Chemistry: physical processes – Physical processes – Crystallization
Patent
1985-05-08
1987-04-14
Lacey, David L.
Chemistry: physical processes
Physical processes
Crystallization
23299, 23301, 423321R, 62532, B01D 902
Patent
active
046575596
ABSTRACT:
The present invention relates to the processing of phosphoric acid by crystallization starting with phosphoric acid and adding relatively large amounts of fine, relatively pure seed crystals to acid which has been cooled to supersaturated conditions. Crystallization thereafter proceeds under conditions which substantially favor growth on the seeds which are added and disfavor secondary nucleation. The present invention particularly describes a seed crystal generator for use in the foregoing process in which relatively high purity phosphoric acid, containing 60% to 66% P.sub.2 O.sub.5 is cooled to a temperature of at least 5.degree. to 10.degree. C. below zero and thereafter nucleated under agitation for less than ten minutes in a small crystallizing vessel.
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Astley Vivian C.
Mollere Phillip D.
Taravella Jody J.
Freeport Research and Engineering Company
Lacey David L.
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