(1. 中南大学 冶金科学与工程学院，长沙 410083；
2. 中南大学 化学化工学院，长沙 410083)
摘 要: 基于超细氢氧化铝粒度分布曲线和红外光谱，通过粒子数计算和3 700~3 000 cm−1间红外光谱分峰拟合，研究了干燥过程中表面活性剂对超细粉体粒度的影响规律。结果表明：加入表面活性剂后，干燥后超细氢氧化铝粒子总数的减少不大于6%；而不加表面活性剂时，粒子总数减少99.98%；同时可能是由于粒度小于0.1 μm的粒子易吸附于表面活性剂的原因，干燥过程中的团聚程度较小，而粒径为0.5~10 μm的粒子团聚较明显。红外光谱分析结果表明：加入表面活性剂A和B后，在1 310 cm−1处出现游离O—H特征峰，同时游离的O—H从32.3%(质量分数)分别增加至39.88%和35.95%，多分子间缔合的O—H特征峰从36.65%分别减少至29.78%和27.79%；这说明表面活性剂的加入可以明显抑制分子间O—H的形成，从而可降低粒子的团聚程度。
关键字: 表面活性剂；超细氢氧化铝；机理
ultra-fine Al(OH)3 in drying process
（1. School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China;
2. School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China）
Abstract: The influence of surfactant on the particle size and agglomeration mechanism was studied in term of the particle numbers calculated from particle size distribution and multi-peak fitting of IR spectra. The results show that the particle number reduces less than 6% with addition of surfactant, while that reduces 99.98% without adding surfactant. The coarse particle (0.5−10 μm) is much easier to be agglomerated than the ultra-fine particle(less than 0.1 μm), which maybe due to the easy absorption of surfactant for the ultra-fine particle. The results from IR show that the characteristic peak appears at 1 310 cm−1 accounting for free O—H when surfactant is added, and then free O—H increases from 32.30% (mass fraction) to 39.88% and 35.95%, respectively, and O—H in association molecular reduces from 36.65% to 29.78% and 27.79%, respectively. This shows that the agglomeration is inhibited by reducing the amount of O—H in association molecules with addition of surfactant in the drying process.
Key words: surfactant; ultra-fine Al(OH)3 powder; agglomeration mechanism
