The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 18, 2014
Filed:
Jun. 18, 2010
Wenfeng Shi, Shizuishan, CN;
Xueqing Chen, Shizuishan, CN;
Yong LI, Shizuishan, CN;
Xudong Xi, Shizuishan, CN;
Tao Guo, Shizuishan, CN;
Wenfeng Shi, Shizuishan, CN;
Xueqing Chen, Shizuishan, CN;
Yong Li, Shizuishan, CN;
Xudong Xi, Shizuishan, CN;
Tao Guo, Shizuishan, CN;
Ningxia Orient Tantalum Industry Co., Ltd., Shizuishan, CN;
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.