CN118492364A - Agglomeration method of high-voltage-resistant tantalum powder, tantalum powder prepared by method and capacitor prepared by tantalum powder - Google Patents
Agglomeration method of high-voltage-resistant tantalum powder, tantalum powder prepared by method and capacitor prepared by tantalum powder Download PDFInfo
- Publication number
- CN118492364A CN118492364A CN202410539810.8A CN202410539810A CN118492364A CN 118492364 A CN118492364 A CN 118492364A CN 202410539810 A CN202410539810 A CN 202410539810A CN 118492364 A CN118492364 A CN 118492364A
- Authority
- CN
- China
- Prior art keywords
- tantalum powder
- powder
- tantalum
- agglomeration
- capacitor
- 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.)
- Pending
Links
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 title claims abstract description 214
- 238000000034 method Methods 0.000 title claims abstract description 61
- 238000005054 agglomeration Methods 0.000 title claims abstract description 58
- 230000002776 aggregation Effects 0.000 title claims abstract description 58
- 239000003990 capacitor Substances 0.000 title claims abstract description 45
- 239000000843 powder Substances 0.000 claims abstract description 86
- 238000010438 heat treatment Methods 0.000 claims abstract description 42
- 229910052715 tantalum Inorganic materials 0.000 claims abstract description 42
- 238000007493 shaping process Methods 0.000 claims abstract description 37
- 239000007788 liquid Substances 0.000 claims abstract description 36
- 238000007873 sieving Methods 0.000 claims abstract description 32
- 239000000463 material Substances 0.000 claims abstract description 28
- 239000002019 doping agent Substances 0.000 claims abstract description 14
- 238000002156 mixing Methods 0.000 claims abstract description 14
- 230000008569 process Effects 0.000 claims abstract description 12
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 36
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 claims description 15
- 239000004327 boric acid Substances 0.000 claims description 15
- LFVGISIMTYGQHF-UHFFFAOYSA-N ammonium dihydrogen phosphate Chemical compound [NH4+].OP(O)([O-])=O LFVGISIMTYGQHF-UHFFFAOYSA-N 0.000 claims description 13
- 229910000387 ammonium dihydrogen phosphate Inorganic materials 0.000 claims description 13
- 235000019837 monoammonium phosphate Nutrition 0.000 claims description 13
- -1 ammonium hexafluorophosphate Chemical compound 0.000 claims description 12
- 239000002253 acid Substances 0.000 claims description 11
- 230000009467 reduction Effects 0.000 claims description 9
- BFNBIHQBYMNNAN-UHFFFAOYSA-N ammonium sulfate Chemical compound N.N.OS(O)(=O)=O BFNBIHQBYMNNAN-UHFFFAOYSA-N 0.000 claims description 8
- 229910052921 ammonium sulfate Inorganic materials 0.000 claims description 8
- 235000011130 ammonium sulphate Nutrition 0.000 claims description 8
- 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 claims description 7
- 239000011734 sodium Substances 0.000 claims description 7
- 229910052708 sodium Inorganic materials 0.000 claims description 7
- 239000007787 solid Substances 0.000 claims description 7
- 238000005406 washing Methods 0.000 claims description 7
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 claims description 6
- 239000011591 potassium Substances 0.000 claims description 6
- 229910052700 potassium Inorganic materials 0.000 claims description 6
- 238000000465 moulding Methods 0.000 claims description 3
- 239000002245 particle Substances 0.000 abstract description 37
- 238000009826 distribution Methods 0.000 abstract description 4
- 230000000694 effects Effects 0.000 abstract description 2
- 238000001914 filtration Methods 0.000 description 25
- 230000000052 comparative effect Effects 0.000 description 20
- 238000005554 pickling Methods 0.000 description 20
- 238000001035 drying Methods 0.000 description 19
- 239000000203 mixture Substances 0.000 description 17
- 239000006228 supernatant Substances 0.000 description 16
- 238000011282 treatment Methods 0.000 description 15
- 238000007599 discharging Methods 0.000 description 12
- 238000004519 manufacturing process Methods 0.000 description 12
- 239000011148 porous material Substances 0.000 description 11
- 238000009833 condensation Methods 0.000 description 10
- 230000005494 condensation Effects 0.000 description 10
- 239000008367 deionised water Substances 0.000 description 10
- 229910021641 deionized water Inorganic materials 0.000 description 10
- 239000000047 product Substances 0.000 description 9
- 238000006722 reduction reaction Methods 0.000 description 9
- 238000002791 soaking Methods 0.000 description 9
- 238000007872 degassing Methods 0.000 description 8
- 238000007885 magnetic separation Methods 0.000 description 8
- 238000000967 suction filtration Methods 0.000 description 8
- 238000001291 vacuum drying Methods 0.000 description 8
- 238000007580 dry-mixing Methods 0.000 description 7
- 229910052751 metal Inorganic materials 0.000 description 7
- 239000002184 metal Substances 0.000 description 7
- RHDUVDHGVHBHCL-UHFFFAOYSA-N niobium tantalum Chemical compound [Nb].[Ta] RHDUVDHGVHBHCL-UHFFFAOYSA-N 0.000 description 7
- 239000002994 raw material Substances 0.000 description 7
- 238000009614 chemical analysis method Methods 0.000 description 6
- 239000012467 final product Substances 0.000 description 6
- 238000005245 sintering Methods 0.000 description 6
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 4
- 239000012535 impurity Substances 0.000 description 4
- 238000002360 preparation method Methods 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 239000006012 monoammonium phosphate Substances 0.000 description 3
- 238000005070 sampling Methods 0.000 description 3
- 239000002904 solvent Substances 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 238000000498 ball milling Methods 0.000 description 2
- 239000011230 binding agent Substances 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 239000010419 fine particle Substances 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 239000002923 metal particle Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- BPUBBGLMJRNUCC-UHFFFAOYSA-N oxygen(2-);tantalum(5+) Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Ta+5].[Ta+5] BPUBBGLMJRNUCC-UHFFFAOYSA-N 0.000 description 2
- 238000011056 performance test Methods 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- 238000001159 Fisher's combined probability test Methods 0.000 description 1
- 102100029360 Hematopoietic cell signal transducer Human genes 0.000 description 1
- 101000990188 Homo sapiens Hematopoietic cell signal transducer Proteins 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 238000005345 coagulation Methods 0.000 description 1
- 230000015271 coagulation Effects 0.000 description 1
- 239000011362 coarse particle Substances 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 238000000748 compression moulding Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000005868 electrolysis reaction Methods 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- 238000010894 electron beam technology Methods 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 238000004108 freeze drying Methods 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 238000005984 hydrogenation reaction Methods 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 229910001338 liquidmetal Inorganic materials 0.000 description 1
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 1
- OHZZTXYKLXZFSZ-UHFFFAOYSA-I manganese(3+) 5,10,15-tris(1-methylpyridin-1-ium-4-yl)-20-(1-methylpyridin-4-ylidene)porphyrin-22-ide pentachloride Chemical compound [Cl-].[Cl-].[Cl-].[Cl-].[Cl-].[Mn+3].C1=CN(C)C=CC1=C1C(C=C2)=NC2=C(C=2C=C[N+](C)=CC=2)C([N-]2)=CC=C2C(C=2C=C[N+](C)=CC=2)=C(C=C2)N=C2C(C=2C=C[N+](C)=CC=2)=C2N=C1C=C2 OHZZTXYKLXZFSZ-UHFFFAOYSA-I 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 238000004663 powder metallurgy Methods 0.000 description 1
- 238000004321 preservation Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 239000011541 reaction mixture Substances 0.000 description 1
- 239000003870 refractory metal Substances 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000011435 rock Substances 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 229910001936 tantalum oxide Inorganic materials 0.000 description 1
- PBCFLUZVCVVTBY-UHFFFAOYSA-N tantalum pentoxide Inorganic materials O=[Ta](=O)O[Ta](=O)=O PBCFLUZVCVVTBY-UHFFFAOYSA-N 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 229910052718 tin Inorganic materials 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
- B22F1/14—Treatment of metallic powder
- B22F1/142—Thermal or thermo-mechanical treatment
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
- B22F1/14—Treatment of metallic powder
- B22F1/148—Agglomerating
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
- H01G13/00—Apparatus specially adapted for manufacturing capacitors; Processes specially adapted for manufacturing capacitors not provided for in groups H01G4/00 - H01G11/00
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Powder Metallurgy (AREA)
- Manufacture Of Metal Powder And Suspensions Thereof (AREA)
Abstract
The invention discloses a high-voltage resistant tantalum powder agglomerating method, tantalum powder prepared by the method and a capacitor prepared by the tantalum powder. The agglomeration method of the high-voltage resistant tantalum powder comprises the following steps: mixing tantalum powder raw powder, and adding a doping agent for dry shaping; adding liquid A into the tantalum powder subjected to dry shaping, vibrating the tantalum powder material, and sieving to perform secondary agglomeration to obtain agglomerated powder; the agglomerated powder after sieving is subjected to high-temperature agglomeration, and the material is subjected to secondary heat treatment. The tantalum powder prepared by the method has good agglomerating effect, can effectively improve the porosity of tantalum powder, particularly the porosity of the surface of tantalum particles, and ensures the open porosity of the surface of the particles. The particle size distribution of tantalum powder is improved, the fluidity of tantalum powder is improved, and the problems of small loose loading and more fine powder of tantalum powder in the agglomeration process are solved. The utilization rate of tantalum powder is improved, the cost is reduced, and the requirement of the capacitor product on the electrical property of the tantalum powder is met. Suitable objects include 5000-50000 μFV/g capacitor grade medium and high voltage resistant tantalum powder.
Description
Technical Field
The invention belongs to the technical field of tantalum powder preparation, and particularly relates to a high-voltage-resistant tantalum powder agglomerating method, tantalum powder prepared by the method and a capacitor prepared by the tantalum powder.
Background
Tantalum metal is a valve metal which can form a dense oxide film on the surface and has the property of single-direction electric conduction. The anode film made of tantalum powder has stable chemical property (especially in acid electrolyte), high resistivity (7.5X10 12 Ω & cm), large dielectric constant (27.6), small leakage current, wide working temperature range (-80-200deg.C), high reliability, shock resistance, and long service life. Tantalum powder is an ideal material for manufacturing tantalum capacitors with small volume and high reliability. Tantalum capacitors have many advantages and are therefore widely used in electronic devices such as aviation, aerospace, communications, computers, and cell phones.
The mass production of tantalum powder has been over 70 years old, but the development of large-scale high speed is only about 50 years. As early as 1904, one had reduced tantalum pentoxide with carbon and the reduced product was refined under vacuum at high temperature to obtain the first ductile tantalum ingot in the world. The later developed fused salt electrolysis method is economical and reasonable and has simple equipment, so that the method has been widely applied. However, the tantalum powder electrolyzed by the traditional process has the advantages of simple particle size, coarse particles and low specific volume, and can not meet the requirement of the electronic industry on high-capacity tantalum powder. Methods such as carbothermic reduction of tantalum oxide, reduction of tantalum hydrogen pentachloride and thermit reduction are not used for industrial production. The tantalum powder prepared by sodium reduction has the characteristics of high purity, complex particle, high specific volume and the like, and becomes a main production process for preparing the tantalum powder at home and abroad. Currently, tantalum powder manufacturers in the world mainly include Cabot group in the United states, HCST group in Germany, and Ningxia eastern tantalum industry Co., ltd.
In terms of material classification, tantalum powders that are specifically used to make capacitors are referred to as capacitor grade tantalum powders. Tantalum powder can be classified into high-voltage tantalum powder (working voltage 25V or more) and low-voltage high-specific volume tantalum powder (working voltage 25V or less) according to the use voltage.
The high-voltage tantalum powder for military products mainly refers to 63V series tantalum powder prepared by electron beam melting, hydrogenation and powder preparation methods, the application range of working voltage is expanded to 50V-100V, and the high-voltage tantalum powder is important in the fields of aerospace, aviation and military. And a part of capacitor-grade medium-high voltage resistant tantalum powder with the working voltage of 25V-50V mainly comprises medium-voltage flaky tantalum powder and other tantalum powder with higher voltage resistance. In recent years, capacitor-grade medium-high voltage resistant tantalum powder with an operating voltage of 25V-50V is a hot spot for future development.
Patent US6576038B1 discloses a new process for the production of tantalum powder agglomerates. A process for agglomerating tantalum-niobium metal powder includes mixing particles with a volatile liquid to form a wet powder, compacting the powder, and drying the compacted powder to form a cake to form agglomerated particles. The flow rate of the tantalum powder is at least 65 mg/s, the pore size distribution is improved, and the Scott density is increased. Patent US6479012 is similarly described.
The patent CN 1197707a discloses a new method for producing tantalum powder, which compacts fine-particle tantalum powder or a mixture of fine-particle tantalum powder and a metal reducing agent to form briquettes before the heat treatment of briquetting, thereby increasing the briquetting effect and being capable of being agglomerated at a lower temperature, thus being capable of producing tantalum powder with low oxygen content and good fluidity and formability. Similar patents also refer to CN1068809C.
The invention of patent CN1238251A provides a method for producing porous tantalum powder, which comprises the following steps: (1) Under the condition of not adding any binder, vibrating, rock and roll sieving the fine tantalum powder, and pre-agglomerating the fine tantalum powder into particles; (2) And carrying out heat treatment on the obtained pre-agglomerated particles at 900-1550 ℃ in the presence of vacuum or inert gas to generate sintering agglomeration among the agglomerated particles. Similar patents also refer to CN 1073480C.
The patent US3976435 invention discloses a method for producing a porous anode for use in the manufacture of electrolytic capacitors. Firstly, wetting tantalum powder with 2-20% of water, enabling the maximum particle size of the tantalum powder to be 10 mu m, compacting by compression molding, condensing, sintering into a porous body, wherein the sintering density is lower than 12g/cc, and the specific volume is not lower than 2000 mu FV/g.
Patent JP2002-134367 discloses a tantalum powder porous molded body tantalum electrolytic capacitor anode and a capacitor and a preparation method thereof. The invention relates to a porous formed body formed by filling a dispersion liquid obtained by mixing tantalum powder, a solvent and a binder into a container of a predetermined shape, and freeze-drying under vacuum. And sintering to obtain the tantalum anode. The resin in the molded article is greatly reduced, the residual carbon content is reduced, and the pore size and the porosity of the molded article can be controlled by adjusting the magnetic solvent amount of the solvent. The patent is mainly used for manufacturing the capacitor.
The invention of patent CN104858436A discloses a preparation method of tantalum powder for a high-reliability high-specific volume electrolytic capacitor, which has the advantages of simple process and strong controllability, and the obtained flaky tantalum powder has low metal impurity content, high specific surface area, good fluidity and formability after agglomeration, high specific volume, low leakage current and high breakdown voltage under high voltage. But not a process combining dry doping shaping and wet shaping.
The most similar patents to the present invention are: patent CN1238251a. However, unlike the patent, the size of the pores on the surface of the tantalum powder particles prepared by the agglomeration method is difficult to control, and if the thought of weak agglomeration with small water addition and short agglomeration time is adopted, the prepared tantalum powder has good aperture ratio, but has limited improvement of physical parameters such as loose density, fluidity and the like, and can not meet the requirement of products; if the thinking of strong agglomeration with a large amount of water and long agglomeration time is adopted, the prepared tantalum powder has relatively improved physical parameters such as bulk density, fluidity and the like, but has very poor surface aperture ratio, under the condition of higher energized voltage, surface apertures are easily filled with oxide films, so that the growth of the oxide films in the particles is blocked, the quality of the film is influenced, the formation of a cathode is blocked, and the use of the tantalum powder under the high-voltage working condition is greatly limited.
Disclosure of Invention
In order to solve the technical problems, the invention provides a high-voltage resistant tantalum powder agglomerating method, tantalum powder prepared by the method and a capacitor prepared by the tantalum powder.
The invention is realized by the following technical scheme.
The invention provides a agglomerating method of high-voltage-resistant tantalum powder, which comprises the following steps:
(1) Mixing tantalum powder raw powder, and adding a doping agent for dry shaping;
(2) Adding liquid A into the tantalum powder subjected to dry shaping, vibrating the tantalum powder material, and sieving to perform secondary agglomeration to obtain agglomerated powder;
(3) The agglomeration powder after sieving is subjected to high-temperature agglomeration, the agglomeration temperature is 80-150 ℃ for 10-15 hours, the temperature is reduced to 50 ℃ after the agglomeration is finished, and then the material is subjected to secondary heat treatment.
Preferably, the tantalum powder raw powder in the step (1) is tantalum powder obtained by a sodium reduction potassium fluorotantalate process, and the tantalum powder raw powder further comprises a step of flaking, wherein the flaking step is performed after the heat treatment, and comprises the steps of processing the tantalum powder raw powder into flakes to obtain flake tantalum powder raw powder, then shaping, and acid washing the tantalum powder before dry shaping.
Preferably, the dry shaping in the step (1) lasts 10 to 60 minutes, the secondary agglomerating in the step (2) lasts 0 to 60 minutes.
Preferably, the doping agent in the step (1) comprises one or more of boric acid, ammonium dihydrogen phosphate, ammonium hexafluorophosphate and ammonium sulfate, wherein the boric acid, the ammonium dihydrogen phosphate and the ammonium hexafluorophosphate doped in the step (1) are all 0-100 ppm, and the ammonium sulfate doped in the step (1) is 0-50 ppm.
Preferably, in the step (2), the secondarily agglomerated tantalum powder material is taken out and subjected to agglomeration molding at a temperature of 80-180 ℃, and the agglomeration is performed in a vacuum state.
Preferably, the liquid A is water, and the addition amount of the liquid A is 10-30% of the weight of the tantalum powder.
A high-voltage resistant tantalum powder is prepared by a agglomerating method of high-voltage resistant tantalum powder.
Preferably, the specific volume of the high voltage resistant tantalum powder is 5000-50000 mu FV/g.
A tantalum capacitor is prepared from high voltage resistant tantalum powder.
Preferably, the tantalum capacitor is a solid tantalum capacitor or a liquid tantalum capacitor, the working voltage of the solid tantalum capacitor is 20-50V, and the working voltage of the liquid tantalum capacitor is 40-125V.
The invention has the beneficial effects that:
1. The dry method and the wet method combined shaping mode effectively improve the apparent density of the product and ensure the aperture ratio of the surface of the tantalum powder particles;
2. The electrical property of the doped tantalum powder is better through one or more combination doping modes;
3. The (-400 mesh) proportion of the ultrafine powder in the tantalum powder is reduced;
4. The utilization rate of the product is improved;
5. The cost is reduced.
Drawings
Fig. 1 is a comparative graph of leakage current for examples and comparative examples of tantalum powders obtained by the present invention.
FIG. 2 is a graph showing the specific capacitance of examples and comparative examples of tantalum powders obtained by the present invention.
Fig. 3 is a graph of comparative loss for examples and comparative examples of tantalum powders obtained in accordance with the present invention.
Detailed Description
The technical solution of the present invention is further described below, but the scope of the claimed invention is not limited to the above.
A method for agglomerating high voltage resistant tantalum powder, comprising the steps of: (1) Putting the tantalum powder raw powder into a V-shaped mixer for mixing, and adding a doping agent for dry shaping;
(2) Adding liquid A into the tantalum powder subjected to dry shaping, standing for 10-60 minutes, putting the wet material into a shaping special machine after standing for vibration agglomeration for 5-30 minutes, sieving with a 35-100 mesh sieve after vibration, repeatedly sieving for 2-4 times, and performing secondary agglomeration to obtain agglomerated powder;
(3) Placing the sieved agglomerated powder into a vacuum drying box for high-temperature agglomeration, wherein the agglomeration temperature is 80-150 ℃ and the period of time is 10-15 hours, and after the agglomeration is finished, the temperature is reduced to 50 ℃ to obtain the material, and the material after drying is subjected to secondary heat treatment.
The tantalum powder raw powder in the step (1) is tantalum powder obtained by a sodium reduction potassium fluorotantalate process, the tantalum powder raw powder further comprises a step of flaking, wherein the flaking step is carried out after heat treatment, the tantalum powder raw powder is processed into flakes to obtain flake tantalum powder raw powder, shaping is carried out, and acid washing is carried out on the tantalum powder before dry shaping to wash out impurities in the tantalum powder.
Firstly, 100Kg of KCl is filled in a reduction furnace, and then 140Kg of potassium fluotantalate (K 2TaF7) is added from a feed port when the temperature reaches 920 ℃ according to the programmed temperature. After pushing, the temperature is reduced to below 850 ℃, then the temperature is increased to 880 ℃, the temperature is kept for lh, the slurry is extracted for 10cm, then stable injection of a certain amount of liquid metal sodium is started, and then the temperature is increased to about 900 ℃ and the temperature is kept. After the completion of the reduction reaction (the reaction is completed, since no reaction heat is generated any more, the temperature is rapidly lowered), the reaction mixture is cooled and discharged from the furnace. Then crushing the reduced material by a jaw crusher, washing with deionized water for 15 hours to ensure that the conductivity of the filtering liquid is less than 500 mu S/cm, and then transferring to an acid washing process for further purification. Specifically, the acid used for pickling is a mixed acid of HN0 3 and HF, wherein the concentration of HNO 3 is 15% (volume percent), the concentration of HF is 0.3% (volume percent), the mixed acid is firstly used for stirring and washing for 2 hours in the pickling process, and then the mixed acid is soaked for 1 hour, wherein the weight ratio of the mixed acid liquid to the solid tantalum powder is 1:1, the tantalum powder after acid washing is dried, the drying condition is 100 ℃/heat preservation for 15 hours, the vacuum degree is-0.08 MPa, the temperature is reduced and cooled to below 50 ℃, the tantalum powder is broken out of the oven to prevent ignition, and the tantalum powder raw powder after sodium reduction is obtained after sieving by 80 meshes. Breaking the air refers to contact with air.
The processing method of the flaky tantalum powder raw powder is preferably ball milling, absolute ethyl alcohol is preferably used as a ball milling medium, and the weight ratio of the preferable ball materials is 4:1 to 10:1 (e.g., 8:1), preferably at a ball mill speed of 80 to 200 revolutions per minute, and preferably for a ball mill time of 5 to 20 hours (e.g., 15 hours).
In a preferred embodiment, the method of manufacture of any of the first aspects of the invention, the step of tableting further comprises a conventional pickling step. For example, conventional pickling conditions are: first pass: pickling with 10-25% HNO 3 + 0.5-1.5% HF for 2-3 hr, soaking for 1-2 hr, and pouring out supernatant. Second pass: pickling with HNO 3+0.5-1.5％HF+1～2％H2O2 of 10-25% for 2-3 hr, soaking for 1-2 hr, pouring out supernatant, rinsing twice with water, filtering with pure water. When the conductivity of the filtering liquid is less than 30us/cm, the suction filtration is stopped, and the filtering liquid is transferred into an oven for high-temperature condensation. Vacuum condensing at 80-180 deg.c for 12-18 hr, stoving at vacuum degree greater than or equal to 3X 10 4 Pa, and sieving with 80-100 mesh sieve.
The treatment conditions for the first heat treatment (i.e. degassing or presintering) are: the vacuum degree is more than 2.8X10 -3 Pa, heating for 30-240 min at 800-1400 ℃ and can be divided into two or three times (for example, heating to 800-1050 ℃ for 30-120 min, then heating to 1250-1350 ℃ for 30-120 min), preferably crushing and sieving by a crusher (for example, a jaw crusher) for 50-80 meshes and magnetic separation after the first heat treatment, and preferably dry mixing for 10-120 min by dry adding 10-150 ppm of fully ground doping agents such as boric acid, ammonium hexafluorophosphate, ammonium dihydrogen phosphate and the like after magnetic separation, so as to reduce the pores among particles, thereby achieving the aim of increasing loose density, namely dry shaping; then adding water for pre-agglomerating, adding water with the weight of 10-30% (for example 18%) of tantalum powder, uniformly mixing, and standing for 10-60 minutes. Sieving with 30-60 mesh (e.g. 50 mesh twice), and then performing high temperature coagulation, preferably under vacuum at 100-120deg.C for 10-15 hr, preferably with vacuum degree of 4×10 4 Pa (e.g. 2×10 4 Pa) or more during drying.
The dry shaping in the step (1) lasts for 10-60 minutes, preferably 20-40 minutes, and the pores among particles are reduced, so that the aim of increasing the bulk density, also called dry shaping, is fulfilled; the secondary agglomeration is carried out in the step (2) and lasts for 0 to 60 minutes, preferably 20 minutes.
The doping agent in the step (1) comprises one or more of boric acid, ammonium dihydrogen phosphate, ammonium hexafluorophosphate and ammonium sulfate, wherein the boric acid, the ammonium dihydrogen phosphate and the ammonium hexafluorophosphate doped in the step (1) are all 0-100 ppm, and the ammonium sulfate doped in the step (1) is 0-50 ppm.
Preferably, in step (1), 0 to 100ppm of boric acid or 0 to 100ppm of ammonium dihydrogen phosphate or 0 to 100ppm of ammonium hexafluorophosphate or 0 to 100ppm of boric acid and 0 to 100ppm of ammonium dihydrogen phosphate or 0 to 100ppm of boric acid and 0 to 100ppm of ammonium hexafluorophosphate and 0 to 50ppm of ammonium sulfate are doped.
In the step (2), the secondarily agglomerated tantalum powder material is taken out and subjected to agglomeration molding at a temperature of 80-180 ℃, preferably 100-150 ℃, and preferably the agglomeration is performed in a vacuum state.
The liquid A is deionized water, the adding amount of the deionized water is 10-30% of the weight of the tantalum powder, and the preferable adding amount is 20% of the weight of the tantalum powder. It is suitable that the water addition amount just can sufficiently wet the tantalum powder without leaving excessive water.
The high-voltage resistant tantalum powder is prepared by a agglomerating method of high-voltage resistant tantalum powder.
Preferably, the specific volume of the high voltage resistant tantalum powder is 5000 to 50000 μFV/g, preferably 5000 to 30000 μFV/g.
A tantalum capacitor is prepared from high voltage resistant tantalum powder.
The tantalum capacitor is a solid tantalum capacitor or a liquid tantalum capacitor, the working voltage of the solid tantalum capacitor is 20-50V, and the working voltage of the liquid tantalum capacitor is 40-125V.
The dry shaping of the doped tantalum powder in the step (2) and the wet shaping in the step (3) and the step (4) are combined, so that the shaping flexibility and diversity are realized, and the problems in the previous agglomeration are solved.
Shaping, also known in the art as pre-agglomeration, refers to the adjustment of the macroscopic particle size distribution of the particles to improve flowability, making the tantalum powder better for use in the capacitor process. Specifically, "dry shaping" as used herein refers to a method of shaping directly by gravity in a V-blender without adding a liquid medium such as water.
The physical quantity used in the art to describe the metal particle size (i.e., particle size) is the Fisher mean particle size (FSSS/. Mu.m). The Fisher average particle diameter is obtained by measuring the flow rate of the powder filled in the metal tube by the air permeation method by using a Fisher sub-sieve, and is related to the size of particles on the one hand and the cohesive strength of the powder on the other hand, the smaller the Fisher average particle diameter is, the larger the specific surface area is for the tantalum powder obtained by the process of reducing potassium fluorotantalate as well, and the similar Fisher average particle diameter can be obtained for the powder with different specific surface areas after the cohesive, and the cohesive powder Fisher average particle diameter is larger for the powder with the same grade.
The Fisher particle size (FSSS/mu m) of the tantalum powder is measured according to the method prescribed by the Fisher method (standard number GB/T3249) of the method for measuring the particle size of refractory metals and compound powders; bulk Density (SBD) was measured according to the method prescribed by the first part funnel method for measuring bulk density of metal powder (Standard No. GB/T1479); the particle size distribution is measured according to the method specified in the standard dry sieving method for determination of the particle size composition of Metal powder (Standard No. GB/T1480); sampling procedure the method specified in the Standard for sampling powders for powder metallurgy (Standard number GB/T5314) is used for sampling.
The detection methods of the elements in the tantalum powder are all determined according to national standards, and the standards comprise determination of carbon content and sulfur content in GB/T15076.82008 tantalum-niobium chemical analysis method, determination of iron, chromium, nickel, manganese, titanium, aluminum, copper, tin, lead and pick in GB/T15076.92008 tantalum-niobium chemical analysis method, determination of phosphorus content in GB/T15076.12-2008 tantalum-niobium chemical analysis method, determination of oxygen content in GB/T15076.142008 tantalum-niobium chemical analysis method, determination of hydrogen content in GB/T15076.15-2008 tantalum-niobium chemical analysis method,
GB/T15076.16-2008 determination of sodium and potassium content by tantalum-niobium chemical analysis method.
The method and the equipment for detecting the electrical property of the tantalum powder in the invention all refer to the national standard
The electric performance test method of GB/T3137-2007 tantalum powder.
Another physical quantity used to describe the thickness of the metal particles is the specific surface area (m 2/g) of the low temperature nitrogen adsorption BET measurement.
For a further understanding of the present invention, embodiments of the invention are described below in conjunction with the examples and the accompanying tables, but it should be understood that these descriptions are merely intended to further illustrate the features and advantages of the invention and are not intended to limit the scope of the claims of the invention.
Example 1:
The high voltage resistant tantalum powder of 5000 mu FVIg-50000 mu FV/g capacitor grade obtained by the method is used as raw material.
First, a tantalum powder raw powder was put into a mixer, and then 20ppm of sufficiently ground boric acid and 20ppm of ammonium hexafluorophosphate were dry-blended.
The tantalum powder material doped with the doping agent is subjected to dry mixing in a V-shaped mixer for 20 minutes, so that the pores among particles are reduced, and the aim of increasing the bulk density is fulfilled.
And (3) discharging, adding 10% deionized water, uniformly mixing, and standing for 20 minutes.
Placing the wet material into a special shaping machine for vibration agglomeration for 5 minutes after standing, sieving with a 40-mesh sieve after vibration, and repeatedly sieving for 3 times.
Placing the sieved agglomerated powder into a vacuum drying box for high-temperature agglomeration, reducing the temperature to 50 ℃ after the high-temperature agglomeration is 80 ℃ and 15 hours are finished, discharging the agglomerated powder out of the drying box, and performing secondary heat treatment and other subsequent treatments to obtain the final tantalum powder product.
The pickling conditions are as follows: first pass: the mixture was washed with 10% HNO 3 +0.5% HF for 2 hours and then with 1 hour, and the supernatant was poured out. Second pass: pickling with 10% HNO 3+0.5％HF+1％H2O2 for 2 hr, soaking for 1 hr, pouring out supernatant, rinsing with water twice, and filtering with pure water. When the conductivity of the filtering liquid is less than 30us/cm, the suction filtration is stopped, and the filtering liquid is transferred into an oven for high-temperature condensation. The vacuum degree is more than 3X 10 4 Pa in the drying process, and then the powder is sieved to 80 meshes.
The treatment conditions for the first heat treatment (i.e. degassing or presintering) are: the vacuum degree is more than 2.8X10 -3 Pa, heating at 800 deg.C for 30 min, crushing and sieving with a crusher (such as jaw crusher) for 50 mesh after the first heat treatment, and magnetic separating, wherein other values are preferable values.
Example 2:
The high voltage resistant tantalum powder of 5000 mu FVIg-50000 mu FV/g capacitor grade obtained by the method is used as raw material.
First, the tantalum powder raw powder was put into a mixer, and then 20ppm of sufficiently ground boric acid and 20ppm of monoammonium phosphate were dry-blended.
The tantalum powder material doped with the doping agent is subjected to dry mixing in a V-shaped mixer for 30 minutes, so that the pores among particles are reduced, and the aim of increasing the bulk density is fulfilled.
And (3) discharging, adding 15% deionized water, uniformly mixing, and standing for 30 minutes.
Placing the wet material into a special shaping machine for vibration agglomeration for 5 minutes after standing, sieving with a 40-mesh sieve after vibration, and repeatedly sieving for 3 times.
Placing the sieved agglomerated powder into a vacuum drying box for high-temperature agglomeration, reducing the temperature to 50 ℃ after the high-temperature agglomeration is 90 ℃ and 15 hours are finished, discharging the agglomerated powder out of the drying box, and performing secondary heat treatment and other subsequent treatments to obtain a final product.
The pickling conditions are as follows: first pass: the mixture was washed with 25% HNO 3 +1.5% HF for 3 hours and then with 2 hours, and the supernatant was poured out. Second pass: pickling with 25% HNO 3+1.5％HF+2％H2O2 for 3 hr, soaking for 2 hr, pouring out supernatant, rinsing with water twice, and filtering with pure water. When the conductivity of the filtering liquid is less than 30us/cm, the suction filtration is stopped, and the filtering liquid is transferred into an oven for high-temperature condensation. The vacuum degree is more than 8 multiplied by 10 4 Pa in the drying process, and then the powder is sieved to 100 meshes.
The treatment conditions for the first heat treatment (i.e. degassing or presintering) are: the vacuum degree is more than 2.8X10 -3 Pa, heating to 800 ℃, preserving heat for 30 minutes, then heating to 1250 ℃ and preserving heat for 30 minutes, preferably crushing and sieving by a crusher (such as a jaw crusher) to 80 meshes after the first heat treatment and magnetic separation, wherein other values are the preferred values in the foregoing.
Example 3:
The high voltage resistant tantalum powder of 5000 mu FVIg-50000 mu FV/g capacitor grade obtained by the method is used as raw material.
First, the tantalum powder raw powder was put into a mixer, and then 70ppm of sufficiently ground boric acid and 70ppm of monoammonium phosphate were dry-blended.
The tantalum powder material doped with the doping agent is subjected to dry mixing in a V-shaped mixer for 50 minutes, so that the pores among particles are reduced, and the aim of increasing the bulk density is fulfilled.
And (3) discharging, adding 18% deionized water, uniformly mixing, and standing for 60 minutes.
Placing the wet material into a special shaping machine for vibration agglomeration for 10 minutes after standing, sieving with a 50-mesh sieve after vibration, and repeatedly sieving for 3 times.
Placing the sieved agglomerated powder into a vacuum drying box for high-temperature agglomeration, reducing the temperature to 50 ℃ after the high-temperature agglomeration temperature is 110 ℃ and 15 hours are finished, discharging the agglomerated powder out of the drying box, and performing secondary heat treatment and other subsequent treatments to obtain a final product.
The pickling conditions are as follows: first pass: the mixture was washed with 20% HNO 3 +1% HF for 2.5 hours and then with 1.5 hours, and the supernatant was poured out. Second pass: pickling with 20% HNO 3+1％HF+1.5％H2O2 for 2.5 hr, soaking for 1.5 hr, pouring out supernatant, rinsing with water twice, and filtering with pure water. When the conductivity of the filtering liquid is less than 30us/cm, the suction filtration is stopped, and the filtering liquid is transferred into an oven for high-temperature condensation. The vacuum degree is more than or equal to 3X 10 4 Pa in the drying process, and then the powder is sieved to 80 meshes.
The treatment conditions for the first heat treatment (i.e. degassing or presintering) are: the vacuum degree is more than 2.8X10 -3 Pa, and can be divided into two heating, heating to 1050 ℃, preserving heat for 120 minutes, then heating to 1350 ℃ and preserving heat for 120 minutes, preferably, crushing and sieving with a crusher (such as a jaw crusher) for 80 meshes after the first heat treatment and magnetic separation, wherein other values are the preferred values in the foregoing.
Example 4:
The high voltage resistant tantalum powder of 5000 mu FVIg-50000 mu FV/g capacitor grade obtained by the method is used as raw material.
First, the tantalum powder raw powder was put into a mixer, and then 90ppm of sufficiently ground boric acid and 90ppm of monoammonium phosphate were dry-blended.
The tantalum powder material doped with the doping agent is subjected to dry mixing in a V-shaped mixer for 90 minutes, so that the pores among particles are reduced, and the aim of increasing the bulk density is fulfilled.
And (3) discharging, adding 20% deionized water, uniformly mixing, and standing for 60 minutes.
Placing the wet material into a special shaping machine for vibration agglomeration for 15 minutes after standing, sieving with a 80-mesh sieve after vibration, and repeatedly sieving for 3 times.
Placing the sieved agglomerated powder into a vacuum drying box for high-temperature agglomeration, reducing the temperature to 50 ℃ after the high-temperature agglomeration temperature is 150 ℃ and 15 hours are finished, discharging the agglomerated powder out of the drying box, and performing secondary heat treatment and other subsequent treatments to obtain a final product.
The pickling conditions are as follows: first pass: the solution was washed with 25% HNO 3 +0.5% HF for 2 hours, then with 2 hours, and the supernatant was decanted. Second pass: pickling with 25% HNO 3+1.5％HF+1％H2O2 for 2 hr, soaking for 1 hr, pouring out supernatant, rinsing with water twice, and filtering with pure water. When the conductivity of the filtering liquid is less than 30us/cm, the suction filtration is stopped, and the filtering liquid is transferred into an oven for high-temperature condensation. The vacuum degree is 3X 10 4 Pa during the drying process, and then the powder is sieved by a 100-mesh sieve.
The treatment conditions for the first heat treatment (i.e. degassing or presintering) are: the vacuum degree is more than 2.8X10 -3 Pa, and the mixture is heated at 1400 ℃ for 240 minutes, preferably, after the first heat treatment, the mixture is crushed and sieved by a crusher (such as a jaw crusher) to 50 meshes, and the magnetic separation is carried out, wherein other values are the preferred values in the foregoing.
Example 5:
The high voltage resistant tantalum powder of 5000 mu FVIg-50000 mu FV/g capacitor grade obtained by the method is used as raw material.
First, a tantalum powder raw powder was put into a mixer, and then 90ppm of sufficiently ground boric acid and 30ppm of ammonium hexafluorophosphate and 40ppm of ammonium dihydrogen phosphate and 20ppm of ammonium sulfate were dry-blended.
The tantalum powder material doped with the doping agent is subjected to dry mixing in a V-shaped mixer for 110 minutes, so that the pores among particles are reduced, and the aim of increasing the bulk density is fulfilled.
And (3) discharging, adding 22% deionized water, uniformly mixing, and standing for 60 minutes.
Placing the wet material into a special shaping machine for vibration agglomeration for 20 minutes after standing, sieving with a 80-mesh sieve after vibration, and repeatedly sieving for 3 times.
Placing the sieved agglomerated powder into a vacuum drying box for high-temperature agglomeration, reducing the temperature to 50 ℃ after the high-temperature agglomeration temperature is 150 ℃ and 15 hours are finished, discharging the agglomerated powder out of the drying box, and performing secondary heat treatment and other subsequent treatments to obtain a final product.
The pickling conditions are as follows: first pass: the mixture was washed with 25% HNO 3 +0.5% HF for 2 hours and then with 1 hour, and the supernatant was decanted. Second pass: pickling with 10% HNO 3+0.5％HF+1％H2O2 for 3 hr, soaking for 2 hr, pouring out supernatant, rinsing with water twice, and filtering with pure water. When the conductivity of the filtering liquid is less than 30us/cm, the suction filtration is stopped, and the filtering liquid is transferred into an oven for high-temperature condensation. The vacuum degree is 3X 10 4 Pa during the drying process, and then the powder is sieved by a 100-mesh sieve.
The treatment conditions for the first heat treatment (i.e. degassing or presintering) are: the vacuum degree is more than 2.8X10 -3 Pa, and the mixture is heated at 1200 ℃ for 150 minutes, and preferably, after the first heat treatment, the mixture is crushed and sieved by a crusher (such as a jaw crusher) to 80 meshes, and the magnetic separation is carried out, wherein other values are the preferred values in the foregoing.
Comparative example 1:
the high-voltage resistant tantalum powder of 5000-50000 mu FV/g capacitor grade obtained by the method is used as a raw material.
Firstly, adding 25% deionized water into tantalum powder, uniformly mixing, and standing for 40 minutes.
Placing the wet material into a special shaping machine for vibration agglomeration for 50 minutes after standing, sieving with a 70-mesh sieve after vibration, and repeatedly sieving for 3 times.
Placing the sieved agglomerated powder into a vacuum drying box for high-temperature agglomeration, reducing the temperature to 50 ℃ after the high-temperature agglomeration temperature is 150 ℃ and 15 hours are finished, discharging the agglomerated powder out of the drying box, and performing secondary heat treatment and other subsequent treatments to obtain a final product.
The pickling conditions are as follows: first pass: the mixture was washed with 25% HNO 3 +1.5% HF for 3 hours and then with 2 hours, and the supernatant was poured out. Second pass: pickling with 25% HNO 3+1.5％HF+2％H2O2 for 3 hr, soaking for 2 hr, pouring out supernatant, rinsing with water twice, and filtering with pure water. When the conductivity of the filtering liquid is less than 30us/cm, the suction filtration is stopped, and the filtering liquid is transferred into an oven for high-temperature condensation. High-temperature condensation is carried out for 18 hours under vacuum at 180 ℃, the vacuum degree is more than or equal to 3 multiplied by 10 4 Pa in the drying process, and then the mixture is sieved by a 100-mesh sieve.
The treatment conditions for the first heat treatment (i.e. degassing or presintering) are: the vacuum degree is more than 2.8X10 -3 Pa, and the mixture is heated at 1400 ℃ for 240 minutes, preferably, after the first heat treatment, the mixture is crushed and sieved by a crusher (such as a jaw crusher) to 80 meshes, and the mixture is magnetically separated, and other values are preferred values in the foregoing.
Comparative example 2:
the high-voltage resistant tantalum powder of 5000-50000 mu FV/g capacitor grade obtained by the method is used as a raw material.
Firstly, adding 28% deionized water into tantalum powder, uniformly mixing, and standing for 60 minutes.
Placing the wet material into a special shaping machine for vibration agglomeration for 30 minutes after standing, sieving with a 70-mesh sieve after vibration, and repeatedly sieving for 3 times.
Placing the sieved agglomerated powder into a vacuum drying box for high-temperature agglomeration, reducing the temperature to 50 ℃ after the high-temperature agglomeration is completed at 120 ℃ for 15 hours, discharging the agglomerated powder from the drying box, and performing secondary heat treatment and other subsequent treatments to obtain a final product.
The pickling conditions are as follows: first pass: the mixture was washed with 10% HNO 3 +0.5% HF for 2 hours and then with 1 hour, and the supernatant was poured out. Second pass: pickling with 10% HNO 3+0.5％HF+1％H2O2 for 2 hr, soaking for 1 hr, pouring out supernatant, rinsing with water twice, and filtering with pure water. When the conductivity of the filtering liquid is less than 30us/cm, the suction filtration is stopped, and the filtering liquid is transferred into an oven for high-temperature condensation. High-temperature condensation is carried out for 12 hours under vacuum at 80 ℃, the vacuum degree is more than or equal to 3 multiplied by 10 4 Pa in the drying process, and then the mixture is sieved to 80 meshes.
The treatment conditions for the first heat treatment (i.e. degassing or presintering) are: the vacuum degree is more than 2.8X10 -3 Pa, heating is carried out for 30 minutes at 800 ℃, preferably, a crusher (such as a jaw crusher) is used for crushing and sieving 50 meshes after the first heat treatment, and magnetic separation is carried out, preferably, doping agent is added after the magnetic separation for dry mixing, and the pore space among particles is reduced, so that the aim of increasing the loose density is fulfilled, namely, dry shaping is fulfilled, and the vacuum degree is 4X 10 4 Pa in the drying process.
Other values are preferred values in the foregoing.
Then, each test was performed on the obtained tantalum powder.
The tantalum powders prepared in examples 1 to 5 and comparative example 1 were tested for various physical properties as shown in Table 1. As can be seen from Table 1, the Fischer particle size of the tantalum powder of examples 1-5 was larger than that of the tantalum powder of comparative example 1, and the bulk density of the tantalum powder of examples 1-5 was significantly larger than that of the tantalum powder of comparative example 1, and the proportion of tantalum powder smaller than 400 mesh in the tantalum powder of examples 1-5 was significantly smaller than that of tantalum powder smaller than 400 mesh in the tantalum powder of comparative example 1.
Table 1: physical properties of tantalum powder
In this table, fss (μm) represents the Fisher particle size, SBD (g/cc) represents the bulk density, +60 (%) represents the proportion of tantalum powder larger than 60 mesh, and 325 (%) represents the proportion of tantalum powder smaller than 325 mesh.
The tantalum powders prepared in examples 1 to 5 and comparative example 1 were tested to have the main impurity contents shown in Table 2.
Table 2: main impurity content (unit: ppm) in tantalum powder
For the electrical performance test, the above examples 1-3 and comparative example 1 powder samples were compression molded, the density of the briquettes was 5.0g/cm 3, the core powder weight was 0.3g, and the mold: phi 3mm, and detecting. Sintering in 10 -3 Pa vacuum furnace at 1700 deg.C for 30 min to obtain sintered cake, and energizing in 0.01% phosphoric acid solution at l60V for 120min at 90deg.C with current density of 60mA/g. The rest are detected by referring to the national standard GB/T3137-2007.
The tantalum powders prepared in examples 1-3 and comparative example 1 were tested and the electrical properties are shown in Table 3.
Table 3: contrast of electrical properties
The powder sample 4, sample 5 and comparative example 2 were press-formed to have a compact density of 5.0g/cm 3 and a core powder weight of 0.15g, and were molded: phi 3mm, and detecting. Sintering in 10 -3 Pa vacuum furnace at 1400 deg.C for 30 min to obtain sintered cake, and energizing in 0.01% phosphoric acid solution at l00V for 120min at 90 deg.C with current density of 90mA/g. The rest are detected by referring to the national standard GB/T3137-2007.
The tantalum powders prepared in examples 4-5 and comparative example 2 were tested and the electrical properties are shown in Table 4.
Table 4: contrast of electrical properties
In this table, K.times.10 -4 (μA/. Mu.FV) represents leakage current, CV (μFV/g) represents capacity, tg.delta. (%) represents loss, and SHV (%) represents volume shrinkage.
As can be seen from the above tables 3 to 4, the tantalum powders prepared in examples 1 to 5 have a lower leakage current overall than that of comparative example 1, indicating that the tantalum powders prepared by the method of the present invention have low leakage current, low loss, high capacity, and significantly improved product properties.
Fig. 1 shows the leakage current comparison of examples and comparative examples of tantalum powders obtained according to the present invention. Fig. 1 graphically shows that anode blocks prepared according to the present invention have lower leakage current.
Fig. 2 shows the specific capacitance comparisons of examples and comparative examples of tantalum powders obtained according to the present invention. Fig. 2 graphically shows that tantalum powders prepared according to the present invention have higher specific capacitance.
Fig. 3 shows the loss comparisons of examples and comparative examples of tantalum powders obtained according to the present invention. Fig. 3 graphically shows that anode blocks prepared according to the present invention have lower losses.
From the above examples, it is clear that these improvements in performance make it more suitable for mass production on capacitor production lines. The requirements of capacitor products on the field of voltage resistance, leakage current and the like of the powder are met. The applicable product of the patent is 5000 mu FVIg-50000 mu FVIg capacitor-grade medium-high voltage resistant tantalum powder.
Claims (10)
1. A method for agglomerating high voltage resistant tantalum powder, comprising the steps of: (1) Mixing tantalum powder raw powder, and adding a doping agent for dry shaping;
(2) Adding liquid A into the tantalum powder subjected to dry shaping, vibrating the tantalum powder material, and sieving to perform secondary agglomeration to obtain agglomerated powder;
(3) The agglomeration powder after sieving is subjected to high-temperature agglomeration, the agglomeration temperature is 80-150 ℃ for 10-15 hours, the temperature is reduced to 50 ℃ after the agglomeration is finished, and then the material is subjected to secondary heat treatment.
2. A method of agglomerating high voltage tantalum powder according to claim 1, wherein: the tantalum powder raw powder in the step (1) is tantalum powder obtained by a sodium reduction potassium fluorotantalate process, the tantalum powder raw powder further comprises a step of flaking, the flaking step is carried out after heat treatment, the tantalum powder raw powder is processed into flakes to obtain flake tantalum powder raw powder, shaping is carried out, and acid washing is carried out on the tantalum powder before dry shaping.
3. A method of agglomerating high voltage tantalum powder according to claim 1, wherein: the dry shaping in the step (1) lasts for 10 to 60 minutes, and the secondary agglomerating in the step (2) lasts for 0 to 60 minutes.
4. A method of agglomerating high voltage tantalum powder according to claim 1, wherein: the doping agent in the step (1) comprises one or more of boric acid, ammonium dihydrogen phosphate, ammonium hexafluorophosphate and ammonium sulfate, wherein the boric acid, the ammonium dihydrogen phosphate and the ammonium hexafluorophosphate doped in the step (1) are all 0-100 ppm, and the ammonium sulfate doped in the step (1) is 0-50 ppm.
5. A method of agglomerating high voltage tantalum powder according to claim 1, wherein: and (3) taking out the secondarily-agglomerated tantalum powder material in the step (2) and performing agglomeration molding at the temperature of 80-180 ℃, wherein the agglomeration is in a vacuum state.
6. A method of agglomerating high voltage tantalum powder according to claim 1, wherein: the liquid A is water, and the adding amount of the liquid A is 10-30% of the weight of the tantalum powder.
7. A high voltage tantalum powder produced by the method for agglomerating a high voltage tantalum powder according to any one of claims 1-6.
8. A high voltage tantalum powder according to claim 7 wherein: the specific volume of the high-voltage resistant tantalum powder is 5000-50000 mu FV/g.
9. A tantalum capacitor produced from the high voltage resistant tantalum powder of any of claims 7-8.
10. A tantalum capacitor as claimed in claim 9 wherein: the tantalum capacitor is a solid tantalum capacitor or a liquid tantalum capacitor, the working voltage of the solid tantalum capacitor is 20-50V, and the working voltage of the liquid tantalum capacitor is 40-125V.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410539810.8A CN118492364A (en) | 2024-04-30 | 2024-04-30 | Agglomeration method of high-voltage-resistant tantalum powder, tantalum powder prepared by method and capacitor prepared by tantalum powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410539810.8A CN118492364A (en) | 2024-04-30 | 2024-04-30 | Agglomeration method of high-voltage-resistant tantalum powder, tantalum powder prepared by method and capacitor prepared by tantalum powder |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN118492364A true CN118492364A (en) | 2024-08-16 |
Family
ID=92242789
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202410539810.8A Pending CN118492364A (en) | 2024-04-30 | 2024-04-30 | Agglomeration method of high-voltage-resistant tantalum powder, tantalum powder prepared by method and capacitor prepared by tantalum powder |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN118492364A (en) |
-
2024
- 2024-04-30 CN CN202410539810.8A patent/CN118492364A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP7432927B2 (en) | Spherical powder-containing anodes and capacitors | |
| EP0909337B1 (en) | Method of making tantalum metal powder with controlled size distribution and products made therefrom | |
| EP0284738B1 (en) | Platelet-containing tantalum powders | |
| US4555268A (en) | Method for improving handling properties of a flaked tantalum powder composition | |
| US3647415A (en) | Tantalum powder for sintered capacitors | |
| US4017302A (en) | Tantalum metal powder | |
| CN101189089B (en) | Process for heat treating metal powder and products made from the same | |
| JPS6048561B2 (en) | Method for producing tantalum metal powder | |
| CZ305376B6 (en) | Nitrided metal powder with low electrochemical potential, process for its preparation and capacitor anode comprising thereof | |
| GB2130246A (en) | Tantalum powder composition | |
| EP3184205B1 (en) | Preparation method for composite tantalum powder | |
| JP2003213302A (en) | Niobium powder, niobium sintered compact, and capacitor using niobium sintered compact | |
| CN103894601B (en) | A kind of preparation method for the high pressure tantalum powder for improving proof voltage energy | |
| JP4828016B2 (en) | Tantalum powder manufacturing method, tantalum powder and tantalum electrolytic capacitor | |
| EP3095540B1 (en) | Method for preparing tantalum powder for high-reliability, high specific capacity electrolytic capacitor | |
| EP0528974B1 (en) | Method of producing high surface area low metal impurity tantalum powder | |
| CN103934452B (en) | A kind of dough method of superelevation specific volume tantalum powder and the tantalum powder prepared by the method | |
| JP6977021B2 (en) | Flaky tantalum powder and its preparation method | |
| CN118492364A (en) | Agglomeration method of high-voltage-resistant tantalum powder, tantalum powder prepared by method and capacitor prepared by tantalum powder | |
| CN113560561B (en) | Spherical tantalum powder, preparation method and application thereof | |
| CN106392060B (en) | A kind of mixing tantalum powder and preparation method thereof | |
| CN103878364B (en) | A kind of preparation method of the middle pressure tantalum powder for improving proof voltage energy | |
| CN118417570A (en) | Tantalum powder preparation method for improving high voltage performance, tantalum powder prepared by method and capacitor prepared by tantalum powder | |
| CN118832171A (en) | Preparation method of high-voltage tantalum powder, anode and capacitor prepared from tantalum powder | |
| KR100484686B1 (en) | Method of Making Tantalum Metal Powder With Controlled Size Distribution and Products Made Therefrom |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |