发明名称 |
Process for extracting alumina from aluminous ores |
摘要 |
In the production of alumina from aluminous ores containing alumina trihydrate and alumina monohydrate comprising a first-stage digestion by digesting alumina trihydrate from a slurry of the ores and a caustic solution and separating the resulting slurry into a caustic aluminate solution and an insoluble residue, and a second-stage digestion by digesting alumina monohydrate from a slurry of the insoluble residue separated in the first-stage digestion and a caustic solution, the present invention provides an improvement wherein scale formation onto a preheater for the slurry in the second-stage digestion is completely or substantially prevented and reduction in heat transfer coefficient of heat transfer surface is remarkably lowered. The improvement is attained by setting up a desilication reaction zone in the course of the first-stage digestion, whereby the slurry introduced into said zone is subjected to desilication reaction treatment.
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申请公布号 |
US4426363(A) |
申请公布日期 |
1984.01.17 |
申请号 |
US19820349666 |
申请日期 |
1982.02.17 |
申请人 |
SUMITOMO ALUMINIUM SMELTING COMPANY, LTD. |
发明人 |
YAMADA, KOICHI;HARATO, TAKUO;KATO, HISAKATSU;SHIOZAKI, YASUMI |
分类号 |
C01F7/06;C01F7/46;C01F7/47;(IPC1-7):C01F7/06 |
主分类号 |
C01F7/06 |
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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