| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of manufacturing ammonium sulfate crystals by which ammonium sulfate crystals of a large particle size are stably manufactured especially even under a crystallization condition where the liquid retention time is short by efficiently reducing excess fine crystals existing in a crystallizer and quickly growing crystals. SOLUTION: At the time when manufacturing ammonium sulfate crystals by such crystallizer for obtaining the ammonium sulfate crystals by evaporating and thickening an ammonium sulfate solution that is equipped with a specified stirrer and classification leg, and in which a mixing zone for circulating the solution inside and outside a draft tube by stirring with the stirrer and a clarifying zone partitioned with buffles are formed, the slurry in the clarifying zone is drawn to be recovered, the recovered slurry is circulated to a neutralization process where sulfuric acid and ammonia are mutually reacted, the crystals in the recovered slurry are dissolved by the heat of neutralization reaction and the solution is returned to the crystallizer, and besides the slurry in the clarifying zone is recovered to be circulated to the neutralization process, the slurry in the clarifying zone is drawn out of the system. COPYRIGHT: (C)2005,JPO&NCIPI
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