Tantalum powder and process for preparing the same, and sintered anode prepared from the tantalum powder
US10513769B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 3, 2014 |
| Grant date | Dec 24, 2019 |
| Priority date | — |
| Expiry date | Nov 3, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01G2009/05
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.