Chemistry: physical processes – Physical processes – Crystallization
Patent
1985-05-08
1987-04-07
Lacey, David L.
Chemistry: physical processes
Physical processes
Crystallization
23301, 423321R, B01D 902
Patent
active
046557903
ABSTRACT:
The present invention relates to the processing of phosphoric acid by crystallization. Wet-process phosphoric acid is purified by cooling it to supersaturated conditions and adding relatively large amounts of fine, relatively pure seed crystal. Crystallization thereafter proceeds under conditions which substantially favor crystal growth on the seeds which are added and disfavor secondary nucleation. To prevent the crystallizing magma from reaching a viscosity which would render further processing difficult, the present invention provides for recycling raffinate in an amount sufficient to maintain the solids content of the crystallizing magma below about 40%.
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Astley Vivian C.
Wiewiorowski Tadeusz K.
Freeport Research and Development Company
Lacey David L.
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