Ningxia Orient Tantalum Industry Co., Ltd.

National Engineering Research Center for Special Metal Materials of Tantalum and Niobium

Xueqing Chen

Guoqi Yang

Yuewei Cheng

Aiguo Zheng

Yuezhong Ma

Wenfeng Shi

Yong Li

Fukun Lin

Xudong Xi

Guoqing Luo

Haiyan Ma

Yinghui Ma

Yanjie Wang

Zhidao Wang

Zhongxiang Li

Zekun Tong

Tao Guo

Yan Yan

Wei Wang

Hui Li

Ting Wang

Chunxia Zhao

Ning Wang

Xiaoyu Tian

Lijun Li

Honggang Zhang

Dejun Shi

Zhonghuan Zhao

Xia Li

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 m/g; the ratio of the boron content of the tantalum powder to the specific surface area of the tantalum powder is 2&#x2dc;16; the boron content is measured in weight ppm, and the specific surface area is measured in m/g; Powder that can pass through a &#x3c1;-mesh screen in the tantalum powder accounts for over 85% of the total weight of the tantalum powder, where &#x3c1;=150&#x2dc;170; and the tantalum powder with high CV has a low leakage current and dielectric loss, and good moldability.

Tantalum powder and preparation method therefor

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 &#x3bc;m.

High-purity tantalum powder and preparation method thereof

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&#x2dc;1, preferably being 1:0.25&#x2dc;0.8, and more preferably being 1:0.4&#x2dc;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.

High specific capacitance capacitor-grade tantalum powder with improved electrical properties and process for making the same

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.

Process for preparing tantalum powder for capacitors

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&#x2dc;1300&#xb0; 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&#x2dc;1600&#xb0; 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.

Process for preparing powder of niobium suboxides or niobium

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Shizuishan, China

Xueqing Chen