发明名称 |
Method for the preparation of phosphoric acid and calcium sulphate |
摘要 |
PCT No. PCT/BE84/00008 Sec. 371 Date Nov. 20, 1984 Sec. 102(e) Date Nov. 20, 1984 PCT Filed Mar. 13, 1984 PCT Pub. No. WO84/03690 PCT Pub. Date Sep. 27, 1984.The present invention provides a continuous method for preparing phosphoric acid and calcium sulphate by reacting calcium phosphate with a mixture of sulphuric acid and phosphoric acid. Our method uses at least three successive crystallization steps: a first step of reacting the phosphate with the mixture of phosphoric and sulphuric acids and forming a-hemihydrate calcium sulphate, a second step of recrystallizing the a-hemihydrate into dihydrate and a third step of transforming the dehydrated calcium sulfate into a hemihydrate or anhydrite II or a mixture of the two. Where desired recycling of the products from the above steps can be used for increasing the efficiency of the above method.
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申请公布号 |
US4588570(A) |
申请公布日期 |
1986.05.13 |
申请号 |
US19840673436 |
申请日期 |
1984.11.20 |
申请人 |
PRAYON DEVELOPMENT |
发明人 |
DAVISTER, ARMAND L.;DUBREUCO, ANDRE R.;THIRION, FRANCIS A. |
分类号 |
C01B25/228;C01B;C01B25/229;C01F;C01F11/46;(IPC1-7):C01B25/16 |
主分类号 |
C01B25/228 |
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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