公开(公告)号：US20170226616A1

公开(公告)日：2017-08-10

申请号：US15125803

申请日：2014-11-03

申请人： NINGXIA ORIENT TANTALUM INDUSTRY CO., LTD.

发明人： Yuewei CHENG ,  Fukun LIN ,  Xueqing ZHANG ,  Guoqing LUO ,  Haiyan MA ,  Yinghui MA ,  Yanjie WANG ,  Xuanyu WANG ,  Dongjie ZHANG

IPC分类号： C22F1/18 ,  B22F9/24 ,  B22F3/10 ,  H01G9/052 ,  C21D3/02 ,  H01G9/042 ,  H01G9/00 ,  B22F1/00 ,  B22F5/00

摘要： 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 m2/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 μm 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 μm, 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 μFV/g and the residual current of less than 1.0 nA/μFV. Meantime, the invention provides an economical process for making the tantalum powder.