel. The method further includes heating a leach residue, which is obtained after the nickel is leached, to 600° C. or more.
- A second aspect of the present invention provides a method for producing (high purity) hematite for ironmaking by a process of adding an oxidant and sulfuric acid to nickel oxide ore and then leaching nickel. The method further includes heating a leach residue, which is obtained after the nickel is leached, to 800° C. or more and 1400° C. or less.
- The present invention can bring about several industrially significant effects.
- First, is possible to easily obtain hematite that has low-grade sulfur and can be used as an iron-making raw material.
- Second, a raw material that can be cheaply and stably procured is used. Thus, hematite with the low-grade sulfur can be obtained inexpensively.
- Third, wastes, such as a leach residue, discharged in a refining process can be applied to the iron-making raw materials, and it is thus possible to remarkably reduce an amount of the scrapped leach residue and further reduce production costs by lowering an environmental risk, reducing scrapping costs, and reducing construction costs of a leach residue disposal yard; and
- Fourth, when hematite with the low-grade sulfur is produced, a special facility is not required, and thus establishment of its producing process is easy.
-
FIG. 1 is a flow chart showing a recovery process of performing high-pressure sulfuric acid leach on a mineral containing valuable metals and iron to recover the valuable metals, and further showing a refining process of hematite having low-grade sulfur which is associated with the recovery process; and -
FIG. 2 is a diagram illustrating a relation between a heating temperature and a grade of sulfur in a leach residue. - The present invention is to heat a leach residue obtained when a mineral, such as nickel oxide ore, containing valuable metals and iron is subjected to high-pressure sulfuric acid leach, to separate sulfur, and to produce high-purity hematite that can be used as an iron-making raw material having a low sulfur content.
-
FIG. 1 illustrates a flow for a recovery process of performing high-pressure sulfuric acid leach on a mineral, such as nickel oxide ore, containing valuable metals and iron to recover the valuable metals and a further flow for a refining process of a production method according to the present invention of producing hematite having low-grade sulfur from a leach residue obtained in association with the recovery process. - The flow for the recovery process of the valuable metals is indicated by an outline arrow, and the flow for the refining process of the hematite according to the invention is indicated by a black arrow.
- A leach residue to be a starting raw material of the present process is obtained as sediment when a leach slurry, which is generated by neutralizing a leachate obtained in the event of high-pressure sulfuric acid leach as illustrated in
FIG. 1 , is subjected to solid-liquid separation. As such, the leach residue is formed in a state in which a reaction product of a neutralizer input in the neutralization process and a surplus acid is contained. Accordingly, limestone or slaked lime added as the neutralizer and sulfuric acid are reacted to neutralize a free sulfuric acid remaining in the leach slurry. Thereby, the leach residue contains sulfur resulting from created calcium sulfate (plaster) by several percentage (%). - Therefore, as a method of separating a sulfur component from such a leach residue containing several percentage of sulfur, the leach residue is heated on given conditions. That is, as illustrated in
FIG. 1 , the iron oxide (hematite) for ironmaking which has low-grade sulfur is refined by roasting the leach residue and evaporating the sulfur component. -
FIG. 2 illustrates a relation between a heating temperature and the sulfur grade in the leach residue. - A temperature at which the leach residue is heated is 600° C. or more, preferably 800° C. or more, which is an effective temperature in order to make the sulfur grade in the leach residue less than 1%. Further, when the heating temperature exceeds 800° C., the sulfur grade is sharply reduced, which is more preferable. When the heating temperature becomes 1300° C., the sulfur grade can be reduced up to 0.1% or less, which is more preferable, but when the heating temperature more preferably exceeds 1400° C., this gives no great difference, and is not very preferable in the aspect of facility investment such as an increase in heating energy or a need for heat resistance of a furnace wall material. Accordingly, the heating temperature is 600° C. or more and 1400° C. or less, and preferably 800° C. or more and 1300° C. or less.
- A heating time is affected by a furnace size and an amount of the residue, and thus may be adequately adjusted. Further, the heating is performed in an oxidizing atmosphere such as atmospheric air. Thereby, along with the heating, the sulfur is removed from the leach residue as sulfur dioxide, and the high-purity iron oxide (hematite) is formed.
- Hereinafter, the invention will be described using examples.
- Nickel oxide ore having 1% nickel grade and 46 to 48% iron grade was adjusted to be a slurry of 30 to 40% by weight, and then was mixed with sulfuric acid of 64% by weight. Subsequently, the slurry was charged into a pressure device, heated to 240 to 250° C., and maintained for one hour, and a leachate was obtained by leaching nickel in the ore (HPAL).
- After the leaching, the leachate was cooled to about 70° C., and then slaked lime was added to neutralize a surplus acid (neutralization). The slurry containing a leach residue after the surplus acid was neutralized (hereinafter the leach residue after the neutralization is referred to as “neutralized residue’) was subjected to solid-liquid separation using Nutsche and a filtering bottle, and was separated into the leachate and the neutralized residue (solid-liquid separation).
- In the neutralized residue, an iron grade was 49.9%, and a sulfur grade was 1.5%.
- Next, the neutralized residue was equally divided into six parts, which were respectively raised to 30° C., 200° C., 800° C., 1000° C., 1200° C., and 1400° C., heated for one hour, and cooled.
- The sulfur grade of the leach residues after the cooling were analyzed, and the analyzed results were illustrated in
FIG. 2 . - As illustrated in
FIG. 2 , it is found that the sulfur grade is reduced up to about 1% at about 600° C., and that, when the temperature exceeds 800° C., the sulfur grade is sharply reduced, and the sulfur can be effectively separated. - In Table 1, results of measuring the iron and sulfur grades in the neutralized residue after the heating are illustrated. The iron and sulfur grades were measured by fluorescent X-ray analysis.
-
TABLE 1 Sulfur grade Sample [% by weight] Supply Neutralized residue 1.5 Heating 800° C. 0.8 1000° C. 0.4 1200° C. 0.2 - With this use of the invention, it is possible to separate the sulfur from the HPAL leach residue, and to refine the hematite so as to be usable as the raw material for ironmaking.
-
FIG. 1 - 1: NICKEL OXIDE ORE
- 2: SULFURIC ACID
- 3: LEACHATE
- 4: NEUTRALIZER
- 5: NEUTRALIZATION
- 6: LEACH SLURRY
- 7: SOLID-LIQUID SEPARATION
- 8: NEUTRALIZED RESIDUE
- 9: ROASTING
- 10: IRON OXIDE FOR IRONMAKING
- 11: SULFUR
- 12: LEACHATE
- 13: VALUABLE METALS
-
FIG. 2 - 1: SULFUR GRADE IN RESIDUE
- 2: TEMPERATURE
Claims (2)
1. A method of producing high purity hematite for ironmaking comprising:
adding an oxidant and sulfuric acid to nickel oxide ore
leaching nickel after adding the oxidant and sulfuric acid to the nickel oxide ore; and
heating a leach residue obtained after the leaching of nickel to 600° C. or more.
2. A method of producing high purity hematite for ironmaking comprising:
adding an oxidant and sulfuric acid to nickel oxide ore;
leaching nickel after adding the oxidant and sulfuric acid to the nickel oxide ore; and
heating a leach residue obtained after the leaching of nickel to 800° C. or more and 1400° C. or less.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
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JP2012062794A JP5424139B2 (en) | 2012-03-19 | 2012-03-19 | Method for producing hematite for iron making |
JP2012-062794 | 2012-03-19 | ||
PCT/JP2013/050671 WO2013140837A1 (en) | 2012-03-19 | 2013-01-16 | Production method for hematite for iron production |
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US20150050200A1 true US20150050200A1 (en) | 2015-02-19 |
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US14/386,222 Abandoned US20150050200A1 (en) | 2012-03-19 | 2013-01-16 | Production method for hematite for iron production |
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US (1) | US20150050200A1 (en) |
EP (1) | EP2829516B1 (en) |
JP (1) | JP5424139B2 (en) |
CN (1) | CN104203830B (en) |
AU (1) | AU2013236727B2 (en) |
CA (1) | CA2867672C (en) |
PH (1) | PH12014502100B1 (en) |
WO (1) | WO2013140837A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10125025B2 (en) | 2014-02-27 | 2018-11-13 | Sumitomo Metal Mining Co. Ltd. | Method for producing hematite for ironmaking |
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Publication number | Priority date | Publication date | Assignee | Title |
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JP5622061B2 (en) | 2013-03-26 | 2014-11-12 | 住友金属鉱山株式会社 | Method for producing hematite for iron making |
JP5440823B1 (en) * | 2013-09-18 | 2014-03-12 | 住友金属鉱山株式会社 | Method for producing hematite for iron making |
CN106673071B (en) * | 2016-12-23 | 2019-01-11 | 天津理工大学 | A kind of method that lateritic nickel ore pickle liquor produces black iron oxide pigment simultaneously except iron |
Citations (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2719082A (en) * | 1951-06-11 | 1955-09-27 | Int Nickel Co | Method for producing high grade hematite from nickeliferous iron sulfide ore |
US2796340A (en) * | 1954-02-04 | 1957-06-18 | New Jersey Zinc Co | Process for roasting sulfide ore concentrates |
US2867506A (en) * | 1956-07-18 | 1959-01-06 | Dorr Oliver Inc | Producing sulphur dioxide gas |
US3042498A (en) * | 1952-06-04 | 1962-07-03 | Int Nickel Co | Apparatus for roasting sulfides |
US3093559A (en) * | 1958-06-20 | 1963-06-11 | Merwin G White | Treatment of lateritic ores |
US3232744A (en) * | 1961-11-16 | 1966-02-01 | Inst Noguchi | Process for producing iron oxide with a low silica content |
US3671197A (en) * | 1970-02-05 | 1972-06-20 | Lummus Co | Treatment of pyrites |
US3854931A (en) * | 1970-04-20 | 1974-12-17 | Boliden Ab | Roasting, coarsening and hardening of iron sulfide materials |
US3957484A (en) * | 1973-10-09 | 1976-05-18 | Simon Otto Fekete | Fluid bed roasting of metal sulphides at high temperatures |
US4069041A (en) * | 1975-07-01 | 1978-01-17 | Boliden Aktiebolag | Method of recovering non-ferrous metals from sulphidic materials |
US4572822A (en) * | 1982-02-15 | 1986-02-25 | Dowa Mining Co., Ltd. | Method of recovering metals from industrial by-products |
JP2001032002A (en) * | 1999-07-16 | 2001-02-06 | Sumitomo Metal Mining Co Ltd | Production of nickel oxide powder |
US20050265910A1 (en) * | 2004-05-13 | 2005-12-01 | Sumitomo Metal Mining Co., Ltd. | Hydrometallurgical process of nickel oxide ore |
US20060133974A1 (en) * | 2004-12-22 | 2006-06-22 | Placer Dome Technical Services Limited | Reduction of lime consumption when treating refractory gold ores or concentrates |
US8052774B2 (en) * | 2009-03-31 | 2011-11-08 | Sumitomo Metal Mining Co., Ltd. | Method for concentration of gold in copper sulfide minerals |
Family Cites Families (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3655364A (en) * | 1970-02-27 | 1972-04-11 | David J I Evans | Process for treating low-iron nickeliferous ores |
DE3935362A1 (en) | 1989-10-24 | 1991-04-25 | Ruhr Zink Gmbh | PROCESS FOR PREPARING JAROSITE-CONTAINING BACKPACKS |
US6428604B1 (en) * | 2000-09-18 | 2002-08-06 | Inco Limited | Hydrometallurgical process for the recovery of nickel and cobalt values from a sulfidic flotation concentrate |
EP1727916B1 (en) * | 2004-03-25 | 2014-11-12 | Intec International Projects Pty Ltd | Recovery of metals from oxidised metalliferous materials |
CN101133171A (en) * | 2005-02-14 | 2008-02-27 | Bhp比利通Ssm技术有限公司 | Process for enhanced acid leaching of laterite ores |
JP5060033B2 (en) * | 2005-09-15 | 2012-10-31 | 大平洋金属株式会社 | Method for recovering nickel or cobalt |
WO2007071020A1 (en) * | 2005-12-23 | 2007-06-28 | Harris G Bryn | Process for recovering iron as hematite from a base metal containing ore material |
CN1858273A (en) * | 2006-06-02 | 2006-11-08 | 李智才 | Normal pressure leaching method for treating low iron nickel oxide ore |
JP4206419B2 (en) * | 2006-09-15 | 2009-01-14 | 友宏 秋山 | Ore processing method, ore processing equipment, iron making method, and iron and steel making method |
CN101338376A (en) * | 2008-08-15 | 2009-01-07 | 中南大学 | Process for comprehensively developing and utilizing nickel, cobalt, iron and magnesium from laterite-nickel ore |
JP5446226B2 (en) * | 2008-09-19 | 2014-03-19 | 住友金属鉱山株式会社 | Method for hydrometallizing nickel oxide ore |
CN101392321B (en) * | 2008-10-31 | 2010-07-28 | 东北大学 | Method for treating nickel-containing laterite by microwave reducing roasting-hematite precipitation conversion method |
CN101886272B (en) * | 2010-01-08 | 2011-11-23 | 中南大学 | Method for extracting indium and preparing iron oxide by slag-free zinc hydrometallurgy of zinc concentrate |
CN102041381B (en) * | 2011-01-17 | 2011-12-07 | 河南永通镍业有限公司 | Method for recovering nickel, cobalt, iron, manganese and magnesium from oxidized nickel ore |
CN102130422B (en) * | 2011-01-28 | 2013-06-05 | 北京航空航天大学 | Nanowire surface plasma laser |
-
2012
- 2012-03-19 JP JP2012062794A patent/JP5424139B2/en active Active
-
2013
- 2013-01-16 EP EP13764493.6A patent/EP2829516B1/en not_active Not-in-force
- 2013-01-16 CA CA2867672A patent/CA2867672C/en not_active Expired - Fee Related
- 2013-01-16 WO PCT/JP2013/050671 patent/WO2013140837A1/en active Application Filing
- 2013-01-16 US US14/386,222 patent/US20150050200A1/en not_active Abandoned
- 2013-01-16 AU AU2013236727A patent/AU2013236727B2/en not_active Ceased
- 2013-01-16 CN CN201380015130.6A patent/CN104203830B/en active Active
-
2014
- 2014-09-22 PH PH12014502100A patent/PH12014502100B1/en unknown
Patent Citations (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2719082A (en) * | 1951-06-11 | 1955-09-27 | Int Nickel Co | Method for producing high grade hematite from nickeliferous iron sulfide ore |
US3042498A (en) * | 1952-06-04 | 1962-07-03 | Int Nickel Co | Apparatus for roasting sulfides |
US2796340A (en) * | 1954-02-04 | 1957-06-18 | New Jersey Zinc Co | Process for roasting sulfide ore concentrates |
US2867506A (en) * | 1956-07-18 | 1959-01-06 | Dorr Oliver Inc | Producing sulphur dioxide gas |
US3093559A (en) * | 1958-06-20 | 1963-06-11 | Merwin G White | Treatment of lateritic ores |
US3232744A (en) * | 1961-11-16 | 1966-02-01 | Inst Noguchi | Process for producing iron oxide with a low silica content |
US3671197A (en) * | 1970-02-05 | 1972-06-20 | Lummus Co | Treatment of pyrites |
US3854931A (en) * | 1970-04-20 | 1974-12-17 | Boliden Ab | Roasting, coarsening and hardening of iron sulfide materials |
US3957484A (en) * | 1973-10-09 | 1976-05-18 | Simon Otto Fekete | Fluid bed roasting of metal sulphides at high temperatures |
US4069041A (en) * | 1975-07-01 | 1978-01-17 | Boliden Aktiebolag | Method of recovering non-ferrous metals from sulphidic materials |
US4572822A (en) * | 1982-02-15 | 1986-02-25 | Dowa Mining Co., Ltd. | Method of recovering metals from industrial by-products |
JP2001032002A (en) * | 1999-07-16 | 2001-02-06 | Sumitomo Metal Mining Co Ltd | Production of nickel oxide powder |
US20050265910A1 (en) * | 2004-05-13 | 2005-12-01 | Sumitomo Metal Mining Co., Ltd. | Hydrometallurgical process of nickel oxide ore |
US20060133974A1 (en) * | 2004-12-22 | 2006-06-22 | Placer Dome Technical Services Limited | Reduction of lime consumption when treating refractory gold ores or concentrates |
US8052774B2 (en) * | 2009-03-31 | 2011-11-08 | Sumitomo Metal Mining Co., Ltd. | Method for concentration of gold in copper sulfide minerals |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10125025B2 (en) | 2014-02-27 | 2018-11-13 | Sumitomo Metal Mining Co. Ltd. | Method for producing hematite for ironmaking |
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EP2829516A1 (en) | 2015-01-28 |
JP5424139B2 (en) | 2014-02-26 |
EP2829516B1 (en) | 2018-12-26 |
EP2829516A4 (en) | 2015-12-09 |
AU2013236727B2 (en) | 2016-06-30 |
WO2013140837A1 (en) | 2013-09-26 |
PH12014502100A1 (en) | 2014-12-10 |
CA2867672A1 (en) | 2013-09-26 |
PH12014502100B1 (en) | 2014-12-10 |
JP2013193923A (en) | 2013-09-30 |
CN104203830B (en) | 2016-11-16 |
CN104203830A (en) | 2014-12-10 |
AU2013236727A1 (en) | 2014-10-09 |
CA2867672C (en) | 2017-08-15 |
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