To provide a method for manufacturing large granular ammonium sulfate by which large granular ammonium sulfate is obtained in a high yield in manufacture of ammonium sulfate.
In the method for manufacturing large granular ammonium sulfate using an ammonium sulfate manufacturing apparatus comprising an evaporator situated in an upper part, a crystallizer situated in an underpart, a down pipe extending from the bottom of the evaporator to the interior of the crystallizer, a supply unit for supplying mother liquor to the crystallizer, a channel for circulating the mother liquor supplied to the crystallizer to the evaporator, and a channel for recovering ammonium sulfate crystals deposited in the crystallizer, the linear velocity (z) of an upward flow of the mother liquor in the crystallizer around the leading end of the down pipe is adjusted to ≥0.10 m/sec.
TAKAHASHI TAKAMASA
YAGI YUKI
Toshieko Kondo