发明名称 |
METHOD FOR PRODUCING HIGH-PURITY TUNGSTEN POWDER |
摘要 |
<p>[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.</p> |
申请公布号 |
EP2484463(A1) |
申请公布日期 |
2012.08.08 |
申请号 |
EP20100820515 |
申请日期 |
2010.09.28 |
申请人 |
JX NIPPON MINING & METALS CORPORATION;JAPAN NEW METALS CO., LTD. |
发明人 |
SATO JIN;TAKEMOTO KOUICHI;SASAKI TAKESHI;OHNO MIKIO;OGURA JUNJI |
分类号 |
B22F1/00;B22F9/22;C22C27/04 |
主分类号 |
B22F1/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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