Patents by Inventor Wenfeng Shi

Wenfeng Shi has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 9199307
    Abstract: The present invention relates to the tantalum powder and the process for preparing the same, and also relates to the electrolytic capacitor anode made of the tantalum powder. More particularly, the present invention relates to the tantalum powder having a BET surface area not more than 0.530 m2/g, Fisher mean particle size not less than 3.00 ?m. The present invention relates to the process for preparing the tantalum powder, wherein the tantalum powder is prepared through reducing tantalum compound with a reducing agent, wherein the tantalum powder as seed is added during reduction, and said tantalum powder as seed is the tantalum powder that has been milled.
    Type: Grant
    Filed: August 2, 2012
    Date of Patent: December 1, 2015
    Assignee: Ningxia Orient Tantalum Industry Co., Ltd.
    Inventors: Guoqi Yang, Wenfeng Shi, Xifang Bao, Yong Li, Zhongxiang Li, Zhangong Dong, Xiaoyan Yang
  • Patent number: 8673052
    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 tanta
    Type: Grant
    Filed: June 18, 2010
    Date of Patent: March 18, 2014
    Assignee: Ningxia Orient Tantalum Industry Co., Ltd.
    Inventors: Wenfeng Shi, Xueqing Chen, Yong Li, Xudong Xi, Tao Guo
  • Publication number: 20120291593
    Abstract: The present invention relates to the tantalum powder and the process for preparing the same, and also relates to the electrolytic capacitor anode made of the tantalum powder. More particularly, the present invention relates to the tantalum powder having a BET surface area not more than 0.530 m2/g, Fisher mean particle size not less than 3.00 ?m. The present invention relates to the process for preparing the tantalum powder, wherein the tantalum powder is prepared through reducing tantalum compound with a reducing agent, wherein the tantalum powder as seed is added during reduction, and said tantalum powder as seed is the tantalum powder that has been milled.
    Type: Application
    Filed: August 2, 2012
    Publication date: November 22, 2012
    Inventors: Guoqi Yang, Wenfeng Shi, Xifang Bao, Yong Li, Zhongxiang Li, Zhangong Dong, Xiaoyan Yang
  • Publication number: 20100326239
    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 tanta
    Type: Application
    Filed: June 18, 2010
    Publication date: December 30, 2010
    Applicant: Ningxia Orient Tantalum Industry Co., Ltd.
    Inventors: Wenfeng SHI, Xueqing Chen, Yong Li, Xudong Xi, Tao Guo
  • Publication number: 20100226070
    Abstract: The present invention relates to the tantalum powder and the process for preparing the same, and also relates to the electrolytic capacitor anode made of the tantalum powder. More particularly, the present invention relates to the tantalum powder having a BET surface area not more than 0.530 m2/g, Fisher mean particle size not less than 3.00 ?m. The present invention relates to the process for preparing the tantalum powder, wherein the tantalum powder is prepared through reducing tantalum compound with a reducing agent, wherein the tantalum powder as seed is added during reduction, and said tantalum powder as seed is the tantalum powder that has been milled.
    Type: Application
    Filed: March 5, 2010
    Publication date: September 9, 2010
    Inventors: Guoqi Yang, Wenfeng Shi, Xifang Bao, Yong Li, Zhongxiang Li, Zhangong Dong, Xiaoyan Yang
  • Patent number: 7727508
    Abstract: 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˜1300° 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˜1600° 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.
    Type: Grant
    Filed: August 22, 2008
    Date of Patent: June 1, 2010
    Assignee: Ningxia Orient Tantalum Industry Co., Ltd.
    Inventors: Wenfeng Shi, Xudong Xi, Yong Li, Xueqing Chen, Wei Wang
  • Publication number: 20090053132
    Abstract: 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˜1300° 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˜1600° 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.
    Type: Application
    Filed: August 22, 2008
    Publication date: February 26, 2009
    Inventors: Wenfeng SHI, Xudong XI, Yong LI, Xueqing CHEN, Wei WANG