撞击流反应-沉淀法制备纳米氧化锌

Preparation of nano zinc oxide by reaction-precipitation in impinging streams

在浸没循环撞击流反应器中,以纯碱与硝酸锌反应-沉淀制得前驱体,经煅烧后得到纳米氧化锌产品。通过正交设计实验研究了Zn(NO3)2浓度、反应温度、反应时间、Na2CO3与Zn(NO3)2摩尔比等因素对产品收率的影响。初步确定了制备纳米氧化锌的最优工艺条件:Zn(NO3)2浓度1.5 mol/L,反应温度60℃,反应时间1 h,Na2CO3与Zn(NO3)2摩尔比1.3∶1;该条件下锌收率可达94%。制得的氧化锌产品经XRD表征,其纯度较高;经TEM表征,其形貌为球形或接近球形;在最优工艺条件下制取的产品平均粒径为20 nm。建立了相关工艺条件与产品收率的数学关系式。

In the submerged circulative impinging stream reactor（SCISR）,sodium carbonate reacted with zinc nitrate to precipitate the precursor which was then calcined to yield nano zinc oxide product.The influences of Zn（NO3）2 concentration,reaction temperature,reaction time,and mole ratio of Na2CO3 to Zn（NO3）2 were investigated by an orthogonal experimental design.The optimal conditions for preparation of nano zinc oxide are Zn（NO3）2 concentration 1.5 mol/L,reaction temperature 60 ℃,reaction time 1 h,and the mole ratio of Na2CO3 to Zn（NO3）2 1.3∶1.Under such conditions the yield of Zn achieved 94%.The zinc oxide product was illustrated by XRD and it had a high purity.The determination of TEM shows that the products are of about spherical shape,and the average size of those obtained products under the optimal conditions is 20 nm.A mathematical relationship of Zn yield versus the process conditions was established.