Ningxia Orient Tantalum Industry Co.

Shizuishan, China

Ningxia Orient Tantalum Industry Co.

Shizuishan, China

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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.


Patent
Ningxia Orient Tantalum Industry Co. | Date: 2017-01-04

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.


Patent
Ningxia Orient Tantalum Industry Co. and National Engineering Research Center For Special Metal Materials Of Tantalum And Niobium | Date: 2017-06-28

The present invention relates to a composite tantalum powder and a process for preparing the same, and to a capacitor anode prepared from the tantalum powder. The method for preparing a composite tantalum powder comprises the following steps of: 1) providing a tantalum powder prepared by a reduction process, and flattening the tantalum powder so as to prepare a flaked tantalum powder; 2) providing a granular tantalum powder prepared from tantalum ingot; 3) mixing the flaked tantalum powder and the granular tantalum powder to give a tantalum powder mixture; and 4) thermally treating the tantalum powder mixture, and then pulverizing, screening to give a composite tantalum powder. The present invention further relates to a composite tantalum powder prepared from the process and the use thereof in a capacitor.


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 m^(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 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. Meantime, the invention provides an economical process for making the tantalum powder.


Patent
Ningxia Orient Tantalum Industry Co. and National Engineering Research Center For Special Metal Materials Of Tantalum And Niobium | Date: 2016-11-02

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 1:0.11, preferably being 1:0.250.8, and more preferably being 1:0.40.6; 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.


Patent
Ningxia Orient Tantalum Industry Co. | Date: 2014-02-27

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.


Patent
Ningxia Orient Tantalum Industry Co. | Date: 2014-01-16

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.


Patent
Ningxia Orient Tantalum Industry Co. | Date: 2015-10-13

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.


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.


Patent
Ningxia Orient Tantalum Industry Co. and National Engineering Research Center For Special Metal Materials Of Tantalum And Niobium | Date: 2015-11-04

A method for preparing a tantalum powder 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.

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