Abstract

277) solution into a reaction kettle, and adding sulfuric acid into the fluorotantalic acid solution, such that the acidity of the fluorotantalic acid solution exceeds 2 mol/L, controlling the temperature of the reaction kettle to exceed 80ºC, adding a precipitant thereto until the pH of the reaction solution is 8-10, then stopping introducing ammonia, and carrying out aging to obtain a tantalum hydroxide slurry; (2) filtering and washing the tantalum hydroxide slurry obtained in step (1), and then subjecting same to solid-liquid separation to obtain a tantalum hydroxide filter cake; (3) drying the filter cake obtained in step (2) to obtain a tantalum hydroxide powder; (4) calcining the tantalum hydroxide powder obtained in step (3), and crushing and screening the calcined sample to obtain a tantalum pentoxide powder; and (5) subjecting the tantalum pentoxide powder obtained in step (4) to a heat treatment at a temperature of 1000-1500ºC to obtain a high-purity tantalum pentoxide powder.

Abstract

A method produces tantalum powder by reducing tantalum oxide with an alkaline earth metal. The method includes (1) mixing tantalum oxide with an excessive alkaline earth metal reducing agent, simultaneously mixing at least one alkali metal and/or alkaline earth metal halide accounting for 10-200% of the weight of the tantalum oxide, heating the mixture to a temperature of 700-1200° C. in a furnace filled with inert gas, and soaking so that the tantalum oxide and reducing agent are subjected to a reduction reaction; (2) at the end of soaking, lowering the temperature to 600-800° C., vacuumizing the interior of the furnace to 10 Pa or less, and soaking under the negative pressure so that the excessive magnesium and tantalum powder mixture are separated; (3) thereafter, raising the temperature of the furnace to 750-1200° C. in the presence of inert gas, and soaking so that the tantalum powder is further sintered in the molten salt; (4) then cooling to room temperature and passivating to obtain a mixed material containing halide and tantalum powder; and (5) separating the tantalum powder from the mixture.

IPC Classes  ?

• B22F 9/20 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using chemical processes with reduction of metal compounds starting from solid metal compounds
• B22F 1/142 - Thermal or thermo-mechanical treatment
• B22F 1/145 - Chemical treatment, e.g. passivation or decarburisation

Abstract

A method produces tantalum powder. The method includes: (1) uniformly mixing a tantalum powder raw material, metal magnesium and at least one alkali metal and/or alkaline earth metal halide, loading the mixture into a container, and putting the container in a furnace; (2) raising the temperature of the furnace to 600-1200° C. in the presence of inert gas, and soaking; (3) at the end of soaking, lowering the temperature of the furnace to 600-800° C., vacuumizing the interior of the furnace to 10 Pa or less, soaking under the negative pressure so that the excessive metal is separated; (4) thereafter, raising the temperature of the furnace to 750-1200° C. in the presence of inert gas, and soaking so that the tantalum powder is sintered in the molten salt after oxygen reduction; (5) then cooling to room temperature and passivating to obtain a mixed material containing halide and tantalum powder; and (6) separating the tantalum powder from the resulting mixture.

IPC Classes  ?

• B22F 1/142 - Thermal or thermo-mechanical treatment
• B22F 1/145 - Chemical treatment, e.g. passivation or decarburisation

Abstract

A low-carbon, high-purity tantalum pentoxide powder has a carbon content of no greater than 15 ppm. A preparation method for the powder includes: (1) adding a fluotantalic acid (H2TaF7) solution into a reaction kettle, controlling the temperature of the reaction kettle at 30-60° C., adding a precipitator until the pH of the reaction solution is 8-10, then stopping introducing ammonia, and aging to obtain a tantalum hydroxide slurry; (2) filtering and washing the slurry obtained in step (1), and then carrying out solid-liquid separation to obtain a tantalum hydroxide filter cake; (3) drying the filter cake obtained in step (2) to obtain white tantalum hydroxide powder; (4) calcining the tantalum hydroxide powder obtained in step (3), crushing and screening the calcined sample to obtain tantalum pentoxide powder; and (5) subjecting the tantalum pentoxide powder obtained in step (4) to heat treatment at a temperature of 1000-1500° C. to obtain the powder.

IPC Classes  ?

• C01G 35/00 - Compounds of tantalum

Abstract

A high-purity tantalum powder and a preparation method therefor. The sum of W, Mo and Nb content of the high-purity tantalum powder is less than 0.6 ppm, Mg content is less than 1 ppm, and oxygen content is less than 600 ppm. The high-purity tantalum powder can be used to prepare a high-purity tantalum target.

IPC Classes  ?

• B22F 1/05 - Metallic powder characterised by the size or surface area of the particles
• B22F 1/142 - Thermal or thermo-mechanical treatment
• B22F 1/145 - Chemical treatment, e.g. passivation or decarburisation
• B22F 9/04 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using physical processes starting from solid material, e.g. by crushing, grinding or milling
• B22F 9/18 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using chemical processes with reduction of metal compounds
• C22F 1/02 - Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working in inert or controlled atmosphere or vacuum
• C22F 1/18 - High-melting or refractory metals or alloys based thereon

Abstract

A method for producing tantalum powder for a capacitor by reducing tantalum oxide using an alkaline earth metal, comprising the following steps: 1) mixing tantalum oxide with an excessive alkaline earth metal reducing agent magnesium, simultaneously mixing at least one alkali metal or alkaline earth metal halide accounting for 10-200% of the weight of tantalum oxide, and in a heating furnace filled with an inert gas, heating the obtained mixture to a temperature of 700-1200°C, and then maintaining the temperature for 1 h to 10 h, so that the tantalum oxide and the reducing agent fully undergo a reduction reaction; 2) after the temperature maintaining is finished, cooling to 600-800°C, vacuumizing the heating furnace to below 10 Pa, and maintaining the negative pressure for 1 h to 10 h, so that the excess metal magnesium is separated from the tantalum powder mixture; 3) then, under an inert gas, increasing the temperature of the heating furnace to a temperature of 750-1200°C, preferably 900-1050°C, and then maintaining the temperature for 1 h to 6 h, so that the tantalum powder is further sintered in molten salt; 4) then cooling to room temperature and performing passivation treatment to obtain a mixed material containing halide and tantalum powder; and 5) separating the tantalum powder from the obtained mixture.

IPC Classes  ?

• B22F 9/20 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using chemical processes with reduction of metal compounds starting from solid metal compounds
• C22B 5/04 - Dry processes by aluminium, other metals, or silicon
• C22B 34/24 - Obtaining niobium or tantalum

Abstract

277) solution to a reaction vessel, controlling the temperature of the reaction vessel at 30-60°C, adding a precipitant until the pH value of the reaction solution is 8-10, then stopping introducing ammonia, and aging same to obtain a tantalum hydroxide slurry; (2) filtering and washing the tantalum hydroxide slurry obtained in step (1), and then subjecting same to solid-liquid separation to obtain a tantalum hydroxide filter cake; (3) drying the filter cake obtained in step (2) to obtain a white tantalum hydroxide powder; (4) calcining the tantalum hydroxide powder obtained in step (3), and then crushing and screening the calcined sample to obtain a tantalum pentoxide powder; and (5) subjecting the tantalum pentoxide powder obtained in step (4) to a heat treatment at a temperature of 1000-1500°C to obtain a high-purity tantalum pentoxide powder.

IPC Classes  ?

• C01G 35/00 - Compounds of tantalum

Abstract

A tantalum powder production method and tantalum powder obtained thereby. The method comprises the following specific steps: (1) uniformly mixing a tantalum powder raw material with magnesium metal and at least one halide selected from alkali metal or alkaline earth metal, putting the mixture into a container, and placing the container in a heating furnace; (2) in inert gas, increasing the temperature of the heating furnace to 600-1200°C, and keeping the temperature for 1-4 h; (3) after the end of temperature keeping, adjusting the temperature of the heating furnace to 600-800°C, evacuating the heating furnace to 10 Pa or below, and keeping negative pressure for 1-10 h so as to separate out excess metal; (4) then, increasing the temperature of the heating furnace to 750-1200°C in inert gas, keeping the temperature for 1-6 h, and sintering the tantalum powder subjected to oxygen reduction in a molten salt; (5) cooling to room temperature, and carrying out passivation treatment to obtain a mixed material containing the halide and the tantalum powder; and (6) washing, pickling, filtering and drying the obtained mixed material to separate out the tantalum powder.

IPC Classes  ?

• B22F 1/142 - Thermal or thermo-mechanical treatment
• B22F 1/145 - Chemical treatment, e.g. passivation or decarburisation
• H01G 9/042 - Electrodes characterised by the material

Abstract

A method for preparing tantalum-tungsten alloy powder, comprising the following steps: providing a tantalum-tungsten alloy ingot; repeatedly smelting the tantalum-tungsten alloy ingot for many times; forging a product of a previous step; placing the product of the previous step in a hydrogen atmosphere to perform hydrogenation heat treatment; mechanically crushing the product of the previous step to obtain coarse powder; sieving, from the coarse powder, powder having a particle size ranging from a μm to b μm, wherein a=10-20, and b=50-60; performing dehydrogenation heat treatment on the product of the previous step under vacuum; adding magnesium powder to the product of the previous step to perform oxygen reduction heat treatment; and performing plasma spheroidization treatment on the product of the previous step, such that the sphericity of the powder reaches more than 99%.

IPC Classes  ?

• B22F 9/02 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using physical processes

Abstract

2/g; Powder that can pass through a ρ-mesh screen in the tantalum powder accounts for over 85% of the total weight of the tantalum powder, where ρ=150˜170; and the tantalum powder with high CV has a low leakage current and dielectric loss, and good moldability.

IPC Classes  ?

• B22F 9/20 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using chemical processes with reduction of metal compounds starting from solid metal compounds
• B22F 3/10 - Sintering only
• B22F 9/04 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using physical processes starting from solid material, e.g. by crushing, grinding or milling
• B22F 1/05 - Metallic powder characterised by the size or surface area of the particles
• B22F 1/142 - Thermal or thermo-mechanical treatment
• H01G 9/042 - Electrodes characterised by the material
• C22C 1/04 - Making non-ferrous alloys by powder metallurgy
• B22F 9/24 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using chemical processes with reduction of metal compounds starting from liquid metal compounds, e.g. solutions
• C22C 27/02 - Alloys based on vanadium, niobium or tantalum
• H01G 9/052 - Sintered electrodes

Abstract

A tantalum powder, a tantalum powder compact, a tantalum powder sintered body, a tantalum anode, an electrolytic capacitor and a preparation method for tantalum powder. The tantalum powder contains boron element, and the specific surface area of the tantalum powder is greater than or equal to 4m 2/g; the ratio of the boron content of the tantalum powder to the specific surface area of the tantalum powder is 2~16; the boron content is calculated in mass ppm, and the specific surface area is calculated in m 2/g; The powder passing through a ρ-mesh sieve in the tantalum powder accounts for over 85% of the total mass of the tantalum powder, where ρ=150~170; and the tantalum powder with high CV has a low leakage current and loss, and good moldability.

IPC Classes  ?

• B22F 1/00 - Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
• B22F 5/00 - Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product
• B22F 9/00 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor

Abstract

Provided are a tantalum flake powder and method for preparation thereof; said tantalum flake powder contains 300-1800 ppm of nitrogen, 10-100 ppm of phosphorus, and 1-40 ppm of boron. The tantalum flake powder has high capacity and low leakage current, good puncture-resistance, and particularly outstanding high-frequency attributes. Doping with nitrogen during oxygen reduction is performed before three thermal treatments are carried out; the solution of performing three thermal treatments and a subsequent process improves the uniformity of distribution of elemental nitrogen and makes up for the deficiency of an oxide film, thereby increasing the pressure resistance of the product, and especially its high-frequency attributes.

IPC Classes  ?

• C22B 34/24 - Obtaining niobium or tantalum
• B22F 9/20 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using chemical processes with reduction of metal compounds starting from solid metal compounds

Abstract

2/g. After the secondary agglomeration, the tantalum powder has a large particle size. The tantalum powder has an average Fisher sub-sieve size (FSSS) of 1.2 to 3.0 μm wherein as measured with a standard sieve mesh, more than 75% of tantalum powder has a +325-mesh, and a particle size distribution D50 of more than 60 μm, that is, the secondary particle size is high. A resultant capacitor anode prepared by sintering the tantalum powder of the invention at 1200° C. for 20 minutes and then being energized at the voltage of 20 V has the specific capacitance of from 140,000 to 180,000 μFV/g and the residual current of less than 1.0 nA/μFV. Meantime, the invention provides an economical process for making the tantalum powder.

IPC Classes  ?

• C22F 1/18 - High-melting or refractory metals or alloys based thereon
• B22F 9/20 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using chemical processes with reduction of metal compounds starting from solid metal compounds
• B22F 1/00 - Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
• H01G 9/052 - Sintered electrodes
• B22F 3/10 - Sintering only
• B22F 5/00 - Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product
• B22F 9/24 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using chemical processes with reduction of metal compounds starting from liquid metal compounds, e.g. solutions
• C21D 3/02 - Extraction of non-metals
• H01G 9/00 - Electrolytic capacitors, rectifiers, detectors, switching devices, light-sensitive or temperature-sensitive devices; Processes of their manufacture
• H01G 9/042 - Electrodes characterised by the material
• H01G 9/04 - Electrodes

Abstract

The present invention relates to a high-purity tantalum powder and a preparation method therefore. The tantalum powder has a purity of more than 99.995%, as analyzed by GDMS. Preferably, the tantalum powder has an oxygen content of not more than 1000 ppm, a nitrogen content of not more than 50 ppm, a hydrogen content of not more than 20 ppm, a magnesium content of not more than 5 ppm, and an average particle diameter D50 of less than 25 μm.

IPC Classes  ?

• B22F 1/00 - Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
• B22F 9/04 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using physical processes starting from solid material, e.g. by crushing, grinding or milling
• B22F 9/02 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using physical processes
• B22F 9/16 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using chemical processes
• C22F 1/18 - High-melting or refractory metals or alloys based thereon
• C23G 1/00 - Cleaning or pickling metallic material with solutions or molten salts

Abstract

Provided is a fine tantalum powder. The fine tantalum powder has a D50 < 5 µm, preferably a D50 < 4.5 µm, and an apparent density of 2.0-6.0 g/cm3, preferably 2.2-4.5 g/cm3. Also provided is a method for manufacturing the fine tantalum powder, comprising: 1) providing a sodium reduced tantalum powder as a raw material; 2) sintering the raw material with a high temperature to obtain a sintered block; 3) performing hydrogen decrepitation of the sintered block to obtain a hydrogenated tantalum powder; and 4) dehydrogenating, deoxygenating, pickling, drying and sifting the hydrogenated tantalum powder.

IPC Classes  ?

• B22F 9/04 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using physical processes starting from solid material, e.g. by crushing, grinding or milling
• B22F 1/00 - Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
• C22C 1/04 - Making non-ferrous alloys by powder metallurgy

Abstract

A method for providing a tantalum powder with a piece+block structure, comprising the following steps: 1) providing a granulous tantalum powder, and dividing same into a first part and a second part; 2) putting the first part of the tantalum powder in a ball mill for ball milling, taking the powder out after the ball milling and sieving same, and obtaining a tantalum powder in the form of a piece; 3) mixing the tantalum powder in the form of a piece and the second part of the tantalum powder to obtain a mixture, and preferably, the mixing proportion of the tantalum powder in the form of a piece and the granulous tantalum powder being 1:0.1˜1, preferably being 1:0.25˜0.8, and more preferably being 1:0.4˜0.6; and 4) performing the steps of water washing, acid washing, and nodularization on the mixture to finally obtain a tantalum powder with a piece+block structure.

IPC Classes  ?

• B32B 15/02 - Layered products essentially comprising metal in a form other than a sheet, e.g. wire, particles
• H01G 9/042 - Electrodes characterised by the material
• B22F 9/04 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using physical processes starting from solid material, e.g. by crushing, grinding or milling
• H01G 9/15 - Solid electrolytic capacitors
• B22F 1/00 - Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
• H01G 9/052 - Sintered electrodes
• H01G 9/04 - Electrodes

Abstract

The present invention relates to the field of rare metal smelting, particularly to a tantalum powder for manufacturing a capacitor, preparation method of the tantalum powder and sintered anode made by the same. The BET of an initial powder of the tantalum powder is 3.0-4.5 m2/g; a secondary agglomerated particle has a large particle size; the FSSS particle size is 1.2-3.0 μm; 75% of the tantalum powder is greater than 325 mesh when measured with a standard sieve; the particle size distribution D50 value is greater than 60 μm; the secondary particle size is large; the specific capacitance of a capacitor obtained by sintering the tantalum powder at a temperature of 1200ºC for 20 minutes and then applying a voltage of 20V is from 140,000 to 180,000 μFV/g; and a residual current therethrough is less than 1.0 nA/μFV. Also provided is a method for preparing the tantalum powder economically.

IPC Classes  ?

• B22F 9/20 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using chemical processes with reduction of metal compounds starting from solid metal compounds
• H01G 9/20 - Light-sensitive devices

Abstract

A method for preparing a tantalum power of capacitor grade, comprising: solid tantalum nitride is added when potassium fluotantalate is reduced by sodium. The method increases the nitrogen content in the tantalum powder, and at the same time improves the electrical performance of the tantalum powder. The specific capacitance is increased, and the leakage current and loss is improved. The qualification rate of the anode and the capacitor product is also improved. The method is characterized in that the nitrogen in the tantalum nitride diffuses between the particles of the tantalum powder, with substantially no loss, and thus the nitrogen content is accurate and controllable.

IPC Classes  ?

• B22F 9/04 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using physical processes starting from solid material, e.g. by crushing, grinding or milling
• C22B 34/24 - Obtaining niobium or tantalum
• H01G 9/00 - Electrolytic capacitors, rectifiers, detectors, switching devices, light-sensitive or temperature-sensitive devices; Processes of their manufacture
• B22F 9/20 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using chemical processes with reduction of metal compounds starting from solid metal compounds
• B22F 9/24 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using chemical processes with reduction of metal compounds starting from liquid metal compounds, e.g. solutions
• C22C 1/04 - Making non-ferrous alloys by powder metallurgy
• C22C 27/02 - Alloys based on vanadium, niobium or tantalum
• H01G 9/025 - Solid electrolytes
• H01G 9/042 - Electrodes characterised by the material
• H01G 9/052 - Sintered electrodes

Abstract

A composite tantalum powder, a preparation method therefor, and a capacitor positive electrode prepared by using the tantalum powder. The method for preparing the composite tantalum powder comprises the following steps: 1) providing tantalum powder prepared by using a reduction method, flattening the tantalum powder to obtain sheet tantalum powder; 2) providing granular tantalum powder prepared by using tantalum ingots; 3) mixing the sheet tantalum powder and the granular tantalum powder to obtain a tantalum powder mixture; and 4) performing thermal treatment of the tantalum powder mixture, breaking the thermally-treated tantalum powder mixture, and sieving the tantalum powder mixture to obtain composite tantalum powder. The present invention also relates to composite tantalum powder prepared by using the method, and uses of the composite tantalum powder in a capacitor.

IPC Classes  ?

• B22F 1/00 - Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
• B22F 9/02 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using physical processes
• B22F 9/16 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using chemical processes
• H01G 9/00 - Electrolytic capacitors, rectifiers, detectors, switching devices, light-sensitive or temperature-sensitive devices; Processes of their manufacture

Abstract

The present invention relates to a tantalum wire for anode lead of tantalum capacitors, characterized in that the cross section of the tantalum wire is approximate rectangular or regular rectangular. The present invention also relates to a process for manufacturing the tantalum wire, comprising the steps of: providing feedstock tantalum wire; subjecting the feedstock tantalum wire to heat treatment; subjecting the heat treated tantalum wire to surface pretreatment to form an oxide membrane on the surface-pretreated tantalum wire; rolling the surface-pretreated tantalum wire by lubricating with lubricant oil to make the cross section of the rolled tantalum wire being approximate rectangular or regular rectangular; subjecting the tantalum wire to final annealing.

IPC Classes  ?

• H01R 43/00 - Apparatus or processes specially adapted for manufacturing, assembling, maintaining, or repairing of line connectors or current collectors or for joining electric conductors
• H01G 9/00 - Electrolytic capacitors, rectifiers, detectors, switching devices, light-sensitive or temperature-sensitive devices; Processes of their manufacture
• H01G 9/012 - Terminals specially adapted for solid capacitors
• H01G 9/048 - Electrodes characterised by their structure
• B21B 1/18 - Metal rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling wire or material of like small cross-section in a continuous process
• B22F 3/24 - After-treatment of workpieces or articles
• B22F 5/12 - Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product of tubes or wires
• C22C 1/04 - Making non-ferrous alloys by powder metallurgy
• H01G 9/052 - Sintered electrodes

Abstract

The present invention relates to a high-purity tantalum powder and a preparation method therefor. The tantalum powder has a purity of more than 99.995%, as analyzed by GDMS. Preferably, the tantalum powder has an oxygen content of not more than 1000ppm, a nitrogen content of not more than 50ppm, a hydrogen content of not more than 20ppm, a magnesium content of not more than 5ppm, and a particle size D50 of less than 25μm.

IPC Classes  ?

• B22F 9/20 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using chemical processes with reduction of metal compounds starting from solid metal compounds

Abstract

A wet ball-milling method for a tantalum powder, which method uses a grinding aid containing a ball-milling medium and a surfactant. The method has a simple process and strong controllability, and the product obtained has a lower content of metallic impurities.

IPC Classes  ?

• C22C 1/04 - Making non-ferrous alloys by powder metallurgy
• B22F 1/00 - Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties

Abstract

A method for preparing a tantalum powder for a high-reliability, high specific capacity electrolytic capacitor, wherein the ratio of the mean particle size of raw material tantalum powder to the mean particle size of flaky tantalum powder is 0.5-25, preferably 1.5-10, and more preferably 2-5. The preparation method of the present invention has a simple process and strong controllability. The obtained flaky tantalum powder has a lower content of metallic impurities, a higher specific surface area, a good fluidity and formability after conglomeration, a higher specific capacity, and a lower leakage current and a higher breakdown voltage when used under a higher voltage.

IPC Classes  ?

• B22F 9/04 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using physical processes starting from solid material, e.g. by crushing, grinding or milling

Abstract

A method for preparing a high-performance tantalum target, a high-performance target prepared by the method, and a use of the high-performance target. The method for preparing the high-performance tantalum target comprises: firstly, preparing a tantalum ingot into a forging blank by a method of cold forging in conjunction with hot forging; then, rolling the forging blank by a hot rolling method; and finally, performing leveling, and performing discharging, milling and surface treatment according to a size of a finished product, so as to obtain the tantalum target. The tantalum target prepared by the method has uniform crystallization, with a grain size between 50 μm and 120 μm. A texture component where a texture (110) dominants in the thickness direction of the target is obtained. A total proportion of three textures (111), (110) and (100) is between 40% and 50%, ensuring a consistent sputtering rate of the tantalum target during use.

IPC Classes  ?

• C22F 1/18 - High-melting or refractory metals or alloys based thereon
• C23C 14/34 - Sputtering
• B21B 15/00 - Arrangements for performing additional metal-working operations specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills
• B21B 45/00 - Devices for surface treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills
• C22C 27/02 - Alloys based on vanadium, niobium or tantalum
• C23C 14/14 - Metallic material, boron or silicon
• H01J 37/34 - Gas-filled discharge tubes operating with cathodic sputtering
• H01L 21/285 - Deposition of conductive or insulating materials for electrodes from a gas or vapour, e.g. condensation
• B21B 1/02 - Metal rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling heavy work, e.g. ingots, slabs, billets, in which the cross-sectional form is unimportant

Abstract

A method of adding part nitrogen-containing salts in the synthetic process of potassium fluotantalate is provided. Since the procedure of nitrogen doping is conducted during the synthetic process of potassium fluotantalate, the nitrogen content that is more uniform than those obtained from other methods is obtained, and moreover, nitrogen is doped at the early stage, so primary particles are directly affected and accordingly become finer, the specific volume of tantalum powder is higher, and smaller leakage current and loss are realized. The method improves the qualified rate of capacitor products.

IPC Classes  ?

• B22F 9/24 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using chemical processes with reduction of metal compounds starting from liquid metal compounds, e.g. solutions

Abstract

A method for providing a tantalum powder with a piece + block structure, comprising the following steps: 1) providing a granulous tantalum powder, and dividing same into a first part and a second part; 2) putting the first part of the tantalum powder in a ball mill for ball milling, taking the powder out after the ball milling and sieving same, and obtaining a tantalum powder in the form of a piece; 3) mixing the tantalum powder in the form of a piece and the second part of the tantalum powder to obtain a mixture, and preferably, the mixing proportion of the tantalum powder in the form of a piece and the granulous tantalum powder being 1:0.1~1, preferably being 1:0.25~0.8, and more preferably being 1:0.4~0.6; and 4) performing the steps of water washing, acid washing, and nodularization on the mixture to finally obtain a tantalum powder with a piece + block structure.

IPC Classes  ?

• H01G 9/042 - Electrodes characterised by the material
• B22F 9/04 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using physical processes starting from solid material, e.g. by crushing, grinding or milling
• H01G 9/15 - Solid electrolytic capacitors

Abstract

A method for preparing a capacitor-grade tantalum powder: when potassium fluotantalate is reduced by sodium, solid tantalum nitride is added, and therefore while the nitrogen content in the tantalum powder is increased, the electrical performance of the tantalum powder is improved, both increasing the specific volume and improving the leakage current and loss. The qualification rate of the anode and capacitor products is improved. The method is characterized in that the nitrogen in the tantalum nitride diffuses between the particles of the tantalum powder, substantially with no loss, and thus the control of the nitrogen content is accurate and controllable.

IPC Classes  ?

• B22F 9/24 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using chemical processes with reduction of metal compounds starting from liquid metal compounds, e.g. solutions

Abstract

A method for agglomerating tantalum powder comprises the following steps: 1) providing tantalum powder; 2) pre-agglomerating the tantalum powder by using the following mode: adding water into the tantalum powder to completely wet the tantalum powder, separating surplus water out, and pouring part or all of the surplus water out; and 3) agglomerating the tantalum powder by using the following mode for a second time: freezing the pre-agglomerated tantalum powder until tantalum powder particles are agglomerated into blocks, and then taking the blocks out and performing vacuum drying of the blocks, pulverizing and sieving the blocks to obtain agglomerated tantalum powder.

IPC Classes  ?

• B22F 1/00 - Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
• B22F 9/04 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using physical processes starting from solid material, e.g. by crushing, grinding or milling

Abstract

A medical implant porous material, comprising: a metallic wire or non-metallic wire braid and a metal layer bonded onto the braid. The medical implant porous material has a relatively high porosity and regular pore size, and there is no problem of closed pores inside the porous material. A method for preparation of a medical implant porous material, comprising the following steps: braiding a metallic wire or non-metallic wire to form a metallic wire or non-metallic wire braid; bonding a metal onto the metallic wire or non-metallic wire braid obtained in the above step to obtain the medical implant porous material.

IPC Classes  ?

• A61L 27/40 - Composite materials, i.e. layered or containing one material dispersed in a matrix of the same or different material
• A61L 27/56 - Porous or cellular materials

Abstract

A tantalum-niobium alloy wire used for an anode lead of an electrolytic capacitor and a manufacturing method thereof. The composition of the tantalum-niobium alloy wire comprises: tantalum of 0.1 to 99.9 wt%, and niobium and unavoidable impurities of the remaining content. The method comprises: material mixing, compression molding, sintering, rolling, annealing, drawing, and optional cleaning and continuous annealing, so as to obtain a tantalum-niobium alloy wire applicable to an electrolytic capacitor. Compared with a normal tantalum metal wire, the tantalum-niobium alloy wire significantly reduces the cost.

IPC Classes  ?

• H01G 9/008 - Terminals
• H01G 9/15 - Solid electrolytic capacitors
• C22C 27/02 - Alloys based on vanadium, niobium or tantalum

Abstract

The present invention provides a tantalum-niobium alloy wire which satisfies use requirements of an anode lead of an electrolytic capacitor and a manufacturing method thereof. The tantalum-niobium alloy wire is characterized in that the chemical composition of the tantalum-niobium alloy wire comprises tantalum of 0.1 to 99.9 wt%, beneficial dopants of 0.001 to 0.2 wt%, and niobium and unavoidable impurities of the remaining content. The tantalum-niobium alloy wire and the manufacturing method thereof according to the present invention effectively improve the high-temperature performance and resistance to brittleness of the tantalum-niobium alloy wire, improve the wire folding performance after high-temperature sintering, and also have advantages of a normal tantalum-niobium alloy wire that the raw materials have a low cost and the effective use length per unit weight is long.

IPC Classes  ?

• H01G 9/042 - Electrodes characterised by the material

Abstract

A powder material used for a capacitor-level tantalum-niobium alloy wire material and a preparing method thereof. The powder material is formed by tantalum powder and niobium powder, wherein the weight proportion of the tantalum powder and the niobium powder is 1:2 to 3:2, the purity of the tantalum powder and the niobium powder is greater than 99.9 wt%, the granularity of the tantalum powder is -80 to -150 meshes, the granularity of the niobium powder is -150 to -200 meshes, and a loose specific weight of the powder material is 3.0 to 4.3 g/cm3. The preparing method of the powder material comprises material proportioning, manual mixing, primary mixing, secondary mixing, and tertiary mixing, thereby obtaining a powder material used for a capacitor-level tantalum-niobium alloy wire material. The preparing method is reasonably designed, and suitable for uniform mixing of two different types of metal powder materials. The whole production process is highly controlled, the product quality is stable, and the manufacturing of the capacitor-level tantalum-niobium alloy wire material is facilitated.

IPC Classes  ?

• B22F 1/00 - Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
• C22C 45/10 - Amorphous alloys with molybdenum, tungsten, niobium, tantalum, titanium, or zirconium as the major constituent
• H01G 4/008 - Selection of materials
• H01G 9/00 - Electrolytic capacitors, rectifiers, detectors, switching devices, light-sensitive or temperature-sensitive devices; Processes of their manufacture
• H01G 9/042 - Electrodes characterised by the material

Abstract

The present invention relates to a base material for high temperature alloy and a process for manufacturing the same. The base material includes following components (by weight): 10-45% Cr, 0.5-12% Nb, 0.7-2.5% Ti, ≦9.0% Mo, ≦8.0% W, ≦2% Mn, ≦1.0% Si, ≦2.0% Al, ≦0.5% C, ≦0.032% O, ≦0.032% N,≦0.01% S, ≦0.02% P, and balance being Fe and unavoidable impurities. The process for manufacturing the base material for high temperature alloy includes following steps: providing raw materials according to the target composition; charging the raw materials in a crucible uniformly layer and layer according to a certain sequence, smelting in vacuum condition; after the materials being melted completely, holding the melt at a temperature; and casting ingot, and cooling to obtain a base material for high temperature alloy.

IPC Classes  ?

• C22C 27/06 - Alloys based on chromium
• C22C 30/00 - Alloys containing less than 50% by weight of each constituent
• C22C 38/00 - Ferrous alloys, e.g. steel alloys
• B22D 7/00 - Casting ingots

Abstract

A method for purifying tantalum powder from a potassium fluotantalate product obtained through metal sodium reduction, the method comprising: removing the part of the metal sodium reduced potassium fluotantalate product containing no tantalum powder; crushing the part containing the tantalum powder; separating the tantalum powder from an alkali metal haloid containing the tantalum powder; removing ultrafine particles and ferromagnetic impurities from the tantalum powder; dissolving the tantalum powder in a pickling agent to remove the impurities; separating the waste pickling agent from the tantalum powder; and drying in various trays to obtain the tantalum powder suitable for subsequent treatment. The device satisfies the four steps of separating the tantalum powder from the alkali metal haloid containing the tantalum powder, removing ultrafine particles and ferromagnetic impurities from the tantalum powder, dissolving the tantalum powder in a pickling agent to remove impurities, and separating the waste pickling agent from the tantalum powder, thus solving the following problems in the prior art: low efficiency of the static mode, large water consumption, poor effect of separating waste pickling agent from the tantalum powder, high labor intensity, and low working efficiency.

IPC Classes  ?

• C22B 34/24 - Obtaining niobium or tantalum

Abstract

Provided is a method for preparing a niobium target material, including: firstly hot extruding a niobium tube blank, and then processing an inner hole of the hot extruded niobium tube blank, thereby obtaining a niobium target material. During a process for preparing a niobium target material of the present invention, the surface of a niobium tube blank is firstly coated with a glass powder, and because the surface of the niobium tube blank is spray-coated with the glass powder, it has a better lubrication effect during an extrusion process, so that the surface quality of the niobium tube blank is better; the subsequent hot extrusion processing and heat treatment facilitate the refinement and homogenization of grains of the niobium tube blank; and finally, the extruded niobium tube blank is machined, and the inner hole of the niobium tube blank is bored and milled by special cutters, so that broken chips can be continuously discharged from the inner hole, avoiding the problem of the influence of accumulation of the broken chips in the inner hole on the surface processing of the inner hole, thereby obtaining a niobium target material with interior uniform grains and a relatively low value of surface roughness. Also provided is a niobium target material.

IPC Classes  ?

• C23C 14/34 - Sputtering
• C23C 14/14 - Metallic material, boron or silicon

Abstract

Provided is a method for preparing a niobium alloy target material, comprising: firstly hot extruding a niobium alloy tube blank, and then processing an inner hole of the hot extruded niobium alloy tube blank, to thus obtain a niobium alloy target material. In the process for preparing a niobium alloy target material of the present invention, a glass powder is firstly applied on the surface of the niobium alloy tube blank, and since the surface of the niobium alloy tube blank is spray-coated with the glass powder, it has a relatively good lubrication effect in a hot extrusion process, so that the surface quality of the niobium alloy tube blank is relatively good; the subsequent hot extrusion processing and heat treatment facilitate the refinement and homogenization of grains of the niobium alloy tube blank; and finally the hot extruded niobium alloy tube blank is machined, and the inner hole of the niobium alloy tube blank is bored and milled by a special cutter, such that broken chips can be continuously discharged from the inner hole, avoiding the problem of the influence of accumulation of the broken chips in the inner hole on the surface processing of the inner hole, thereby obtaining a niobium alloy target material with uniform and fine internal grains and a relatively low surface roughness value. Also provided is a niobium alloy target material.

IPC Classes  ?

• C23C 14/34 - Sputtering
• C23C 14/14 - Metallic material, boron or silicon

Abstract

The present invention relates to a hot forging process for a high-performance tantalum target material, and the process thereof comprises the steps of: initially subjecting a tantalum ingot to a first forging by a cold forging method, subsequently washing with an acid, and heat-treating; then subjecting the same to a second forging by a hot forging method, again washing with an acid and heat-treating; and then subjecting the same to a third forging by a hot forging method. The present invention corresponds to subjecting a large-diameter (a diameter larger than or equal to 160 mm) tantalum ingot for a high-performance tantalum target material to forging by combining cold forging and hot forging processes, together with a suitable heat treatment process so as to obtain the grain size and textural composition required for the product. The rolled blank material produced by the present invention can be used to obtain a high-performance tantalum target material which has a predominant and uniform texture (110) in the thickness direction of the target material and satisfies the use requirements for high-end sputtering base stations; compared with a common tantalum target material, the high-performance tantalum target material not only achieves the textural composition on which the (110) texture is predominant in the thickness direction (110) of the target material, but also provides a higher requirement of uniformity of the texture, thus ensuring a consistent sputtering rate during use.

IPC Classes  ?

• B21J 5/06 - Methods for forging, hammering, or pressing; Special equipment or accessories therefor for performing particular operations
• B21J 5/08 - Upsetting

Abstract

A method for preparing a high-performance tantalum target, a high-performance target prepared by the method, and a use of the high-performance target. The method for preparing the high-performance tantalum target comprises: firstly, preparing a tantalum ingot into a forging blank by a method of cold forging in conjunction with hot forging; then, rolling the forging blank by a hot rolling method; and finally, performing leveling, and performing discharging, milling and surface treatment according to a size of a finished product, so as to obtain the tantalum target. The tantalum target prepared by the method has uniform crystallization, with a grain size between 50 μm and 120 μm. A texture component where a texture (110) dominants in the thickness direction of the target is obtained. A total proportion of three textures (111), (110) and (100) is between 40% and 50%, ensuring a consistent sputtering rate of the tantalum target during use.

IPC Classes  ?

• C23C 14/34 - Sputtering

Abstract

Provided is a hot rolling process for a high-performance tantalum target. The method comprises: preheating first a forged blank to 900-1,200 °C; then rolling; and performing acid cleaning till tantalum metal luster occurs without mottles. A high-performance tantalum target which comprises uniform and consistent texture components with textures along the thickness direction (110) of the target predominant and meets the use requirements of a high-end sputtering base can be obtained by using a high-performance tantalum target rolling blank produced by heating and rolling. Compared with an ordinary tantalum target, the high-performance tantalum target not only achieves texture components with textures along the thickness direction (110) of the target predominant, but also meets higher requirements on the uniformity of the textures, and therefore a consistent sputtering rate during using is ensured.

IPC Classes  ?

• B21B 1/26 - Metal rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling bands or sheets of indefinite length in a continuous process by hot-rolling
• B21B 37/32 - Control of flatness or profile during rolling of strip, sheets or plates using roll camber control by cooling, heating or lubricating the rolls
• C23C 14/34 - Sputtering

Abstract

2/g, Fisher mean particle size not less than 3.00 μm. The present invention relates to the process for preparing the tantalum powder, wherein the tantalum powder is prepared through reducing tantalum compound with a reducing agent, wherein the tantalum powder as seed is added during reduction, and said tantalum powder as seed is the tantalum powder that has been milled.

IPC Classes  ?

• B22F 9/24 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using chemical processes with reduction of metal compounds starting from liquid metal compounds, e.g. solutions
• B22F 1/00 - Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
• H01G 9/042 - Electrodes characterised by the material
• H01G 9/052 - Sintered electrodes

Abstract

A method for passivating tantalum metal surface, comprises cooling tantalum metal to or below 32°C and/or passivating tantalum metal surface by oxygen-containing gas with a temperature of 0°C or below. Also provided is an apparatus for passivating tantalum metal surface for applying the method, comprising a heat treatment furnace, a device for forcedly cooling argon and/or a device for cooling oxygen-containing gas.

IPC Classes  ?

• C23C 8/12 - Oxidising using elemental oxygen or ozone
• F28B 1/00 - Condensers in which the steam or vapour is separated from the cooling medium by walls, e.g. surface condenser

Abstract

The present invention provides a process for preparing a tantalum powder with high specific capacity, which process comprising the steps of, in sequence, (1) a first reduction step: mixing tantalum oxide powder and a first reducing agent powder homogenously, and then carrying out reduction reaction in hydrogen and/or inert gas or vacuum atmosphere to obtain a tantalum suboxides powder; (2) a second reduction step: mixing the tantalum suboxides powder obtained from the step (1), in which impurities have been removed, and a second reducing agent powder homogenously, and then carrying out reduction reaction in hydrogen and/or inert gas or vacuum atmosphere to obtain a tantalum powder having high oxygen content; (3) a third reduction step: mixing the tantalum powder having high oxygen content obtained from the step (2), in which impurities have been removed, with a third reducing agent powder homogenously, and then carrying out reduction reaction in hydrogen and/or inert gas or vacuum atmosphere to obtain a tantalum metal powder suitable for capacitors; wherein after each reduction step, the oxidation product of reducing agent and the residual reducing agent are removed from the reaction product.

IPC Classes  ?

• B22F 9/20 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using chemical processes with reduction of metal compounds starting from solid metal compounds
• B22F 1/00 - Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties

Abstract

A method for preparing tantalum powder for the capacitor comprises the following steps: (1) the first reduction step: the low oxidation state tantalum powder is obtained by uniformly mixing the tantalum oxide with the first reducing agent powder and the reduction reaction is proceeded under hydrogen and/or inert or vacuum gas; (2) the second reduction step: the higher oxidation state tantalum powder is obtained by uniformly mixing the low oxidation state tantalum powder obtained in step (1) with the second reducing agent powder and the reduction reaction is proceeded under hydrogen and/or inert or vacuum gas; (3) the third reduction step: the final tantalum powder is obtained by uniformly mixing the high oxidation state tantalum powder obtained in step (2) with the third reducing agent powder and the reduction reaction is proceeded under hydrogen and/or inert or vacuum gas. The oxidation products of the reducing agents and residual reducing agents are removed from the reaction products after each reduction step.

IPC Classes  ?

• B22F 9/20 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using chemical processes with reduction of metal compounds starting from solid metal compounds

Abstract

A tantalum powder, a preparation method thereof and an electrolytic capacitor anode made of the tantalum powder are provided. The tantalum powder has BET surface area of not more than 0.530 m2/g and Fisher average particle size of not less than 3.00 μm. The method of preparing the tantalum powder is provided, wherein the tantalum powder is prepared through reducing tantalum compound with a reducing agent. The method is characterized in that a tantalum powder is added as seed during reduction, and said seed of tantalum powder is the tantalum powder that has been milled.

IPC Classes  ?

• B22F 9/18 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using chemical processes with reduction of metal compounds

Abstract

A tantalum filament used for an anode of a tantalum capacitor, the cross section of the tantalum filament is approximate rectangular or regular rectangular. A manufacturing method of the tantalum filament, comprises the steps: performing heat treatment to the raw tantalum filament; performing surface treatment to the tantalum filament after being treated so that an oxide film is formed on the surface of tantalum filament; lubricating by means of lubricative oil and rolling the tantalum filament after being pretreated so that the cross section of the tantalum filament is approximate rectangular or regular rectangular; annealing the tantalum filament finally.

IPC Classes  ?

• H01G 9/012 - Terminals specially adapted for solid capacitors

Abstract

The present invention relates to valve metal particles uniformly containing nitrogen and a method for preparing the same, and a valve metal green pellet and a sintered pellet made from the particles, and an electrolytic capacitor anode. The present invention provides valve metal particles uniformly containing nitrogen, wherein the difference ratio of nitrogen contents of particles is 20% or less. The present invention provides a process for preparing said valve metal particles uniformly containing nitrogen, wherein the raw material particles of the valve metal were heated in a nitrogen-containing gas at a temperature of 200° C. or less for 2 hours or more. The present invention also provides a valve metal green pellet made from said valve metal particles. The present invention also provides a valve metal sintered pellet.

IPC Classes  ?

• H01G 9/042 - Electrodes characterised by the material
• H01G 9/045 - Electrodes characterised by the material based on aluminium
• C23C 8/24 - Nitriding
• C23C 8/48 - Nitriding

Abstract

A method for preparing valve metal particles uniformly containing nitrogen includes: the raw material particles of the valve metal are heated in a nitrogen-containing gas at a temperature of 200°C or less for 2 hours or more. The valve metal particles prepared by above method uniformly contain nitrogen, wherein the difference ratio of nitrogen contents of particles is 20% or less.

IPC Classes  ?

• B22F 1/00 - Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
• B22F 9/04 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using physical processes starting from solid material, e.g. by crushing, grinding or milling
• H01G 9/052 - Sintered electrodes
• H01G 4/008 - Selection of materials

Abstract

The present invention relates to a process for preparing powders of niobium suboxides or niobium, wherein the process comprising: mixing the niobium oxides as raw material with reducing agent, conducting a reaction at a temperature in the range of 600~1300°C in an atmosphere of vacuum or inert gas or hydrogen gas, leaching the reaction product to remove the residual reducing agent and the oxides of the reducing agent and other impurities, heat treating at a temperature of the range of 1000~1600°C in an atmosphere of vacuum or inert gas, and screening to obtain the powders of niobium suboxide or niobium of capacitor grade. According to the present invention, the niobium oxides were directly reduced into capacitor grade niobium suboxides or niobium with reducing agents which can be easily removed by mineral acids, wherein the speed of the reaction can be controlled and the reaction can directly reduce the niobium oxides into capacitor grade niobium suboxides or niobium powder. According to the present invention, the process is simple with high yield and high productivity. The products obtained have good flowability, low impurities, uniform distribution of oxygen, and have good electrical properties.

IPC Classes  ?

• C01G 33/00 - Compounds of niobium
• B22F 9/20 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor using chemical processes with reduction of metal compounds starting from solid metal compounds

Abstract

The present invention relates to a process for preparing powders of niobium suboxides or niobium, wherein the process comprising: mixing the niobium oxides as raw material with reducing agent, conducting a reaction at a temperature in the range of 600˜1300° C. in an atmosphere of vacuum or inert gas or hydrogen gas, leaching the reaction product to remove the residual reducing agent and the oxides of the reducing agent and other impurities, heat treating at a temperature of the range of 1000˜1600° C. in an atmosphere of vacuum or inert gas, and screening to obtain the powders of niobium suboxide or niobium of capacitor grade. According to the present invention, the niobium oxides were directly reduced into capacitor grade niobium suboxides or niobium with reducing agents which can be easily removed by mineral acids, wherein the speed of the reaction can be controlled and the reaction can directly reduce the niobium oxides into capacitor grade niobium suboxides or niobium powder. According to the present invention, the process is simple with high yield and high productivity. The products obtained have good flowability, low impurities, uniform distribution of oxygen, and have good electrical properties.

IPC Classes  ?

• C01G 33/00 - Compounds of niobium

Abstract

3. Said tantalum and/or niobium metal particles have improved pore size distribution of the sintered anodes and increased pellet crush strength. The present invention further provides an electrolytic capacitor anodes made from the tantalum and/or niobium particles according to the present invention having a capacitance of from about 5,000 μFV/g to about 300,000 μFV/g.

IPC Classes  ?

• B22F 1/00 - Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties

Abstract

A method for spherically granulating and agglomerating metal particles such as tantalum and/or niobium powders is described in the present invention, which includes the steps of: a). comminuting the metal particles to form fine particles having D50 less than 50 쎽m: b). granulating the comminuted metal particles comprising volatile liquid, for example, tantalum and/or niobium particles comprising volatile liquid, to form wet spherical particles; c). still drying the wet spherical particles and removing volatile liquid to form flowable pre-agglomerated particles with increased bulk density; d). heat treating the pre-agglomerated particles; e). screening the heat treated powder to obtain the flowable agglomerated particles. The present invention provides a flowable spherical agglomerated metal particles, and especially tantalum and/or niobium particles having improved properties. The present agglomerated tantalum powder have a flow rate of at least about 2.0 g/sec, a BET surface area of from about 0.2 to about 6.0 m2/g, a FSSS of at least 1.0 쎽m, a Scott bulk density of from about 1.2 g/cm3 to about 5.5 g/cm3. The present agglomerated niobium powder have a flow rate of at least about 1.0 g/sec, a BET surface area of from about 0.5 to about 8.0 m2/g, a FSSS of at least 1.0 쎽m, a Scott bulk density of from about 0.7 g/cm3 to about 3.5 g/cm3. Said tantalum and/or niobium metal particles have improved pore size distribution of the sintered anodes and increased pellet crush strength. The present invention further provides an electrolytic capacitor anodes made from the tantalum and/or niobium particles according to the present invention having a capacitance of from about 5,000쎽FV/g to about 300,000쎽FV/g.

IPC Classes  ?

• B22F 1/00 - Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
• B22F 9/00 - Making metallic powder or suspensions thereof; Apparatus or devices specially adapted therefor
• H01G 9/042 - Electrodes characterised by the material