| 摘要 |
1,155,721. Superphosphoric acid; orthophosphoric acid. SINCAT-SOC INDUSTRIALE CATANESE S.p.A. 16 June, 1966 [18 June, 1965[, No. 26937/66. Heading C1A. Superphosphoric acid having a P 2 0 5 content generally of 68-76 wt. per cent is produced by dispersing aqueous orthophosphoric acid in a rising stream of hot gas of increasing crosssection under conditions in which a fluidized bed of droplets of orthophosphoric acid is established, from which smaller droplets of superphosphoric acid are entrained by the emergent hot gas, and separating the superphosphoric acid from said emergent gas. An apparatus for this process comprises a frustoconical or frusto-pyramidal section 5, a restriction 3, a lower section 1 and a gas inlet zone 2. The orthophosphoric acid is injected orthogonally at 4, and the superphosphoric acid formed is separated in (e.g. cyclone) separator 8. Preferably, the hot gases (e.g. air) used are at 250-1100‹ C., and the rate of gas flow in the restriction is 20-100 m./sec. The emergent hot gases, after separation of the superphosphoric acid therefrom, may be used for preliminary concentration of dilute aqueous orthophosphoric acid (e.g. up to a P 2 0 5 concentration of 45- 50%), and this may be carried out in apparatus of the same type as for the main process (Example 3).
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