喷雾式添加氨水对氢氧化铝佐剂质量一致性的影响

Effects of spray adding ammonia water on quality consistency of aluminum hydroxide adjuvant

目的通过喷雾式添加氨水制备氢氧化铝佐剂,分析其对佐剂质量批间一致性的影响。方法分别以喷雾和流加方式添加氨水至三氯化铝溶液各制备3批氢氧化铝佐剂,比较两种氨水添加工艺制备的佐剂粒径、pH、外观等质量指标。结果喷雾方式添加氨水制备的3批佐剂平均粒径为(96.7±8.6)nm,pH为4.93±0.02,透析后沉淀量为(20.9±0.4)g/L;流加方式添加氨水制备的3批佐剂平均粒径为(161.0±24.7)nm,pH为4.85±0.06,透析后沉淀量为(105.6±13.8)g/L。相较于流加,以喷雾式添加氨水制备的3批佐剂为均一的乳白色悬液,粒径更小,透析后透析袋底部大颗粒沉淀明显减少,批间一致性更好。结论采用喷雾方式将氨水加入三氯化铝溶液中,可使氨水与三氯化铝溶液接触更加充分,产物更加均匀,有助于提高氢氧化铝佐剂外观、粒径、pH等质量指标的批间一致性。

Objective To prepare aluminum hydroxide adjuvant by spray adding ammonia water,and to analyze its influence on inter-batch consistency of quality index.Methods Three batches of aluminum hydroxide adjuvants were produced by spray and flow addition of ammonia water into aluminum trichloride solution,respectively.The quality indexes including particle size,pH and appearance of the adjuvant produced by two ammonia water adding ways were compared.Results The average particle size,pH,post-dialysis precipitation of three batches of adjuvants using the spray adding way of ammonia water were(96.7±8.6)nm,4.93±0.02,(20.9±0.4)g/L,respectively.However,the average particle size,pH,post-dialysis precipitation were(161.0±24.7)nm,4.85±0.06,(105.6±13.8)g/L,respectively,when the three batches of adjuvants were made by adding ammonia water in flow.Comparing with the way of flow adding,the three batches of adjuvants made by spray adding had the characteristics of uniform milky suspension appearance,smaller particle size,less post-dialysis precipitation,and better inter-batch consistency.Conclusion The reaction between ammonia water and aluminum trichloride is more uniform and sufficient when the ammonia water is added into the aluminum chloride solution by spray,and the inter-batch consistency of quality indexes including appearance,particle size,and pH is improved.