发明授权
- 专利标题： Method for recovering calcium fluoride from fluoroetchant
- 专利标题（中）： 从异氟醚中回收氟化钙的方法
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申请号： US953960申请日： 1992-10-01
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公开(公告)号： US5362461A公开(公告)日： 1994-11-08
- 发明人: Tadahiro Ohmi , Hiroyuki Harada , Nobuhiro Miki , Toshiro Fukutome , Matagoro Maeno , Norio Terasawa , Yoshihiro Eto , Masahiro Sakata
- 申请人： Tadahiro Ohmi , Hiroyuki Harada , Nobuhiro Miki , Toshiro Fukutome , Matagoro Maeno , Norio Terasawa , Yoshihiro Eto , Masahiro Sakata
- 申请人地址： JPX Tokyo
- 专利权人： Kurita Water Industries, Ltd.
- 当前专利权人： Kurita Water Industries, Ltd.
- 当前专利权人地址： JPX Tokyo
- 优先权： JPX283747 19911003; JPX89775 19920313; JPX146278 19920512
- 主分类号： C01F11/22
- IPC分类号： C01F11/22
摘要：
Calcium fluoride with high purity of very small content of unreacted calcium carbonate and silica is recovered from an etchant mainly composed of hydrogen fluoride or hydrogen fluoride and ammonium fluoride. The etchant is reacted with calcium carbonate with transfer directions of the etchant and calcium carbonate being controlled within a composition region in which mole equivalent ratio of ammonium fluoride/hydrogen fluoride is specified.
公开/授权文献
- US5971681A Drawbar guide ring with drive keys 公开/授权日：1999-10-26
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