Methods for preparing high-purity molybdenum or tungsten powder and high-purity oxides powder of the same
US4762695A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 4, 1987 |
| Grant date | Aug 9, 1988 |
| Priority date | — |
| Expiry date | Sep 4, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S423/14
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
High-purity molybdenum or tungsten powder can be produced by a process comprising (a) decomposing a powder or an oxide powder of molybdenum or tungsten with hydrogen peroxide water; (b) bringing the resulting aqueous solution of molybdenum or tungsten into contact with a cation exchange resin; (c) concentrating the aqueous solution; and (d) reducing a concentrated solid material. By omitting reducing step (d), one can obtain high-purity molybdenum or tungsten oxide powders. Because the Mo and W powders and MoO.sub.3 and WO.sub.3 powders prepared by this invention are of an extremely high purity, they are useful as materials for targets of VLSI elements.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.