CA2475667C - Cobalt carbonate of low alkali metal content, method for producing the same and cobalt oxide produced from the same - Google Patents
Cobalt carbonate of low alkali metal content, method for producing the same and cobalt oxide produced from the same Download PDFInfo
- Publication number
- CA2475667C CA2475667C CA2475667A CA2475667A CA2475667C CA 2475667 C CA2475667 C CA 2475667C CA 2475667 A CA2475667 A CA 2475667A CA 2475667 A CA2475667 A CA 2475667A CA 2475667 C CA2475667 C CA 2475667C
- Authority
- CA
- Canada
- Prior art keywords
- carbonate
- alkali metal
- cobalt
- sodium
- content
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 229910052783 alkali metal Inorganic materials 0.000 title claims abstract description 108
- 150000001340 alkali metals Chemical class 0.000 title claims abstract description 107
- 229910021446 cobalt carbonate Inorganic materials 0.000 title claims abstract description 76
- ZOTKGJBKKKVBJZ-UHFFFAOYSA-L cobalt(2+);carbonate Chemical compound [Co+2].[O-]C([O-])=O ZOTKGJBKKKVBJZ-UHFFFAOYSA-L 0.000 title claims abstract description 75
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 44
- 229910000428 cobalt oxide Inorganic materials 0.000 title abstract description 22
- IVMYJDGYRUAWML-UHFFFAOYSA-N cobalt(ii) oxide Chemical compound [Co]=O IVMYJDGYRUAWML-UHFFFAOYSA-N 0.000 title abstract description 20
- 238000006243 chemical reaction Methods 0.000 claims abstract description 63
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 claims abstract description 55
- 239000007864 aqueous solution Substances 0.000 claims abstract description 36
- 238000000034 method Methods 0.000 claims abstract description 34
- 150000001868 cobalt Chemical class 0.000 claims abstract description 15
- 239000012266 salt solution Substances 0.000 claims abstract description 7
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical group [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 36
- UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 claims description 13
- 229910000030 sodium bicarbonate Inorganic materials 0.000 claims description 7
- 235000017557 sodium bicarbonate Nutrition 0.000 claims description 7
- 150000008044 alkali metal hydroxides Chemical class 0.000 claims description 4
- OBWXQDHWLMJOOD-UHFFFAOYSA-H cobalt(2+);dicarbonate;dihydroxide;hydrate Chemical compound O.[OH-].[OH-].[Co+2].[Co+2].[Co+2].[O-]C([O-])=O.[O-]C([O-])=O OBWXQDHWLMJOOD-UHFFFAOYSA-H 0.000 claims description 3
- 229910000288 alkali metal carbonate Inorganic materials 0.000 claims description 2
- 150000008041 alkali metal carbonates Chemical class 0.000 claims description 2
- 159000000000 sodium salts Chemical class 0.000 claims description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 abstract description 16
- 239000011734 sodium Substances 0.000 description 36
- 229910052708 sodium Inorganic materials 0.000 description 34
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 33
- 239000000243 solution Substances 0.000 description 21
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 18
- 150000003839 salts Chemical class 0.000 description 11
- 238000005406 washing Methods 0.000 description 10
- 239000002244 precipitate Substances 0.000 description 9
- 229910000029 sodium carbonate Inorganic materials 0.000 description 9
- 235000017550 sodium carbonate Nutrition 0.000 description 9
- -1 LOW ALKALI METAL Chemical class 0.000 description 8
- 229910017052 cobalt Inorganic materials 0.000 description 8
- 239000010941 cobalt Substances 0.000 description 8
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 8
- 230000000052 comparative effect Effects 0.000 description 7
- 238000001914 filtration Methods 0.000 description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- 239000003153 chemical reaction reagent Substances 0.000 description 6
- 238000007796 conventional method Methods 0.000 description 6
- 230000003247 decreasing effect Effects 0.000 description 6
- 239000000706 filtrate Substances 0.000 description 6
- 239000000463 material Substances 0.000 description 6
- 239000007787 solid Substances 0.000 description 6
- GVPFVAHMJGGAJG-UHFFFAOYSA-L cobalt dichloride Chemical compound [Cl-].[Cl-].[Co+2] GVPFVAHMJGGAJG-UHFFFAOYSA-L 0.000 description 5
- HIYNGBUQYVBFLA-UHFFFAOYSA-D cobalt(2+);dicarbonate;hexahydroxide Chemical compound [OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[Co+2].[Co+2].[Co+2].[Co+2].[Co+2].[O-]C([O-])=O.[O-]C([O-])=O HIYNGBUQYVBFLA-UHFFFAOYSA-D 0.000 description 5
- 229910021503 Cobalt(II) hydroxide Inorganic materials 0.000 description 4
- ASKVAEGIVYSGNY-UHFFFAOYSA-L cobalt(ii) hydroxide Chemical compound [OH-].[OH-].[Co+2] ASKVAEGIVYSGNY-UHFFFAOYSA-L 0.000 description 4
- 150000002500 ions Chemical class 0.000 description 4
- 239000007788 liquid Substances 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- 239000002002 slurry Substances 0.000 description 4
- 238000003756 stirring Methods 0.000 description 4
- ATRRKUHOCOJYRX-UHFFFAOYSA-N Ammonium bicarbonate Chemical compound [NH4+].OC([O-])=O ATRRKUHOCOJYRX-UHFFFAOYSA-N 0.000 description 3
- 239000003513 alkali Substances 0.000 description 3
- 239000001099 ammonium carbonate Substances 0.000 description 3
- 238000001354 calcination Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000007858 starting material Substances 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 2
- 229910000013 Ammonium bicarbonate Inorganic materials 0.000 description 2
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 2
- 235000012538 ammonium bicarbonate Nutrition 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- ZJRWDIJRKKXMNW-UHFFFAOYSA-N carbonic acid;cobalt Chemical compound [Co].OC(O)=O ZJRWDIJRKKXMNW-UHFFFAOYSA-N 0.000 description 2
- 229910000001 cobalt(II) carbonate Inorganic materials 0.000 description 2
- 230000018044 dehydration Effects 0.000 description 2
- 238000006297 dehydration reaction Methods 0.000 description 2
- ZFTFAPZRGNKQPU-UHFFFAOYSA-N dicarbonic acid Chemical compound OC(=O)OC(O)=O ZFTFAPZRGNKQPU-UHFFFAOYSA-N 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 229910052700 potassium Inorganic materials 0.000 description 2
- 239000011591 potassium Substances 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 230000001131 transforming effect Effects 0.000 description 2
- BVKZGUZCCUSVTD-UHFFFAOYSA-M Bicarbonate Chemical compound OC([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-M 0.000 description 1
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 1
- 229910002651 NO3 Inorganic materials 0.000 description 1
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 1
- UIIMBOGNXHQVGW-DEQYMQKBSA-M Sodium bicarbonate-14C Chemical compound [Na+].O[14C]([O-])=O UIIMBOGNXHQVGW-DEQYMQKBSA-M 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- RRPXXFMVPWMACY-UHFFFAOYSA-N [Co].O=[Co]=O Chemical compound [Co].O=[Co]=O RRPXXFMVPWMACY-UHFFFAOYSA-N 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- 235000012501 ammonium carbonate Nutrition 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 125000005587 carbonate group Chemical group 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 150000001768 cations Chemical class 0.000 description 1
- 229910010293 ceramic material Inorganic materials 0.000 description 1
- KKWAPDPZGBKBTI-UHFFFAOYSA-J cobalt(2+) dicarbonate Chemical compound [Co+2].C([O-])([O-])=O.[Co+2].C([O-])([O-])=O KKWAPDPZGBKBTI-UHFFFAOYSA-J 0.000 description 1
- UBEWDCMIDFGDOO-UHFFFAOYSA-N cobalt(2+);cobalt(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[O-2].[Co+2].[Co+3].[Co+3] UBEWDCMIDFGDOO-UHFFFAOYSA-N 0.000 description 1
- 239000003086 colorant Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000004993 emission spectroscopy Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- 229910001416 lithium ion Inorganic materials 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- 239000012066 reaction slurry Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- KKCBUQHMOMHUOY-UHFFFAOYSA-N sodium oxide Chemical compound [O-2].[Na+].[Na+] KKCBUQHMOMHUOY-UHFFFAOYSA-N 0.000 description 1
- 229910001948 sodium oxide Inorganic materials 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- 238000004065 wastewater treatment Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G51/00—Compounds of cobalt
- C01G51/04—Oxides
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G51/00—Compounds of cobalt
- C01G51/06—Carbonates
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
- C09C1/00—Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
- C09C1/0009—Pigments for ceramics
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
Disclosed are a method for producing a cobalt carbonate of low alkali metal content at a low cost in high productivity, and a cobalt oxide of low alkali metal content and high performance produced from the cobalt carbonate. The method comprises reacting an aqueous cobalt salt solution with a carbonate of an alkali metal to produce the cobalt carbonate; wherein: (1) a reaction temperature is controlled at less than or equal to 25°C, and/or (2) an aqueous solution of the carbonate of an alkali metal containing a hydroxide of the alkali metal in an amount of 5 to 40g/L is used as the carbonate of the alkali metal.
Description
SPECIFICATION
COBALT CARBONATE OF LOW ALKALI METAL CONTENT, METHOD FOR PRODUCING THE SAME AND COBALT OXIDE PRODUCED
FROM THE SAME
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
The present invention relates to cobalt carbonate of a low alkali metal content, a method for producing the same and cobalt oxide produced from the same, more specifically a method for producing cobalt carbonate of a low alkali metal content at a low cost in high productivity, and cobalt oxide of a low alkali metal content and high performance produced from the cobalt carbonate.
DESCRIPTION OF THE PRIOR ART
Cobalt oxide has been used as a pigment for potteries and a colorant for glass products. Recently, a demand of the cobalt oxide has been growing rapidly as a ceramic material for electronic device parts, e.g., those for condensers, varistors and thermistors, and as a material for lithium ion batteries and organic synthesis catalysts.
When the cobalt oxide is used for the above-mentioned purposes, in particular for the electronic device and the battery, an alkali metal is cited as an impurity which causes various problems, e.g., abnormal sintering, reduced electronic resistance and deteriorated electromagnetic properties, while they are produced or in service. In particular, it is highly desirable to contain no sodium.
It is difficult for a common method used for removing the alkali metal, e.g., by wet washing or evaporation under heating, to remove efficiently and sufficiently the alkali metal from cobalt oxide containing an alkali metal. Therefore, a cobalt salt as a starting material for cobalt oxide is pretreated to reduce alkali metal content. Several methods for producing a cobalt salt of low alkali metal content have been proposed, and the representative ones are described below. They have been contributing to production of cobalt oxide of low alkali metal content, but each involves its own disadvantages.
(1) Precipitation of highly filterable cobalt basic carbonate is produced from an aqueous cobalt salt solution using a sodium-free carbonate of an alkali, e.g., ammonium bicarbonate or ammonium carbonate. This method can produce .cobalt oxide of low ammonium content by washing the precipitate, which is highly filterable, and subsequent calcination to reduce ammonium content. However, the method involves disadvantages of high production cost, because ammonium bicarbonate used as a reactant is relatively expensive, and,'in particular, high cost for waste solution treatment because ammonium ions are massively present in the solution.
COBALT CARBONATE OF LOW ALKALI METAL CONTENT, METHOD FOR PRODUCING THE SAME AND COBALT OXIDE PRODUCED
FROM THE SAME
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
The present invention relates to cobalt carbonate of a low alkali metal content, a method for producing the same and cobalt oxide produced from the same, more specifically a method for producing cobalt carbonate of a low alkali metal content at a low cost in high productivity, and cobalt oxide of a low alkali metal content and high performance produced from the cobalt carbonate.
DESCRIPTION OF THE PRIOR ART
Cobalt oxide has been used as a pigment for potteries and a colorant for glass products. Recently, a demand of the cobalt oxide has been growing rapidly as a ceramic material for electronic device parts, e.g., those for condensers, varistors and thermistors, and as a material for lithium ion batteries and organic synthesis catalysts.
When the cobalt oxide is used for the above-mentioned purposes, in particular for the electronic device and the battery, an alkali metal is cited as an impurity which causes various problems, e.g., abnormal sintering, reduced electronic resistance and deteriorated electromagnetic properties, while they are produced or in service. In particular, it is highly desirable to contain no sodium.
It is difficult for a common method used for removing the alkali metal, e.g., by wet washing or evaporation under heating, to remove efficiently and sufficiently the alkali metal from cobalt oxide containing an alkali metal. Therefore, a cobalt salt as a starting material for cobalt oxide is pretreated to reduce alkali metal content. Several methods for producing a cobalt salt of low alkali metal content have been proposed, and the representative ones are described below. They have been contributing to production of cobalt oxide of low alkali metal content, but each involves its own disadvantages.
(1) Precipitation of highly filterable cobalt basic carbonate is produced from an aqueous cobalt salt solution using a sodium-free carbonate of an alkali, e.g., ammonium bicarbonate or ammonium carbonate. This method can produce .cobalt oxide of low ammonium content by washing the precipitate, which is highly filterable, and subsequent calcination to reduce ammonium content. However, the method involves disadvantages of high production cost, because ammonium bicarbonate used as a reactant is relatively expensive, and,'in particular, high cost for waste solution treatment because ammonium ions are massively present in the solution.
(2) Production of cobalt hydroxide from an aqueous cobalt salt solution using an alkali metal hydroxide, and subsequent removal of impurities, e.g., an alkali metal, from the resulting precipitate by repeated washing (refer to, e.g., Japanese Patent Publication No. 55-62814). This method involves a disadvantage of low productivity resulting from difficulties in washing and filtration on a commercial scale because the precipitate is of. very fine cobalt hydroxide particles, very. difficult to filtrate and settle.
(3) Precipitation of cobalt basic carbonate (also referred to as basic cobalt carbonate) produced from an aqueous cobalt salt solution using sodium carbonate or sodium bicarbonate, and subsequent washing the resulting precipitate with a sodium hydroxide solution and then with water, to produce cobalt basic carbonate of low sodium content (refer to, e.g., Japanese Patent Publication No. 7-196323). This method can remove sodium by washing a water-insoluble double salt e.g., sodium cobaltate dicarbonate (Na2[Co(CO3)2]=4H2O), which is precipitated as a by-product in the case of high carbonate ion content in a solution, with a sodium hydroxide solution to decompose the salt and thereby to produce cobalt carbonate of low sodium content. However, it involves disadvantages of increased costs, e.g., those resulting from an additional step of alkali washing needed before a water-washing step, which is normally adopted, and those associated with use of sodium hydroxide or the like.
As discussed above, cobalt carbonate, e.g., cobalt basic carbonate, is a more preferable starting compound for cobalt oxide of low sodium content than cobalt hydroxide, because it is highly filterable and can be easily treated by water-washing. Moreover, a carbonate of an alkali metal is preferable than a carbonate of an alkali., because it can avoid problems associated with waste water treatment.
Under these circumstances, there are demands for methods for producing cobalt carbonate of low alkali metal content at a low cost in high productivity, and for cobalt oxide of low alkali metal content and high performance produced from the cobalt carbonate. The term cobalt carbonate used in this specification means a cobalt carbonate compound in the broad sense, including cobalt basic carbonate having hydroxide group in addition to carbonate group.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method for producing cobalt carbonate of low alkali metal content at a low cost in high productivity in consideration of the problems involved in the conventional techniques. It is another object of the present invention to provide cobalt oxide of low alkali metal content and high performance produced from the cobalt carbonate.
The inventors of the present invention have found, after having extensively studied, in particular, cobalt carbonate for a method for producing cobalt oxide to attain the above objects, that cobalt carbonate of low alkali metal content can be produced at a low cost in high productivity when specific reaction conditions are adopted, and have achieved the present invention.
A first aspect of the present invention provides a method for producing cobalt carbonate of low alkali metal content, which comprises reacting an aqueous cobalt salt solution with a carbonate of an alkali metal to produce the cobalt carbonate under at least one of the following conditions:
(1) a reaction temperature is controlled at 25 C or lower, and (2) an aqueous solution of an alkali metal carbonate containing of an alkali metal hydroxide in an amount of 5 to 40g/L is used as the carbonate of an alkali metal. The temperature in the first aspect may be controlled at 14 to 18 C.
In a first major embodiment of the first aspect, a sodium salt is used as the carbonate of an alkali metal.
As discussed above, cobalt carbonate, e.g., cobalt basic carbonate, is a more preferable starting compound for cobalt oxide of low sodium content than cobalt hydroxide, because it is highly filterable and can be easily treated by water-washing. Moreover, a carbonate of an alkali metal is preferable than a carbonate of an alkali., because it can avoid problems associated with waste water treatment.
Under these circumstances, there are demands for methods for producing cobalt carbonate of low alkali metal content at a low cost in high productivity, and for cobalt oxide of low alkali metal content and high performance produced from the cobalt carbonate. The term cobalt carbonate used in this specification means a cobalt carbonate compound in the broad sense, including cobalt basic carbonate having hydroxide group in addition to carbonate group.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method for producing cobalt carbonate of low alkali metal content at a low cost in high productivity in consideration of the problems involved in the conventional techniques. It is another object of the present invention to provide cobalt oxide of low alkali metal content and high performance produced from the cobalt carbonate.
The inventors of the present invention have found, after having extensively studied, in particular, cobalt carbonate for a method for producing cobalt oxide to attain the above objects, that cobalt carbonate of low alkali metal content can be produced at a low cost in high productivity when specific reaction conditions are adopted, and have achieved the present invention.
A first aspect of the present invention provides a method for producing cobalt carbonate of low alkali metal content, which comprises reacting an aqueous cobalt salt solution with a carbonate of an alkali metal to produce the cobalt carbonate under at least one of the following conditions:
(1) a reaction temperature is controlled at 25 C or lower, and (2) an aqueous solution of an alkali metal carbonate containing of an alkali metal hydroxide in an amount of 5 to 40g/L is used as the carbonate of an alkali metal. The temperature in the first aspect may be controlled at 14 to 18 C.
In a first major embodiment of the first aspect, a sodium salt is used as the carbonate of an alkali metal.
In the first aspect, the alkali metal content may be 0.7% by weight or less, and the cobalt carbonate may be basic.
In a second major embodiment of the method, sodium bicarbonate is used as the carbonate of an alkali metal.
In a third major embodiment of the method, the reaction temperature is controlled at 10 to 20 C.
In a fourth major embodiment of the method, sodium hydroxide is used as the hydroxide of an alkali metal.
The second aspect of the present invention provides cobalt carbonate of low alkali metal content produced by the method.
A third aspect of the present invention provides cobalt oxide of low alkali metal content produced from the cobalt carbonate.
The method of the present invention can produce cobalt carbonate of low alkali metal content at a low cost in high productivity, and cobalt oxide produced from the cobalt carbonate contains an alkali metal at a low content and exhibits high performance. As such, they have very high industrial values.
DETAILED DESCRIPTION OF THE INVENTION
Cobalt carbonate of low alkali metal content, the method for producing the same and cobalt oxide produced from the same of the present invention are described in more detail below.
In a second major embodiment of the method, sodium bicarbonate is used as the carbonate of an alkali metal.
In a third major embodiment of the method, the reaction temperature is controlled at 10 to 20 C.
In a fourth major embodiment of the method, sodium hydroxide is used as the hydroxide of an alkali metal.
The second aspect of the present invention provides cobalt carbonate of low alkali metal content produced by the method.
A third aspect of the present invention provides cobalt oxide of low alkali metal content produced from the cobalt carbonate.
The method of the present invention can produce cobalt carbonate of low alkali metal content at a low cost in high productivity, and cobalt oxide produced from the cobalt carbonate contains an alkali metal at a low content and exhibits high performance. As such, they have very high industrial values.
DETAILED DESCRIPTION OF THE INVENTION
Cobalt carbonate of low alkali metal content, the method for producing the same and cobalt oxide produced from the same of the present invention are described in more detail below.
The method of the present invention produces cobalt carbonate of low alkali metal content by a reaction of a .carbonate of an alkali metal with a cobalt salt in the form of an aqueous solution, wherein (1) a reaction temperature is controlled at 25 C or lower, and/or (2) an aqueous solution of carbonate of an alkali metal containing 5a a hydroxide of alkali metal in an amount of 5 to 40g/L is used as the carbonate of an alkali metal. The cobalt carbonate of low alkali metal content is used for producing cobalt oxide.
1. Method for producing cobalt carbonate The method of the present invention produces cobalt carbonate by the reaction of a carbonate of an alkali metal with a cobalt salt in the form of an aqueous solution, while satisfying at least one of the conditions (1) and (2):
(1) a reaction temperature is controlled at 25 C
or lower, and (2) an aqueous solution of carbonate of an alkali metal containing a hydroxide of an alkali metal at a concentration of 5 to 40g/L is used as the carbonate of an alkali metal.
More specifically, the method of the present invention produces cobalt carbonate by the reaction of a carbonate of an alkali metal with a cobalt salt in the form of an aqueous solution, wherein (A) a reaction temperature is controlled at 25 C or lower, (B) an aqueous solution of carbonate of an alkali metal containing a hydroxide of an alkali metal at 5 to 40g/L is used as the carbonate of an alkali metal, or (C) an aqueous solution of carbonate of an alkali metal containing a hydroxide of an alkali metal at 5 to 40g/L is used as the carbonate of an alkali metal and, at the same time, reaction temperature is controlled at 25 C or lower.
Each of controlling reaction temperature at 25 C
or lower, and using an aqueous solution of carbonate of an alkali metal containing a hydroxide of an alkali metal at 5 to 40g/L as the carbonate of an alkali metal has an essential meaning for the method of the present invention for producing cobalt carbonate. Each leads to a solution for producing cobalt carbonate of low alkali metal content in high productivity on a commercial scale, which is a technical theme for the conventional techniques.
By contrast, the conventional method for producing cobalt carbonate cannot give cobalt carbonate of low alkali metal content by a simple procedure for the following technical problems. For example, some of the conventional methods react a cobalt salt, e.g., cobalt chloride, nitrate or sulfate, in the form of aqueous solution with sodium carbonate or bicarbonate incorporated in the solution to produce cobalt carbonate in the form of precipitate. The resulting cobalt carbonate contains sodium at 1 to 4% by weight, which cannot be removed by water-washing.
The high content of sodium conceivably results from a water-insoluble double salt of alkali metal, e.g., sodium cobaltate dicarbonate (Na2[Co(CO3)2] - 4H20) partly formed in the system to contaminate the product precipitate of cobalt carbonate. The reaction mechanism for producing the double salt conceivably involves the Co ion which forms the Co-carbonate complex ion in a solution of high carbonate ion concentration and also forms a double salt of the complex ion with a monovalent cation, e.g., that of sodium.
It is therefore essential to allow the cobalt carbonate producing reaction as the major reaction to preferentially proceed while controlling the double salt producing reaction, for which each of controlling reaction temperature at 25 C or lower, and using an aqueous solution of carbonate of an alkali metal containing a hydroxide of alkali metal at a given content as the carbonate of an alkali metal is effective.
The method for controlling the reaction for the above production method is not limited. For example, the reaction can be controlled by incorporating an aqueous solution containing a cobalt salt at a given content with an aqueous solution containing a carbonate of an alkali metal at a given content in a given mixing ratio, or by controlling addition rate of an aqueous solution of carbonate of an alkali metal in such a way to control the reaction solution at a given pH level.
For the former approach, content of the carbonate of an alkali metal in the aqueous solution of cobalt salt is not limited, but preferably 1.0 to 1.5 chemical equivalents required for transforming cobalt in the aqueous solution into CoCO3 in order to recover cobalt at a high rate. For the latter approach, pH level of the reaction solution is not limited, but preferably 6.5 to 8.0 in order to recover cobalt at a high rate.
The carbonate of an alkali metal for the above production method is not limited. For example, sodium or potassium is used as the alkali metal. In particular, sodium carbonate and sodium bicarbonate are preferable for their inexpensiveness. Sodium bicarbonate is more preferable, because it is low in alkalinity, and hence excellent in pH controllability for the reaction to keep sodium content at a low level more easily.
(1) Production Method (A) Production Method (A) involves a procedure to control reaction temperature at 25 C or lower, wherein reaction temperature is controlled at 25 C or lower, preferably 10 to 20 C, more preferably 14 to 18 C. More specifically, decreasing reaction temperature retards the double salt producing reaction more than the cobalt carbonate producing reaction as the major reaction. Therefore, it is decreased to room temperature or below to control production of the double salt. The reaction system operating at above 25 C cannot give cobalt carbonate of sufficiently low alkali metal content for electronic device and battery materials because of its insufficient effect of controlling the double salt producing reaction. Decreasing reaction temperature increases the effect of controlling the double salt producing reaction. However, it is 10 C or higher for the present invention, because decreasing the level excessively is accompanied by increased cooling system cost.
(2) Production Method (B) Production Method (B) involves a procedure which uses an aqueous solution of carbonate of an alkali metal containing a hydroxide of an alkali metal at 5 to 40g/L as the carbonate of an alkali metal. More specifically, incorporation of a hydroxide of an alkali metal brings favorable effects, e.g., increasing OH ion in the reaction solution while decreasing CO32- ion content, and triggering the reaction for producing the hydroxide simultaneously with that for producing the carbonate, the former proceeding faster than the latter, thereby accelerating production of the hydroxide and carbonate while controlling production of the double salt to decrease alkali metal content.
In Production Method (B), a hydroxide of an alkali metal is incorporated in the aqueous solution of carbonate of an alkali metal at 5 to 40g/L, preferably 20 to 40g/L, more preferably 20 to 30g/L. At below 5g/L, the effect of decreasing sodium content of the cobalt carbonate product may be insufficient. At above 40gIL, on the other hand, cobalt hydroxide may be the major component of the precipitate produced, because the reaction for producing the hydroxide will prevail over that for producing the carbonate.
As a result, the precipitate is composed of finer particles, to have deteriorated filterability and washability.
Reaction temperature for the above method is not limited, and it is carried out at a reaction solution temperature of room temperature or higher. The hydroxide of an alkali metal for the above method is not limited. For example, sodium or potassium is used as the alkali metal.
Sodium hydroxide is particularly preferable because of its inexpensiveness.
(3) Production Method (C) Production Method (C) is a combination of Production Methods (A) and (B), involving a procedure which uses an aqueous solution of carbonate of an alkali metal containing a hydroxide of an alkali metal at 5 to 40gIL as the carbonate of an alkali metal, and another procedure to control reaction temperature at 25 C or lower. Each of these procedures is carried out under the conditions similar to those for Production Method (A) or (B).
2. Cobalt carbonate Cobalt carbonate of the present invention is the one containing an alkali metal at a low content, produced by one of Production Methods (A) to (C) described above. The cobalt carbonate precipitate produced is separated into the solid and reaction filtrate by centrifugal separation or the like, and the solid is washed with water and then dehydrated.
Cobalt carbonate of the present invention contains an alkali metal at 0.3% or less and 0.1% or less, both by weight, when produced by Production Method (A) or (C) operating at 25 and 20 C, respectively, and 0.7% or less and 0.3% or less, both by weight, when produced by Production Method (B) operating under the preferable conditions for the latter. By contrast, cobalt carbonate produced by the conventional method operating at 30 to 70 C
contains an alkali metal at 1 to 4% by weight.
As discussed above, the production method of the present invention gives cobalt carbonate of lower alkali metal content.
3. Cobalt oxide Cobalt oxide of low alkali metal content of the present invention is produced from the cobalt carbonate as the starting compound, which is produced by the method described above and calcined. It contains an alkali metal at a lower content than the one produced by the conventional method, and is suitable as materials for electronic device and battery, for which materials containing an alkali metal, e.g., sodium, is unsuitable.
The method for producing the cobalt oxide is not limited. It is produced by calcination of the cobalt carbonate, preferably heated at 350 C
or higher in air. At a calcination temperature below 350 C, the carbonate may be decomposed insufficiently and left undecomposed in the product.
EXAMPLES
The present invention is described in more detail by EXAMPLES and COMPARATIVE EXAMPLES, which by no means limit the present invention. Cobalt carbonate was analyzed for metal and moisture contents by the following procedures in EXAMPLES and COMPARATIVE
EXAMPLES.
(1) Analysis of metal contents The dehydration-treated sample was dried at 105 C for 24 hours, and analyzed by ICP emission spectrometry.
(2) Analysis of moisture content The dehydration-treated sample was dried at 105 C for 24 hours, and measured for weight difference before and after the drying treatment.
(EXAMPLE i) Cobalt carbonate was prepared by Production Method (A), and evaluated for its sodium content.
First, 20L of a 140g/L aqueous solution of sodium bicarbonate as the carbonate of an alkali metal was put in a reaction tank, to which 20L of a 50g/L aqueous solution of cobalt chloride was added in 30 minutes for the reaction, while reaction temperature was kept at 18 C with stirring. The carbonate of the alkali metal was added to the aqueous cobalt salt solution at 1.0 chemical equivalent required for transforming cobalt into CoCO3.
The reaction was allowed to continue for 20 minutes, and the resultant slurry was centrifugally separated into cobalt carbonate (solid) and reaction filtrate (liquid). The separated cobalt carbonate was repulp-washed with water and centrifugally dehydrated again. It was analyzed for sodium content. The result is given in Table 1.
(EXAMPLE 2) Cobalt carbonate was prepared by Production Method (A), and evaluated for its sodium content.
First, IL of a 50gIL aqueous solution of cobalt chloride was put in a reaction tank, to which a 100g/L aqueous solution of sodium carbonate (reagent grade) as the carbonate of an alkali metal was added for the reaction, which was allowed to proceed for 4 hours while reaction temperature was kept at 14 C with stirring, where the reaction solution was adjusted at a final pH level of 7.7.
The resultant slurry was separated into cobalt carbonate (solid) and reaction filtrate (liquid) by filtration under a vacuum. The separated cobalt carbonate was repulp-washed with water and dehydrated again by filtration under a vacuum. It was analyzed for sodium content. The result is given in Table 1.
(EXAMPLE 3) Cobalt carbonate was prepared by Production Method (A), and evaluated for its sodium content.
It was prepared in the same manner as in EXAMPLE 2, except that a 73g/L aqueous solution of sodium bicarbonate (reagent grade) was used as the carbonate of an alkali metal and the reaction solution was adjusted at a final pH level of 6.9. The resultant cobalt carbonate was analyzed for sodium content. The result is given in Table 1.
(EXAMPLE 4) Cobalt carbonate was prepared by Production Method (A), and evaluated for its sodium content.
It was prepared in the same manner as in EXAMPLE 1, except that reaction temperature was controlled at 25 C . The resultant cobalt carbonate was analyzed for sodium content. The result is given in Table 1.
(EXAMPLE 5) Cobalt carbonate was prepared by Production Method (C), and evaluated for its sodium and moisture content.
First, a 100g/L aqueous solution of sodium carbonate (reagent grade) as the carbonate of an alkali metal was incorporated with sodium hydroxide to 10g/L. Next, the above aqueous solution containing the alkali metal was pumped into a 1L reactor together with a 50g/L aqueous solution of cobalt chloride (reagent grade), and the reaction was allowed to proceed while reaction temperature was kept at 18 C with stirring. These aqueous solutions were pumped in such a way to keep the residence time at 1 hour and reaction solution pH level at 7.5.
The resultant slurry was separated into cobalt carbonate (solid) and reaction filtrate (liquid) by filtration under a vacuum. The separated cobalt carbonate was washed with sprayed water and dehydrated again by filtration under a vacuum. It was analyzed for sodium content. The result is given in Table 1.
(EXAMPLES 6 to 9) Cobalt carbonate was prepared by Production Method (B) in each of EXAMPLES 6 to 9, and evaluated for its sodium and moisture contents.
First, a 100g/L aqueous solution of sodium carbonate (reagent grade) as the carbonate of an alkali metal was incorporated with sodium oxide to 5, 10, 20 or 40g/L. Next, the above aqueous solution containing the alkali metal was pumped into a 1L reactor together with a 50g/L aqueous solution of cobalt chloride (reagent grade), and the reaction was allowed to proceed while reaction temperature was kept at 70 C with stirring. These aqueous solutions were pumped in such a way to keep the residence time at 1 hour and reaction solution pH level at 7.5.
The resultant slurry was separated into cobalt carbonate (solid) and reaction filtrate (liquid) by filtration under a vacuum. The separated cobalt carbonate was washed with sprayed water and dehydrated again by filtration under a vacuum. It was analyzed for sodium, cobalt and moisture contents. The result is given in Table 2.
(COMPARATIVE EXAMPLE 1) Cobalt carbonate was prepared in the same manner as in EXAMPLE 6, except that sodium hydroxide was incorporated in the aqueous sodium carbonate solution to 50g/L as the aqueous carbonate solution containing the alkali metal. The resulting cobalt carbonate showed deteriorated filterability. It was analyzed for sodium, cobalt and moisture contents.
The result is given in Table 2.
(COMPARATIVE EXAMPLE 2) Cobalt carbonate was prepared in the same manner as in EXAMPLE 6, except that sodium hydroxide was not incorporated in the aqueous sodium carbonate solution as the aqueous carbonate solution containing the alkali metal. It was analyzed for sodium, cobalt and moisture contents. The result is given in Table 2 Table 1 Production Reaction Slurry pH during Na content of Method temperature the reaction process cobalt carbonate ( C) (% by weight) EXAMPLE 1 (A) 1.8 - 0.01 EXAMPLE 2 (A) 14 7.7 0.02 EXAMPLE 3 (A) 14 6.9 0.01 EXAMPLE 4 (A) 25 0.30 EXAMPLE .5 (C) 18 0.02 Table 2 Production NaOH Reaction Na, Co and moisture Method content of temperature contents of cobalt the aqueous ( C) carbonate Na2CO3 /o b wei ht) solution Na Co moisture contents*
EXAMPLE 6 (B) 5 70 0.68 49.0 26.0 EXAMPLE 7 (B) 10 70 0.52 51.2 25.9 EXAMPLE 8 (B) 20 70 0.22 51.8 27.7 EXAMPLE 9 (B) 40 70 0.13 52.5 50.4 COMPARATIVE (B) 50 70 0.13 52.8 62.5*
COMPARATIVE - 0 70 0.92 50.3 22.4 * Cobalt carbonate showed deteriorated filterability when it contained moisture at 60%
or more.
As shown in Table 1, cobalt carbonate prepared in each of EXAMPLES
1 to 4 by Production Method (A) and in EXAMPLE 5 by Production Method (C) at a reaction temperature for the present invention contained sodium at a low level.
As shown in Table 2, cobalt carbonate prepared in each of EXAMPLES
6 to 9 by Production Method (B) using the aqueous solution of carbonate of an alkali metal incorporated with sodium hydroxide at a given content for the present invention contained sodium at a low level. By contrast, cobalt carbonate prepared in each of COMPARATIVE EXAMPLES 1 and 2 using the aqueous solution of carbonate of an alkali metal incorporated with sodium hydroxide at a content out of the range for the present invention showed unsatisfactory result with respect to sodium content or moisture content (which relates to filterability).
As discussed above, cobalt oxide produced from cobalt carbonate of low alkali metal content of the present invention, produced by the method of the present invention, contains an alkali metal at a sufficiently low content to be suitable as materials for electronic device and battery, in particular for purposes for which materials containing an alkali metal, e.g., sodium, is unsuitable.
1. Method for producing cobalt carbonate The method of the present invention produces cobalt carbonate by the reaction of a carbonate of an alkali metal with a cobalt salt in the form of an aqueous solution, while satisfying at least one of the conditions (1) and (2):
(1) a reaction temperature is controlled at 25 C
or lower, and (2) an aqueous solution of carbonate of an alkali metal containing a hydroxide of an alkali metal at a concentration of 5 to 40g/L is used as the carbonate of an alkali metal.
More specifically, the method of the present invention produces cobalt carbonate by the reaction of a carbonate of an alkali metal with a cobalt salt in the form of an aqueous solution, wherein (A) a reaction temperature is controlled at 25 C or lower, (B) an aqueous solution of carbonate of an alkali metal containing a hydroxide of an alkali metal at 5 to 40g/L is used as the carbonate of an alkali metal, or (C) an aqueous solution of carbonate of an alkali metal containing a hydroxide of an alkali metal at 5 to 40g/L is used as the carbonate of an alkali metal and, at the same time, reaction temperature is controlled at 25 C or lower.
Each of controlling reaction temperature at 25 C
or lower, and using an aqueous solution of carbonate of an alkali metal containing a hydroxide of an alkali metal at 5 to 40g/L as the carbonate of an alkali metal has an essential meaning for the method of the present invention for producing cobalt carbonate. Each leads to a solution for producing cobalt carbonate of low alkali metal content in high productivity on a commercial scale, which is a technical theme for the conventional techniques.
By contrast, the conventional method for producing cobalt carbonate cannot give cobalt carbonate of low alkali metal content by a simple procedure for the following technical problems. For example, some of the conventional methods react a cobalt salt, e.g., cobalt chloride, nitrate or sulfate, in the form of aqueous solution with sodium carbonate or bicarbonate incorporated in the solution to produce cobalt carbonate in the form of precipitate. The resulting cobalt carbonate contains sodium at 1 to 4% by weight, which cannot be removed by water-washing.
The high content of sodium conceivably results from a water-insoluble double salt of alkali metal, e.g., sodium cobaltate dicarbonate (Na2[Co(CO3)2] - 4H20) partly formed in the system to contaminate the product precipitate of cobalt carbonate. The reaction mechanism for producing the double salt conceivably involves the Co ion which forms the Co-carbonate complex ion in a solution of high carbonate ion concentration and also forms a double salt of the complex ion with a monovalent cation, e.g., that of sodium.
It is therefore essential to allow the cobalt carbonate producing reaction as the major reaction to preferentially proceed while controlling the double salt producing reaction, for which each of controlling reaction temperature at 25 C or lower, and using an aqueous solution of carbonate of an alkali metal containing a hydroxide of alkali metal at a given content as the carbonate of an alkali metal is effective.
The method for controlling the reaction for the above production method is not limited. For example, the reaction can be controlled by incorporating an aqueous solution containing a cobalt salt at a given content with an aqueous solution containing a carbonate of an alkali metal at a given content in a given mixing ratio, or by controlling addition rate of an aqueous solution of carbonate of an alkali metal in such a way to control the reaction solution at a given pH level.
For the former approach, content of the carbonate of an alkali metal in the aqueous solution of cobalt salt is not limited, but preferably 1.0 to 1.5 chemical equivalents required for transforming cobalt in the aqueous solution into CoCO3 in order to recover cobalt at a high rate. For the latter approach, pH level of the reaction solution is not limited, but preferably 6.5 to 8.0 in order to recover cobalt at a high rate.
The carbonate of an alkali metal for the above production method is not limited. For example, sodium or potassium is used as the alkali metal. In particular, sodium carbonate and sodium bicarbonate are preferable for their inexpensiveness. Sodium bicarbonate is more preferable, because it is low in alkalinity, and hence excellent in pH controllability for the reaction to keep sodium content at a low level more easily.
(1) Production Method (A) Production Method (A) involves a procedure to control reaction temperature at 25 C or lower, wherein reaction temperature is controlled at 25 C or lower, preferably 10 to 20 C, more preferably 14 to 18 C. More specifically, decreasing reaction temperature retards the double salt producing reaction more than the cobalt carbonate producing reaction as the major reaction. Therefore, it is decreased to room temperature or below to control production of the double salt. The reaction system operating at above 25 C cannot give cobalt carbonate of sufficiently low alkali metal content for electronic device and battery materials because of its insufficient effect of controlling the double salt producing reaction. Decreasing reaction temperature increases the effect of controlling the double salt producing reaction. However, it is 10 C or higher for the present invention, because decreasing the level excessively is accompanied by increased cooling system cost.
(2) Production Method (B) Production Method (B) involves a procedure which uses an aqueous solution of carbonate of an alkali metal containing a hydroxide of an alkali metal at 5 to 40g/L as the carbonate of an alkali metal. More specifically, incorporation of a hydroxide of an alkali metal brings favorable effects, e.g., increasing OH ion in the reaction solution while decreasing CO32- ion content, and triggering the reaction for producing the hydroxide simultaneously with that for producing the carbonate, the former proceeding faster than the latter, thereby accelerating production of the hydroxide and carbonate while controlling production of the double salt to decrease alkali metal content.
In Production Method (B), a hydroxide of an alkali metal is incorporated in the aqueous solution of carbonate of an alkali metal at 5 to 40g/L, preferably 20 to 40g/L, more preferably 20 to 30g/L. At below 5g/L, the effect of decreasing sodium content of the cobalt carbonate product may be insufficient. At above 40gIL, on the other hand, cobalt hydroxide may be the major component of the precipitate produced, because the reaction for producing the hydroxide will prevail over that for producing the carbonate.
As a result, the precipitate is composed of finer particles, to have deteriorated filterability and washability.
Reaction temperature for the above method is not limited, and it is carried out at a reaction solution temperature of room temperature or higher. The hydroxide of an alkali metal for the above method is not limited. For example, sodium or potassium is used as the alkali metal.
Sodium hydroxide is particularly preferable because of its inexpensiveness.
(3) Production Method (C) Production Method (C) is a combination of Production Methods (A) and (B), involving a procedure which uses an aqueous solution of carbonate of an alkali metal containing a hydroxide of an alkali metal at 5 to 40gIL as the carbonate of an alkali metal, and another procedure to control reaction temperature at 25 C or lower. Each of these procedures is carried out under the conditions similar to those for Production Method (A) or (B).
2. Cobalt carbonate Cobalt carbonate of the present invention is the one containing an alkali metal at a low content, produced by one of Production Methods (A) to (C) described above. The cobalt carbonate precipitate produced is separated into the solid and reaction filtrate by centrifugal separation or the like, and the solid is washed with water and then dehydrated.
Cobalt carbonate of the present invention contains an alkali metal at 0.3% or less and 0.1% or less, both by weight, when produced by Production Method (A) or (C) operating at 25 and 20 C, respectively, and 0.7% or less and 0.3% or less, both by weight, when produced by Production Method (B) operating under the preferable conditions for the latter. By contrast, cobalt carbonate produced by the conventional method operating at 30 to 70 C
contains an alkali metal at 1 to 4% by weight.
As discussed above, the production method of the present invention gives cobalt carbonate of lower alkali metal content.
3. Cobalt oxide Cobalt oxide of low alkali metal content of the present invention is produced from the cobalt carbonate as the starting compound, which is produced by the method described above and calcined. It contains an alkali metal at a lower content than the one produced by the conventional method, and is suitable as materials for electronic device and battery, for which materials containing an alkali metal, e.g., sodium, is unsuitable.
The method for producing the cobalt oxide is not limited. It is produced by calcination of the cobalt carbonate, preferably heated at 350 C
or higher in air. At a calcination temperature below 350 C, the carbonate may be decomposed insufficiently and left undecomposed in the product.
EXAMPLES
The present invention is described in more detail by EXAMPLES and COMPARATIVE EXAMPLES, which by no means limit the present invention. Cobalt carbonate was analyzed for metal and moisture contents by the following procedures in EXAMPLES and COMPARATIVE
EXAMPLES.
(1) Analysis of metal contents The dehydration-treated sample was dried at 105 C for 24 hours, and analyzed by ICP emission spectrometry.
(2) Analysis of moisture content The dehydration-treated sample was dried at 105 C for 24 hours, and measured for weight difference before and after the drying treatment.
(EXAMPLE i) Cobalt carbonate was prepared by Production Method (A), and evaluated for its sodium content.
First, 20L of a 140g/L aqueous solution of sodium bicarbonate as the carbonate of an alkali metal was put in a reaction tank, to which 20L of a 50g/L aqueous solution of cobalt chloride was added in 30 minutes for the reaction, while reaction temperature was kept at 18 C with stirring. The carbonate of the alkali metal was added to the aqueous cobalt salt solution at 1.0 chemical equivalent required for transforming cobalt into CoCO3.
The reaction was allowed to continue for 20 minutes, and the resultant slurry was centrifugally separated into cobalt carbonate (solid) and reaction filtrate (liquid). The separated cobalt carbonate was repulp-washed with water and centrifugally dehydrated again. It was analyzed for sodium content. The result is given in Table 1.
(EXAMPLE 2) Cobalt carbonate was prepared by Production Method (A), and evaluated for its sodium content.
First, IL of a 50gIL aqueous solution of cobalt chloride was put in a reaction tank, to which a 100g/L aqueous solution of sodium carbonate (reagent grade) as the carbonate of an alkali metal was added for the reaction, which was allowed to proceed for 4 hours while reaction temperature was kept at 14 C with stirring, where the reaction solution was adjusted at a final pH level of 7.7.
The resultant slurry was separated into cobalt carbonate (solid) and reaction filtrate (liquid) by filtration under a vacuum. The separated cobalt carbonate was repulp-washed with water and dehydrated again by filtration under a vacuum. It was analyzed for sodium content. The result is given in Table 1.
(EXAMPLE 3) Cobalt carbonate was prepared by Production Method (A), and evaluated for its sodium content.
It was prepared in the same manner as in EXAMPLE 2, except that a 73g/L aqueous solution of sodium bicarbonate (reagent grade) was used as the carbonate of an alkali metal and the reaction solution was adjusted at a final pH level of 6.9. The resultant cobalt carbonate was analyzed for sodium content. The result is given in Table 1.
(EXAMPLE 4) Cobalt carbonate was prepared by Production Method (A), and evaluated for its sodium content.
It was prepared in the same manner as in EXAMPLE 1, except that reaction temperature was controlled at 25 C . The resultant cobalt carbonate was analyzed for sodium content. The result is given in Table 1.
(EXAMPLE 5) Cobalt carbonate was prepared by Production Method (C), and evaluated for its sodium and moisture content.
First, a 100g/L aqueous solution of sodium carbonate (reagent grade) as the carbonate of an alkali metal was incorporated with sodium hydroxide to 10g/L. Next, the above aqueous solution containing the alkali metal was pumped into a 1L reactor together with a 50g/L aqueous solution of cobalt chloride (reagent grade), and the reaction was allowed to proceed while reaction temperature was kept at 18 C with stirring. These aqueous solutions were pumped in such a way to keep the residence time at 1 hour and reaction solution pH level at 7.5.
The resultant slurry was separated into cobalt carbonate (solid) and reaction filtrate (liquid) by filtration under a vacuum. The separated cobalt carbonate was washed with sprayed water and dehydrated again by filtration under a vacuum. It was analyzed for sodium content. The result is given in Table 1.
(EXAMPLES 6 to 9) Cobalt carbonate was prepared by Production Method (B) in each of EXAMPLES 6 to 9, and evaluated for its sodium and moisture contents.
First, a 100g/L aqueous solution of sodium carbonate (reagent grade) as the carbonate of an alkali metal was incorporated with sodium oxide to 5, 10, 20 or 40g/L. Next, the above aqueous solution containing the alkali metal was pumped into a 1L reactor together with a 50g/L aqueous solution of cobalt chloride (reagent grade), and the reaction was allowed to proceed while reaction temperature was kept at 70 C with stirring. These aqueous solutions were pumped in such a way to keep the residence time at 1 hour and reaction solution pH level at 7.5.
The resultant slurry was separated into cobalt carbonate (solid) and reaction filtrate (liquid) by filtration under a vacuum. The separated cobalt carbonate was washed with sprayed water and dehydrated again by filtration under a vacuum. It was analyzed for sodium, cobalt and moisture contents. The result is given in Table 2.
(COMPARATIVE EXAMPLE 1) Cobalt carbonate was prepared in the same manner as in EXAMPLE 6, except that sodium hydroxide was incorporated in the aqueous sodium carbonate solution to 50g/L as the aqueous carbonate solution containing the alkali metal. The resulting cobalt carbonate showed deteriorated filterability. It was analyzed for sodium, cobalt and moisture contents.
The result is given in Table 2.
(COMPARATIVE EXAMPLE 2) Cobalt carbonate was prepared in the same manner as in EXAMPLE 6, except that sodium hydroxide was not incorporated in the aqueous sodium carbonate solution as the aqueous carbonate solution containing the alkali metal. It was analyzed for sodium, cobalt and moisture contents. The result is given in Table 2 Table 1 Production Reaction Slurry pH during Na content of Method temperature the reaction process cobalt carbonate ( C) (% by weight) EXAMPLE 1 (A) 1.8 - 0.01 EXAMPLE 2 (A) 14 7.7 0.02 EXAMPLE 3 (A) 14 6.9 0.01 EXAMPLE 4 (A) 25 0.30 EXAMPLE .5 (C) 18 0.02 Table 2 Production NaOH Reaction Na, Co and moisture Method content of temperature contents of cobalt the aqueous ( C) carbonate Na2CO3 /o b wei ht) solution Na Co moisture contents*
EXAMPLE 6 (B) 5 70 0.68 49.0 26.0 EXAMPLE 7 (B) 10 70 0.52 51.2 25.9 EXAMPLE 8 (B) 20 70 0.22 51.8 27.7 EXAMPLE 9 (B) 40 70 0.13 52.5 50.4 COMPARATIVE (B) 50 70 0.13 52.8 62.5*
COMPARATIVE - 0 70 0.92 50.3 22.4 * Cobalt carbonate showed deteriorated filterability when it contained moisture at 60%
or more.
As shown in Table 1, cobalt carbonate prepared in each of EXAMPLES
1 to 4 by Production Method (A) and in EXAMPLE 5 by Production Method (C) at a reaction temperature for the present invention contained sodium at a low level.
As shown in Table 2, cobalt carbonate prepared in each of EXAMPLES
6 to 9 by Production Method (B) using the aqueous solution of carbonate of an alkali metal incorporated with sodium hydroxide at a given content for the present invention contained sodium at a low level. By contrast, cobalt carbonate prepared in each of COMPARATIVE EXAMPLES 1 and 2 using the aqueous solution of carbonate of an alkali metal incorporated with sodium hydroxide at a content out of the range for the present invention showed unsatisfactory result with respect to sodium content or moisture content (which relates to filterability).
As discussed above, cobalt oxide produced from cobalt carbonate of low alkali metal content of the present invention, produced by the method of the present invention, contains an alkali metal at a sufficiently low content to be suitable as materials for electronic device and battery, in particular for purposes for which materials containing an alkali metal, e.g., sodium, is unsuitable.
Claims (4)
1. A method for producing cobalt carbonate or basic cobalt carbonate containing an alkali metal at 0.7% by weight or less, which comprises:
reacting an aqueous cobalt salt solution with a carbonate of an alkali metal to produce the cobalt carbonate or basic cobalt carbonate, under at least one of the following conditions:
(1) a reaction temperature is controlled at 14 to 18°C, and (2) an aqueous solution of an alkali metal carbonate containing an alkali metal hydroxide in an amount of 5 to 40 g/L is used as the carbonate of an alkali metal.
reacting an aqueous cobalt salt solution with a carbonate of an alkali metal to produce the cobalt carbonate or basic cobalt carbonate, under at least one of the following conditions:
(1) a reaction temperature is controlled at 14 to 18°C, and (2) an aqueous solution of an alkali metal carbonate containing an alkali metal hydroxide in an amount of 5 to 40 g/L is used as the carbonate of an alkali metal.
2. The method according to claim 1, wherein the carbonate of an alkali metal is a sodium salt.
3. The method according to claim 2, wherein the carbonate of an alkali metal is sodium bicarbonate.
4. The method according to claim 1, 2 or 3, wherein the alkali metal hydroxide is sodium hydroxide.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2003278115A JP4321170B2 (en) | 2003-07-23 | 2003-07-23 | Method for producing cobalt carbonate or basic cobalt carbonate having a low alkali metal content |
| JP2003-278115 | 2003-07-23 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2475667A1 CA2475667A1 (en) | 2005-01-23 |
| CA2475667C true CA2475667C (en) | 2012-02-21 |
Family
ID=33562744
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA2475667A Expired - Lifetime CA2475667C (en) | 2003-07-23 | 2004-07-21 | Cobalt carbonate of low alkali metal content, method for producing the same and cobalt oxide produced from the same |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JP4321170B2 (en) |
| AU (1) | AU2004202607B2 (en) |
| CA (1) | CA2475667C (en) |
| FR (1) | FR2857957B1 (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4880909B2 (en) * | 2005-03-03 | 2012-02-22 | 大平洋金属株式会社 | Purification method for removing sulfur from nickel compounds or cobalt compounds, and ferronickel production method |
| CN102910686A (en) * | 2011-08-04 | 2013-02-06 | 深圳市格林美高新技术股份有限公司 | Cobalt carbonate preparation method and superfine cobalt powder preparation method |
| JP6770252B2 (en) * | 2017-02-07 | 2020-10-14 | 住友金属鉱山株式会社 | Cobalt carbonate manufacturing equipment and manufacturing method |
| CN106745330A (en) * | 2017-04-01 | 2017-05-31 | 来安县万博丰环保科技有限公司 | A kind of cobalt carbonate preparation method and super-fine cobalt powder preparation method |
| CN113292109B (en) * | 2020-02-24 | 2023-11-07 | 荆门市格林美新材料有限公司 | Preparation method of low-sodium superfine cobalt carbonate |
| CN111892094B (en) * | 2020-06-22 | 2024-04-12 | 荆门市格林美新材料有限公司 | Mass production method of low-impurity high-solubility basic cobalt carbonate |
| CN113816435B (en) * | 2021-08-27 | 2022-11-15 | 广东邦普循环科技有限公司 | Crystal transition precursor and preparation method thereof |
| CN114988489B (en) * | 2022-05-30 | 2023-11-21 | 荆门市格林美新材料有限公司 | Cobalt oxide and preparation method and application thereof |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19519328C1 (en) * | 1995-05-26 | 1997-01-23 | Starck H C Gmbh Co Kg | Process for the preparation of basic cobalt (II) carbonates, the cobalt (II) carbonates produced by the process and their use |
| TW412505B (en) * | 1995-05-26 | 2000-11-21 | Starck H C Gmbh Co Kg | Process for producing spheroidally agglomerated basic cobalt (II) carbonate |
| DE19540076C1 (en) * | 1995-10-27 | 1997-05-22 | Starck H C Gmbh Co Kg | Ultrafine cobalt metal powder, process for its preparation and use of the cobalt metal powder and the cobalt carbonate |
-
2003
- 2003-07-23 JP JP2003278115A patent/JP4321170B2/en not_active Expired - Lifetime
-
2004
- 2004-06-15 AU AU2004202607A patent/AU2004202607B2/en not_active Expired
- 2004-07-21 CA CA2475667A patent/CA2475667C/en not_active Expired - Lifetime
- 2004-07-21 FR FR0408053A patent/FR2857957B1/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| FR2857957A1 (en) | 2005-01-28 |
| JP4321170B2 (en) | 2009-08-26 |
| JP2005041737A (en) | 2005-02-17 |
| AU2004202607A1 (en) | 2005-02-10 |
| AU2004202607B2 (en) | 2009-01-29 |
| CA2475667A1 (en) | 2005-01-23 |
| FR2857957B1 (en) | 2007-05-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP2003137550A (en) | Manufacturing method for zirconia/ceria-based composite oxide | |
| CN112320780B (en) | Method for recycling iron phosphate waste | |
| EP0972748A1 (en) | Method of manufacturing pseudo-boehmite | |
| US20040131530A1 (en) | Spheroidally agglomerated basic cobalt(II) carbonate and spheroidally agglomerated cobalt(II) hydroxide, a process for producing them and their use | |
| WO2009100767A1 (en) | Process for producing red iron oxide | |
| CN116375084B (en) | Preparation method of vanadium pentoxide | |
| CA2475667C (en) | Cobalt carbonate of low alkali metal content, method for producing the same and cobalt oxide produced from the same | |
| EP0024131B1 (en) | A method of obtaining alumina from clay and other alumino-silicates and alumina obtained by this method | |
| ZA200105624B (en) | Lime treatment. | |
| EP3067320B1 (en) | Method for producing aqueous zirconium chloride solution | |
| CN1270143A (en) | High purity magnesium hydrate and preparation thereof | |
| KR0142920B1 (en) | Manufacture of high-purity zirconium oxychloride crystals | |
| KR20080080350A (en) | Method for producing metal oxide nanoparticles with controlled properties, and nanoparticles and preparations prepared by the method | |
| CA3255673A1 (en) | PURIFICATION OF MnSO 4 SOLUTIONS | |
| KR20030055506A (en) | A method for manufacturing of cerium hydroxide removal of fluoride from the bastnasite | |
| WO2022040797A1 (en) | Nanomaterial composites useful for the extraction and recovery of lithium from aqueous solutions | |
| AU678097B2 (en) | Process for producing nickel hydroxide from elemental nickel | |
| RU2128626C1 (en) | Method of preparing magnesium oxide | |
| EP0055707B1 (en) | Preparation of dihydroxyaluminium sodium carbonate | |
| JPH07196323A (en) | Method for producing cobalt oxide with low sodium content | |
| RU2019511C1 (en) | Process for preparing zinc oxide from zinc containing products | |
| KR101543922B1 (en) | Method for preparing manganese oxide from manganese dust | |
| JP4552324B2 (en) | Method for producing cobalt oxide particles by neutralization method | |
| JPH0624743A (en) | Production of spherical zinc oxide powder | |
| CN110697786A (en) | Preparation method of mangano-manganic oxide |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request |