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.

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 tantalum powder has a specific surface area of greater than or equal to 4 m2/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 measured in weight ppm, and the specific surface area is measured in m2/g; Powder that can pass through a ?-mesh screen in the tantalum powder accounts for over 85% of the total weight of the tantalum powder, where ?=150˜170; and the tantalum powder with high CV has a low leakage current and dielectric loss, and good moldability.

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 tantalum powder has a specific surface area of greater than or equal to 4 m2/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 measured in weight ppm, and the specific surface area is measured in m2/g; Powder that can pass through a ?-mesh screen in the tantalum powder accounts for over 85% of the total weight of the tantalum powder, where ?=150˜170; and the tantalum powder with high CV has a low leakage current and dielectric loss, and good moldability.

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 ?m.

Abstract: The invention relates to the rare metal smelting field, and particularly, the present invention relates to a tantalum powder for preparing capacitors and a process for preparing the tantalum powder, and to a sintered anode prepared from the tantalum powder. As to the tantalum powder as provided by the invention, its primary tantalum powder has a BET of from 3.0 to 4.5 m2/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 ?m 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 ?m, 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 ?FV/g and the residual current of less than 1.0 nA/?FV.

Abstract: Provided are a flaked tantalum powder and method for preparation thereof; said flaked tantalum powder contains 300-1800 ppm of nitrogen, 10-100 ppm of phosphorus, and 1-40 ppm of boron. The flaked tantalum 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.

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.

Abstract: The invention relates to the rare metal smelting field, and particularly, the present invention relates to a tantalum powder for preparing capacitors and a process for preparing the tantalum powder, and to a sintered anode prepared from the tantalum powder. As to the tantalum powder as provided by the invention, its primary tantalum powder has a BET of from 3.0 to 4.5 m2/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 ?m 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 ?m, 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 ?FV/g and the residual current of less than 1.0 nA/?FV.

Abstract: The present invention provides a process for preparing tantalum powders for use in an electrolytic capacitor with high reliability and high specific capacitance, characterized in that the ratio of the average particle size of raw tantalum powders to the average particle size of tantalum flake powders is 0.5-25, preferably 1.5-10, more preferably 2-5. The process of the present invention is simple and has good controllability, the tantalum flake powder obtained has low content of metal impurities, high specific surface area, and after agglomerated, have good flowability and moldability, have high specific capacitance, and when used under high voltage, have low leakage current and high breakdown voltage.

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 ?m.

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.

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.

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 ?m; 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.

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.

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 ?m; 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.

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 ?m; 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.