Ningxia Orient Tantalum Industry Co., Ltd.

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

Fukun Lin

Guoqi Yang

Yuewei Cheng

Xueqing Chen

Yinghui Ma

Yanjie Wang

Guoqing Luo

Haiyan Ma

Aiguo Zheng

Zhidao Wang

Xueqing Zhang

Lijun Li

Honggang Zhang

Xuanyu Wang

Hui Li

Chunxia Zhao

Dongjie Zhang

Ning Wang

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 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/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 &#x3bc;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 &#x3bc;m, that is, the secondary particle size is high. A resultant capacitor anode prepared by sintering the tantalum powder of the invention at 1200&#xb0; 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 &#x3bc;FV/g and the residual current of less than 1.0 nA/&#x3bc;FV. Meantime, the invention provides an economical process for making the tantalum powder.

Tantalum powder and process for preparing the same, and sintered anode prepared from the tantalum powder

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

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Shizuishan, China

Fukun Lin