Struvite was prepared by semi-batch method with phosphoric acid and the mother liquor from magnesium-hydroxide production as raw materials. Influences of operating conditions, such as stirring speed, feed location, feed rate, reactant concentration,and adding amount of seed，on crystal size distribution ( CSD) of struvite were investigated. Results showed properly increasing stirring speed,decreasing feed rate, or decreasing reactant concentration all could make the average crystal size increase and the coefficient of variation ( C. V. ) decrease; feeding in the propeller area could create larger crystal size and better CSD than feeding in the surface;and seeding appropriately could cause average size of products increase significantly and the CSD more uniform.%以脱镁母液和磷酸为原料,采用半间歇操作方式制备磷酸铵镁,研究了操作条件(包括搅拌转速、加料位置、加料速度、反应物浓度、晶种加入量)对磷酸铵镁晶体粒度分布的影响.结果表明:适当提高搅拌转速、降低加料速度和降低反应物浓度均可增大产品的平均粒径并减小其变异系数;在桨区加料所得产品平均粒径较大且粒度分布较好;加入适量晶种可以显著增大产品的平均粒径并使其粒度分布更加均匀.
展开▼
