As for ammonium sulfate which is one of the nitrogen fertilizers, besides those that are synthesized, there are "Recovered Ammonium Sulfate" which is recovered from the waste water of caprolactam, MMA and AN manufacturing facilities, and "By-product Ammonium Sulfate" which is made by absorbing sulfuric acid from the ammonium contained in Coke Over Gas (COG). "Recovered Ammonium Sulfate" and "By-product Ammonium Sulfate" account for 90% of the total ammonium sulfate manufacturing amount. In either case, ammonium sulfate is produced by equipment combining unit operations such as the evaporative concentration, crystallization, solid and liquid separation, and drying of an aqueous solution containing ammonium sulfate. Tsukishima Kikai applies the double propeller (DP) crystallizer which is our core product, EW centrifuge separator, and fluid bed drying machine for ammonium sulfate manufacturing, and the equipment is characterized to manufacture large particle sizes and high quality products. Our technology obtain high evaluation from our customers by such our represent experience.