发明授权
US4477427A Process for the preparation of alkali-poor .alpha.-alumina for ceramic
purposes
失效
用于制备用于陶瓷目的的贫碱α-氧化铝的方法
- 专利标题： Process for the preparation of alkali-poor .alpha.-alumina for ceramic purposes
- 专利标题（中）： 用于制备用于陶瓷目的的贫碱α-氧化铝的方法
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申请号： US440260申请日： 1982-11-09
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公开(公告)号： US4477427A公开(公告)日： 1984-10-16
- 发明人: Jozsef Matyasi , Gyorgy Kaptay , Laszlo Zsembery , Bela Kokeny , Jozsef T. Toth , Maria Toth Nee Homostrei , Imre Penzes
- 申请人： Jozsef Matyasi , Gyorgy Kaptay , Laszlo Zsembery , Bela Kokeny , Jozsef T. Toth , Maria Toth Nee Homostrei , Imre Penzes
- 申请人地址： HUX Budapest
- 专利权人： Magyar Aluminiumipari Troeszt
- 当前专利权人： Magyar Aluminiumipari Troeszt
- 当前专利权人地址： HUX Budapest
- 优先权： HUX3358/81 19811110
- 主分类号： C01F7/44
- IPC分类号： C01F7/44 ; C04B35/111 ; C01F7/30 ; C01F7/02
摘要：
Process for the preparation of alkali-poor .alpha.-alumina for ceramic purposes. Technical grade aluminum hydroxide is activated and calcinated in the presence of a mineralizing mixture comprising halides and boron compounds. The process further comprises activating aluminum hydroxide at a temperature of 500-600 degrees C., washing the activated product with alkali-free water containing calcium ions and having a conductivity not exceeding 70 .mu.S/cm until the alkali content expressed in Na.sub.2 O becomes lower than 0.15% by weight, adding 0.4-0.7% by weight of a mineralizing mixture to the washed product, and calcinating the same at a temperature of 1200-1350 degrees C.
公开/授权文献
- US5696058A Solids-free, essentially all-oil wellbore fluid 公开/授权日：1997-12-09
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