Invention Grant
- Patent Title: Method for producing high-purity tungsten powder
- Patent Title (中): 生产高纯度钨粉的方法
-
Application No.: US13498252Application Date: 2010-09-28
-
Publication No.: US08764877B2Publication Date: 2014-07-01
- Inventor: Jin Sato , Kouichi Takemoto , Takeshi Sasaki , Mikio Ohno , Junji Ogura
- Applicant: Jin Sato , Kouichi Takemoto , Takeshi Sasaki , Mikio Ohno , Junji Ogura
- Applicant Address: JP Tokyo JP Osaka
- Assignee: JX Nippon Mining & Metals Corporation,Japan New Metals Co., Ltd.
- Current Assignee: JX Nippon Mining & Metals Corporation,Japan New Metals Co., Ltd.
- Current Assignee Address: JP Tokyo JP Osaka
- Agency: Howson & Howson LLP
- Priority: JP2009-229570 20091001
- International Application: PCT/JP2010/066810 WO 20100928
- International Announcement: WO2011/040400 WO 20110407
- Main IPC: B22F9/26
- IPC: B22F9/26 ; B22F9/22 ; C22C27/04

Abstract:
Provided is a method for producing a high-purity tungsten powder having a phosphorus content of less than 1 wtppm; wherein an ammonium tungstate solution containing 1 wtppm or more of phosphorus as an impurity in terms of the inclusion in tungsten is used as a starting material, this solution is neutralized with hydrochloric acid at a temperature of 50° C. or less to adjust the pH at 4 or more and less than 7 so as to precipitate ammonium paratungstate undecahydrate crystals, the resulting solution is heated to 70 to 90° C. and filtered in a high-temperature state so as to obtain ammonium paratungstate pentahydrate crystals, the obtained crystals are calcined so as to form a tungsten oxide, and the tungsten oxide is subject to hydrogen reduction so as to obtain a high-purity tungsten powder. Additionally provided is a method for producing a high-purity tungsten powder having a phosphorus content of 0.4 wtppm or less; wherein the ammonium tungstate solution is neutralized with hydrochloric acid to adjust the pH at 4 or more and 6 or less, and this solution is subject to the same procedure as described above so as to obtain a high-purity tungsten powder. Consequently, the phosphorus content can be efficiently reduced.
Public/Granted literature
- US20120180600A1 Method for Producing High-Purity Tungsten Powder Public/Granted day:2012-07-19
Information query