均匀碱化制备高纯聚合氯化铝的形态特征

Characteristics of High-purity Polyaluminum Chloride Species Prepared by Homogeneous Alkalization

用高纯铝粉和结晶氯化铝在沸腾回流状态下均匀碱化反应制得了数种盐基度不同的聚合氯化铝.液体试样在B%≥83%时出现白色浑浊,固体试样在B%≥80%、露置空气中时观察到颗粒因吸潮溶胀产生的自动炸裂现象,其固体氧化铝含量最高可达48%以上.通过Ferron逐时络合t-A曲线反映,该HPAC中Alb含量较少、Alc含量偏高,Alc是聚铝离子的稳定存在形态.在IR特征光谱区中1 090 cm-1、970 cm-1和778 cm-1左右的吸收峰,反映了聚铝离子的缩聚程度.XRD表明不同盐基度的固体结构有明显差别,随着盐基度的增加,2θ=8.4°处的小角散射峰特别明显.在27Al NMR谱测定中Al13簇合离子的共振吸收与溶液浓度和盐基度有关.

Several kinds of polyaluminum chlorides of different basicity were prepared by the reaction of homogeneous alkalization with aluminum powder of high - purity and aluminum chloride hexahydrate in a state of boiling and refluxing. White haziness appeared in the liquid samples in B% ≥ 83%. When the solid samples in B% ≥ 80% were put in the open air, it was observed that granules produced the phenomena of bursting automatically for moisture absorption and swelling. The alumina content of their solids could be more than 48%. It was showed by the t - A curves of Ferron timed complex that there were less Alb contents in this HPAC, and that Alc. contents were high side, Alc was the stable existing species of polyaluminum ions. The IR absorption peaks of 1 090 cm^-1, 970 cm^-1 and 778 cm^-1 or so in IR characteristic spectrum district indicated the polycondensation extent of polyaluminum ions. XRD indicated that the solid structures of different basieity had obvious difference. With the increase of basicity, the small angle scattering peaks in 20 = 8.4° became especially obvious. The NMR absorption of the Al13 cluster ion was related to solution strength and basicity in ^27Al NMR spectrum determination.