均一化大颗粒硫酸铵结晶高效制备工艺研究

High efficiency preparation of homogeneous large granular ammonium sulfate crystals

以己内酰胺副产硫酸铵母液为原料制备大颗粒硫酸铵晶体。研究了p H、搅拌转速、晶种添加量、添加剂用量等结晶操作参数对硫酸铵晶体晶习、粒度及粒度分布的影响。通过正交实验优化了制备2~4 mm大颗粒硫酸铵晶体的工艺条件。在优化条件下制得了颗粒粗大、近似六面体的硫酸铵晶体,而且晶体粒度分布均匀、硬度和强度大、纯度高、流动性好,粒度为2~4 mm的晶体占结晶总质量的90%以上。

With ammonium sulfate mother solution from byproducts of caprolactam producing process as raw material, homo-geneous large granular ammonium sulfate crystals were obtained.The effects of process conditions,such as pH of solution, agitation speed,seeds added amounts,and additive dosage,on the crystal habit,particle size,and size distribution were in-vestigated, and the process conditions of large granular ammonium sulfate crystals with 2~4 mm were optimized by orthogonal experiments.Thick hexahedron type crystals were obtained underthe optimal conditions which had good physical propertities： homogenous size distribution,good hardness,high strength,high purity,as well as good flowability.More than 90% of crystal-lization products accounted for the size range of 2-4 mm.